HydroStream6

iTrader: (16)

I've always run genuine GM LQ4 MLS head gaskets. They've always treated me well. Recently I've been pushing a touch of water now and then and I want to address it before it turns into an issue.

Setup is 370ci, PT7875, LS6 cam, stock 317s, E85, 20psi, ARP hardware, etc... somewhere around 1000 crank hp.

I'm assuming my back pressure is decently high due to the small turbine and my ci and power level.

My main question here is are the LS9 gaskets going to help me any over the LQ4 gaskets that I've been running, or should I look into another solution all together? I've gotten a quote for camaroandreas's coopering setup, and it is sort of pricey but I'm willing to do it if it's the next best option short of buying beefier heads.

So, does anyone have LQ4 vs LS9 gasket experience? Or comments on the coopering setup? I'm all ears.

Thanks,
Adam

HydroStream6

iTrader: (16)

Lots of peeks, no one?

compgto

iTrader: (7)

I have no clue what coopering is, but i just swapped a set of LS9 head gaskets in my LS1 along with studs and it cured my water pushing problem.

stock48

iTrader: (17)

On my combos 20psi and a couple hard full 1/4 mile pass's with the lq4 mls would get the rad hose a little stiff but didn't push water. With ls9 gasket at 20psi there is no pressure in cooling system whatsoever.. Also it isn't just boost that will make it push timing plays a big part as well.

skinnies

iTrader: (33)

Put on some ls9's, no reason you should push at that level if the tune is good.

HydroStream6

iTrader: (16)

Cool, good replies I'm sure my cylinder pressure is up there. For the price of the LS9s, I'll give them a shot. Anyone coating their gaskets on install?

skinnies

iTrader: (33)

dry here

compgto

iTrader: (7)

Mine are dry

9sectruck

iTrader: (9)

I plan on seperating my layers and copper coating each layer for my build.
dont know if it will help much, cant hurt

stevieturbo

Ensure both block deck and head are perfectly smooth.

I assume you're using ARP studs ? Torqued to ?

Perhaps a better stud ?

Or if pushed, maybe go to 1/2" studs.

But using normal ARP studs with basic 5 layer LS2 gaskets on mine Ive never had any issues. Torqued to 75lbft I think I did last time.

It's also very easy to keep an eye on things by monitoring pressure in the cooling system. This will tell you almost immediately how the gaskets/setup are performing.

HydroStream6

iTrader: (16)

ARP studs @ 75lbs here as well. I know some go to 80lbs without issue.

I'm running the 3 layer gaskets. I'm going to try the LS9s and see how it goes. I think they are a 5 or 7 layer right?

Good idea to keep tabs on the coolant system pressure. I think I will look into that. Very easy way to keep and eye on it.

Thanks for the replies everyone!

stevieturbo

I think the LS9 are 7 layer.

Some do go to 80lbft, but I didnt bother. Although my 75lb was re-torquing after a few hours. ie loosen each one in turn 180deg then retorque one at a time
This often does see another 30-45deg of rotation.

Ive only ever used the 3 and 5 layer GM gaskets. Only downside against the LS9, is they'll be a lot larger than your bore size.

denmah

iTrader: (2)

arp bolts blown on with an impact gun, stock head gaskets, swapped one bolt at a time.

20lbs of boost in the turbo truck no water issues.
soon to be 20lbs in fairmont 2

02anti_vnm

iTrader: (32)

I had cometic mls gaskets, fel-pro mls gaskets, sometimes with copper spray, sometimes without Tried several different things but would always blow head gaskets after a couple weeks. Finally went to ls9 gaskets and seemed to make a pretty big difference but they eventually blew after about a couple months. So whether it was in the tune ( highly doubt) the setup or just bad luck I have to say that the ls9s made a big difference

BLOWNBLUEZ06

iTrader: (17)

If you're using equal length studs (used in newer blocks), you should be using ARP-2000's, part # 234-4319
My method: Clean surfaces until your rags don't come off with any stains using lacquer thinner. De-burr any raised edges, Torque them dry and only use ARP Ultra Torque lubricant when torquing them. It's the only product that will provide you with a reasonable guarantee you'll hit your yield on the first torque attempt.

Some 3-layer gaskets (LS7) cover steam holes and will enhance the problem. Have you ever checked the alignment of those holes??

Here's a quote with pics from the original post that first turned me on to this issue.