[jfrahm]

Most of the head gaskets that fail in these cars fail due to corrosion on the coolant side. Dissimilar metals, poor water quality, coolant that does not protect well, and time conspire to eat the gaskets up. Change that coolant, use good coolant, good water. 'Refresh' the coolant at least once a year by getting some of the older stuff out and fresh coolant in so there are fresh additives in there to keep the chemistry in balance. A wet vac works wonders for getting coolant out, or a suction gun.

The modern coolants seem to stay a nice bright cheery color even long after the additives are depleted and the chemistry is eating away at your internals, so if it looks clean that means nothing.

I do not suggest you change your HG before supercharging your motor. If you have tuning or fuel quality problems your HG might burn through and you might as well burn up an old one. You could benefit from decarboning the engine, which you might do when you swap HGs but you can also do that with some water injection without pulling things apart. Yes you might need a general head rebuild but for my money I'd much rather poke around in there after 1000 supercharged miles than just before I strap on a blower. I suggest budgeting for a head refresh, but consider using the opportunity to see how the motor is doing on boost.

I am at a decision point with my SC setup and will probably put a 1.4mm tall gasket in if I tear into the motor. I need to get the SC migrated to my 92 which has a fresh head but I assume it has the weak rods and it might need an oil pickup tube. I have a set of forged rods to throw at it, so despite the fresh head it might be coming apart. I'm tempted to just pull the oil pan and see what's up in there, strap on the SC and go. I suspect the rod issues are a result of detonation so with water injection, quality fuel and good sense they might not be an issue. It's possible they have already been changed out too I suppose. I do not particularly want to pull the oil pan and then decide I should pull the motor, but I guess I could pull the head and do the rod swap with the engine in the car but I'd rather have the motor on a stand and all winter to monkey with it. Since the last time I pulled a 944 motor I took it out the bottom maybe it's no big deal but I was thinking I'd go out the top this time. Hmmm.

-Joel.

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[Pauli]

Are most folks using "distilled" water vs tap or other? How much of a factor do you think this might have?

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[flash]

distilled water ONLY - no point in bothering with phosphate free coolant if you are just going to dump minerals in there from the tap water - these radiators clog VERY easily - they need all the help we can give them

while there is a certain amount of wisdom in waiting to see how a motor does with an incomplete SC, it does not apply to my kit, as the tuning will already be done - no need to wait, and in fact, waiting could be worse, as the carbon build up could cause detonation that would not occur if the head was redone, or at least free of carbon - we have factored this into the tuning, but still, better to be safe and driving happy than to be whining about having to take it to the shop - for this reason we highly recommend at least a full run-rite treatment, and recommend a head freshening if it has not been done in the last few years

also, valve guide leak can and will cause seal failure, which will result in high oil consumption, and result in pouring oil into the chamber, resulting in premature detonation, so those want to be in top shape too

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[Fox944]

Head gaskets should be replaced regardless of ether or not you are oing to mod imho. The gasket was one of the first things i changed on my car. I'm running a 3-layer stainless steel head gasket.

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[flash]

agreed - they do age out - i was absolutely stunned to see mine, with only 50k on it, regularly changed phosphate free coolant and only distilled water as long as i and the previous owner had it - that accounts for all but the first 2 years of its life

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[flwbyu]

For those of you who have already done this, can you give us a rough figure on the head gasket? Also, what people should look out for, etc.. I am only asking because I am getting ready to do the same thing.. Thanks!

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[flash]

a valve job is inexpensive relative to the labor to R&R the head, so an obvious thing to do while it is off

the book rate on labor to R&R a head is 11 or 12 hours

the gasket alone is about $100, but you will need other seals and stuff - an entire seal kit including a gasket is about $300

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[Lear35A]

For the head R & R I bought the Victor Reintz cylinder head gasket set from AutohausAZ ($210.18). I was not too impressed for two reasons. One, there was no list of what parts were in there, either by description or part number. You had to figure out what was each o-ring, seal, gasket, etc. was for. Second (and this is the worst) it just plain was not complete. If I pull a head or overhaul the bottom end (I bought their gasket set for that too) I want to replace everything. I had to order a slew of little o-rings and gaskets from Sunset once I figured out what has not been included (see complaint 1). All this cost time and money, the two things you are trying to save when ordering a gasket set, right.

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[Lear35A]

Here's another pictorial to help justify a proactive head gasket replacement. Coolant got into my block via a crack, but a blown had gasket would have the same effect. It's nasty. Coolant mixed with oil make a non-lubricating brownish froth. It's everywhere, of course. In the oil cooler, in the oil thermostat housing, every oil hose, passageway, balance shaft housings, etc. You almost have to pull the block out and apart to clean everything.
You can also see how much oil I was pulling into the combustion chamber by the crud on top of the pistons. That's worn valve stem seals (and probably some ring wear as well).
This is a 100K engine.

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[flash]

yeah - we all tend to think our cars are newer or tougher than they really are, especially those of us who have had them for a while - the prevailing mentality is "it's never been a problem, so why would it be now?"

this is faulty logic, and usually results in extreme disappointment

these cars are now old - the youngest one is 15 years old and the oldest is 19 - that's asking a lot of a performance car - would you go out and by a 15 year old honda? we all think they are incredibly reliable commuters, yet we would not buy an old one without expecting problems - what makes this car any different?

it's time people - the head gaskets are due to start failing on all of these cars, whether you supercharge or not

i'm scared to death about the white car - it only has 19k on it - this is actually worse than the blue one as far as risk potential goes - i'm already trying to figure out how to get that one done

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