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Rebuilding S2 cylinder head

zcacogp

New member
Chaps,

My S2 has just clocked over 190,000 miles. She runs as well as ever, pulls like a train and never fails to put a smile on my face. (That's not true, actually; whenever she throws up a bill she puts a frown on my face, but you know what I mean!) Bar a very large stone chip on the bonnet, there is nothing at all wrong with her.

However there are occasionally mutterings on here about the long-term life of S2 headgaskets. And some have a general view that the inner valve springs aren't to be relied upon at high mileages - several people seem to have had one break. Given that I will happily drive my car for another 190,000 miles I'd like her to remain the paragon of reliability that she has been to date, and plan to fit a refreshed cylinder head. I have bought Ed Hodgson's old head from his S2 (thanks Ed!) which has a similar mileage on it and am wondering what to do to refresh it before swapping it over.

A new head gasket is clearly a good idea. And apparently Ed's old hydraulic lifters are noisy, so something needs doing about them. My OPC quoted me a cool £36.30p each for replacements (yes, each, plus VAT, total cost just under £700!) but it seems that VW part number 050 109 309 J is a direct replacement and will be around £100 for a set from the likes of ECP/GSF. The alternative would be to try rebuilding them (like this: https://www.youtube.com/watch?v=ySf0r8GGMOY), but it looks like a prize faff.

Next up would be the valve springs. My OPC quoted me £21.25 per set (inner and outer), so this would be a mere £408. I haven't tried any other suppliers for these - Max at Frazerpart will be my first port of call - but are there any alternatives? Failing that, is there any way of identifying which springs (if any) are on the way out and which ones are still going strong? I can see the logic of replacing them all and doing the job properly, but £400 is a big chunk of cash for a few small springs.

What about the valves? I'll be taking the head to a machine shop to have the work done but is it likely that it will need new valves? What about the guides? How do you tell what needs replacing? I'll certainly ask to have them lapped-in again, and possibly re-cut.

And, while it's all apart, is there anything else that I would do well to think about? 20 years ago I would be going hugger-mugger about having the whole lot gas-flowed but I suspect that Porsche probably did a pretty good job when they made the head and hence there isn't much to gain here. The chain was changed less than a year ago and the cams are in excellent condition, so no need to swap anything there. Belts ditto.

Also, does any one know of a good machine shop to tackle this sort of work somewhere within striking distance of East London? There was a good one out in Redbridge but I think they have closed down.

Thanks for your input.


Oli.
 
Oli,
I'm in the same boat, and I believe Rob Dimond is too! Compression test suggested my HG has had it so I want to get the head refreshed at the same time. I have bought a spare head and was planning on getting the valve guides replaced and a skim. My view on the valves, springs and lifters is to replace only those that are clearly dead or about to die. The engine shop should be able to test the valve springs and weed out any duds. My plan was to have the head work done before stripping the old one off to do the HG, thus minimising downtime.

If you can hang on until August, I will be back and not a million miles from you (NW Essex) and we can perhaps get a bulk buy deal from a machine shop to do yours, mine and Rob's at the same time?

Tom

ETA, Burton Power in Ilford are supposed to be good for engine work. They are Ford specialists but an engine is an engine......
 
Hi Oli

As you know I'm more a turbo man than the S2 but would expect them to both have similar overhaul duties...for light machine work over the years i have used Middlesex Boring in Mill Hill which isn't too far away although I'm sure there must be something closer to you. I would get the valve guides done (and of course new valve stem seals), they are fairly cheap both in parts and machining although admittedly you have double the number. I would also get the head skimmed or at least checked, again not a great expense.

To check the valve guides pull them out a little from their seats and try rocking the valve stem within it's guide, there should be very little side to side movement, at most just a faint sense of a rock. There may be details for checking springs in the workshop manual, for the turbo the spring stiffness is very important and the details are all there( corrected with shims), I would suspect that the S2 has similar guidelines. Lifters rarely wear, it's more a case of them getting stuck due to a varnish type substance that builds up within the check valve mech and so you may be able to just clean them, sometimes this can be achieved while they are still on the car with the various chemical products available out there, the best of which is by forte but this may be a trade only product. Once out of the car they can be checked to see how long they take to leak down..iirc it should be anywhere between 10-60 secs for a good lifter, there are some video's on youtube that may help...I did a quick check and found this one for rebuilding VW lifter's which i would assume are similar to the Porsche lifters https://www.youtube.com/watch?v=ySf0r8GGMOY


One thing to note when dis-assembling....label everything as you want the parts to go back from where they came, especially the lifters,,, valves too even if fitting new guides.

have fun

Pete
 
Oli,
What an erudite ,eloquent & far from pedantic post for a change ,particularly from a Southerner.[:)].Thank you for my inclusion in the PCGBFPC-I love acronyms.

I would suggest :-
a) Clean springs,valves & lifters thoroughly .
b)Place all springs in type together on a flat surface & check their comparative heights with a straight edge.Then carefully examine each one for any small cracks (if any).
Reject any that are shorter than the general average and/or have any evidence of cracks.
c)Check all valves in type sets for damage,cracks & measure the wear part of the stem & list the dims-check the lifter contact areas & also the collet retainer neck for damage.Assess the contact area on each valve seating area for pitting/cracking-reject any falling below the average or at least if heavier pitting only put to one side.
d)Hydraulic lifters-I have little experience of problems other than contamination by oil sludges,etc so a really good clean should be all that is necessary,but then allowing for pedantry,just fit new at the best price you can find-after all they work hard enough.
 
