Engine Rebuild

[Alistair E]

The engine's out while I sort out the clutch so I thought I would give it a clean and sort out any problems. The head's off and the bores look in good condition, visually. Car has done 140k.

While it's off is there anything I should be doing to the bottom end?
What checks can I do on the bores and the rings? Should I re-ring the pistons, although at nearly £30 per piston from Eurocarparts I'm reluctant. If you do suggest re-ringing, where is the best place to buy rings? Anything I should check regarding mains and big ends? The engine did use some oil but did not visibly smoke.

What should I check with the head and how do I check it? I will remove the valves and grind them in? How do I check for guide wear?

It's a stock engine so any measurements you can give that can be checked would be appreciated.

I'm also looking to get it back to a position where the oil stays clean for longer than a day and the water will retain some of the coolant colour rather than turning a full rusty colour. Any suggestions as to how to clean block and head?

Any other suggestions/advice would be gratefully received.

Thanks

Alistair

[Jamo]

If your serious and keeping the car at 140k and the engine already in bits it would be an excellent time to replace the rod and crank shells with the RS2 ones.

Crank seals should also be replaced front and back and maybe consider a new oil pump ( very optional ).

I personally wouldn't touch the rings as you then have to get them all regapped, hmm tricky one that.

[GazzaG60]

id send in the head for a clean up. have new guides and seal fitted. doesn't cost a lot.

you could take the bock apart but ask yourself the question. why am i donig this. my advise is dont plan to inspact plan to change.

i fitted the scats with new rod bearings when i had mine apart. i should have honed and re-rung but i din't. the shop skimmed the piston for me after removing the rings with a proper tool and refitted them for me to the same piston. i simply dropped them back in. seems to be good. maybe not the seal of a new ring but then again unless they are run in hard after new ones dont seal too well anyway. theres too much pussying about with runnning in to do it properly in some cases.

plenty of oil down the bores adn turn her over and check for a lip on the top of the bore and any marks down the bore. look on one side more than the other as this is where the piston is pushed into the sidewall. take photos as clear as possible if in doubt.

if you dont like messing i can recommend impulse in rochdale. they did the work on my head, skimmed my pistons and weightmatched my rods and pistons to i think 0.5g and i slapped it back together. impulse will build it all for you if you like.

[Nace20]

i would also be interseted with what should i clean the block

[Audi Parts Guru]

If your serious and keeping the car at 140k and the engine already in bits it would be an excellent time to replace the rod and crank shells with the RS2 ones.

Apart from being new, what advantage would this give him Jamo?

[Fat Audi 80]

Unless you have any real doubts about the bottom end (Or are going for a serious power upgrade), I would personally leave it. These engine are bullet proof and you are likely to do more harm than good breaking it open. (I am not casting aspirsions on your skills btw).

As for the head, I WOULD have that cleaned and new seals and guides though.

Cheers,

Steve.

[wez 47]

hi Alister, just incidently i'm on the wirral also, regarding your head, i would give it a complete overhall as its in bits, check all components as a matter of habit for signs of wear ie cam lobes, buckets, valve spring heights at compression and at rest, valves {seats stems, guides}, valve inserts in head etc etc, the only thing i would replace as far as the head goes unless significant wear was found would be the valve stem oil seals, head gasket + head bolts, as i said if there was reasonable wear on the buckets for example which i doubt on that miledge provided its had regular good quality engine oil changes i would also throw a new set of buckets + valve springs in there also, + have the guides checked for wear, replaced if necessary. the valves should be cleaned and relapped into the head as a matter of coarse anyway also. finally check the head face is true also, a reface is cheap if needed but probably unnecessary unless youve fried/ blown the head gasket. whilst the head is off i would remove the rods + pistons, check the bores for signs of wear, hone them, remove the pistons from the rods+ clean the ring grooves + oilways with a suitable cleaning agent and also a snapped ring and fit a new set of rings to each piston, fit a new set of mains + big end shells, rod bolts.with the rods removed you could measure the big end journals, to be extra thorough you'd have to drop the crankto do the mains .As far as the oil pump goes is it really necessary to change the complete unit?, i would of thought renewing the spring and plunger is sufficient, runnig the engine in is easy, your basically only bedding the rings into the bores to create a good seal as the shells are essentially run in once the engine is fired up. a set of rings only take 5-600 miles to bed in , by just driving the ar sensbly, taking the revs up in increments, eg the first 50 mile rev up to 2500rpm, 50-100mile no more than 3000rpm, 100-300 mile 3500rpm the remainder don't take it above 4000rpm. once youv'e done 5-600 mile i wouldn,t automatically open her up , but rather take the revs higher briefly in short stints. the engine will probably loosen up and feel more lively ater about 2-300 0ies.finally i would flush, drop the oil at the 1000mile mark + renew, with a new filter, have a quick check of the oil youv'e dropped for any metal particles, not that there should be provide its been run in right, the components replaced were measured + fitted correctly during rebuild.hey preto youve basically got a new engine, cheers wez.

