Author Topic: Rock solid engine.  (Read 908 times)

Offline BSA_54A10

  • Wise & Enlightened
  • *
  • Join Date: May 2008
  • Posts: 1839
  • Karma: 29
    • BSA National
Re: Rock solid engine.
« Reply #15 on: 06.10. 2019 12:15 »
We will have to agree to dissagree.
Dry bores and a 3 minute run in.
Different with a fully rebuilt engine where you have replaced bushes & bearings but for a simple rering dry .
Even when I do a full rebuild, the rigs get gurn in dry then I baby the rest of the engine for it's first couple of hundred miles, changing the oil every 50 or so followed by a retorque on the head.
Bike Beesa
Trevor

Online Rex

  • Valued Contributor
  • ****
  • Join Date: Apr 2017
  • Posts: 447
  • Karma: 0
Re: Rock solid engine.
« Reply #16 on: 06.10. 2019 15:58 »
Horses for courses. A race bike might have a new engine every race. A private bike needs to go for many years between rebuilds.

True of course, but the principle here is that the rings are bedded-in ASAP. BTW I wouldn't attempt the "bloodline" bit either!
Modern oil is so good that it seems to be a common problem on the Net of people who've smothered the pistons  and bores in high quality oil only to find that the engine is still smoking like a WW1-era frigate many miles later, which, as we all appreciate, means doing the job all over again..

Online RDfella

  • Resident Legend
  • *****
  • Join Date: Aug 2017
  • Posts: 502
  • Karma: 4
Re: Rock solid engine.
« Reply #17 on: 06.10. 2019 17:52 »
And how does all this work when you've got chrome bores? Been building engines (almost all rebored) since 1960 and for a living mid 70's on, and always put plenty of oil on the piston and rings and never had a problem. I've heard you shouldn't use a top quality oil for running in, but I always used either straight 30 for diesels or 20/50 for petrol. Mineral, naturally.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Online AdrianJ

  • Moving Up
  • **
  • Join Date: Oct 2018
  • Posts: 99
  • Karma: 1
Re: Rock solid engine.
« Reply #18 on: 09.10. 2019 17:38 »
Latest update.
I have removed rocker box, timing covers and primary chaincase.
Rockers are free.
Removed idler (half time)  gear in timing chest.
Camshaft and magneto are free. Dynamo is free. Crankshaft still locked.
Small amount of black sludge (teaspoon) in the sump.
Haven't taken the clutch off but the outer sprocket has some hooked teeth, which I did not notice on rebuild.
On Friday I will remove the clutch, head and barrels.
I should know what's what after that.
Regards,
 Adrian.
'53 Plunger Flash, Steib S500.


Offline a10gf

  • Wise & Enlightened
  • *
  • Join Date: Sep 2006
  • Posts: 2653
  • Karma: 42
  • West Coast, Norway & Alpes Maritimes, France
    • A10 GF
Re: Rock solid engine.
« Reply #19 on: 09.10. 2019 19:18 »
Sorry for the need\cause for this detective work, but looking forward to reading news of your findings (and hopefully a good solution), good luck.

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline Swarfcut

  • Resident Legend
  • *****
  • Join Date: Oct 2018
  • Posts: 691
  • Karma: 9
Re: Rock solid engine.
« Reply #20 on: 11.10. 2019 08:44 »
Adrian...I have just read through your earlier posts to get a handle on your problem. If you have done all you intended, the motor has a new SRM pump, new pistons, rebore,  new timing bush and a crank grind.....can't tell if you had the journals metal sprayed and ground back to standard.  Nor can I tell with a quick read whether this was the first time it has run since the rebuild.

 You are familiar with the engine from your experiences with a later S/A model, if I understand correctly, so please confirm whether these basic assumptions are correct.

 Your last post indicated the sump was "dry" as if the small amount of sludge  in there was all to be found.....no trace of any oil. So we await the next instalment.

Swarfy.

Online AdrianJ

  • Moving Up
  • **
  • Join Date: Oct 2018
  • Posts: 99
  • Karma: 1
Re: Rock solid engine.
« Reply #21 on: 11.10. 2019 09:11 »
Hi Swarfy,
Thanks for looking at that lot.
Most of your assumptions are correct. Yes I have done all you mention. No metal spraying just a regrind to first undersize.
Third time run, previous were just a couple of quip blips, total running time less thsn three minutes.
No there was oil in the sump it just hadn't wet sumped. The sludge was in the oil and on the magnetic drain plug, which is not near the non return valve.
The SRM pump turns freely by hand and was full of oil, oil also seems to be getting to the rockers, there was oil in the banjo unions.
Today the clutch and primary drive come off. Clutch is quite wobbly.
Regards,
Adrian.
'53 Plunger Flash, Steib S500.


Offline Swarfcut

  • Resident Legend
  • *****
  • Join Date: Oct 2018
  • Posts: 691
  • Karma: 9
Re: Rock solid engine.
« Reply #22 on: 11.10. 2019 10:50 »
Adrian, Just a mention about the clutch...as long as the small "half  circle retainers" are in place and supporting the thrust washer behind the clutch drum, the clutch inner will be hard against the thrust washer as the centre nut is tightened. The only lateral support  for the chainwheel is in effect the running clearance between the thrust washer face, the back face of the inner drum and the faces of the chainwheel. Too tight.....it drags and seizes. Too loose...it wobbles. The centre rollers are too narrow to prevent all the wobble. To quote a saying "They all do that, Sir" In practice as long as the chain doesn't catch the inner chaincase, that's good enough for now.

