Blowing stacked head gaskets.

[BIGMOOSETURBO]

Just wondering if anyone has had trouble with stacked head gaskets or the head shim. Seems like a weak link to me but I'm a rookie. I would like to avoid low compression pistons and rods in order to run more boost on pump gas. Thoughts?

 

[KnappAttack]

Use the HD ARP head studs torqued to Ted's spec and you won't have any trouble with stacking gaskets together dry. The weak link with boost is the fuels octane, and the lack of knowledge with the owner/operator, not the gaskets.

 

[BIGMOOSETURBO]

Thanks Mike. Its good to know that no one is blowing them out. Seems like the way to go.

 

[Ted Jannetty]

Just wondering if anyone has had trouble with stacked head gaskets or the head shim. Seems like a weak link to me but I'm a rookie. I would like to avoid low compression pistons and rods in order to run more boost on pump gas. Thoughts?

You could have trouble with any gasket combo but it is not the gasket that is the problem, in most cases it would be too much boost on too low of an octane or too lean a mixture.

boost spikes due to poorly designed boost controllers.

If you use OEM gaskets dry, and torque following my procedure you will not have a problem with gasket sealing.

You should have a look at the Boost calculator Sticky at the top of the Turbo superhcarger section to get a feel for what you can run for fuel and boost combo.

Stock engine RX1 93 octane fuel 7 psi
Stock engine Apex 93 octane 8 psi
2 gaskets on RX1 10 psi 93 octane.
3 gaskets on Apex 11 psi on 93 octane.

The Fuel is the single most important part of the equation, and the Big LIMTER.

General rules.

 

[kinger]

TQ spec on ARP studs are 45lbs not 38 like in ted's spec because he is using factory studs.

 

[Ted Jannetty]

TQ spec on ARP studs are 45lbs not 38 like in ted's spec because he is using factory studs.

I don't recommend ARP studs until you get to a full blown Race engine.

 

[kinger]

Exactly just making sure people understand. I believe at 45ft-lbs your right on the edge of the stud pulling out of the block!

 

[kinger]

Think 91 fuel with 3 gaskets and 10 psi SC apex is OK? The calculator shows 92 octane, what if you can only get 91? Use the NOS racing octane booster that would make it 93 but not sure how hard it is on the sensors and stuff. Any input on that?

 

[mbarryracing]

I remember Dynotech Jim commenting about this very topic regarding stock vs bigger head studs... Would you rather pop a head gasket or break a block due to detonation? What is the next weakest part after stronger studs? Which is less expensive? Ah, just don't detonate, right?
So how strong is the stock block to accomodate the higher yield strength of the bigger studs? Can you stretch the bigger stud adaquately in a stock block? Fastening 101, bolts need to stretch / yield to retain a clamp force...
Hmmm.

 

[lightningpro-fred]

Why take a chance with 93 octane. It`s difficult to rely on the consistency of pump fuels. Why not run 100 ll av gas ( which is not real expensive)
OR blend in some TOLUENE. Has any one tried this?

 

[kinger]

Thoughts on the octane requirement of 3 gaskets calc shows 92 at 10psi, think 91 would be enough to cause detonation? Thanks


I like stock studs, the ARP's were a PITA and sitting on my bench right now.

 

[Skydog]

I believe at 45ft-lbs your right on the edge of the stud pulling out of the block!



YES YES YES YOU ARE!!!!! Been there,,,,

Skydog

 

[Turk]

i ran 91 cdn on my cpr turbo at 10-12 pounds boost with 10:1 pistons all day long with no probs at 1400' elevation.

 

[Blue shadow]

Any thing over 18 psi should have the ARP studs .

 

[mulot30th]

I run arp studs on my low 10psi boost rx1 mtn with a head shim and 94 octane pump fuel.

BTW torqued the studs to 42#, not 45... this is too much