Hey I'm doing a pretty extensive vq35de FI build up and I'm holding off on buying the proper head gaskets until I can get a few of other's suggestions. Among other supporting mods I'm running CP 96mm pistons so I'll be going to the 96mm bore. I am going to run the supertech block guard also. My power goals are to build for ~700hp but run at 500hp for reliability.

So I'm running a 96mm bore, my understanding is to run +1mm so a 97mm head gasket, would 98mm (+2mm) be too big?

How thick is too thick? I'm already going 8.5:1 with the CP's so i don't really want to drop the compression too much further and lose all the bottom end, the heads have been decked and the block will probably be decked also so I'm thinking the .5/.6 thick should be decent.

Is it worth paying for the Cosworth/HKS or is the Cometic decent? I've dealt with Cometic in the past and I've not has issues with them but many other people have.

Thanks much for any advice

 

**** the search button broke again? They should fix that. Seriously 5 mins of searching and you have a dynosty or hks headgasket on order, throwing out the block guard, and know that going even from 8.0 from 8.5(no way in hell your gona do it unless stacking like 4 headgaskets...........) is only about a .5-1% drop in power which you wont notice.

 

crazy phone double post

 

lol, yeah I did the search, didn't find the answers I'm looking for.

Why not run the block guard? I'm concerned the open deck design isn't suited for the psi of forced induction and the higher revs that I'm going to be running.

Yeah I'm not too worried about the thickness, just was looking for other's experiences.

Anyone have issues with Cosworth or Cometic? Or for that matter anyone happy with either?

Thanks for the advice

 

You should do some research before you start building. Stock block holds up to 900whp. Block guard unless you tack it to the block will vibrate and cause more harm than good. Who ever told you to use a bigger HG than the bore? If you going with 96mm bore your HG should be 96mm.
Higher revs have nothing to do with the block and sleaves

 

I went with commetic , binder is running commetic also and he's at 650whp

 

yep, cometic 100mm gaskets are run on the big bore 1000hp builds and hold up. Prep on teh heads/block and evenly torqued head studs are the main deciding factor if you will hold a head gasket or not. L19's torqued to 85ftlbs on almost any head gasket on the market now will hold plenty of power.

I've always ran the cometic gaskets in my car with no issues. The only one that has ever failed is the first one due to the tuner running 28* timing on 14lbs of boost. After 8 pulls it finally let go due to detonation on the dyno. GRD tuning in chicago in case anyone wants to never go to them. They didn't pay a dime for fixing my car after that either.

anyways, I refuse to spend 360$ on a headgasket set when cometics work perfectly fine. twice the cost for a product that will hold the same. Anyone that says cometics fail easily are looking up old info before they started making stopper ring sets about 5 years ago. All the new head gasket sets run stopper rings, including the new OEM HR gaskets.

 

i picked up a set of dynostys own headgaskets simply because he said that ran into QC issues with the cometics.

op exactly what konrad said on the block guard do some searchs not just here but other platforms as well, nearly everyone who runs one without welding it in place has issues. every block is different so its not possible for them to machine one that fits your block perfect, so it will come loose not if.

 

how much boost and revs are you going to be running?