The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: muskrat on 31.01. 2022 08:30
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G'day Fellas.
Well I've been threatening to do this foe a while. Now all the others are going so to speak, it's her time.
!st surprise was the rear chain joiner link fell apart when I removed it *ex*
Lump out and on the bench. Remove G/box. Now I need a stand for the motor. 1 beer later job done.
Pull pinion with bearing separator and modify 11/16 bs socket to remove prv (used to have one).
Split cases and pull crank out. Really surprised with the little wear on the journals. Only 1/2 thou on the TS journal and 1/4 thou on the big ends. Amazing considering the flogging she gets *ex*. I'll throw in a new ts bush (0.010 and new big end shells 0.010) no grind necessary. A new ds bearing and the bottom end will be back together in no time.
Hold the bus. Just found a few cracks in the crank case. A musky rev head problem. The through bolts into the crank case have caused a few sml cracks. Instead of a 5/16 thread I used helicoils so it was a bit weak. Now looking for a good welder to rectify. BUGGA
Stay tuned.
Cheers
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continued
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I know you want more
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Those barrel through bolts do look very close the edges of the case. Is that where the cracks are?
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It proves once again that as long as these engines get good lubrication they are tough old birds. When was the sludge trap last cleaned?
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musky i am pleased to see that big puller in action, i bought some and when i opened the box i thought oh dear should i be working on BIG stuff *good3*
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G'day GB.
The sludge trap was cleaned about 25-30 years ago. The bearings and journals are in good condition considering the flogging I've given them. I'll be pulling the plugs to have a look tonight.
Yes the studs are close to the edge (like me!). I should have tapped 5/16 straight into the case instead of going bigger for helicoils. With the racer I had those areas built up with weld inside and out. May do the same here but I don't want to loose the engine number, it has a crack that I plugged a few years ago with JBWeld.
G'day bergs.
Yes a very handy puller, that's the small one. Will also be used to remove the drive side bearing.
Cheers
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Great topic, great pictures *smile*
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Hi Musky,
The timing side main journal on the crank looks a bit ridged when I zoom in on the photo?
I think it could do with a polish up ?
John
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Hi Musky, Great series of pictures. Thank you.
As you know I am no expert in matters A10 but from what I have gleaned thus far in my BSA journey; as well as the sludge trap clean out I would be considering whether the conn. rods should be renewed at this point. Is that something you are concerned about given the way you ride the thing!?
Other than that the internals certainly are looking good. (I agree with John, if you are renewing the timing side bush I would also get the journal polished up regardless.)
So I'm interested to know how many miles "flogging" has the old girl been subjected to and are you running an oil filter or not?
Good luck with the weld repair etc.
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G'day John, BON.
The TS journal isn't that bad but will get a polish and custom bush to suit. I haven't removed the bush yet to check for out of round in the case. An over and under size bush may be on the cards.
The rods will be polished and put under the microscope. The little end bushes are perfect.
The speedo never kept the mileage well but at a rough guesstamate I'd say 60,000 miles. I used 20/50 most of her life with an in line filter. When I noticed the 8thou clearance in the TS bush I've been using 40/70 *eek* with a good dose of Nulon E10.
Tonight I removed the sludge trap plugs. DS came easily but the TS was a bitch ruining 3 impact bits (note to self don't be too heavy with the center pop on the new ones). I was surprised at how little sludge there was. I'd say about 1/2 to 1/3 of a cc. One place the muck can hide is the hole under the plug of a drilling on the TS web.
I also cleaned the cases to look for cracks/damage.
Cheers
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Now the cracks. *pull hair out*
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Testament to modern oils, regular changes and filtration I would say.
Re. Cracks. What a nightmare.
I don't mean to be teaching granny to suck eggs but all I can suggest would be to 'V' out the entire length of each crack and a little beyond as deep as you dare to go then TIG weld after thorough degreasing. It would be a good idea if not essential to preheat the cases generously with Oxy before welding too. There may be a specific filler material that is best suited to the BSA alloy which seems to be very soft and therefore very pure. I'm afraid I can't recommend anything. Wherever possible it would pay to build up the areas/internal bosses with additional weld material to strengthen things. Then I guess take the threads/inserts deeper wherever possible, use longer studs and put them in with a generous helping of red loctite.
Then face east and make another sacrifice to the Beezer gods!
Best of luck with it all Musky
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Well, there's the danger of ignoring the red warning about someone having posted while you were typing. Bago's description is clear, so read here at your option.
Oh, you're having some fun now. This is just about the time you wish you'd gone to welding school. Probably not telling you anything you don't know, but it looks to me like each through-bolt hole needs thickness buildup along side of it, inside and out (not just crack filling). I could be seeing an illusion but, in the fouth photo, there is a long line that looks like a giant crack. Is it? By the way, do you have a mill to go with that beautiful lathe? Skimming the crankcase barrel seating face seems to be in the cards.
Richard L.
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On second thought, is that long line that looks like a crack actually a sand-casting parting line?
Richard L.
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Me, again. Not intending to jam the airwaves, but, another question. Do you use the original crankcacase studs that are next to the through-studs?
Richard L.
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G'day Richard.
That is a casting line in the 4th photo.
In my apprenticeship I missed the 6 months of welding in the blacksmiths shop and spent it in the machine shop, they were down 1 tradesman. I can glue two pieces of steel together but that's all. I have a stick/mig/tig machine, the son will have to teach me how to use it. Yes a mill would be handy (I need a bigger shed already!).
G'day BON.
