Disaster strikes!!

[Paul190H]

Damm-dropped the S2 to the garage this morning for an MOT after weeks of work. Returned 10 mins later to find them struggling to start it. Turns out the cam chain guide decided to get itself jammed and strip the teeth on both cams rendering them useless and leaving me with as yet undisclosed number of bent valves!!! Changed the belts in August pretty much as soon as I got her, wish i'd known about the chain guides! []

Still could have been worse, at least I wasn't doing 70 down the road or the MOT tester revving the arse off it for the emissions test!

Thus begins the search for new cams and untold valves and yet more work! Old cars, gotta love them! So it will be a head off, replacement valves and get the good ones re-profiled, new head gasket, chain and guides and replacement cams.

Anything else worth doing whilst the heads off? [8|]

Cheers
Paul.

 

[colin944]

Polish the inlet tracks?

 

[edh]

Oh no - That's going to be expensive! A replacement engine might be cheaper.

My s2 had new cams 5 years ago - I think the bill was around £1k and that was without valves and headwork as the problem was caught on inspection before it broke.

 

[924nutter]

Oh mate I am really sorry to hear about your disaster, and twice as many vales to bend. You already know it is not going to be cheap. The cams alone will give you a fright. However Tref has just hoiked his S2 engine out because of a funnny noise (see link in S2 engine noise thread) but strangely everything in the head, cam, valve, chain, tensioner area seems ok, even though my money is on a dry hydraulic tappet. Maybe a chat with him and some of your tappets might sort you out cheaply, only a suggestion. The pistons will have ding marks but luckily due to heat of combustion the valve exhaust valve stems are fairly malleable and the valves bend fairly easily, so don't despair. I know exactly how you feel, I took the 924T for the MOT in 2005, with a new cam belt and filters at home, to ready it for the national event at Brands Hatch. On the way back from the MOT the cam belt went. It bent four valves and cost the best part of £1500 by the time I had finished, but I did replace all 8 vaves, collets, retainers, and three new tappets. Finished it 06:00 am on the Saturday of the event and drove it to Brands.

 

[zcacogp]

That's not good news at all Paul, I'm sorry to hear it.

£1000 for cams? Crumbs. There must be a cheaper alternative source - didn't Fen's old mechanic in Devon manage to source him a pair for a lot less money than the going rate?


Oli.

 

[Paul190H]

Ok so i'm going down the used route I think. Just purchased a relatively low mileage (reputed) S2 head so i have cams and valves. My guy is going to get the valves re-profiled and I'll re-use the cams with all new chain, guides and gaskets etc. Might look at polishing the inlet tracks but the car is not going to be tuned so not sure there is any gain by just doing that?

I assume the cams sits in schell bearings and these would merit replacement?

Thanks for all your input.

 

[edh]

ORIGINAL: zcacogp

That's not good news at all Paul, I'm sorry to hear it.

£1000 for cams? Crumbs. There must be a cheaper alternative source - didn't Fen's old mechanic in Devon manage to source him a pair for a lot less money than the going rate?


Oli.

Andy Moss - he did my car as well. Cams were £322 + VAT each IIRC, the total bill was around a grand.


A s/h head sounds a good move - as longs as everything checks out OK

 

[Veerzigzag]

Just purchased a relatively low mileage (reputed) S2 head so i have cams and valves

Always useful to know where you got it from and how much, since we all (or I at any rate) have a "bent valves" plan B (along with an "MoT failure - rusty sills" Plan B).
Will also be interesting to hear about progress and sorting out things like the inevitable gouges in the piston crowns - photos would be appreciated.
There but for the grace of God......

 

[timmyturtle]

I have read that polishing anything on these engines can make them worse,unless you have experience on s2 heads.

 

[jasonp]

sorry to hear of your bad news and really hope you can sort it without costing a small fortune,,regards jason p

 

[Veerzigzag]

A couple of cams have appeared on eBay - search for Porsche 944 S2 camshafts and you should find them - starting at £125 the pair and look to be in good nick...

 

[Paul190H]

ORIGINAL: Paul190H

Ok so i'm going down the used route I think. Just purchased a relatively low mileage (reputed) S2 head so i have cams and valves. My guy is going to get the valves re-profiled and I'll re-use the cams with all new chain, guides and gaskets etc. Might look at polishing the inlet tracks but the car is not going to be tuned so not sure there is any gain by just doing that?

