Musche

Hello all,
As the owner of a newly acquired 89 Turbo w/ M030 and 150k miles, I am in the process of fixing oil leaks and refurbishing worn out parts (brakes, struts, shocks, brakes, clutch,etc....I got it cheap). Since I have the engine out and on a stand, I'm replacing all the seals and gaskets. The one issue I have though is the head gasket. Prior to the extrication, the head gasket did not leak and the car passed a leakdown test and it is the only thing I haven't loosened up yet. I've read the horror stories on the board here of broken stud mounts, widefire vs. stock, o-ringing, etc. I'm starting to reach the end of my budget and since the weather is getting better, I need to get this car back together. Obviously, it would be great to have the head and block refurbished, valve job, hardened studs, etc. but this is major $$ and as they say, "If ain't broke, don't fix it." As I look at it, I have three major choices, A) Leave the head alone, B) Replace the head gasket and retorque the stock bolts, or C) Bite the bullet and spend the $$ to do it right. For now I'm running stock boost and I want to get the car on the road. Redoing the head is not out of the question down the road if I decide to start messing with higher boost. What do you guys think? Can anyone comment on reusing the stock head studs? My money tree is running out of leaves!

Helstrm

I have not seen anyone break the head studs,.. Most of the breaks I read about are from the exhaust (Header) Bolts. Unless you plan on running high boost I would leave the stock head studs in there and just replace the head gasket.

I have a set of ARP studs going into mine because I plan on running higher boost and I stole them off of ebay for $91

jwl

If this is the first time the heads been off you'll be fine. After three times the studs will need to be replaced.

theedge

Really?

Jeremy Himsel

While I'm not aware of any data to suport it, JWL provided you with the most realistic advice about head studs. Lindsey, Vitesse, Cervelli, all reused stock head studs on high-HP applications numerous times. I have only replaced them on one 951 and reused the originals a half-dozen time. To date, I've yet to pop a head gasket. Re-use the original studs, check the head and block decks to ensure they're flat, and just put new nuts on them and you'll be fine.

Tom M'Guinn

If the head and gasket have 150k miles on them, I'd say you should bite the bullet and have the valves done, replace the gasket, and flip a coin regarding the studs. Studs aren't free, but they will never be easier to replace then while the motor is out.

z3bra

Something else to consider with ARP/Raceware head studs:

In speaking with Lindsey Racing a month or so ago, I was told that there is actually a higher incidence of HG failures using the ARP/Raceware parts because they're a little too good. It was the feeling of the guy I spoke with (I believe it was Dave but I can't recall for sure) that there are a few spots in the head by the #4 cylinder that allow air pockets to form in the water passage because of poor design in the casting itself. Because of this you get a greater amount of expansion in that area on the head and because the ARP/Raceware studs don't have as much give as the stock studs, something's got to give and it usually ends up being the HG. He said he's seen this happen enough times and on cars where the labor was not suspect that it isn't likely to be just coincidence and that from cutting up an old core with a band saw to look at the cross section he thinks he's found the problem spot and is working on a fix for it.

Anyway, I'm not trying to talk you out of running the good studs, but for what a set costs I'd be a little ticked off if installing them made me start eating head gaskets on a regular basis and I think it's at least something to think about if you're considering a set.

z3bra

Can't argue with that. I'm doing mine right now for an incredibly stupid reason. I snapped one of the two bolts off for the little water passage up by the #1 cylinder on the driver's side of the engine trying to put an adel clamp on it for the oil pressure sensor wire routing. I was a little pissed off that one bolt cost me about 600 bucks between a valve job/valve guide replacement/mill of the head, head gasket set and all the other miscellaneous charges that seem to come out of any of this work. On the upside, after looking at my head, the guy at the shop said I probably would be looking at a failure within a year or so on the HG because of where he could see carbon sneaking out a little bit around the fire rings. The previous HG wasn't the original and some asshat just used an orbital sander on the head last time around to even it out it would appear. Thankfully they didn't use it on the deck of the block at least.

On the subject of the OE nuts for the studs, Is there anything fancy about them that requires using the OE nuts only or are they just Class 10 M12 x 1.5 mm Hex nuts? I'll be damned if I can see anything unusual about them other than the Class 10 aspect. If someone knows I'd love to hear what's so special about them, otherwise I'm just getting some at the industrial hardware store if they have any class 10 ones in stock (they might not as the 1.5 thread pitch is somewhat of the bastard child on M12 fasteners where 1.25 mm is the more popular fine pitch and 1.75 mm is the coarse pitch.) So if ya know what the deal is speak up.

Oh and regrettably, there is no such thing as a 12 point M12 x 1.25 Class 10 metric nut. Yeah it's eye candy but 12 point nuts are rather sexy all in all if that sort of thing is your bag.

Tom M'Guinn

Z3bra,

Just a point of reference, Garrity used to buy nuts from a non-Porsche fastener, so at least he thought they were standard stuff. Of course, some of his motors blew up so ya never know...

As for the Lindsey comment about Raceware studs causing gasket failures, I would love to hear from some of our more experienced engine builders. Sounds dubious to me.

z3bra

It's not the studs themselves that are the problem so much as the fact that it's a byproduct of having a better fastening system in place for the cylinder head that exposes a weakness in the design of the head itself. I haven't got a thing against raceware or ARP, I've used ARP stuff plenty of times in the past on other cars and haven't had the slightest problem from doing so. This really is a case of the Raceware studs being almost "too good."

Helstrm

The only problem with that theory is that the stock stud stretch under high boost and that is what causes HG failure. Basically having your head walk on you. The ARP\Raceware don't give, so they should hold the head in place. If this causes me to blow a HG then so be it, I would rather the pressure blow out a $100 HG instead of the block...

Dal Heger

I don't buy that ARP (or any other bolts) will cause head gasket failure in the mode that you describe. What I do buy is that the people that have installed the ARP/Raceware bolts didn't follow the recommended procedure and re-tightened them after running the car for 1000 miles or so. You don't have to do that with the stock studs. As for the stock studs... They are NOT torque to yield studs. They can be reused many times. They don't stretch under normal use.

I'm also with Helstrm, I'd rather have the studs stretch/headgasket fail than blowing a hole in my piston or block.

Dal.

Musche

Thanks for all the great information. My main concern is whether I can reuse the stock studs and it appears that this is a possibility as long as I use new nuts/washers (still not sure why). I want to get some miles on the car and become familiar with it before I go tweaking. Removing the engine and having the heads/intake/bottom end done at a later time is not out of the question. Most of my experience has been with American iron and P-car mechanics/specialists are two to three hours away. This kind of work would be a great winter project next year.

JDeitz951

Musche,

If you want to stop bleeding the green stuff (temporarily), skip the head for now. You can always do it after it's in the car. Not hard at all.