OK, what would you do?!

[appletonn]

As per a previous post, I noticed that I was missing a nut from one of the exhaust manifold studs earlier this week - unfortunately, I noticed at the same time that I was also missing part of the stud that it was once attached to....[8|]

So, in advance of a lengthy trip to Le Mans in June, and not wanting to inhale too many toxic fumes en route, should it start to blow, which it inevitably will at some point, once the gasket starts to disintegrate, I popped into see Jonny at Unit 11 this morning to see what my options were - desperately hoping that it might somehow be possible, through the powers of witchcraft (well, people are extracting 400hp+ from 3.2 944t engines through the same process...?!), to remove the stud in situ.

You can probably guess what is coming next...[&:]

Basically, either the engine would have to come out to be able to access the stud, or just the head off - just not accessible enough with everything in situ[8|]

So, do I...
1. Ignore it as it isn't blowing yet, and walk around going "tra la la la la" every time I open the bonnet, so as not to think about the missing nut/stud staring me in the face ....aaaarrrrggghhhhh?[] OR
2. Get head removed, that one stud sorted and head put back as is with just new gasket set etc...[>:] OR
3. Whilst head is off, it would be daft not to get valves and valve seats recut along with guides if required and oil seals, along with head skim and replace all of the exhaust manifold studs whilst they are accessible...[]

I know that I have probably answered my own question, but just wanted to share the pain[]

Incidentally, the compressions checked by Hartech in december were 150psi on all 4 cylinders, so hopefull nothing too wrong with the pistons/bores/head?

Answers on a postcard no later than Thursday[]

And yes Oli, I did hear that you don't get this issue with S2s.....[]

 

[edh]

When were the belts & waterpump last done? (easy while you're in there)

Isn't the headwork really going to depend on what you find? - there's no real reason to get anything done if it's not needed.

you know that if you don't do it it's likely to fail about 5 hours before you leave for Le Mans (not while you're there, because missing it would be worse [])

 

[sawood12]

Personally i'd be inclined to get it sorted, especially if I had a trans-continental road trip planned as you do. Sods law dictates that it will go when you are on that trip - and it will go at the most inconvenient and inopportune time possible.

As to having your head refurbed 'while your in there' I personally wouldn't bother (assuming 150psi is a good compression test figure). Again sods law dictates that if you mess with it, it'll go at the wrong time due to some small part that was left out during the rebuild or some other problem while the head was apart - unless of course you are tempted to install larger valves and a high lift camshaft!!

 

[appletonn]

All belts (inc alternator) were done by Hartech in December - I found invoices for new waterpump in 2004.

You're quite right in what you are saying, but once the head is off, then it would be false economy not to get the head reconditioned whilst I was in there?

As you say, if I don't do that then Dr Sodt's Law will undoubtedly kick in....[8|]

The car has done 134000 miles, so the head ought to need a bit of tlc by now?

With a new head gasket, that would mean I could turn the boost up even more?!.....[][][][8|]

 

[sawood12]

Mmm - I was advocating that if you get the head refurbed then sods law will dictate that something will go wrong on the basis that if it aint broke, don't fix it (but feel free to modify it!). Mileage is not a very good indicator of condition of mechanical parts. A 50k mile garage queen that is backed in and out of the garage once a week for it's wash and polish could be (probably is) in a hell of a worse state than a 180k motorway mile-muncher. Again assuming the compression test figures are good and you are seeing no other signs of head issues then just have it removed and refitted. Removing and refitting the head is a fairly quick job for an experienced specialist and a fraction of the cost of a rebuild. I would replace the belts though as they are cheap and the old ones coming off anyway.

 

[edh]

The belts are only a few months old - no need to waste them!

 

[stevespic]

My last trip of the year to the ring was on tender hooks due to me loseing my locking wheel nut key [], this might sound a bit petty compared to your problem but i went to nearly every garage in swindon and no one would even attempt to remove them due to the Mcgaurd lock type[] ! Knowing anything could happen doing a 1000 mile plus trip to germany and back, plus two days tracking, i was left with a similar dilemma to yours now, except the only option i had was to order another key from germany which would take a week and i only had three days...I went anyway and god must of been on my side as i had no problems with the car... If i was you and my Mrs and bank balanced allowed i would just get what ever needs doing done...you know your going to do it sooner or later anyway and at least your trip to Le Mans can be with a clear head about the car.[]

 

[333pg333]

150psi c/r on all 4 is great by the way. I would get it done and just refresh the head. You're not modifying it so there's no need to fear the unknown. Of course if you have bags 'o' cash then doing head mods and bigger cam is just such a nice treat but that really is a bigger and more expensive job than you imagine.
Do the stud, refresh the head and go away feeling secure.

