Reciever Groove

[stay`tee]

Had a lot of experience with 'Ole Skool Turboed aircooled motorcycle motors,, back then we o'ringed the block and used a copper head gasket with very little Block/Head sealing problems  , today with the watercooled motors, folks add/machine a receiver groove to the head,, what is the engineering/mechanical reasoning to support doing this ??

[Stainless1]

Keeps the water in place...
We o-ringed the zx10 we ran in the 90s, not for turbo, but for N20...
The copper gasket would leak water under pressure... cut a larger receiver groove, allowing someplace for the copper to go, the motor stopped spitting up water after the run.
Of course, we were initially working with dry block numbers, weren't a lot of bike motors that were wet then.

[rouse]

over the years there have been several different methods use to seal up blown engines. How much you do depends on the amount of combustion pressure you end up with. Ie. a Blown Nitro motor may have over 4000 PSI to deal with as apposed to a mild gasoline engine may only have ,say 1800 PSI.

I'm not convinced that the best solution to stop failed head gaskets has been designed yet. To date, the best for high pressure is to put a wire ring in the block "O-ring the block" and put a matching groove in the head. This really has more to do with trying to stop the gasket from "creeping" than for sealing. The gasket compression is for the leakage, but ex-stream High pressure tends to plastic deform the gasket and push it out from between the head and block. O-rings or supposed to stop this from happening, and do help some of the time, or at least till the pressure gets high enough to shove it out even with the O-rings.

I have had gasket creep with a N/A engine, in that case the first cure is to go for a better seal, if that don't work, next up would be to O-rings. What a pain?

Rouse

[WOODY@DDLLC]

Good article about being groovy: http://www.engineprofessional.com/EPQ2-2016/index.html#p=62

[manta22]

When Ford dropped their racing support there was a huge sale of parts at Holman & Moody. Among other things, I bought a 302 Trans-Am block that was machined for O-rings; I think it was a '69 block. I believe Ford had good success with copper O-rings sealing combustion pressure.

Regards, Neil  Tucson, AZ

[stay`tee]

Keeps the water in place...
We o-ringed the zx10 we ran in the 90s, not for turbo, but for N20...
The copper gasket would leak water under pressure... cut a larger receiver groove, allowing someplace for the copper to go, the motor stopped spitting up water after the run.
Of course, we were initially working with dry block numbers, weren't a lot of bike motors that were wet then.

What clamping pressures are we talking here ?, also what studs etc ?,, if you have water leakage one side, whats happening in the combustion(hot/pressure) side ??

As we know copper is extremily maluable (spelling), my understanding is that a piano wire oring, with correct tenshion upon it, fully compresses into the copper ??,

My way of thinking is that by adding a machined groove you are streatching the copper at the orings sides, thus creating a weak point,, also isnt giving the copper "somewhere to go" defeating the purpose of having a oring in there ??

[rouse]

My way of thinking is that by adding a machined groove you are streatching the copper at the orings sides, thus creating a weak point,, also isnt giving the copper "somewhere to go" defeating the purpose of having a oring in there ??
[/quote]

That's what the top Fuel engine have done, and to date that still works the best. Not saying they don't blow head gaskets, they do, but they wouldn't get away from the starting line without them.

[rouse]

When Ford dropped their racing support there was a huge sale of parts at Holman & Moody. Among other things, I bought a 302 Trans-Am block that was machined for O-rings; I think it was a '69 block. I believe Ford had good success with copper O-rings sealing combustion pressure.

Regards, Neil  Tucson, AZ

That reminded me of Carol Miller, that has been a while.

Rouse

[stay`tee]

My way of thinking is that by adding a machined groove you are streatching the copper at the orings sides, thus creating a weak point,, also isnt giving the copper "somewhere to go" defeating the purpose of having a oring in there ??

That's what the top Fuel engine have done, and to date that still works the best. Not saying they don't blow head gaskets, they do, but they wouldn't get away from the starting line without them.
[/quote]

with all due respect, Top Fuel motors are a "Completely" different animal,, monky see, monky do  ,, just about one out of every two fuel passes sees a gasket pushed at any time after fireup 

 

[gkabbt]

Here are a couple of pics from a guy on turboford.com that used MoldStar square cut rings in the block and head.
Seems to seal up REALLY good on his turbo combination.
Here is the link to his build on turboford.com and the pics are about 1/2 way down the 1st page:

http://forum.turboford.org/ubb/ultimatebb.php?ubb=get_topic;f=30;t=000040

HTH,
Gregg

[wobblywalrus]

One good prevention method is to set the ignition timing at the most retarded setting that gives good power.  Also, if copper gaskets are used, vacuum furnace annealing is far better than the open flame method.  The new copper gaskets I use are furnace annealed before they go on the bike.  These simple tricks make sealing a whole lot more reliable with or without the grooves.

[Stainless1]

Actually I think it locks the gasket in place basically putting a little step in it.  Without the receiver groove, the copper would not clamp enough to keep the water in, seemed like the oring did not seat completely in the copper so the other surfaces of the head were not clamped well. 
Yes we were using studs and more than stock torque, been almost 20 years ago, those numbers went away many beers ago.
I would think MLS gaskets would be the way to go these days.  If you are pushing those out already then o-ringed copper would be the next step. If you try it without a receiver groove, let us know what happens.

[John Burk]

Found this about the Moldstar o rings

"The Molstar rings were special order and purchased through the machine shop that did the work. I dont have much info on those but I'll be buying another set soon. The rings are flush with the cyl bore. The shop that did it is an extremely knowledgeable shop in Denver, NC.

Headgasket is a Fel-Pro 8993 that I remove the fire ring, then use die grinder to open up the cylinders so they clear the rings."

[Jack Gifford]

O-rings & copper gaskets & receiver grooves are the time-proven scheme for sealing very high combustion pressures. It's known as a labyrinth-type seal- as are the rectangular-section sealing rings shown in a post above.

But copper gaskets typically require some additional means of sealing coolant. For instance, SCE (and other suppliers) will optionally "print" elastomer sealing rings around coolant passages of copper gaskets. Before these were available I applied a bead of sealant around such passages- also around high pressure oil passages through the deck, such as top-end oiling of early hemi V8 engines.

[stay`tee]

uuuummmm, thankyou for the imput fellas  ,, thinking that I will go with my 'ole skool tried and proven set up, oring protrusen(spelling) @ 25* of copper gasket thickness with a spray of Copper Coat to help keep the fluids contained,