There is a local engineer that knows his stuff. I'll give him a look. Yes I plan on building those areas up inside and out. If I remember correctly *roll* there is about 1/8 gap between inside of case and the barrel skirt.
Or should I be looking for another set of cases?
Cheers
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If you saw the post that was once here, forget it. The crankcase I saw on eBay blows.
Richard L.
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G'day Fellas.
Starting to make a list of parts required. Thought I'd treat the new build to an SRM oil pump. All major suppliers I've used in the past including SRM are out of stock. Found one at De Groot just awaiting an email of how many beer tickets.
Guesstamate on cost of rebuild at this stage is $3K. *eek*
Cheers
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G'day Fellas.
Pump on it's way fro DeGroot just a tad under $600AU.
Now for the bad news. My local guru said it would cost an arm and a leg to fix the cases properly (he is pedantic,builds race motors).
So please see Wanted section.
I'll keep gathering parts needed for a full rebuild and hope I have some luck before the National in October.
Cheers
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G'day Fellas.
I was a bit down last night and parts had arrived for the XT so put my mind to that.
Got up at 5am to check my emails and saw a few responses.
Richard, I owe you a big sloppy kiss. Usually after checking in on the Forum I have a look at ebay. I'll send him a message. And he's just down the road (500 miles)
berger, ebay must have changed something, searching just for a listing # gives me nothing.
Swarfy, I can modify it to take a seal. Finally get to use the lathe without the gap.
It's a 52 model so not far out. Now for the big question. Do I turn her into an A10 *????* I'd need the top end and a crank (bugga I used to have them!!)
Cheers
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G'day Fellas.
I was a bit down last night and parts had arrived for the XT so put my mind to that.
Got up at 5am to check my emails and saw a few responses.
Richard, I owe you a big sloppy kiss. Usually after checking in on the Forum I have a look at ebay. I'll send him a message. And he's just down the road (500 miles)
berger, ebay must have changed something, searching just for a listing # gives me nothing.
Swarfy, I can modify it to take a seal. Finally get to use the lathe without the gap.
It's a 52 model so not far out. Now for the big question. Do I turn her into an A10 *????* I'd need the top end and a crank (bugga I used to have them!!)
Cheers
A pint of your favorite would be quite adequate, if I ever get down there. Thank you.
Richard L.
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G'day Fellas.
I was a bit down last night and parts had arrived for the XT so put my mind to that.
Got up at 5am to check my emails and saw a few responses.
Richard, I owe you a big sloppy kiss. Usually after checking in on the Forum I have a look at ebay. I'll send him a message. And he's just down the road (500 miles)
berger, ebay must have changed something, searching just for a listing # gives me nothing.
Swarfy, I can modify it to take a seal. Finally get to use the lathe without the gap.
It's a 52 model so not far out. Now for the big question. Do I turn her into an A10 *????* I'd need the top end and a crank (bugga I used to have them!!)
Cheers
Musky, you must have searched ebay.com or au and not ebay.co.uk (they are different) see pic
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Well, Muskie can very well think and speak for himself, but it seems to me that the one in Oz for AU$470 is a better bargain after welding, filing, grinding, shaping and shipping. (not that I figured that out in advance).
Richard L.
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Hi All
I would agree with Richard, the UK ebay one mentioned needs a lot of repair
37 plonker has two other sets of crankcases a lot rougher than the set linked to
but they also need welding
John
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It is a tricky one Musky for sure. I wish I could help you out as I can Tig weld reasonably well, pretty much anything but so much depends on the material. I have had cast ally that welded easily and cleanly no worries at all and I've had some that was an absolute nightmare. Anyone taking the job on is taking a big risk that they might have all sorts of trouble and then the issue becomes their problem. I think this is why these sorts of repairs are normally so expensive to get done, they would really rather you took the job down the street to someone else!
If you are considering replacements then have a go yourself! Nothing to lose really. Do lots of practice, checkout the Uni of YouTube. You must have heaps of suitable tryout pieces lying around in the shed! Preparation is everything so dig it out as much as you can, clean it up with acetone and then clean it some more. Heat it up as hot as you dare with Oxy or a propane torch and let rip with the tig. Build up successsive layers and keep going until you know you've put enough on or you'll have to heat it all up again. Don't worry about putting too much on, you can always file/die grind/ machine it off again.
Lets face it it is not that critical. The bike was running for god knows how long with those severely weakened and cracked threads and everything was fine! You only need to do enough...
Have some fun with it and who knows you might even get a result *smile*
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G'day Fellas.
I bought the $470AU one in Melbourne. Still by the time I replace all the bushes and bits add another $5-600. I just bought an SRM pump from DeGroot for $595 so that's a grand and a half and a lot to go. SRM cam & followers $720 etc etc. Expecting around the $4K mark.
For a 40 hr week I get $800 *pull hair out*
Ho Hum off twerk I go.
Cheers
PS: Yes Kiwi I searched International but didn't realize UK has their own *roll*
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Looks like I'm too late - was going to advise Musky to avoid buying new cases and sort the originals instead. Mainly because what's causing the problem still remains - drilling the cases for through bolts. There simply isn't enough 'meat' there for it to survive.
Yes, I'm aware cracks can be strange things, often travelling further than realised, but never the less I'd have prepared them for welding plus counter-bored the through-bolt holes to around 3/4" dia x 1" deep. I'd then have turned up some plugs to snugly fit those holes from LM25 and had them welded in too. As for cost, I was surprised at Musky's quote. The guy I use used to run a stainless / alloy fabrication shop and his welds are superb (example attached). I'd estimate his bill to weld those cracks and attach those plugs would be around £30. The inserts suggested would, if decently hand-finished, not look out of place. Maybe even be passed off as a BSA comp-shop special! At least there'd be no more cracking.
