Head Gasket RnR Fair Price at an Indie Shop?
08-03-2018, 04:03 PM
#16
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I sometimes like to think that I know a lot about 928s, been playing with them more than I should for 12 years now. And Greg and I have been putting the above 59K mile GT motor back together. I put together everything we'd need to assemble the motor, all nice and clean and plated, in little baggies in order of assembly. I figured, a day to assemble the short block, a day to assemble the heads/timing belt bits, and a day to assemble the intake, fuel rails, and accessories and test-run it. How hard can it be? (Completely discounting the couple of day's collective time cleaning, driving around getting powdercoating, plating, and machine shop work done....)
This car hasn't run since 1994 and the motor came apart (for still-unknown reasons) several owners before Stan, who was kind enough to gather all the bits together and send them to me. So we got the shortblock assembled, then found the ding I didn't notice in the top of the cylinder tower, so back apart it came. The block got decked, we re-obsessively cleaned everything and put the shortblock back together. So that's 2 days of work
First the heads were .008" thicker at the rear than the front. And the valve guides were out of spec. So those got done. Of course I'd noticed the brass galley plugs in the head but didn't think too much of them. And I'd not really bothered to clean the schmutz out of the pressure relief pistons in the heads, I just assumed that since the galley plugs had been replaced, they'd be clean. Bzzt. So we do a marathon day and a half (what, 12 hours or so?) and get the heads and intake on. Then it's probably two hours to get the engine on Greg's test stand. Run the thing and in 5 minutes the galley plugs are leaking.
So we're beating ourselves up about not having fixed the 'fixed' galley plugs while the heads were bare, but the consolation is at least it leaked on the stand and not back in the car. It'd be 1.5 days to put the motor in the car, and another day to get it back out, since most of the galley plugs aren't coming out in-car....
All of which is to say, the only time I burn myself on any 928 project is when I make assumptions about things without verifying. And Greg is the way he is about this because he's lived the above story a thousand times. And fortunately he's got a solution to this that I would never have figured out. (Hint- did you know that there are 5 different sizes of galley plugs available between 12.2 and 13.2 mm? And that if you hammer brass bar stock into aluminum heads the goddamned holes are no longer round?). Sigh.
Brass plugs make baby GT Jesus cry green tears:
This car hasn't run since 1994 and the motor came apart (for still-unknown reasons) several owners before Stan, who was kind enough to gather all the bits together and send them to me. So we got the shortblock assembled, then found the ding I didn't notice in the top of the cylinder tower, so back apart it came. The block got decked, we re-obsessively cleaned everything and put the shortblock back together. So that's 2 days of work
First the heads were .008" thicker at the rear than the front. And the valve guides were out of spec. So those got done. Of course I'd noticed the brass galley plugs in the head but didn't think too much of them. And I'd not really bothered to clean the schmutz out of the pressure relief pistons in the heads, I just assumed that since the galley plugs had been replaced, they'd be clean. Bzzt. So we do a marathon day and a half (what, 12 hours or so?) and get the heads and intake on. Then it's probably two hours to get the engine on Greg's test stand. Run the thing and in 5 minutes the galley plugs are leaking.
So we're beating ourselves up about not having fixed the 'fixed' galley plugs while the heads were bare, but the consolation is at least it leaked on the stand and not back in the car. It'd be 1.5 days to put the motor in the car, and another day to get it back out, since most of the galley plugs aren't coming out in-car....
All of which is to say, the only time I burn myself on any 928 project is when I make assumptions about things without verifying. And Greg is the way he is about this because he's lived the above story a thousand times. And fortunately he's got a solution to this that I would never have figured out. (Hint- did you know that there are 5 different sizes of galley plugs available between 12.2 and 13.2 mm? And that if you hammer brass bar stock into aluminum heads the goddamned holes are no longer round?). Sigh.
Brass plugs make baby GT Jesus cry green tears:
08-03-2018, 04:31 PM
#17
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This thread explains why Todd and I are building a motor for my 87 (having a spare 89 motor helps do this). Instead of pulling that one apart and starting down the road described here, I'll have a completely fresh motor ready to go in.
Old motor will be torn down, tagged, bagged.....and put on the shelf where the 89 was.
Old motor will be torn down, tagged, bagged.....and put on the shelf where the 89 was.
08-03-2018, 11:56 PM
#18
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I might send this thread to the guy I took these heads too for the machine work.
He will never touch another Porsche part from me.
He will never touch another Porsche part from me.
08-04-2018, 12:14 AM
#19
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You misunderstand. I wasn't referring to the 'warped GT heads.' I know that we both know that ...
... this -^ is true.
I was referring to this:
where I think your $1200 estimate includes no welding and post-welding correction.
For purposes of the readers who might be 'here' in this thread now or at some point in the future, I'm thinking that they should prepare themselves for more outside service expense for the heads if they pull them. I think the number of 928 heads running around that won't require at least some welding is an increasingly low number. This is almost certainly true for 928s that haven't had regular coolant changes throughout their lives.
Based upon my small data set, I'd have folks budget for $2500 for head rework and, if the 928 in question is known to have been sitting for years with no coolant changes (hello super-low mileage BaT 928s) then I'd prepare them for the worst case: $2000 for good used heads from Mark and $1200 to freshen them.
Cost depends totally on the amount of welding.
I was referring to this:
For purposes of the readers who might be 'here' in this thread now or at some point in the future, I'm thinking that they should prepare themselves for more outside service expense for the heads if they pull them. I think the number of 928 heads running around that won't require at least some welding is an increasingly low number. This is almost certainly true for 928s that haven't had regular coolant changes throughout their lives.
