favorite/best head gasket for boost

October 01, 2018, 07:13 PM

Bruce Williams

Recently installed new larger blower on my dragster. Went from older 1071 to new HH 1471.
Boost jumped from 10 psi to 17 and blew out the Cometic head gaskets.
Looks like I need something better at sealing.
What is being used on boosted applications?

October 01, 2018, 07:15 PM

T/D6591

Bruce why not copper and o-ringed? When i changed jets i ended up having to change head gaskets. Super Angry

October 01, 2018, 07:34 PM

jenavet

definitely needs to be o ringed

October 01, 2018, 07:45 PM

"The Bender"

I ran Cometics successfully up to 20+#, but if it gets lean you're in trouble.

O-ring it and be done with it.........

272" Spitzer
540 Chevy
The Blower Shop XR1
FTI XPM Series Converter
FTI Level 6 Powerglide
3.69@199
.916 60'

2017 Bradenton Heads Up Madness
Open Outlaw Champ

2018 PDRA T/D #5
2019 PDRA T/D #2

2020 Retired From T/D Competition....

2020 Bradenton NMCA Hemi Shootout Winner

2021 getting back into bracket racing with a Gen3 Hemi powered 87 Cutlass.

October 01, 2018, 08:10 PM

Big Steve

Mine is o ringed on head, grooved in block. Using Flat out Gaskets, coated copper gaskets. 18-27 lbs boost.

Clark very makes good gaskets but not coated so you have to silicon around all the water jacket holes if your block is wet

Very important to re torque copper head gaskets after first heat cycle

October 01, 2018, 10:53 PM

Bruce Williams

quote:
Originally posted by T/D6591:
Bruce why not copper and o-ringed? When i changed jets i ended up having to change head gaskets.

Moe, the cometics are what came with the engine/car when I bought it.
I had planned on rebuilding after the Vegas Div.
I'll just be doing that sooner. Still planning on running a wet block and looking for opinions on which will work best.

October 02, 2018, 06:21 AM

"The Bender"

I don't think you can beat the Cometics other than going to O-rings.

That being said watch your tune up, make sure it's not lean, read your plugs. Be a little conservative with timing and don't go over 20# boost. Make sure the deck surface of the heads are flat. Do you know the CR of the engine?

I'm assuming it's a BBC, does it have the valley head studs?

October 02, 2018, 08:11 AM

wideopen231

sce cooper gasket and O-ring w/o question. Cost is lot less than burnt head. Works even when tuneup goes bad and at some point it will.

October 02, 2018, 12:33 PM

Bruce Williams

quote:
Originally posted by "The Bender":
I don't think you can beat the Cometics other than going to O-rings.

I'm assuming it's a BBC, does it have the valley head studs?

It's a factory Bow Tie block. So unless they were added buy the previous owner, I will say no.
If they are not there I will add them.

October 02, 2018, 01:55 PM

RPROGAS

It’s wet.

Bob

October 27, 2018, 08:11 AM

Alaskaracer

Copper gaskets and o-rings with receiver grooves...

I run a nitrous combo and that's what I use, run it more N/A than anything. Couple decent coats on each side with copper spray a gasket and not one single leak. Takes some work to get the heads off too. Nice because you can reuse the gaskets, saves some coin on refresh or teardown...and you can play with thickness of the gaskets too for tuning.....just a thought.

October 27, 2018, 08:28 AM

S/S Dart

To the OP: where did the Cometics fail?
between cylinders? or were you pushing out coolant? We run Cometics and have started to push combustion pressure into cooling system at about 18#'s....head gaskets show some"fretting"
or removal of black coating on both sides of the gasket near the block coolant holes at the rear cylinders..Heads may be lifting.Spoke with engineer at Cometic last week and he suggested
Torquing the head, leaving it set for several hours, then mark ,loosen headbolt stud/nut and retorque...We're probably going to go the copper
O-ring route although I prefer the overall ease of using the MLS gasket.Considering new head studs as well as these have been with the motor for years....As Bender stated, Lean tune up is tough on parts with Cometics and boost....Any one else experience combustion pressure in cooling system from head gaskets leaking?
Thanks...

October 28, 2018, 10:50 AM

NEMO963

Similar experience, ran cometic and had great luck at 16lbs, at 18 started to show some fretting as you described. At 20-22 lbs had some pressurization of the cooling system and evidence on the deck that combustion was escaping from cylinder to water passenge. Would reseal (static compression didn’t change) and tried the retorque as described with no luck. Went to o-ring and copper gasket with copper spray and no problems at 32 lbs.

October 28, 2018, 11:27 AM

S/S Dart

Thanks Nemo !! Did you O-Ring the head and put Receiver groove on the block?...

October 28, 2018, 11:43 PM

NEMO963

My o-ring is in the block with the receiver in the head.

October 30, 2018, 07:14 AM

Rhino

I use flat-Outs or clarks. 35psi all day long !!

November 03, 2018, 11:44 PM

Bruce Williams

quote:
Originally posted by S/S Dart:
To the OP: where did the Cometics fail?
between cylinders? or were you pushing out coolant? We run Cometics and have started to push combustion pressure into cooling system at about 18#'s....head gaskets show some"fretting"
or removal of black coating on both sides of the gasket near the block coolant holes at the rear cylinders..Heads may be lifting.Spoke with engineer at Cometic last week and he suggested
Torquing the head, leaving it set for several hours, then mark ,loosen headbolt stud/nut and retorque...We're probably going to go the copper
O-ring route although I prefer the overall ease of using the MLS gasket.Considering new head studs as well as these have been with the motor for years....As Bender stated, Lean tune up is tough on parts with Cometics and boost....Any one else experience combustion pressure in cooling system from head gaskets leaking?
Thanks...

Gasket failed on #7 cylinder. Burnt through to head stud and on to the water jacket. Burnt the head, but I will be able to weld it up easily. Made 17# boost when it happened.
I will be going to O rings and copper gaskets.

November 04, 2018, 05:57 PM

S/S Dart

Bruce..Was that on an iron block? Very similar
failure on our motor...# 7 as well with the stud at the 5oclock position on that cylinder at 18#'s
We're going copper and O-rings as well...What size bore were you running...??

November 08, 2018, 08:42 PM

Bruce Williams

quote:
Originally posted by S/S Dart:
Bruce..Was that on an iron block? Very similar
failure on our motor...# 7 as well with the stud at the 5oclock position on that cylinder at 18#'s
We're going copper and O-rings as well...What size bore were you running...??

Yes Iron Bowtie block #7 at 5 o'clock 4.530 bore. I bought a new Merlin 4 block so I will be starting out at 4.500.

December 24, 2018, 10:48 AM

Larry Heath

I've always wanted to try the Willis/Cooper rings.
Maybe I can talk a friend with a boosted bike (20-35 psi) to go that route.I am told that even if the head lifts a bit they are pretty good at staying sealed.

https://en.wikipedia.org/wiki/Wills_Ring