Of course, welding invites the annoyance of distortion. Here, having learnt from my initial attempt at modifying my GF rear chaincase, I'd recommend annealing the cases after welding before any 'tweaking' was carried out. I discovered my rear case was as brittle as cast iron and cracked extensively under tweaking because I didn't anneal it first. On reflection, 60yrs being vibrated by an engine would certainly be enough to cause work-hardening. Not straightforward, though, as annealing really requires knowledge of the material in hand. I'd expect chaincases, being die-cast thin section, to be LM6 (high silicon) or similar. On the other hand, BSA crankcases are usually sand cast and, being 'chunky' would not require much silicon. Maybe LM4, then.
But what about semi-unit cases? They have an attached thin section (daft idea, combining the chaincase with the crankcase - makes casting and machining unnecessarily more difficult) and so the silicon content of these may be higher than expected.
The reason I mention this, is because annealing alloy varies fairly widely according to type and, to further complicate matters, high silicon variants can act a bit strange when it comes to machining after anneal. For the record, I annealed my chaincase inner at 300*C in the Rayburn oven for a couple of hours, letting the temp slowly reduce over another couple of hours to around 150 before removal. Seemed to work OK and was nicely pliable when it came to removing distortion.
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G'day RD.
Thanks for the insight. You certainly know you stuff.
Yes the whole problem is due to the through bolting exercise. The top end of the plunger motor was a hand me down from the A7SS racer. The head & barrels had been modified for through bolts so drilled the plunger cases. My mistake was drilling oversize to take 5/16 helicoils and not having enough meat around them. The racer had weld built up inside & out around those spots.
So now the *????* is do I look for a std head & barrels for the new/old cases.
Cheers
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G'day BON
Thanks for the encouragement. I have a new stick/mig/tig welder, I've only ever done stick. I'll get #2 son over to show me how to use it.
Now to start spending the kids inheritance *grins*
The SRM web site is a pain. Click on A7 A10, click on bottom end, 39 pages of mostly Notrun or Trihard stuff. *pull hair out*
My list so far = $2071.90AUD + the $1000 already spent.
Cheers
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G'day BON
Thanks for the encouragement. I have a new stick/mig/tig welder, I've only ever done stick. I'll get #2 son over to show me how to use it.
Now to start spending the kids inheritance *grins*
The SRM web site is a pain. Click on A7 A10, click on bottom end, 39 pages of mostly Notrun or Trihard stuff. *pull hair out*
My list so far = $2071.90AUD + the $1000 already spent.
Cheers
Good man. It is tricky to start with, requiring hand eye coordination and you are doing different things with both hands at the same time so if you can play a piano you'll be fine! It really is all practice though and once it has clicked you'll never look back.
I had the same experience the other night looking for my clutch items, assumed it must be me doing it wrong. Wrote an email to them instead as I just couldn't find everything although they must have the parts as you can get the whole assembly if you want to take out another mortgage.
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Seems like a replacement standard head and barrels would just add to your costs and bring along their own new set of problems there Musky, better the devil you know I say. >:D
I tend to agree with RD that seeking a suitable repair of the original cases might be best. Maybe have another think about the repair method, I like RD's idea of machining out the damaged holes and welding in new inserts that can then be drilled and tapped anew. Once you are clear as to exactly how you want it repaired try to get another 2 quotes and see how they stack up although last time I checked 30 quid was about $55 AUD so I'm not sure about how current his prices are! *smile*
Hang on to the new/old cases just in case you still need them and then if not put them back on the market down the track.
I do however appreciate we are all living this from our lounge rooms and only trying to help...that's the thing with these forums, lots of free advice which is great (and has certainly helped me) but in the end "you da man" who has to make it all happen!
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The SRM web site is a pain. Click on A7 A10, click on bottom end, 39 pages of mostly Notrun or Trihard stuff. *pull hair out*
My list so far = $2071.90AUD + the $1000 already spent.
Cheers
Those are rookie numbers, you need to up your game ;)
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G'day BON.
Yes that's my problem! Blind right eye and deaf in left ear. So not only 1/2 blind but I have little balance to boot. Once she's rolling, no problem!
G'day Kickaha.
That price list included SRM con rods (no stock) so that would shave $800 off. I figure SRM might be a few $$$ more for most parts but they have a rep to uphold.
Tonight I'm just polishing the HD for a show on Sat. Polishing the BSA in no time, the HD takes all night *bash*
Cheers
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G'day Fellas.
Not sure if it worked but I merged the last few reply's from the Wanted topic as it was going astray.
Cheers
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I checked 30 quid was about $55 AUD so I'm not sure about how current his prices are! *smile*
The 'updrive' case in the pic that I gave as an example of my pal's welding - all the welding on that case plus a couple of other bits was £20. This week. *smile*
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Musky,
I happened upon an A10 aluminum head that has been modified for through bolting. Do you need one? I have no plans to do that to any of my engines. I was going to see about restoring the original bolt pattern and using it down the road.
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G'day Seabee.
I'd certainly be interested. I was thinking of doing the same. The alloy head would be easier than the barrels. With mine I threaded the outer 4 holes and made threaded alloy plugs. Then drilled new holes 1/2 in the head, 1/2 in the plugs. Could do the same again in reverse. Worth a try. Then I'd need to find a set of big fin A7 barrels.
