Head stud recommendation?
01-20-2003, 06:32 PM
#1
Cruisin'
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Head stud recommendation?
'78 930 Turbo with ~most~ of the head studs failed by what appears to be tensile fracturing... I suspect the car was flogged repeatedly, without benefit of proper cool-down run. We have no documented history on this one, other than it was the usual 'grey' import. Any recommendation is appreciated.
01-20-2003, 09:08 PM
#2
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RaceWare, ARP, factory steel studs are available. No experience with any on a turbo, just the RaceWare on my old '81SC. The factory steel studs are cheaper by far, but everyone has a preference.
Jim
Jim
01-21-2003, 12:26 PM
#3
RL Technical Advisor
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by DrEntropy:
<strong>'78 930 Turbo with ~most~ of the head studs failed by what appears to be tensile fracturing... I suspect the car was flogged repeatedly, without benefit of proper cool-down run. We have no documented history on this one, other than it was the usual 'grey' import. Any recommendation is appreciated.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Dr. E:
Quite common, actually.......Head stud failures on those engines was due to a well-documented problem with those Dilivar studs and exacerbated by the thermal cycles that all Turbos' go through. Higher than stock boost only made the situation worse.
We've used Raceware, ARP and the Factory 993 steel studs with great success. All of them will be superior and trouble free, compared to those OEM Dilivars.
<strong>'78 930 Turbo with ~most~ of the head studs failed by what appears to be tensile fracturing... I suspect the car was flogged repeatedly, without benefit of proper cool-down run. We have no documented history on this one, other than it was the usual 'grey' import. Any recommendation is appreciated.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Dr. E:
Quite common, actually.......Head stud failures on those engines was due to a well-documented problem with those Dilivar studs and exacerbated by the thermal cycles that all Turbos' go through. Higher than stock boost only made the situation worse.
We've used Raceware, ARP and the Factory 993 steel studs with great success. All of them will be superior and trouble free, compared to those OEM Dilivars.
01-21-2003, 02:29 PM
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Cruisin'
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Thanks Steve.
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?
01-22-2003, 12:38 AM
#5
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</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dr Entropy:
<strong>Thanks Steve.
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">My pleasure!
Its no isolated circumstance; it common on all 78-89 engines using any of those Dilivar studs. Some SC's and 78-79 Turbos had broken valve springs and they are suffered excessive valve guide wear. Turbos wear their valve stems and piston ring lands out fairly early on.
That's about it; the rest are heat-related issues. You'll buy a lot of parts during any decent Turbo rebuild.
<strong>Thanks Steve.
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">My pleasure!
Its no isolated circumstance; it common on all 78-89 engines using any of those Dilivar studs. Some SC's and 78-79 Turbos had broken valve springs and they are suffered excessive valve guide wear. Turbos wear their valve stems and piston ring lands out fairly early on.
That's about it; the rest are heat-related issues. You'll buy a lot of parts during any decent Turbo rebuild.
01-23-2003, 05:24 AM
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Cruisin'
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</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Steve Weiner-Rennsport Systems:
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dr Entropy:
<strong>Thanks Steve.
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">My pleasure!
Its no isolated circumstance; it common on all 78-89 engines using any of those Dilivar studs. Some SC's and 78-79 Turbos had broken valve springs and they are suffered excessive valve guide wear. Turbos wear their valve stems and piston ring lands out fairly early on.
That's about it; the rest are heat-related issues. You'll buy a lot of parts during any decent Turbo rebuild.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Steve,
Again: Thank you for the info.
The lands appear fine, and the liners still have the cross-hatch in 'em all the way down! Looks as if the thing was assembled yesterday. Haven't disassembled the heads yet to check guides/stems for wear.
Next 'hand-holding' quiery: What is the latest on sealants? I.E.: case halves, studs etc. The "grey stuff" the factory used is what I've found here, so am -assuming- this thing has not been taken down to component level before, though the turbo shows evidence of some sort of engine failure: fins "tipped" and missing. Turbo 'red tagged' (authorised bebuild?) housing is pitted/corroded and I consider it "FUBAR" as well.
BTW: Case studs were sealed with what appears to be the Wurth orange-red RTV: Further evidence the case has not been split before. Apologies for being so 'forensic' with this, but I'm trying to establish some sort of base-line for this machine and have conflicting evidence (turbo wear vs. liner NON-wear)... guess I should shut up and just rebuild it, huh?
<strong> </font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dr Entropy:
<strong>Thanks Steve.
I had to assume from the number of OEM studs I found failed, this couldn't be an isolated circumstance. I've not "laid hands" on one of these engines since they were new ('78 Lanham, MD), and so may need a bit of "hand-holding." Are there any other "well documented" component frailties I should be aware of?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">My pleasure!
Its no isolated circumstance; it common on all 78-89 engines using any of those Dilivar studs. Some SC's and 78-79 Turbos had broken valve springs and they are suffered excessive valve guide wear. Turbos wear their valve stems and piston ring lands out fairly early on.
That's about it; the rest are heat-related issues. You'll buy a lot of parts during any decent Turbo rebuild.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Steve,
Again: Thank you for the info.
The lands appear fine, and the liners still have the cross-hatch in 'em all the way down! Looks as if the thing was assembled yesterday. Haven't disassembled the heads yet to check guides/stems for wear.
Next 'hand-holding' quiery: What is the latest on sealants? I.E.: case halves, studs etc. The "grey stuff" the factory used is what I've found here, so am -assuming- this thing has not been taken down to component level before, though the turbo shows evidence of some sort of engine failure: fins "tipped" and missing. Turbo 'red tagged' (authorised bebuild?) housing is pitted/corroded and I consider it "FUBAR" as well.
BTW: Case studs were sealed with what appears to be the Wurth orange-red RTV: Further evidence the case has not been split before. Apologies for being so 'forensic' with this, but I'm trying to establish some sort of base-line for this machine and have conflicting evidence (turbo wear vs. liner NON-wear)... guess I should shut up and just rebuild it, huh?
