The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: magicflem on 08.08. 2014 08:55

Title: New rebuild 1963 A10
Post by: magicflem on 08.08. 2014 08:55
I am sure this question must have been raised before, somewhere - but I can't find it!!
Just finished an engine rebuild on my 1963 A10 RGS, there is a head gasket leak on the primary side and a spray of oil from the breather under the bike.
Would the spray of oil and overheating all be related to the leaking head gasket - could gases leak thru the gasket and into the case via the push rod tunnel?
Would a retension of the head gasket (haven't done this yet) solve the problem?
Help!!!
Regards,
Kim 
Title: Re: New rebuild 1963 A10
Post by: muskrat on 08.08. 2014 09:59
g'day Kim.
Was it a composite or solid head gasket? Was it annealed properly?
If can leak into the tunnel and would pressurize the case but so would blow by the rings if their not bed in yet.
A proper re-torque of the head (rockerbox off) is only 5 minutes away from lifting the head to try a new annealed gasket.
You could re-torque the four outside bolts, but it's something I wouldn't make a habit of.
Cheers 
Title: Re: New rebuild 1963 A10
Post by: magicflem on 08.08. 2014 10:30
Ahhhh, beautiful Lake Conjola.....
Thanks Musky, I did cherry the solid copper gasket on the BBQ wok burner. Hopefully a re-tension will solve the problem.
What do you suggest lbs for bolts?
Also, do you run in hard or otherwise?
Regards,
Kim 
Title: Re: New rebuild 1963 A10
Post by: a10gf on 08.08. 2014 12:01
Hello, try a search for head torque, lots of info available, for both alu and iron.
And remember how the different search options works > http://www.a7a10.net/forum/index.php?topic=1352.0
Title: Re: New rebuild 1963 A10
Post by: RichardL on 08.08. 2014 13:08
Kim,

Is there any possibility that your annealing method brought some area of the gasket to partial melting and, theferfore, surface deformation? If re-torquing the exposed four bolts does it, count yourself lucky, but I suspect a new gasket or, at least, re-annealing will be called for.  Have you done a compression test? Maybe both sides are leaking. Before and after tests could tell you if the re-torquing did the trick.

Richard L.
Title: Re: New rebuild 1963 A10
Post by: muskrat on 08.08. 2014 13:40
30Ft/Lb with oiled bolts. (I give my cafe 35)
I don't baby mine, keep under 4000rpm for 1st hundred miles and don't lug it up hills.
How many miles since rebuild?
Cheers
Title: Re: New rebuild 1963 A10
Post by: magicflem on 08.08. 2014 23:45
Only 20 odd miles since rebuild - I will re-tension head and see how we go.
I will let you know if this is a fix.
Thanks all.
Kim
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 09.08. 2014 00:33
Kim,
            Did you check the head and barrel faces for flatness?
The head can tend to get a bit of a warp.

Trev.
Title: Re: New rebuild 1963 A10
Post by: magicflem on 09.08. 2014 05:12
Checked all head bolts this morning - no movement from 30 ft lbs as originally set when the head went on during rebuild.
Will now have to take head off and fit new solid copper gasket.
This is the way I intend to go:
1. Anneal head gasket with "Mapp" Gas to cherry red then immediately quench in cold water.
2. Clean gasket with "Brilo" sponge.
3. Clean all surfaces with "Prepsol".
4. Check head for warp - what is the best way of checking?
5. Coat both sides of gasket with "Permatex Copper Spray-A-Gasket Hi Temp Adhesive" just before fixing in place.
6. Fix gasket, head, thick washers and "wasted" bolts.
7. Torque to 20 ft lbs then 25 ft lbs then final 30 ft lbs. Then leave overnight, tap each bolt head with brass drift then check ft lbs again.     
Is there anything wrong with my method?
Kim
Title: Re: New rebuild 1963 A10
Post by: muskrat on 09.08. 2014 05:56
Sounds just as I would do it. Fingers crossed.
To check for flatness chalk the surfaces and rub them together. look for shiny spots.
Cheers
Title: Re: New rebuild 1963 A10
Post by: magicflem on 09.08. 2014 07:15
Just took the head off and guess what a found.....
The timing side barrel sleeve has dropped 2.77mm!!! not happy #$@$%@^#$$$$
How the hell can engineers get it so wrong?
Has any body had this happen before and would it be part of my head gasket problem?
Kim
Title: Re: New rebuild 1963 A10
Post by: muskrat on 09.08. 2014 07:41
BUGGA *eek*.
If your really care full you could push it back in and use a really small scotch key in the top to hold it or two small pins at the bottom of the skirt (chamfered on the inside to be flush with the bore).
Or. Get a new one made 0.002" bigger on the OD. Pray the other one stays put.
Wish it was just a head gasket.
Cheers
Title: Re: New rebuild 1963 A10
Post by: duTch on 09.08. 2014 08:36