PM me to discuss $$$
Cheers
G'day RD.
My fella charges $100 (￡55 per hour). To do it properly the two bad ones would need to be broken out completely then re-made. He recons 8-10 hours work then the re-machining.
Cheers
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Understand your work estimate now, Musky.
I was assuming that with your machining ability and engine building experience you'd be doing the preparation / refinishing and all that had to be farmed out would be the 1/4 hr or so alloy welding required.
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G'day RD.
Most of my engine modification work was done whilst I worked in a machine shop. Now I only have a cheap Chinese lathe and drill press.
The ZA10 cases should be here by Wednesday so will focus on building that first. Yet to decide if to go standard or the full roller route.
https://cybermotorcycle.com/archives/bsa-a10/ https://cybermotorcycle.com/archives/bsa-a10/convertingcam.htm
Cheers
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55 GBP/hr sounds about right for a professional welder (based on US prices), mabe even cheap. I think RD's pal, if a professional, was just charging him as a friend for the welding rod. The certifieed welder that built up a new boss for one of my sump plate screws told me that with aluminum casting about 75% of the time is in prep, mostly cleaning. He also told me not to bother with any of the prep because he would just have to redo it to be confident with his work.
Richard L.
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Not so, Richard. From my previous post you'll see I estimate the actual welding would take around 15 - 20 mins. So 1/3 x £55 =?
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G'day Fellas.
I had a nice big box on my doorstep when I got home from work. The ZA10 cases have arrived. The engine number dates to 52 but I can't see a date stamp anywhere. My old cases have one inside the primary. Another difference is the sump pickup tube. Mine had a tube up the side, these have a hole down near the sump plate.
It's late and after a hard day at work I'll look closer tomorrow.
Let the fun begin.
Cheers
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Not so, Richard. From my previous post you'll see I estimate the actual welding would take around 15 - 20 mins. So 1/3 x £55 =?
I stand corrected.
Richard L.
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A pick up pipe low down seems strange. All Plungers I've seen have the pipe bolted to the inner crankcase. Possible someone has modified the case to mimic the later S/A design, or worse a S/A crankcase half that has been modified and matched to a standard Plunger drive side. Have a good look at what you have before reaching for the tools.
This sounds a bit unusual as from my experience I have never seen or heard of this.
Cheers
Swarfy.
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Hi, great topic in the making *wink2*, one question, any reason for keeping it in the 'sheltered' Member's Chat?
Diminishes the audience quite drastically > hidden from guest visitors (many) \ members not logged in \ members with few post (5 posts needed for Member's board access).
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G'day E.
I'll move it over to A7 & A10 Engine. Yes the world should know om my antics.
G'day Fellas.
I washed the cases last night with CLR. Didn't do a bad job. I found the date stamp, it's 6 months younger than the old cases. The pick up tube is missing and a few of the primary screw holes need attention. All the other threads are in good condition. The tube and missing studs will be swapped over from the old cases. Tonight I'll remove the cam & idler bushes and measure up the timing side bush hole incase I have to make an oversize OD.
Question time. Does anyone have the dimensions to convert the drive side to a seal from a slinger and same for the primary/mainshaft seal?
Cheers
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Nerd box froze.
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Musky, if you put a seal into the crankcase you should use the splined sleeve which goes with it. It has a wider face to register with the seal.
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G'day Musky.
Look to be a pretty good set. Reviewed my earlier cautionary post, the lowdown hole is the mounting for the missing pick up pipe.
When it comes to oilseals in general, like bearings, there are standard sizes which manufacturers will choose to achieve economies of scale. So, in the case of the mainshaft seal, the Oilseal size is defined by intended shaft diameter, hole size in the casting and finally the width of seal required to match the thickness of the casting. Any bearing supplier list should give a cross reference to commercially available substitutes for the real thing from these dimensions. Seals come in Metric and Imperial sizes, and also differ in the lip profile type and intended direction of shaft rotation. Most are a steel pressing, with the seal material moulded on.
But as always, there are exceptions, peculiar to makes and models. The original mainshaft seal looked like a resin impregnated fabric cup.
Crank seal is probably a special too, but along with the unique gearbox sprocket seal, widely available.
Hole on a handy seal type crankcase is 55.5mm/ 2 3/16". To add to Trev's know how, yes the slinger type drive sleeve is too big, at 46mm/ 1 13/16". This should closely match the crank hole in these slinger cases. Drive sleeve for seal type is smooth edged to run on the seal, and slightly smaller at 43mm/ 1 11/16". All dimensions taken from used parts to hand, measured with caliper and eye.
For those folks running early cases and oil entering the primary, worth checking your bitza has the correct drive sleeve.
An extra note for all you Plunger builders. Pay close attention to the integrity of the pick up pipe and its seal into the crankcase. I had one split at the right angle weld where it fits the case.....no scavenge, oil everywhere....fault took some finding and of course the whole motor is built around this pesky li'l bugger. The ball valve always seems to have very limited lift on these early models so a good clean out of carbonised oil is a must.
Cheers.
Swarfy.
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G'day Trev.
Thanks M8. Just another part to hunt for.
G'day Swarfy.
I have two good bearing/seal shops close by. I'll annoy them.
Wondering if I can turn down the plunger one to match a seal?
Been quite a while since I visited the bottom end of the plunger. It's starting to come back yo me now.
