99Fbody99

O-ringing the head/block when done correctly places a tremendous amount of stress on a cylinder head deck surface. This process requires more head/block stiffness to support the attempt to redistribute more of the available load away from the fasteners and onto the "wire" generating a "high sealing pressure" zone. The problem is it can easily exceed the abilities of the head deck structure and generate enough deck deflection to "beam" between the bolt load paths. When this occurs (usually in the middle or weakest point) you will actually have LESS sealing pressure that with a basic MLS or graphite composition gasket. Applying additional load into the head via fastener torque, head bolt diameter is absolutely useless when this condition exists as you have already exceeded the heads ability to carry the load away from the bolt boss.

Also, the stock cylinder heads with the relatively thin deck is the worst combination to try to effectively attempt using this technique.
This was assuming it was done properly let alone incorrectly which usually generates an almost immediate failure. Additionally, there is no set singe "right way" to do this as each application has its own unique properties.

If you want my 02, pick up a set of STOCK GM MLS L92 headgaskets and assemble to GM/ARP assembly specs.

Dave

TurboGibbs

iTrader: (6)

Thanks for your input. You are right along with what I was thinking but i'm not smart enough to put it to words. It seems so many people want to jump down someones throat and accuse them of poor installation.

Cam72aro

iTrader: (28)

I cant tell by the pics, but is there a reciever groove in the heads? It appears that something with this is the problem. Maybe not lined up? Not deep enough, etc. My 2 cents, hope it helps.

engineermike

Subscribing. I was thinking about starting a new project - a 2nd gen RX7 with a 414 LSx and L92 heads with a T9X turbo for pump gas use. This may change my mind. I know people can't get head gaskets to consistenly hold up on production LTx heads at high boost due to the thin deck surfaces.

TurboGibbs

iTrader: (6)

No there is no reciever grooves. I didn't need them in SBC's. This is new charted territory for me and learning as I go.

kp

iTrader: (34)

I honestly dont think there is enough clamping force with stock studs for copper gaskets and o-rings on these. I have had some pretty nasty looking gaskets and have never had any carbon on the deck side at all, only the head side so whatever you did, it didnt work

I get around 50-75 passes at 15-17psi before I start to see some block marks on the outside between the head and block and then I swap gaskets (GM MLS) but I run mine pretty hard. I'm not going to try to figure out a better solution, if I want more power I'll wait for the 6 bolt blocks to come out, I have the time..

TurboGibbs

iTrader: (6)

Thanks, i'm not out on a fence on my own. Well said.

427

iTrader: (3)

I run a reciever groove in the block with the o-ring in the head.
The gaskets are all different numbers depending on the engine, but I like .04X thick with a bore .030-.040 bigger than the bore on the block.
My reciever groove is .060 wide.

Kurt

kp

iTrader: (34)

FWIW this is what my heads looked like after thirty 17psi and two 20psi passes:



When someone comes up with a good soluton I'll try it, so far the fusion or whatever cometic and SCE titans dont work and they seem to work well on other engines so who knows. Just looking at the block deck and heads plus the spacing of the bolts its pretty obvious there isnt a lot of meat there. I'm a little more used to BBC and SBCs But these are great engines none the less..

TurboGibbs

iTrader: (6)

LOL. That looks familiar. I have 3 sets of heads that look similar to that.

Cam72aro

iTrader: (28)

What are you referring to? If you run a oring in the block then you have to run a groove on the head.

TurboGibbs

iTrader: (6)

That may be the case with an LSx based engine but I didn't have to on the 2 sbc's that I ran this set-up on.

68charcoal

I didn't buy a brand new truck and tear it apart either. Plus part of that 15 years was starting over after my little brother burned it to the ground.

Cam72aro

iTrader: (28)

I have done several race small blocks and you have to put a reciever groove in the head. Where does the copper gasket go on the top side? I have never built a ls1 with o-ring, but I know that on oring block and copper head gaskets there has to be a reciever groove in the head. I can bet money that this is your problem. I would check into this. Hope it helps, Josh

TNTramair

iTrader: (15)

subscribing.....

TurboGibbs

iTrader: (6)

I bet that is the problem as well in this case. Factory heads have too thin of a deck to handle the load of the wire. The sbc's I did was with aftermarket aluminum heads with Moroso Ceramic Seal in the water and no receiver grooves.

TurboGibbs

iTrader: (6)

Yeah, that sucked.

Brains

iTrader: (7)

Okay since we're all discussing wires -- say the wire is in the block, .041" wire sticking ~.012" off the face of the block. No receiver groove in the 853 heads, .060" copper gaskets. They seal fine for a while, and then start pumping up the cooling system after a while (several months) at ~10psi boost pressure. Wanting to make the car go for years rather than months, what would the peanut gallery say would be the smartest move?

1. Remove the wire and run MLS gaskets
2. Add a receiver groove and continue to run copper gaskets
3. Leave the wire in, run MLS gaskets, say "**** it" and hope for the best

Slowhawk

iTrader: (12)

Sorry,never touch the stuff.There is no reason too.Even our 1600hp race cars stay away from o-rings/copper.

Cam72aro

iTrader: (28)

I had them on a 14:1 406 with a 250 shot. Copper head gaskets are known to leak around the water jackets. I would not go with them for a street driver. I would go with a cometic or a good composite gasket. The oring copper gasket is kinda a race car technology that is good for that, but not for the street. my 2 cents, Josh