Based upon my small data set, I'd have folks budget for $2500 for head rework and, if the 928 in question is known to have been sitting for years with no coolant changes (hello super-low mileage BaT 928s) then I'd prepare them for the worst case: $2000 for good used heads from Mark and $1200 to freshen them.
08-04-2018, 02:01 AM
#20
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You misunderstand. I wasn't referring to the 'warped GT heads.' I know that we both know that ...
... this -^ is true.
I was referring to this:
where I think your $1200 estimate includes no welding and post-welding correction.
For purposes of the readers who might be 'here' in this thread now or at some point in the future, I'm thinking that they should prepare themselves for more outside service expense for the heads if they pull them. I think the number of 928 heads running around that won't require at least some welding is an increasingly low number. This is almost certainly true for 928s that haven't had regular coolant changes throughout their lives.
Based upon my small data set, I'd have folks budget for $2500 for head rework and, if the 928 in question is known to have been sitting for years with no coolant changes (hello super-low mileage BaT 928s) then I'd prepare them for the worst case: $2000 for good used heads from Mark and $1200 to freshen them.
... this -^ is true.
I was referring to this:
where I think your $1200 estimate includes no welding and post-welding correction.
For purposes of the readers who might be 'here' in this thread now or at some point in the future, I'm thinking that they should prepare themselves for more outside service expense for the heads if they pull them. I think the number of 928 heads running around that won't require at least some welding is an increasingly low number. This is almost certainly true for 928s that haven't had regular coolant changes throughout their lives.
Based upon my small data set, I'd have folks budget for $2500 for head rework and, if the 928 in question is known to have been sitting for years with no coolant changes (hello super-low mileage BaT 928s) then I'd prepare them for the worst case: $2000 for good used heads from Mark and $1200 to freshen them.
03-11-2019, 04:36 PM
#21
Since I'm just about to get another set of heads back from my machinist I figured this thread could use an update. This set of heads came off a 90 GT and besides the coking up the head gaskets looked good with no welding needed. He did find that 5 of the intake and one exhaust valves were out of tolerance for his liking so I had him put new ones in. ALL of the valve guides were out of spec and leaking seals. Car only had 70k on it. MY cost was a tad over $1200 for the head work with out any welding being needed.
03-11-2019, 05:23 PM
#22
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Since I'm just about to get another set of heads back from my machinist I figured this thread could use an update. This set of heads came off a 90 GT and besides the coking up the head gaskets looked good with no welding needed. He did find that 5 of the intake and one exhaust valves were out of tolerance for his liking so I had him put new ones in. ALL of the valve guides were out of spec and leaking seals. Car only had 70k on it. MY cost was a tad over $1200 for the head work with out any welding being needed.
Does your cost figure include ‘new’ valves?
03-11-2019, 05:54 PM
#23
03-12-2019, 06:50 AM
#24
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Since I'm just about to get another set of heads back from my machinist I figured this thread could use an update. This set of heads came off a 90 GT and besides the coking up the head gaskets looked good with no welding needed. He did find that 5 of the intake and one exhaust valves were out of tolerance for his liking so I had him put new ones in. ALL of the valve guides were out of spec and leaking seals. Car only had 70k on it. MY cost was a tad over $1200 for the head work with out any welding being needed.
03-12-2019, 09:28 AM
#25
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I've had a few sets of 87+ sets of heads R&R'd and the valve stem seals replaced - that cost me $450. Recently, I had a set of 89 heads that needed to some welding and valve stem seals replaced and they put the after market valve springs, retainers and located disks and that set me back $720 all in. I've been lucky that all the guides and valve have been in spec. And my guy is local to me, picks them up and delivers them.
03-12-2019, 10:16 AM
#26
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03-12-2019, 12:17 PM
#27
I've had a few sets of 87+ sets of heads R&R'd and the valve stem seals replaced - that cost me $450. Recently, I had a set of 89 heads that needed to some welding and valve stem seals replaced and they put the after market valve springs, retainers and located disks and that set me back $720 all in. I've been lucky that all the guides and valve have been in spec. And my guy is local to me, picks them up and delivers them.
I have one guy here that was in that price range, worked out of his own garage similar to how I do my work but after walking in to his place I knew I'd most likely not be back. Not a clean surface in the place. Didn't give me any confidence. His work seemed okay but I couldn't get over the amount of filth in his joint. The guy I'm using now is high priced but after talking to him a few times I knew he was the guy to go to. Clean joint and was doing all the work for a local shop I know well and they send him their Ferrari/Lotus stuff. He used to work for the shop that refused to do my heads a decade ago and started his own place. Apparently he'd been doing my buddies shop work after hours because the owner where he worked wanted to do the quick and easy American stuff.
03-12-2019, 12:36 PM
#28
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I have one guy here that was in that price range, worked out of his own garage similar to how I do my work but after walking in to his place I knew I'd most likely not be back. Not a clean surface in the place. Didn't give me any confidence. His work seemed okay but I couldn't get over the amount of filth in his joint. The guy I'm using now is high priced but after talking to him a few times I knew he was the guy to go to. Clean joint and was doing all the work for a local shop I know well and they send him their Ferrari/Lotus stuff. He used to work for the shop that refused to do my heads a decade ago and started his own place. Apparently he'd been doing my buddies shop work after hours because the owner where he worked wanted to do the quick and easy American stuff.
I guess I got lucky. And high prices do not always translate to better work, BTDT, too.
Oh, Gary Grimes and Grimes Machine shop that builds amazing engines like this Pro Stock Vega.
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03-13-2019, 07:32 AM
#29
Sweet, glad you found a guy that works.