I've joined another group, "The Sons Of Alzheimers"
Cheers
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Oilseal size for gearbox mainshaft is defined by intended shaft diameter,.... Etc.
Wow, a post full of vital information for Plunger owners. Thank you Swarfy 👍 This forum is a great resource for owners.
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This forum is a great resource for owners.
Glad you've finally realIzed this, GB. *whistle* >:D *welcome* *smile*
Richard L.
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Musky, I am pretty sure that the diameters are the same only the width varies. And again I think that the same seal as the swinging arm case is used.
Russ had a case machined in the not too distant past.
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I spoke to Russ about the splined sleeve. Swarfy is correct on the diameter of the seal type sleeve at 1 11/16". The other is 1 13/16".
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G'day Fellas.
My first part arrived today.
Looks too good to hide in a motor *smile*
From De Groot only took 2 weeks from NL
Cheers
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musky did you get the nice prv to go with it?
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G'day bergs.
Not yet but it's on the list.
I pulled all the bushes out of the "new" case and measured the holes. All good even the main hole so now can order all the bushes and bearing.
Cheers
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Musky be careful with the camshaft and idler bushes the engineer who did all the line boring on mine told me the bushes i had bought were no good because they slid onto the cam and he had to make all new ones. he said there's loads being sold that are no good. even when they squeeze up a bit in the case he said they are hit and miss when on the bearing surfaces of the cam etc.
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Thanks bergs.
I was looking to get SRM stuff, not because it's double the price ($50 each) but hopefully double the quality *dunno2*
I could make my own but the right material is expensive.
Cheers
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If bushes are to be line bored then in the raw there must be excess material on the ID to enable the boring process to result in finished bearing surfaces perfectly in line and to the appropriate running clearance. Bushes that slip onto a camshaft are maybe OK for simple replacement into matching cases, and a used cam, but certainly can't be relied on for the perfection sought by some.....Good enough for me, though.
Swarfy.
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G'day Swarfy.
Correct, even in matching cases there will be discrepancies. Thinking hard about making my own.
*beer*
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G'day Fellas.
Not much happening whilst waiting for parts. Yesterday I took the drive side case to the local engineer to weld up the broken primary cover screw holes.
Cheers
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Muskie,
I hope that wasn't too big of a hurt. Did you also build up the ones that appear to have been flattened out by a loose chain?
Richard L.
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Word of warning, Musky. Welding those areas will likely distort the case.
Check it on a flat plate after - if it ends up curved (on the face mating with the cover) don't try and straighten it out, as it'll likely crack all over the place. DAMHIK!
I had real problems after welding my SA rear primary case. Hairline cracks everywhere after trying to straighten it. I ended up with another cover and annealed it after welding - around 300*C in my Rayburn cooker for a couple of hours before letting the temp drop slowly to around 180 before removing and air cool. Removed the work hardening and allowed easy re-setting with no cracking.
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G'day Richard, RD.
Norm (the engineer) said he will be "cooking" the case before and after tig welding. I will certainly be checking when it returns.
Cheers
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G'day Fellas.
Got home from work yesterday to find a box of goodies waiting for me. I put in an order with Andrew at Priory Magnetos on the 15/03 and it arrived 24/03 *ex* I can't get bits from Sydney that quick. Thankyou Andrew.
Still have to source a few more bits and waiting for Norm to weld up the primary screw holes. Don't want to rush things.
Cheers
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G'day Fellas.
Got home from work yesterday to find a box of goodies waiting for me. I put in an order with Andrew at Priory Magnetos on the 15/03 and it arrived 24/03 *ex* I can't get bits from Sydney that quick. Thankyou Andrew.
Still have to source a few more bits and waiting for Norm to weld up the primary screw holes. Don't want to rush things.
Cheers
Thank you, Musky. Andrew
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G'day Fellas.
Got the case back from the welder. He had some issues but got it done (not very pretty but it's inside.
My cover is a little miss matched (pic 6).
Spent a few hours bolting the cases together then bolting on the g/box and clutch to check clearances. Dremel to the rescue.
Next, while the box is on I'll make a boss for a proper seal for the mainshaft.
Cheers
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I know from experience with a damaged cover, that the oil that penetrates the aluminium , makes tig welding awkward and thats after, warming it up to try and sweat the absorbed oil out
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G'day Fellas.
Been very slow the last month (life gets in the way).
More parts have arrived from Mikes Classic Cycle Spares including a set of NOS con rods.
I've shrunk in the cam & main bushes into the cases. New reamers arrived yesterday. Bored the d/s case to take the crank seal (NOS 67-2071 cush drive sleeve also from Mike) to stop the wet sump oil entering the primary (shouldn't happen with the new SRM pump).
The new mainshaft/primary seal is a nice fit in the original hole in the case and I can use the old seal housing to hold it in.
Tonight I'll make a new dowel for the crank case halves and bolt them together. Make some pilots for the reamers and not have a beer till done!
Will take pics and post tomorrow.
Cheers
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G'day Fellas.
As posted elsewhere I've got the bottom end back in the frame. So I thought I'd better update this.
I successfully reamed the cam and main bush using my home made pilots and expanding reamers, all were given 0.0015" clearance. Dropped in the cam & crank and the cases went together nicely. Both spin with no perceivable play.
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How did you ream the blind bush with an adjustable reamer, Musky?
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G'day Trevor.
I didn't. I spent another $78 on a 19mm hand reamer and cut the tapered end off. Then used a similar method as the main bush.