 geez mate, that's a total bitch agree the gasket would've been preferred...

 Regarding the:-
Quote
6. Fix gasket, head, thick washers and "wasted" bolts.

 The bolts won't be 'wasted' unless you don't use them, it's usually best to use 'waisted' bolts in the head..!
Title: Re: New rebuild 1963 A10
Post by: magicflem on 09.08. 2014 09:11
Thanks guys....
Looks like the sleeve just touched the crank but lucky no damage to it or my new con rods.
It will be a trip to my regular engineers at Winsor on Monday with barrel, head and pistons.
I will have them replace both sleeves just to be sure.
The old sleeves will end up with the bloke who originally put them in - he may look a little funny with them inserted where they shouldn't be inserted!!
Kim
Title: Re: New rebuild 1963 A10
Post by: muskrat on 09.08. 2014 20:36
The last set I had done had a small step at the bottom of the skirt for the sleeve to but against so it couldn't drop.
Are you buying proper sleeves or having foreign ones machined?
Cheers
Title: Re: New rebuild 1963 A10
Post by: RichardL on 09.08. 2014 21:42
Muskrat,

Aren't they all "foreign", depending on where you are? Do you mean Asian as opposed to Englandian?

Richard L.
Title: Re: New rebuild 1963 A10
Post by: chaterlea25 on 09.08. 2014 22:03
Hi Kim,
Shit luck about the liners, maybe lucky the result wasnt a lot worse

Make sure the head has not been damaged where the "thick washers " seat
all the heads I have come accross need spotfacing to ensure a flat surface for the washers
I make my own washers 3mm thick

HTH
John
Title: Re: New rebuild 1963 A10
Post by: kiwipom on 09.08. 2014 23:28
hi guys, Dutch are you going to correct this one? ( had a small step at the bottom of the skirt for the sleeve to but against so it couldn't drop)
 go on give Musky an `English` lesson,cheers
Title: Re: New rebuild 1963 A10
Post by: kiwipom on 09.08. 2014 23:32
hi guys/ Magicflem, perhaps the original engineer will fix his cock-up for free,cheers
Title: Re: New rebuild 1963 A10
Post by: magicflem on 09.08. 2014 23:53
I don't think I want to see that "engineer" again!!
Title: Re: New rebuild 1963 A10
Post by: magicflem on 10.08. 2014 00:09
Can I please have your thoughts on liners....
Should liner have a step on outer surface at top and barrel machined to accept. This would prevent sleeve dropping - or am I totally up the wrong tree?
Also, where is a good supplier of quality liners?
Regards,
Kim 
Title: Re: New rebuild 1963 A10
Post by: bsa-bill on 10.08. 2014 08:57
genuine Hepolite still come up on Ebay now and then

http://www.ebay.co.uk/sch/i.html?_odkw=Hepolite&_osacat=14780&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XHepolite+liners&_nkw=Hepolite+liners&_sacat=14780 (http://www.ebay.co.uk/sch/i.html?_odkw=Hepolite&_osacat=14780&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XHepolite+liners&_nkw=Hepolite+liners&_sacat=14780)