 

[appletonn]

Thanks all - head refresh it will be then.

Now I just have to hope that nothing else is found once it is off...![8|]

It hasn't used much oil at all in 1000 miles of exploring the performance, so coupled with the cylinder pressures, there cannot be much wrong[]??!!!

 

[morris944s2john]

I agree, option 3. The car will run better for it as well!

 

[George Elliott]

Nick, are you sure the stud is "part missing", it may be you have a stud dropped out and you have an easy repair, I cannot understand how it could be part missing.
Can you check the depth of the hole?
FWIW, I would go Option 2 if it needs the head off.
If you let someone start messing with you're valves with ceramic seats on the exhaust you're a braver man than me. I would suspect they will either charge you for a "rebuild" but take one look at it and stick it back on as there is nothing wrong with it or let some apprentice loose with a valve grinder.
Ignore the comments if our opinion of "Specialists" or Garages happen to differ.
Hope you get it sorted successfully
George
944t

 

[appletonn]

George, Jonny at Unit 11 builds 911 race engines as part of his business for all of those classic 911 rs/rsr that are heavily featured in all of the mags of late and what he doesn't know about the engineering and physics of engine building isn't worth knowing. There was a 964 engine there part built when I popped in. He is definitely the 911 guru in my neck of the woods, but I concede, not quite as famiar with the 944 lump, although he is currently rebuilding a N/A 944 8v at present.

I used the wrong terminology, as the valves would be relapped into their seats, as opposed to being recut, but I agree that it would be unwise to let any old mechanic mess with our engines.

In terms of the stud, unfortunately both Jonny and I had checked the depth of the hole independantly, and come to the same conclusion - stud has snapped almost flush with the head[8|]

I appreciate the concerns though, as I am a 'if it aint broke...' kind of person too[]

Will keep you all appraised of how I get on - might be useful for someone one day!

 

[Diver944]

I think you will be very pleasantly surprised how much more sprightly the car will feel on it's return [8D]

Most of us with mildly modified Turbo's are driving cars around the 280-320bhp mark but this is still with an original engine and head. Simply bringing the head back to original spec will make quite a bit of difference as 17 odd years of carbon build up will suddenly be no more and the valves will be sealing and moving 100% like they are supposed to []

 

[appletonn]

My car is going into Jonny at Unit 11 on the 14th April for its head removal/refresh.

I've asked him to replace all of the exhaust manifold head studs, as another one is bound to snap, due to the age, sooner or later and he is going to get the head cleaned, lightly skimmed and 'refreshed' with new stem seals etc.

The question is, do i just opt for the standard head gasket or is there a new & improved alternative? I have read before that even the 'witchcraft boys' have recommended the standard one as it is fine as long as it is relatively new and hence not corroded away etc.

I await the advice of the oracles of this forum....[]

That means you Paul....[]

 

[pauljmcnulty]

I await the advice of the oracles of this forum....

That means you Paul....

Me? Haven't got a clue, mate! []

 

[appletonn]

Call yourself the moderator....[8|][]

Next Paul please[]

 

[333pg333]

There are a few options but it looks like many of the vendors and modifiers in the US are gravitating back towards the stock one. The alternatives are made of metal and are harder to get a really good seal and often are more prone to leakage. You have to have both head and block 100% flat and also it is advisable to go up to larger headstuds. Not that the stock ones are insignificant. Next time your at the guru's workshop, get him to show you a 911 one compared to one of ours. The 911 ones look like a bit of wire compared. However I digress. I'm sure you will be fine with a stock one. Unless you are going to be shooting for well over 400hp at high boost levels there's no need to change.
PS if you stumbled across a 2.7 head / cam combo for cheap, you could consider upgrading to those but that's a nicety rather than a neccessity.

 

[appletonn]

Thanks for the responses, I think the standard one will do fine.

I do not envisage going for much more power tbh ( fingers crossed[8|] ) but improvements to improve the drivability are always possible.

Once the head and paintwork bits n bobs are done, then I just intend to drive it as much as possible all summer long - can't wait to take it to Le Mans in June and stretch its legs []