Cheers
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Hi musky, really going to town on the motor to say the least , don't stop and count up how much you've spent or my guessing would be a heart attack would result ,good job mate ! *beer*
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G'day Fellas.
Came across my first snag. Thought I'd put the barrels on to check the rods are central. They wouldn't go onto the studs! *pull hair out* I opened up the holes but still wouldn't fit. *bash* I was working from the back side of the motor and didn't notice the rub mark on the crankcase bridge. The back of the r/h barrel skirt was hitting. First I ground a little off the skirt but didn't want to go too far as I've had one break there on the racer. So I took the dremel to the bridge! Was surprised how much I had to take off, nearly 2mm *eek*. Then I made three dowels to fit neatly over the front and two rear studs and into the enlarged barrel holes. Barrels on and checked the rod positions. All good central and square *smile*
Cheers
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Was this originally an A7 case used with the shorter spigot A7 barrels? I'm thinking your build is A10, but nevertheless reckoned all basic crankcase castings were the same. Another conundrum.
Swarfy.
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G'day Swarfy.
The "new" cases were ZA10 but all A7 & A10 cases of the same year group are the same. The cases are a # stamped matched pair and although the bolt/stud holes and the case/barrel face align there is evidence that one side wasn't quite square in the machinists jig. Most barrels I have seen have grinder marks on or around the skirts to account for this.
I doubt very much if the removal of material at this point will weaken the cases.
I still can't find any A7SS +40 pistons. I could reuse the old ones but they do have scoring. A set of std T150 rings will fit. The bore is good, only a 0.001' taper. The barrels had been sleeved so I can't open them up to +60.
Cheers
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Hi Musky
Would these work for you?
https://www.ebay.co.uk/itm/275236096768
John
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G'day Trev.
Thanks M8. Just another part to hunt for.
G'day Swarfy.
I have two good bearing/seal shops close by. I'll annoy them.
Wondering if I can turn down the plunger one to match a seal?
Been quite a while since I visited the bottom end of the plunger. It's starting to come back yo me now.
I've joined another group, "The Sons Of Alzheimers"
Cheers
Musky, I will soon have a 43mm drive sleeve surplus to my requirement, it’s on the bike at the moment but needs replacing with the correct 46mm one which should arrive next week.
I can drop the 43mm one in the post but it might take a while to reach you. Let me know if you want it.
Also really interested in how you’re going to improve the main shaft oil seal arrangement, though I doubt I have the skills to follow your lead.
Jase
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G'day John, they will do nicely. Thank you.
"May not post to Australia." I'll send him a message.
G'day Minto.
Thanks for the offer mate. I found nos one up in Queensland.
Re the mainshaft seal. I ground off the rivets and removed the two plates. Got a double lip seal from the local Engineering Supplies that fit the shaft and was a neat fit in the case. Riveted the original plates back on with just a smear of silastic. Time will tell.
Cheers
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Hi Musky
I put a "watch" on them on my ebay and received an offer to buy for £125 *????*
Then I noticed they are JP's so I wonder if you could get the same in Oz ?
If he doesn't post maybe a UK member could step in as a broker *????*
John
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I think that the "May not post to (wherever)" line has to do with the seller not indicating the method, rather than a prohibition. I any case, if it is, indeed, a prohibition, I'm sure someone in the UK will help. I'm not expert in this, but I'm guessing there are commercial brokers who deal with such eBay restrictions from shy or recalcitrant sellers.
Richard L.
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G'day John, they will do nicely. Thank you.
"May not post to Australia." I'll send him a message.
G'day Minto.
Thanks for the offer mate. I found nos one up in Queensland.
Re the mainshaft seal. I ground off the rivets and removed the two plates. Got a double lip seal from the local Engineering Supplies that fit the shaft and was a neat fit in the case. Riveted the original plates back on with just a smear of silastic. Time will tell.
Cheers
No worries pal, I’ll stick it on the bay.
That’s pretty much what I did with mine, though my confidence in it’s oil-tightness is pretty low, everything else on my bike seems to leak, why shouldn’t that.
What kind of rivets did you use? I’ve only got a pop riveter, you reckon those would be up to the job next time?
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G'day John.
I just checked and have no response about postage. What I did notice is the price going from 150 to 165 GBP *ex* The only JP's down here are 6.6:1.
Any offers to buy and forward on to me *ex*
G'day Minto.
I just used normal pop rivets and glue.
Cheers
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Any offers to buy and forward on to me
I'm willing to help if I can. Are you able to identify a seller in the UK?
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Musky, ring JP and see what they can do for you.
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G'day GB.
That would be great mate. I'll take Trevor's advice first and if no luck I'll give you a hoi tomorrow night (your day).
https://www.ebay.co.uk/itm/275236096768?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
Cheers
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G'day Fellas.
Next installment.After getting the barrels to fit properly I marked where the through studs are to be. This time I made sure they are in the middle of the case, only moving them 0.5mm. Drilled and tapped them and made new studs. 5/16" into the case and up to 10mm at the top. The 5/16" thread I made large by about 5 thou" to be tight into the case. All good, nice and square.
G/box on with new sprocket and seal. The yellow hose is from the breather exit to under the motor.
Pics of the ms and crank seals. Lump back in the frame and primary on. Much easier to man handle without the top end on.
Cheers
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Looking good Musky. I like your degree disc and pointer - think I spent too much on mine!! *sarcastic*
Col
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G'day Fellas
Trevor, I rang JP and the only ones they can supply are 6.6:1. Way to low for my alloy head, 357 cam, 932 carb *ex*
So GB expect a PM. Those pistons look very similar to my old 8:1's.