I assume the cams sits in schell bearings and these would merit replacement?

Thanks for all your input.

Hi guys, quick update! Dead cams, so get those chain guides checked!! []






Shame really as the head looked in great nick!




All inlet valves bent, difficult to pick up but you can see different height of followers!




Replacement cams








Replacement head, skimmed and valves re-profiled! The head had previously had work done, the valves are marked in order!







My garage is a bit snowed under at the moment but hope to see the old head off this week! Will keep you posted.


A quick shot of one of my other interests, any other watch fans out there?




Cheers
Paul.

 

[Paul190H]

Hmm, still not got the photo bit quite right! [8|]

 

[Frenchy]

Car will fix Paul and should be better than ever, i like my watches, just sold Rolex Sub Anniversary, have a few Tag's a Carrera twin time Auto a mint F1 Orange face and an old favorite 2000 series quartz that must be 30 years old, sold a Omega Speedmaster which i could not get on with, will be looking for another Roly Datejust sometime, simple but i like them stainless with white gold fluted bezel and white face.

 

[944 man]

I share an interest in watches, although I don't have any time for Panerai.

 

[Paul190H]

Nice collection, been down the Rolex route but have been firmly entrenched in the Panerai camp for a few years, have a 232, 22BT and a 360. Simplicity is what Panerai is all about! Yep should not be long, looking forward to getting her back on the road, missing the best of the weather at the moment!

 

[Paul190H]

ORIGINAL: 944 man

I share an interest in watches, although I don't have any time for Panerai.

Horses for courses, be a bit dull if we all liked the same brands!

 

[924nutter]

Right first thing don't number the valves with centre pop marks. I am pretty sure the edge of the crater will glow red and cause pinking, and it will be a mare trying to get the suction cup to adhere to the valve head for grinding the valves in, which will be tedious as unleaded valve seats do not grind in in five minutes I use tippex which washed off with tippex thinner when final assembly was the next stage.
Better than polishing the ports is matching the inlet to the manifold. Fit the gasket to the head and draw round the shape of the gasket on the head and remove metal up to the line and blend in but do not over polish. As it is only air entering the port the benfeits of polishing the ports is not as clear cut as it used to be on carburettor engines. When you have matched the head to the gasket do the same to the manifold. Apply the same principle to the exhaust. That is if the ports don't match particularly well. The alignment was crap on my 924 but then the 2.0l is a VAG derived powerplant.

I really cant believe that someone has apparently centre punched the valve face. A blow sufficiently hard to indent the metal cant be good for the valve.

 

[Paul190H]

ORIGINAL: 924nutter

Right first thing don't number the valves with centre pop marks. I am pretty sure the edge of the crater will glow red and cause pinking, and it will be a mare trying to get the suction cup to adhere to the valve head for grinding the valves in, which will be tedious as unleaded valve seats do not grind in in five minutes I use tippex which washed off with tippex thinner when final assembly was the next stage.
Better than polishing the ports is matching the inlet to the manifold. Fit the gasket to the head and draw round the shape of the gasket on the head and remove metal up to the line and blend in but do not over polish. As it is only air entering the port the benfeits of polishing the ports is not as clear cut as it used to be on carburettor engines. When you have matched the head to the gasket do the same to the manifold. Apply the same principle to the exhaust. That is if the ports don't match particularly well. The alignment was crap on my 924 but then the 2.0l is a VAG derived powerplant.

I really cant believe that someone has apparently centre punched the valve face. A blow sufficiently hard to indent the metal cant be good for the valve.

Unfortunately they were already done, the valves have been re-profiled and refitted. Would it be advisable to get the burrs removed?

 

[924nutter]

I would put them in a lathe and try to remove the raised burr leaving just an indentation, perhaps using a sharpening stone on the face, coarse, fine, then a high speed polish with oiled wet and dry about 1200 grade, not a cutting tool. I appreciate this was how you recieved the head, it mentioned it just as some advice to other readers. I read many books and articles, including the mystery tale of a Saab turbo that was an inveterate "pinker" after a head reface. A thicker head gasket was tried and they has the head off three times before someone suggested removing the sharp edge of the combustion chamber that had been created during the refacing proceess. It turned out the the sharp edge was glowing hot and was indeed the culprit, and when it was removed it cured the problem.