I fitted liners in my Flash some 14 - 15 years back, cant recall if the had a step, some advertised above don't , most do, also they don't come with bottom cut out for con rod, the shop do this.
Title: Re: New rebuild 1963 A10
Post by: duTch on 10.08. 2014 12:30

 Haha- why me... *eek* *beer*

Quote
hi guys, Dutch are you going to correct this one? ( had a small step at the bottom of the skirt for the sleeve to but against so it couldn't drop)
 go on give Musky an `English` lesson,cheers

 Weeell...I did see it earlier, but had stuff to do so thought I'd mull it over, or stay out of it..but then forgot... *conf*
 Glad you spotted it though, takes the pressure off me.....I did think a step at the top might be better, and aren't they slightly tapered..?? Mine were sleeved, but that was a long time ago....??
  *beer*
 
Title: Re: New rebuild 1963 A10
Post by: chaterlea25 on 10.08. 2014 12:37
Hi Kim,
A10 liners are not usually stepped at the top
However they must have less interference fit where the cylinders project below the base flange
If they are too tight there they will split the spigots
The theorie on liners is that they will always run hotter than the surrounding cylinder and should not come loose or move, however a too tight piston to liner clearance will cause the pistons to nip the liners and drag them south  *eek*

HTH
John
Title: Re: New rebuild 1963 A10
Post by: magicflem on 12.08. 2014 04:06
Have got another cylinder with liners that have a "top hat". I am going to re-use my STD sized 9:1 JP Pistons with new rings of course but I am now wondering if 0.005" piston to bore clearance is too little. Also, how do I check that the connecting rod alignment is correct???? HELP..
Kim 
Title: Re: New rebuild 1963 A10
Post by: edboy on 12.08. 2014 11:57
wrong post bill.
this interesting thread is about oil leaks caused by a loose liner worming itself south into the warp drive.
Title: Re: New rebuild 1963 A10
Post by: chaterlea25 on 12.08. 2014 20:29
Hi Kim,
A length of 3/4in. silver steel (drill rod) should pass through both small end bushes simulatatiously
without binding, with the rod through the small ends the crank should rotate as much as the bar will allow
without any problem, and keep checking the 3/4 bar is free to rotate

HTH
John
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 12.08. 2014 21:57
I wouldn't have used JP pistons to start with. They have a reputation for growing.
Title: Re: New rebuild 1963 A10
Post by: magicflem on 12.08. 2014 22:57
Trev,
Can you recommend a good piston?
Regards,
Kim
Title: Re: New rebuild 1963 A10
Post by: fringedweller on 12.08. 2014 23:54
I've used JP pistons in several bikes including the Super Rocket with no problems for a few years now.
 One was a dirt track T****ph which would get a good flogging, no problems.
 Of course I like them as they are made in South Oz, so I look after the local blokes.
Don
Title: Re: New rebuild 1963 A10
Post by: magicflem on 13.08. 2014 00:10
Don,
If I am using STD sized 9:1 JP Pistons I am now wondering if 0.005" piston to bore clearance is too little.
Regards,
Kim
Title: Re: New rebuild 1963 A10
Post by: fringedweller on 13.08. 2014 01:34
JP recommend 5thou unless running a sidecar, which requires a little more clearance.
I'm running 8:1 comp in the Super Rocket, plenty of power and smooth.
Crank , mains etc rebuilt by Martyn Adams of MDA eng, another South Oz company.
Some people say he is expensive , but it stays fixed.
Don
Title: Re: New rebuild 1963 A10
Post by: magicflem on 14.08. 2014 09:40
Would it hurt to go 0.006 or 0.007thou?
Title: Re: New rebuild 1963 A10
Post by: BSA_54A10 on 14.08. 2014 20:16
Going out another thou is basically "wearing" the bore.
It won't greatly affect the engine other than reducing the life of this bore.
I have never had a problem with JP pistons only the rings he fits to them which I never use.
Title: Re: New rebuild 1963 A10
Post by: muskrat on 14.08. 2014 21:19
My rule of thumb is for road use 4 and track (racing) is 6 using cast pistons. Forged pistons require a thou or two more.
Cheers
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 14.08. 2014 22:19
Kim, are there any signs that the pistons picked up the sleeve? Such as sieze marks.
I have had good results with GPM pistons in 2 Rocket engines and a Norton Atlas as have some of my mates.
There are some here who have not.
In my low compression engines, 7.25:, I have used pistons which came in a plain unbranded box, probably Taiwanese, but looked good and so far are performing well.
As to JP, I recently did some work on an A65 which has new JP pistons fitted. They looked very good compared to the old production heavy things of the past and I suppose that I am prejudiced against the new ones.
The rings don't seem to be up to the job as the engine seemed too smokey to me, maybe time and a few miles will improve it