Cheers
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G'day fellas.
Greybeard has bought the pistons for me. Now the 3-4 week wait for them to swim halfway around the word.
With the SRM oil pump and the inner timing cover on I primed the crankcase with a cup of oil. I attached a tube to the feed pipe and filled it with oil. Turning the motor over by hand showed the pump was taking oil. Probably another 30-40 turns had oil coming out the return pipe. Holding the rods up and turning the crank by hand was slow. I joined the feed and return pipes with he tube. Placed condoms on the rods and was now able to use the kick lever to spin her over a lot quicker. Oil kept flowing round and round.
I haven't drilled the case for a oil pressure gauge or bought an SRM OPRV yet so will do before the pistons arrive.
Cheers
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You might consider using a couple of elastic bungies to keep the conrods upright.
I hope you are going to wash those condominiums before you use them again.
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You might consider using a couple of elastic bungies to keep the conrods upright.
I hope you are going to wash those condominiums before you use them again.
G'day GB.
I tried elastic bands and bungie cords to no avail.
Mate, condoms are a one use only. I hate the smell of burning rubber in the morning *eek*
Cheers
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G'day Fellas.
Wild cold wet windy out so gave her a head job *eek* Just a quick wash and decoke then a light grind of the valves & seats. Didn't really need the grind but wanted to check the guides. All good and back together. Also gave the rockerbox a wash.
The barrels got a clean and fresh coat of gloss heat resistant 2 pack black.
The top end of this motor is from my 57 A7SS racer. Been on since the mid 90's so has a few *eek* bits *whistle*
Cheers
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G'day Fellas.
The new pistons arrived yesterday so tonight I got a bit done.
The compression height of the new are 3mm shorter. The old ones were 8.5:1, the new look like 7 or 7.5:1. I don't really need to ride her like I stole her any more *whistle*. Next the scales came out. The new pistons bare are only 1g heavier but the pins are 10g heavier *eek* The old pins had a straight bore but the new pins bore is tapered (thick in the middle). Too late in the evening (beers) to work out balance factors and how much 10g will alter it. Think I'll go with the old pins. They fit nicely in the new rod little ends with no perceivable play and measure 0.001mm (0.00025") under. *bash*
Then the lathe and dremel got a bit of use. First cut a 30 degree chamfer in the skirts fore and aft and dremel the sides to blend in. This cuts through the oil on the cylinders instead of rolling it down with the flat edge of the skirt. It also aids little end lube and cools the crown of the piston.
Hopefully by the end of the weekend she will be buttoned up.
Cheers
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Crime? Should be a requirement - these days you don't know what's up there ......
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G'day Fellas.
She lives. Started 3rd kick. No horrible noises. You know how it is, all the thoughts of did I tighten that, did I locktight that as you give it the first kick.
Now I'll take her for a lap and bed the rings in, then check the timing.
Will have to go back and fill in the gaps with the story.
Cheers *beer* *beer* *beer* *beer*
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*clap* *clap* *clap* Well done mate..... I've enjoyed your postings.. *clap* *clap* *clap*
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G'day Fellas.
Continuing on from reply #95.
I used the old pins and heated the pistons with the hot air gun to mount them on the rods. Pushed in nice and easy, burnt my fingers before I used gloves *bash*. Made a piston support out of the trusty nylon cutting board and ring compressors out of poly pipe and hose clamps. Installed two of the through studs to keep the barrels square and slid them down over the pistons. Less chance of breaking a ring that way.
Installed the studs with red loctite. I annealed the head gasket bring it up to red all over the when cooled gave it a good coat of coppercoat.
The head slid down the studs nicely and was torqued down to 20-25-30ftlb.
Next was the job we all love "not" the rocker box. I must have done it hundreds of times but it still took me two goes at it. As I don't use the springs on the rocker shafts (shimmed instead) the rockers flop down so use elastic bands to hold them up. You will notice the extra large cover studs and 4 long box bolts. This top end was from my 57 A7SS racer and all the threads were shot. Quick fix go bigger *work*. The beauty of it in a plunger means the rocker box isn't stressed by the s/a head steady so rarely leaks. For tappet clearance I gave them 12 and 14 to start.
Then it was time to throw all the ancillary bits on. Probably the most time consuming part of the job. I left the tank off and hooked up my auxiliary tank to see if she lives.
Third kick she bursts into life and ran for a couple of minutes. On with the tank and out on the road. I like to put load on as soon as possible. About 15 minutes around the back streets of Lithgow and back in the shed. Off with the primary to check the timing. Spot on 35 degrees so didn't touch it. Back on with the primary and back out on the road. This time up and down Scenic Hill twice to load her up a bit but not labor her.
All good, no horrible noises and no oil leaks *smile*
Cheers
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G'day Fellas.
This morning when she was cold (1C in the shed) I checked the tappets. They had closed up a tad so reset at my preferred gaps. 10 & 14 is 2 thou bigger than in the book but I don't ride like the book *eek*
Started 2nd kick and sounds great (no baffles) through 40 year old stainless pipes.
I won't ride now till the new carb arrives.
Cheers.
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Geez that's a beast Musky.
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That all looks great 👌 Well done; it almost looks like you've done it before 👍
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There used to be a varnish-like substance (Wellseal if I recall correctly - came in a small bottle) that one could paint onto gaskets. Often used on head gaskets. Dunno if it's still obtainable. Have some somewhere but never think to use it.
