Rock Head gasket - Toyota Nation Forum : Toyota Car and Truck Forums

Mk3shadow · 04-12-2006, 12:58 PM

I was wondering if anyone new how much boost a rock head gasket would hold? ive been to there site and they couldnt tell me anything about it.

thanx for the time
MK3Shadow

Jeeves · 04-12-2006, 01:09 PM

Head gaskets do not "hold" boost.
A head gasket's purpose is to seal the head to the block.

Good Seal = Ability to maintain compression in the chamber

HOWEVER,
Detonation (Also known as Kocking/Pinging (NOT Rod Knocking)) also occurs more frequently at elevated boost levels and it kills head gaskets. So, Metal head gaskets (MHG's) resist the effects of detonation much better than composite (OEM) head gaskets do.

Really it all comes down to tuning. In theory you could run 200PSI on a composite gasket, if it wasn't detonating, would one sanely try it? No, MHG's afford you that little bit of buffer space between destroying a head gasket and tuning.

Lastly, What is a "Rock Head Gasket"? Never Ever heard of 'em. Even a google search showed two whole items.

newCSbeliever · 04-12-2006, 03:15 PM

i think rock is just a manufacturer. in which case im going to assume they make more than one line of head gaskets. so you will probably need to get the part number for the one you are looking at and call the company, and boost should not be mentioned when you do so. perhaps ask them about max recommended compression on that gasket. and actually the amount of boost you are running will mathmatically change your effective compression ratio although the dimentions of you compression chamber havent changed. i know of a very good book about calculating all that stuff. its called Maximum Boost by Corky Bell. its something good to read before you boost the heck out of your motor.

Jeeves · 04-13-2006, 12:17 AM

Interestingly enough Corky Bell is a Subaru Affectionado. He and I talked every now and then when I owned my subie.

Talked to a buddy of mine. Indeed Rock is a manufacturer, however they're a very very shitty one. They make pisons that are good to "600hp" on ebay, for the 7m. I saw one grenade @ <400hp. Didn't know the brand till I asked tonight.

So, if their head gaskets are anything like their pistons. RUN AWAY from them.

SuprAdam · 04-13-2006, 08:36 AM

Why not go with a tried and tested gasket? Don't wonder into unchartered territory, especially with 7m head gaskets.

HKS MLS gaskets starts around $115 last I checked.

If you want an affordable MLS gasket, look into titan motorsports lineup.

And if you want something more forgiving look into cometic gaskets.

OR if you are shooting for a stock-ish setup, use a toyota gasket.

TcmaBoy · 04-13-2006, 03:23 PM

Or if you have lots of money to waste you can have your head and blocked grooved for metal O ring gaskets.

***bgrieger*** · 04-13-2006, 03:49 PM

Affordable and the cream of the crop: Titan is HKS. A friend did a side by side comparison a few weeks back and confirmed that the titan gasket is identical down to the rivets and appearance of the materials. It appears Titan is supplied by the very same maker that provides them to HKS.

Jeeves · 04-13-2006, 10:10 PM

However, I'd much prefer a Greddy gasket over an HKS. The HKS is a metal clone of the OEM gasket. If you've ever looked at one, it blocks coolant passages and does some other unfriendly stuff. The Greddy is designed to be solid where it needs to be, and open where it should be, unlike the OEM/HKS/Titan.

Mk3shadow · 04-17-2006, 03:13 PM

Thanx for all the info, I bought a Greddy GREX Metal HeadGasket $194.99 shipped