head casting 25506293? in place of 8445s?

[forcefed86]

Recently having head issues on a budget build. I have these heads in great shape sitting in the shop. Will these work with the 86 intake? I only have my alternator to worry about accesory wise. Looks like I can make that work.

Any reason not to use these? They will be seeing around 550hp. I'm hoping to get another season out of this engine. Come winter it's getting an LS1.

I've seen this.

Buick V6 Cylinder Head Guide

And read a few posts. I know the water jackets seem to be the main difference. Do these effect HG choice? Are they a direct "bolt-on"?

 

[Squid4life]

I'd run them. Those aren't the more desirable 6293's with the bridge in the outer coolant passage, but should be fine. Other than the bridge, they are pretty much 8445s.

 

[bison]

I ran a set of them over 700hp with no issues

 

[forcefed86]

Alrighty... Did you use SS hg's by chance? Reason I ask is I somehow blew out a composite gasket. No indication of knock. Switched to SS this time around and had no problems. Really don't feel like dropping another $150 on head gaskets I just changed. I have a factory graphite set. THis will be the third HG change in 500 miles.

Thanks

 

[turbofabricator]

What brand Graphite? If by chance they were ROL brand, they will only work to about 30 horsepower (Ok, I'm exageratting a bit there). There is no wire inside the fire ring of that gasket. They look identical to a Felpro 9441pt, but are going to blow at next to nothing in the power range. I have used the Felpro 944's at over 600 HP with no issues.

 

[forcefed86]

They were victor reinze? (sp?) Suppose to be factory replacement gaskets. I'll see what brand the spares I have are. They came with the 3.8 summit rebuild kit I ordered.

Here is a pic of the blown gasket. Plug literally looked perfect. No speckling on piston etc. 18* timing and 11.5-11.8 AFRS 20psi. #6 cylinder

Been to almost 30 now at 17* timing. I've been keeping the AFRs in the mid to high 10's though.

Thanks for the input!

 

[bison]

There was definitely detonation there. Carbon tracking on the fire ring. I did run rjc stainless. There was zero compression leakage however. I ran c12 most of the time and occasionally q16 with 28-33psi/22-24*. I did 3 retorques. The engine was pounded on that tune for over a year before I cracked the #1 piston.

 

[naste87t]

go with a set of cometics and be done with it.

 

[bison]

go with a set of cometics and be done with it.

Yeah, cometics will prevent detonation

 

[forcefed86]

Thats odd the gasket let loose I had no KR and I have an audible caspers sensor that never sounded as well. The KR function is working properly. Plugs looked clean as could be. No speckling etc. I thought I may have had some sort of issues with he head not clamping down properly. The sensor defiantly works. May have skipped detonation and went straight into pre-ignition. Possible low 12 AFRs were just to lean for this setup. I run 12.5 afr's on my daily driver at 30+psi with no issues. (all tuned on e85)

As far as HG's go I believe the SS RJC gaskets are cheaper. And the cometics require a 50 RA special finish to be done "properly".

The RJC silicone sealer on the SS gaskets is a bastard to get cleaned off. Other wise I may be able to reuse the SS gasket? Anyone have experience with this? I know I have reused factory "shims" as head gaskets in the past without issue. I believe the "special" silicone sealer RJC uses is just structural construction grade silicone.

like so...

Amazon.com: Black Tremco Proglaze SSG Structural Glazing Silicone Sealant: Home Improvement

 

[bison]

Thats odd the gasket let loose I had no KR and I have an audible caspers sensor that never sounded as well. The KR function is working properly. Plugs looked clean as could be. No speckling etc. I thought I may have had some sort of issues with he head not clamping down properly. The sensor defiantly works. May have skipped detonation and went straight into pre-ignition. Possible low 12 AFRs were just to lean for this setup. I run 12.5 afr's on my daily driver at 30+psi with no issues. (all tuned on e85)

As far as HG's go I believe the SS RJC gaskets are cheaper. And the cometics require a 50 RA special finish to be done "properly".

The RJC silicone sealer on the SS gaskets is a bastard to get cleaned off. Other wise I may be able to reuse the SS gasket? Anyone have experience with this? I know I have reused factory "shims" as head gaskets in the past without issue. I believe the "special" silicone sealer RJC uses is just structural construction grade silicone.

like so...

Amazon.com: Black Tremco Proglaze SSG Structural Glazing Silicone Sealant: Home Improvement

Detonation/pre-ignition still uncontrolled combustion events.

 

[forcefed86]

Right, but you get alot less warning with pre-ignition... Or so I'm told. :biggrin:

 

[naste87t]

Yeah, cometics will prevent detonation

They may not prevent detonation but they sure can take a lot more abuse and wont blow out as easy as the 944 or any other head gasket that is composed of graphite and a steel ring.

 

[bison]

They may not prevent detonation but they sure can take a lot more abuse and wont blow out as easy as the 944 or any other head gasket that is composed of graphite and a steel ring.

Yup. Instead your rod bearings and crank take the beating. Just what I'd want

 

[forcefed86]

These are the spare HG's I have. would you suggest using the felpros over these?

I've got an email out to RJC about reusing the SS gaskets as well.

Thank you.

Sealed Power Z2601138 - Sealed Power Gasket Sets - Overview - SummitRacing.com

 

[turbofabricator]

These are the spare HG's I have. would you suggest using the felpros over these?

I've got an email out to RJC about reusing the SS gaskets as well.

Thank you.

Sealed Power Z2601138 - Sealed Power Gasket Sets - Overview - SummitRacing.com

Yes, the FelPro 9441pt's are the ones you neeed. Cut the fire ring apart on the gasket you blew and see if there is a steel wire INSIDE the wrapped metal section. If not, that's why they blew. I have tried just about every head gasket out there over the years and non are immune to failure. Maybe a StageII on center 3.8 block with a StageII IRON head would hold a gasket to the point of killing a rod, but usually even Cometics with a StageII will fail between the cylinders.

 

[gs462]

They were victor reinze? (sp?) Suppose to be factory replacement gaskets. I'll see what brand the spares I have are. They came with the 3.8 summit rebuild kit I ordered.

Here is a pic of the blown gasket. Plug literally looked perfect. No speckling on piston etc. 18* timing and 11.5-11.8 AFRS 20psi. #6 cylinder

Been to almost 30 now at 17* timing. I've been keeping the AFRs in the mid to high 10's though.

Thanks for the input!

IF you have done this 3 times in 500 miles you should quit beating on the car and tune it cuz something isnt right.

 

[forcefed86]

IF you have done this 3 times in 500 miles you should quit beating on the car and tune it cuz something isnt right.

I wouldn't be changing it because it blew this time around. I'm changing it because the head pedestal is cracked. First time was a fuel pump failure, second was the composite gasket pictured above. Third would be the one I'm about to do.

 

[naste87t]

Yup. Instead your rod bearings and crank take the beating. Just what I'd want

Bison, Bison, Bison: SMH....:tongue:

 

[bison]

Bison, Bison, Bison: SMH....:tongue:

banned bitch!