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Musky's balls are so huge that his engine may blow a gasket of he doesn't put jollop on. I just anneal mine, (the gasket that is).
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G'day SHM.
I've used it for many many years on head gaskets. Especially on the 14:1 A7SS racer. Never had a blow out. Yes I anneal the gasket first, this may be the 3rd time it as been re-used.
https://tinyurl.com/37c4rmbe
• Helps dissipate heat, prevents overheating of gaskets and improves thermal transmission. • Most common applications are exhaust manifold gaskets and cylinder head shim gaskets. • Can be used on new multi-layer gaskets when indicated . • Contains metallic copper to help improve thermal transfer and eliminate heat build-up. • Remains soft without drying to allow repositioning of the gasket. • Operating temperature from -45 ° C to + 260 ° C. • Resistant to liquids commonly used in the workshop, including gasoline • Fills application surface imperfections • Typical applications are engine head gaskets, exhaust manifold gaskets, turbocharger flanges, carburetor gaskets.
I'm trying a cheaper version this time (only 7.5:1 in this motor). Dupli-Color Aerosol Spray Copper Gasket Cement 340g .
You can see by the pics the outside 4 head bolt holes have been moved outwards by 1/2 a hole for the through studs. Lani at Copper gaskets unlimited made me gaskets with ears to suit.
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There used to be a varnish-like substance (Wellseal if I recall correctly - came in a small bottle) that one could paint onto gaskets. Often used on head gaskets. Dunno if it's still obtainable. Have some somewhere but never think to use it.
Wellseal is still available and it's still recommended when fitting Sunbeam S7/8 head gaskets.
Comes in a tube now and is still one of the better gasket goos.
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nice job Musky, can you explain/show me a bit more information/pics about your piston ring compressor?? I'm trying to work out how you fit it to confidently know the rings are fully compressed, and also how you remove it after the barrels are fully past the pistons...cheers
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G'day Jules.
Very simple mate. Cut a piece off a 90mm poly pipe about 1,1/4" long, slit it and wrap it around your piston and mark where it overlaps, cut the overlap plus 1/4" off, smooth off all edges. Lightly oil the rings and inside of the poly, ensure the rings are in position (no gaps over the pins or fore an aft). Use a 75mm hose clamp to compress the lot putting the gap of the poly at the rear and the screwy bit of the hose clamp at the front. Tighten the clamp till it won't spin on the piston and then back off 1/2 a turn till it just can spin. Lower the barrels on slowly and square. You can see at the gap in the poly once your down past the oil ring. Now undo the clamp fully and pull it out (I move it up over the barrel skirt first, just incase), then the poly can be flexed off the piston up onto the skirt and pulled off. Refer to pic #72.
Cheers
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got it, I can see it now, thanks Musky....
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I used Musky's method years ago.... it works well.. *clap*
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G'day Fellas.
I threw the new Premier 932 on last week and did a quick pilot/idle adjustment. Did 15 minutes around town then checked the timing. All good. A couple of runs up Scenic hill to bed her in. I was going to tune the main & needle on Sunday but was too hungover *sick*
Tonight I checked the fuel height in the carb. In the past I've had trouble getting the fuel height right and not flood. The slight downdraft of an alloy head makes it difficult. The book says 170 to 240 thou" below the gasket (body/bowl), 240 was as high as it would go.
I hooked up my test tool (bowl bung with 1/4" hose spear) to the bowl ant turned the fuel on. Bl@@dy perfect at 240.
Hope to get out this w/end to get her tuned right.
Cheers
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G'day Fellas. I'm back!
It's been a while, I haven't been riding her much ue to the buggered hip.
To fill a bit of a gap https://www.a7a10.net/forum/index.php?topic=13293.2685 reply # 2688 new rockerbox fitted and inlet valve guides got seals.
Not much to do in the shed today (see next installment in "what did you do to your bike today) so I took her for a spin to warm her up and give her the 1st oil change at about 150 miles. Dropped the sump plate and filter off. Was what I expected. Bugger all on the filter *ex* I only use Permatex #3 on gaskets so no gasket stuff and only one or two tiny bits of glitter. Very happy. Now for the next 500 miles.
Cheers
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Musky,
That is brilliant - can't believe so little muck on the screen. rocked my confidence in my own skills. :(
Col
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I actually work part time for a UK classic bike dealer plus my own bikes and yet I still like reading the detail in these posts, despite working on the whole range of classics, 1914 to 1974. Bus man's holiday or just a sad b'strd?
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G'day Sakura.
I must be a masochist as I went back to page 1 and read it all again!
Cheers
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Placed condoms on the rods and was now able to use the kick lever to spin her over a lot quicker. Oil kept flowing round and round.
Hi Musky,
I use protective stretch netting over rods to protect them from dings. It came with something I bought. Obviously needs to be large enough to keep the mesh closed up for maximum protection.
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G'day Fellas.
I had my first decent ride over the weekend. Only 140Km each way and 6 weeks after total left hip replacement! Camped in a tent.
She don't like starting from cold (under 5C) so I'll look for a choke/cable and lever (never had this trouble down the coast).
After coming down the hill and sitting at the control tent she just sat there idling for 4-5 minutes and took off like a rabbit.
Oh I luv the new premier 932 carb ( yes 932 on an A7 *ex*).
Took 3 kicks in the morning (more than I did!) and flew up the hill (ok 2nd in a few spots). Sat on 60-70 mph the whole way home and sat there idling while I opened the gate and shed. I love my 1951 A7 plunger.
Cheers