 If you had oil return, oil was being pumped into the engine. If the PRV was blowing off too early, low pressure to the crank would mean possible seizure here.  As it has been rebored, a better chance it is a bore seizure, as long as the pump and PRV are working OK.

 I could be wrong, but that is where I'll put my money.

Swarfy.

Online AdrianJ

  • Moving Up
  • **
  • Join Date: Oct 2018
  • Posts: 99
  • Karma: 1
Re: Rock solid engine.
« Reply #23 on: 11.10. 2019 11:05 »
Swarfy,
Sounds like I didn't tighten the clutch enough.
The retainers are there - the chain had caught on the inner chaincase when I got the bike so it's difficult to tell if it's happening now.
If it was a bore seizure - why would it now be free? I had it relined back to std as it was at +60.
 I'm not sure it's any stiffer than when I'd finished putting it together.
I think I'll take the head off and have a look - it'll make retiming it easier anyway. I wonder if the liners could have slipped - not lipped! I'll find out tomorrow.
Regards,
Adrian
'53 Plunger Flash, Steib S500.


Offline Swarfcut

  • Resident Legend
  • *****
  • Join Date: Oct 2018
  • Posts: 691
  • Karma: 9
Re: Rock solid engine.
« Reply #24 on: 11.10. 2019 11:22 »
Adrian....I thought it was still locked up, didn't realise your bore and pistons are free.

Online AdrianJ

  • Moving Up
  • **
  • Join Date: Oct 2018
  • Posts: 99
  • Karma: 1
Re: Rock solid engine.
« Reply #25 on: 11.10. 2019 11:36 »
Swarfy,
Sorry - I've just realised one of my posts seems to have gone missing.It said that everything was locked up till I took the clutch and engine sprocket off. I've put the engine sprocket back on temporarily and it's still free but stiff.
It surprised me - thought it would be crankshaft or pistons.
Still a bit stiff but I'm not sure it's too stiff.
After I've had the head off I'll try rebuilding but it may be some time as I think I do need a new clutch basket. I the teeth aren't badly hooked but they are very sharp and shiny on the reverse - wonder if they have hit the chaincase. I could dress them and rebuild with this clutch.
Regards,
Adrian
'53 Plunger Flash, Steib S500.


Offline Swarfcut

  • Resident Legend
  • *****
  • Join Date: Oct 2018
  • Posts: 691
  • Karma: 9
Re: Rock solid engine.
« Reply #26 on: 11.10. 2019 12:25 »
   I would be inclined to lubricate the bores, take off the PRV and rotate the engine gently on the crank drive sleeve and check for an oil feed into the PRV cavity. Assure yourself the PRV is serviceable, and fingers crossed you have oil to the crank.  Try it again without lifting the head......any damage is done, and as long as it is free, see if it will go. Bear in mind a well built engine will be fairly stiff, not like it was when you first got the bike.  For a short term test stick with the old clutch unless it is so worn that the chain is riding up on the teeth and jamming on the case....fresh evidence of contact will be apparent.  Common for a piston that has just nipped up to free off, sometimes you can be lucky. Still thinking if it was the clutch, there should be something clearly amiss and fixable.

Swarfy.

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Join Date: Nov 2007
  • Posts: 4918
  • Karma: 45
Re: Rock solid engine.
« Reply #27 on: 11.10. 2019 12:46 »
Well, I just tried to read most of this thread for the first time. On the simplistic side, has it been confirmed that the sludge trap was cleaned prior to restarting after sitting for some time (years, perhaps)? Wiped out rod bearings could have a tiny impact on smooth or frozen crank rotation.  *eek* ;)

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Online Klaus

  • Valued Contributor
  • ****
  • Join Date: Jun 2015
  • Posts: 351
  • Karma: 9
Re: Rock solid engine.
« Reply #28 on: 11.10. 2019 13:12 »
Hi Adrian,

you've wrote there was only a teespon black sludge in the sump. So there was no oilfeed to the crank, it sounds to me.

Years ago I bought a new SRM Oilpump, but it was not plug and play. I fit this pump normal way and the crank were solid. When I loosen the bolds the crank were free to rotate. Tighten the bolds, crank jammed. I've heared from a blocke there was a burst engine because the wormdrive was brocken to rotate the gears from the oilpump.
So please have a look at your Oilpump if she realy feed.

Cheers Klaus


If you think, everything is under control, you are not fast enought.

Online AdrianJ

  • Moving Up
  • **
  • Join Date: Oct 2018
  • Posts: 99
  • Karma: 1
Re: Rock solid engine.
« Reply #29 on: 11.10. 2019 14:16 »
RichardL- yes the sludge traps were cleaned.
Klaus - I meant there was a teaspoon of black sludge along with the oil, not making myself clear. The oil pump must be feeding because I get an oil return.
Swarfy - yes I'll lubricate the bores, check the PRV - although I think it was working after the rebuild, at least oil was getting to it because that was how I checked that the pump was primed,  and try the clutch again tomorrow.
Regards,
 Adrian
'53 Plunger Flash, Steib S500.