Hi Oli - how was Berlin?

Some of the lifters are kaput - a direct result of oil pickup failure at Spa. No idea which ones or how many. I did try a treatment in the oil but it didn't help.

I will get a pic of the headgasket at some point - it was a bit thin in places.. [:D]
 
Chaps,

Thanks for the replies - very helpful. To answer the points one by one (in true pedantic style >WavesAtVitesse< [;)] ) ....

- Tom, I'm in no rush at all and most certainly can wait until August. I didn't know that you and Rob Diamond were doing the same and the idea of angling for a three-way discount sounds like a great idea to me! If the machine shop can spot dud valve springs then that would bring down the cost quite considerably. Burton Power sounds good and there is another suggestion (see below).

- Pete, thanks. Stem seals would be a given, as would a check and maybe a light skim if necessary. Thanks for the details of how to check for guide wear; in practice, I'd need to have the head stripped to do this so I'll have to leave it to the machine shop. It's helpful to know that it's not expensive though. By the sounds of it from Ed, the lifters are toast so it'll be a new set. That video is helpful but it's quite a lot of work for 16 lifters so I'd probably buy a new set.

- Appleton (senior) - thanks, that's a helpful set of instructions, although I think that level of detail will need to be handled by the machine shop as I don't have a valve spring compressor to dismantle the old head to check the springs. However it's good to know that duff springs can be spotted and they don't necessarily all have to be replaced. Good to have you in the club as well!

- Ed, Berlin was great, thanks for asking! Many thanks for recommending the TV Tower (the booking was very necessary) and Classic Remise as both were good (Classic Remise particularly). Yes, if you have a pic of the headgasket that would be good as I'd be interested to see it. Here's a photo of a Goddess and a BMW motorcycle for you in exchange:

DSC_0251_zpsyl4qzdpr.jpg


And does anyone care to guess what this emblem is? (Hint - it's distantly relevant to 944's)

DSC_0201_zpsqa3s3vbh.jpg


- Dave, thanks for the PM about Thurston engineering in Ongar. That's pretty easy for me to get to and is one to consider. Can you recommend them?


Oli.
 
About cleaning lifters...experience in my youth witnessed an old-timer rebuilding a V8 cam in block engine that was so gummed up inside you could hardly see the camshaft. While disassembling the engine, the hydraulic lifters went straight into the solvent tank where they sat for 2 days while other work was being done. He then disassembled them, gave them a good brush and dried with compressed air. Upon assembly, a good squirt of oil and they were ready to go. In sort - the u-tube video is spot on and unless your lifters are badly scored - they can probably be restored to service. Yes its fiddly work but so rewarding!
 

ORIGINAL: zcacogp

Chaps,

Thanks for the replies - very helpful. To answer the points one by one (in true pedantic style >WavesAtVitesse< [;)] ) ....

- Tom, I'm in no rush at all and most certainly can wait until August. I didn't know that you and Rob Diamond were doing the same and the idea of angling for a three-way discount sounds like a great idea to me! If the machine shop can spot dud valve springs then that would bring down the cost quite considerably. Burton Power sounds good and there is another suggestion (see below).

- Pete, thanks. Stem seals would be a given, as would a check and maybe a light skim if necessary. Thanks for the details of how to check for guide wear; in practice, I'd need to have the head stripped to do this so I'll have to leave it to the machine shop. It's helpful to know that it's not expensive though. By the sounds of it from Ed, the lifters are toast so it'll be a new set. That video is helpful but it's quite a lot of work for 16 lifters so I'd probably buy a new set.

- Appleton (senior) - thanks, that's a helpful set of instructions, although I think that level of detail will need to be handled by the machine shop as I don't have a valve spring compressor to dismantle the old head to check the springs. However it's good to know that duff springs can be spotted and they don't necessarily all have to be replaced. Good to have you in the club as well!

- Ed, Berlin was great, thanks for asking! Many thanks for recommending the TV Tower (the booking was very necessary) and Classic Remise as both were good (Classic Remise particularly). Yes, if you have a pic of the headgasket that would be good as I'd be interested to see it. Here's a photo of a Goddess and a BMW motorcycle for you in exchange:

DSC_0251_zpsyl4qzdpr.jpg


And does anyone care to guess what this emblem is? (Hint - it's distantly relevant to 944's)

DSC_0201_zpsqa3s3vbh.jpg


- Dave, thanks for the PM about Thurston engineering in Ongar. That's pretty easy for me to get to and is one to consider. Can you recommend them?
Oli.


Yes,
when i had my triumph stag i had the heads skimmed and pressure tested, 6 of the valves were letting by and this was after the engine was supposedly rebuilt.
i was very pleased with the results.
cheers
Dave
 
Gosnays Engineering Romford,

Burton Engineering Newbury Park

I will think of a few more

one of my fellow 968 owners had his done in Hertforshire I will find out where.

Audi A100 lifters are only .5mm taller so they work fine and you can get a set of 16 on ebay for about £40

a few of the 68ers have had a head refresh and the bill at an indie normally comes to about 3.5 k with belts and rollers and water pump OUCH!


http://www.ebay.co.uk/itm/201290191352?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 

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