Trev.
Title: Re: New rebuild 1963 A10
Post by: magicflem on 15.08. 2014 02:53
This is one of the JP pistons
Title: Re: New rebuild 1963 A10
Post by: magicflem on 15.08. 2014 08:47
Can I ask what rings you suggest please  BSA_54A10?
Regards,
Kim
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 16.08. 2014 00:16
Little bit of a "grab" there, Kim.
Title: Re: New rebuild 1963 A10
Post by: Brian on 22.08. 2014 06:20
As the subject of liners was discussed here I thought I would add a bit more.

I knew I had some A10 liners but it has taken me a couple of weeks to find them, I really must have a clean out oneday.

Anyway here are some pics of genuine Hepolite liners for a A10 plus a scan of the fitting instructions. You will see they are parrallel (no step at top) but they do have the relieved section at the bottom that John (Chaterlea25) referred to.
Title: Re: New rebuild 1963 A10
Post by: WozzA on 22.08. 2014 07:28
Kabana only $1 each....  you've had that tucked away for awhile...  *eek*
Title: Re: New rebuild 1963 A10
Post by: magicflem on 22.08. 2014 07:36
WozzA,
Have I missed something: "Kabana"? "$1.00 each"?
Kim
Title: Re: New rebuild 1963 A10
Post by: duTch on 22.08. 2014 07:59

 
Quote
Have I missed something: "Kabana"? "$1.00 each"?
Maybe just a decade or two..... *smile*

 But at least it says '$', not  '£'......!
Title: Re: New rebuild 1963 A10
Post by: magicflem on 22.08. 2014 08:19
Ahhhhh.....
Must be showing my age - I don't read newspapers, everything is online for me!!
Sorry guys.
Kim
Title: Re: New rebuild 1963 A10
Post by: magicflem on 29.08. 2014 03:08
OK.
Since we last spoke I have been busy locating another barrel that has not been sleeved. Bingo, found one and now I have decided to also buy new pistons (+60thou 8.25:1 GPM's).
The new barrel and associated bibs and bobs are with my new engineer being treated to a bit of a bore and a bit of a hone.
Now, for my next question - how do I ensure that when running in I do not overheat the engine and nip up a piston. Is it a matter of raising the needle a notch or not overreving etc..... help, I need advice!!
Regards,
Kim   
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 30.08. 2014 00:24
I wouldn't worry about the carby settings.
Just ride the bike normally without lugging it on hills, revving won't hurt it.
Make sure that the bloke that bores it gives it enough clearance.
Title: Re: New rebuild 1963 A10
Post by: magicflem on 30.08. 2014 00:55
Thanks Trev. The GPM pistons spec is 3 to 3.5thou piston to bore clearance. Is this too little?
Kim
Title: Re: New rebuild 1963 A10
Post by: trevinoz on 30.08. 2014 22:37
Kim,
          I would give it another thou but it is up to you.

Trev.
Title: Re: New rebuild 1963 A10
Post by: morris on 30.08. 2014 22:47
Service sheet 216 says .0011 to .0031
Title: Re: New rebuild 1963 A10
Post by: muskrat on 31.08. 2014 00:18
That would be for split skirt pistons Morris. I agree with Trev, 4 - 4 1/2 thou is good.
Cheers