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Restart engine

PostPosted: Sat Mar 16, 2019 11:09 am
by davidj
Morning,

I have a twin cam engine which was (allegedly) rebuilt in 1980 and has not been run since. Initial inspection shows no play in the water pump and the oil is new.

Can you advice what is the best course of action prior to starting up or should I go for a complete strip down first? The car, an S3, is in bits and at the moment, the body can still be lifted off the chassis, so access to the engine is OK. However, as I rebuild the car, removal of the engine will obviously get more difficult.

Are there any quick checks to identify if any work has been done on the engine? Since it has been stood for 29 years, I guess the water pump seal is shot, so this is the ideal time to replace.

Thanks in advance.

Cheers, David

Re: Restart engine

PostPosted: Sat Mar 16, 2019 3:29 pm
by alan.barker
Imho i would at least remove the Sump to have a look. Remove Big End Caps + Mains to check to be sure.
It will only take a W/E and Gasket Sets + Water Pump Kit. Don't forget the Graphogen for Bearing assembly.
Maybe a chance to have no Oil Leaks also :roll:
Alan

Re: Restart engine

PostPosted: Sat Mar 16, 2019 4:05 pm
by davidj
Thanks. I think I have already accepted I will have to remove the head and change the water pump seal, and at this point fit I will fit a cartridge water pump.

It is therefore not a big deal to remove the crank caps. However, is there any obvious indication that the crank has been reground and all is well? When I have done this in the past, I have automatically sent the crank for re-machining and purchased new bearings. In this case, it might not be required. Likewise, if the bores have very light surface rust but no wear step, are they ok to clean up?

I guess I don't wish to go through the pain (and cost) of full rebuild when there is no need, as the engine may have been rebuilt in the past.


Ta.

Re: Restart engine

PostPosted: Sat Mar 16, 2019 8:04 pm
by miked
I have pulled three apart in the last couple of years that were rebuilt and then stored. By so called experts.
I personally would pull it out and strip it down and clean and examine. I found all sorts of issues from rust to loads of graphogen paste (gone thick). Blocking crank oil ways. Too much sealant, stripped threads on timing quadrant pivot and timing tensioner adjuster. Cam tunnels full of crap. Blocked (on purpose with sealant and with gunge) mechanical seal tell tale holes. Poorly assembled water pump seals and impellors without proper clearance.
General lack of cleaning. Tight gudgeon pins in small end. On two engines.
These engines are now pretty expensive. How has it been stored?
If it is all good, you get to know that and re seal properly with new gaskets and seals. You get to sleep peacefully. Also maximum confidence in the engine.
Also learn a lot. Miles Wilkins book is ideal.
My two pennies worth.
Mike

Re: Restart engine

PostPosted: Sat Mar 16, 2019 8:21 pm
by USA64
miked wrote:I have pulled three apart in the last couple of years that were rebuilt and then stored. By so called experts.
I personally would pull it out and strip it down and clean and examine. I found all sorts of issues from rust to loads of graphogen paste (gone thick). Blocking crank oil ways. Too much sealant, stripped threads on timing quadrant pivot and timing tensioner adjuster. Cam tunnels full of crap. Blocked (on purpose with sealant and with gunge) mechanical seal tell tale holes. Poorly assembled water pump seals and impellors without proper clearance.
General lack of cleaning. Tight gudgeon pins in small end. On two engines.
These engines are now pretty expensive. How has it been stored?
If it is all good, you get to know that and re seal properly with new gaskets and seals. You get to sleep peacefully. Also maximum confidence in the engine.
Also learn a lot. Miles Wilkins book is ideal.
My two pennies worth.
Mike

How long were they sitting? You're making me nervous!

Re: Restart engine

PostPosted: Sat Mar 16, 2019 8:45 pm
by ericbushby
When I bought my car in 2011 the engine had been overhauled, but had stood unused for an unknown time but definitely less than 5 years. perhaps a couple of years. It was apparently running well and drove onto a trailer OK.
Soon after it broke an outer valve spring but did no damage.
When I replaced all the springs, the old ones were different lengths when not compressed showing that some had distorted under constant pressure and could not work properly (or that they were crap springs. I do not have the experience in that.)
Sorry to bring you more work.
Eric in Burnley
S3SE Type 45

Re: Restart engine

PostPosted: Sat Mar 16, 2019 9:01 pm
by miked
Good point Eric. I forgot to mention i changed springs on ones that had sat 20 years plus due to differeing lengths.
The engines i mention were 20 years plus and one about 10.
For the cost of springs it is worth it.

Re: Restart engine

PostPosted: Sun Mar 17, 2019 10:34 am
by davidj
Ok, thanks. You have convinced me. You have unfortunately confirmed what I was thinking. The engine has been stood for 29 years, so I guess it will need some TLC.

Thanks,

David

Re: Restart engine

PostPosted: Sun Mar 17, 2019 11:23 am
by alan.barker
Dave, you will never regret your decision. I bought a +2S that had stood still for 23 Years and the only problem was to deglaze the Cylinders and fit new Rings. The Engine had not been turned over regular and the Rings had made a Rust line in a Cylinder :shock:
Alan

Re: Restart engine

PostPosted: Mon Mar 18, 2019 1:17 pm
by denicholls2
If the engine was rebuilt and not run, the crosshatch lines in the cylinder bores will confirm that for you -- they will be fresh. Since you planned to pull the head anyway, I would stop there with positive signs and confirmation of no excess end float in the bottom end. Turn through a few turns to confirm no rust rings after giving them a shot of Kroil or equivalent. The head should also visibly show "recent" (in terms of run time) machine work on valve seats.

Any issues in the bores and you'll need to play with the bottom end to re-hone anyway.

Re: Restart engine

PostPosted: Thu Mar 21, 2019 10:15 am
by davidj
Thanks for all your comments

"confirmation of no excess end float in the bottom end." How can I do that? I do have a DTI and potentially could measure the play in the big ends, but I would have thought it would be difficult to get any accurate and meaningful results.


Cheers,