How much should this cost (pros please weigh in)

[Overpaid Slacker]

Assume that a 930 motor is delivered to you, stripped of all ancillaries and ready to get into. Assume also that the parts (incl. gasket set) are delivered with the motor, so no add'l cost for those materials:

leak-down test
swap cams (964 to SC)
replace all valves and springs/clips/retainers
replace all head studs
put the motor back together (w/o reattaching ancillaries)

The story goes that, after a loooong wait to get the cams swapped and valves/springs installed, the motor is put back into the car w/ all the bits attached. It starts immediately and runs fine, except for what sounds like an exhaust leak.

Pull the motor back out b/c no leak in the exhaust itself is evident. Motor is re-stripped of ancillaries and sent back to machinist. Initial concerns then became jug/case seal, which wasn't the problem, but instead a blown head gasket. Machinist says that the "bad" cylinder's head studs were properly torqued and doesn't know why it blew, but suggests new head studs at this point (this did not come up during the initial re-build, during which effort he had far more than enough time to determine whether they "needed" changing).

I've known the mechanic for 15 years and trust him, so I know he'll take care of me from his end. I'm using the machinist my mechanic strongly recommended, who is responsible for a delay of more than 2 months. So I'm not going to get all worked up, and ruin what's been a good relationship with my wrench, but I'm also looking for an all-in price to have done all the machinist's work in one shot -- not having to pay essentially twice for what should've been taken care of from the start.

Thanks in advance,

JP

[gsxrken]

I could see a mentality on the part of the machinist to assemble with whatever he was given parts-wise. Sometimes they're bothered by the low-margin customer supplying parts (wrong part, poor quality part, not enough parts to finish, etc. all = inevitable delays and now a headache on the backend to boot). You don't need to take the barrels off to do camshafts, but what pro wouldn't strongly recommend (let alone not even mention) changing the studs on a 25 year old 930 when it's out and in a machine shop??? What was your wrenches' take on the situation?

[beepbeep]

head gasket? on 930?

I tought those heads didn't have any gaskets...

[RarlyL8]

930s do not have head gaskets.
A good set of headstuds will set you back $500 alone. A proper rebuild is $3000 in parts. Plan to spend that and then some. Don't get cheap with this or it'll bite you.

[911pcars]

So if the head studs were okay, what caused the head gasket to blow? Seems like this is not a head stud issue unless they weren't tightened properly in the first place.

Sherwood

[304065]

JP,

So, you had a ni-resist head gasket in a machined groove in the cylinder head, to improve the sealing against the cylinder under all that boost.

Wrench put it together, ran, sounds like leak, now he tells you the niresist is corrputed and you need new head studs?

Two issues: 1) The niresist gasket may not have been correctly installed in the first place; and 2) If you had old dilavar studs top and bottom, he should have recommended you upgrade to ARP. I'm surprised you didn't have some kind of aftermarket studs in there in the first place given the state of tune of that engine.

Dude, you don't want to hear this but I'm gonna say it: as politely as possible, get the motor from your mechanic and take it to Deman, Protomotive, Rudtner, somebody with turbo experience. There's no excuse for the *****-show you've been put through, and it would erode my confidence that when I got on it (and baby, you GONNA get on it) things wouldn't break in an expensive way.

[Overpaid Slacker]

Kos - you're right, and were right a month ago, but I'm in this far and it'd seriously further delay the matter. At the end of the day, given the attention this machinist has put into the motor, I think I'll be able to trust it. We know DeMan goofed Gaijinda's motor -- twice, and not everyone is happy (immediately) with Rudtner's results. So it's not like those guys are a dead solid lock on "first time" perfection. However, it would have taken a lot less time to get through the glitches and I'd have been on the road now, I know.

Guys -
Cramer is right. The 930 had had gaskets installed by the p/o b/c the motor was putting out around 425 hp and there were 500+ plans on the drawing board. It had been "done" (and done well) a few years ago by the p/o, so it wasn't like it was the first time it'd been touched/tuned. I'm pretty sure the p/o used Porsche head studs during his rebuild (when he made this monster motor he didn't change the turbo or the wastegate either -- strange). As far as recommending new head studs immediately; I can't get on the machinist too hard -- he was delivered a souped-up motor that obviously had been worked on (twin plug, crankfire ign, etc.) and probably concluded that the head studs had been updated when the motor was rebuilt and were appropriate for its output; so absent any obvious issues, they'd be OK.

This really wasn't "on the cheap" in the sense that I was trying to cut out his margin on the parts. The machinist is not a dedicated Porsche guy, though he's done a few motors and a lot of air cooled VW power.

As an aside, much of the delay has been the result of an excess of caution on his part -- I ordered the new cam from WebCam and the machinist called them for some info on the cam.
Somebody at WebCam told the machinist that their spring kit provided 100# of pressure on the seat and he got it into his head that I NEEDED 100# at the seat. It took three days and getting him on the phone with Randy Aase (sp?) and the guy that Pelican uses to rebuild their stuff to convince him that 60# was sufficient for a motor that would not spend most of its waking hours at 8000 rpm. That kind of stuff is frustrating, but it's frustrating for a good reason -- the guy is very careful. And, frankly, the only thing that's gone "wrong" is this headgasket issue -- and they're not stock and a bit tricky.

One of the few issues we haven't had (knock wood) is wrong or improper parts being bought.

When he'd first torn the motor down he said a valve had been bent and I knew I wanted to go to SC cams -- my ordering the parts wasn't an issue. He'd asked that I source what I wanted b/c I was more familiar with this stuff. Whatever he needed, he called my wrench to tell me and ask me to order. The only exception being when the new head studs issue arose, he suggested ARP, I said "fine" and the machinist ordered them b/c he's got a contact at ARP.

My wrench is as exasperated as I am in the sense that he's got a bay occupied by an inert german rocketship for the duration of the machinist's exercise. He knows I'm at the end of my rope with this and is apologetic for the delay; but he is steadfast in his conviction that the machinist is trustworthy and capable. Others in this biz upstate swear by this machinist's work.

The machinist comes very highly recommended for his fastidiousness and results, but what I don't want to pay too much for is his learning curve. The parts cost what they cost and I haven't cut corners on parts for cost. The only cost variable I can attempt to control is the labor and that's why I'm asking for a ballpark figure.

Sorry, this rambled a bit and I don't have the time to make it shorter. Thanks for listening.

JP