[wez 47]

Ps; Also;

Forgot to mention as far as rings+ stem seals go i would always replace with genuine Audi parts if possible as i've always found that where these are concerned they are of better quality than pattern parts, cheers wez.:top +bottom end gasket/seal kits also.

[wez 47]

pps;

Fit a new cambelt as well.

[Alistair E]

Thanks for the replies so far. Differing advice from a few of you as to whether or not to do the bottom end. The aim is to put an RS2 turbo etc on looking for late 300's bhp (I've been saying I would do that for the last 3 yrs).

Wez
It would be nice to have a fully rebuilt engine, but the funds are slightly scarce at the moment. I will do all the necessary checks and work on the head, but I'm less inclined to do too much to the bottom end. I still need to price up big end and main shells but I'm guessing they're not going to be overly cheap. I might nip to Birkenhead Engines at lunchtime today and see what sort of prices they charge. Unless you've got any better suggestions for who to use.
I'm not afraid to do the spanner work myself, but I'm less sure on the measuring/checking side.

The bores have virtually no lip at the top and a quick inspection has not shown up any marking.

Can anyone supply a comprehensive list of measurements that should be checked? It might be an idea if that sort of information was readily available on a couple of stickys, one for the head and one for the bottom end.

Cheers

Alistair

[Alistair E]

p.s. to your p.p.s.

Only changed the cambelt two months ago. With foresight, I would have known that the clutch was going to give me a problem and the engine would be coming out and I would have left changing the belt until now.

These things are sent to try us.

Fit a new cambelt as well.

[GazzaG60]

either do it or dont. no going in half way saying ill inspect it and replace if needed is what i mean.

runnnig in is a discussion done many times before and best left out of topic i think.

id set my stall out and say yes or no to the rebuild first.
then id get a waterpump, gaskets, new water rail seals from audi (been there done that with the leak)inlet and exhaust gaskets.
id get some ARP bolts for the head and a new rocker gasket kit.

start making up the tool to fit the crankpully back on. we used a piece of a wagon axle stand welded to a flat piece that had a hole cut in it to fit over the stub. dont forget the stupid washer thats 25 quid that fits between the crank pulley. otherwise its full strip again.

whilst its our sort the engine mounts too and other little bits like that.

[Alistair E]

Well, just been to Birkenhead engines and was pleasantly surprised. Not sure if prices are plus vat but even so. Having said that, I didn't ask who made everything.

Bottom end gasket set £51
B/E sputter bearings £65
Main bearings £20
Piston rings £72
Valve guides £4 each

He quoted about £100 labour for overhauling the head. That's taking my gasket set and fitting it with new guides, cutting seats and lapping valves.

£10 to strip and check oil pump.

Can someone tell me, how do you measure and gap new piston rings?

Still looking for answers on how to clean block and head for clean oil and water.

Thanks

Alistair

[Alistair E]

Nuts, bolts & studs

I was told a while ago by a friend that I should not use stainless steel nuts and bolts on susension items. I not sure of the reason but I think it was something to do with the shear strength of stainless. Might be useful to hear any other views.

The reason for including the question in this thread was that I was thinking of using stanless fastenings for the parts around the exhaust manifold. Not sure if you can get stainless studs, but you can get stainless aerotight nuts. I was thinking about stainless nuts for the turbo etc nuts aswell. Any thoughts? Is there any problem with the temps involved. What about the mixing of stainless nuts on steel exhaust studs?

Alistair

[GazzaG60]

use copper nuts for the exhaust. you dont want to snap studs down there ever.

you could use some cleaner in the block. the head will get flushed before it is skimmed and cleaned up. id wait till its back together. then put a hose down a water hose and wait till it runs clean out of the other side. expect your radiator and whathaveyou to add some crud to the water.