Cutting O-rings into the block instead of the head?

[Begle1]

Has anybody ever cut O-ring grooves into the block instead of the head?


Does anybody have any idea what a good diameter/ depth/ width of the grooves would be?




(It turns out that I'm getting machine shop work done after all. )

[diesel freak01]

Fire rings in our tractor are cut into the sleeves. Not sure why you couldn't cut them to the block. As long as the gasket is makes for it.

[BC847]

It is the recomeneded way of installing the O-rings.

Folks normally have them installed in the head simply because the head is easily (relatively) removed and sent to the machine shop. But then when you have the head milled you have to recut the groove for the O-rings again. For that reason, the block is the the preffered option.

But then you've got to have the ways and means of getting the grooves cut in the block.

The standard head-gasket works with the block install just like the head install. (We're talking O-rings, not fire-rings ).

[Begle1]

That's what I thought...

So what size/ protrusion/ diameter O-rings are typical?

I'm going to have my new block in the machine shop as soon as I can tear it down.

[93flatbed]

http://www.cumminsforum.com/forum/94-98 ... block.html

[ellis93]

http://www.cumminsforum.com/forum/94-98-performance-parts-discussion/1011258-diy-cut-o-rings-block.html

Very nice link,good info to know the next time I have head gasket issues.

[Lunatic76]

Dumb question but what is the purpose or benefits of fireringing?

[PToombs]

Like O-rings, they hold the gasket in place. The thing that makes them better is if the head pops and you have it surfaced you don't have to cut the grooves again because they are in the block.

[oldestof11]

Fire rings =/= O-rings

On your head gasket is a metal ring around the cylinders. That is a fire ring. It does all the sealing of the combustion chamber between the block and the head.

If you are o-ringing, block or head. It pinches the fire ring when you torque down the head. This helps to give a better seal.

Fire ringing is the process of deleting the stock fire ring the the headgasket and putting in something like the o-rings. The problem with this is the constant expansion and contraction of the warm-up and cooling of running the engine lets them get loose. The plus side is supposedly better sealing.

[RCCUMMINS89]

Unless one has some mystical 9 billion hp race only engines... fire rings completely blow in comparison..just my .02. I've never seen where they are truly reliable.

O rings and good studs will pretty much hold anything.

[ellis93]

Unless one has some mystical 9 billion hp race only engines... fire rings completely blow in comparison..just my .02. I've never seen where they are truly reliable.

O rings and good studs will pretty much hold anything.

Not 100% true,show me an undependable Mack motor without 1million miles on it. I think it's all about clamping force and surface area/thickness. Our engines have little of all three. I don't know of anyone torquing down a head to 350lbs.

[RCCUMMINS89]

So you are telling me that the Mack engine has "stand alone" fire rings that are used by having a ring cut into the block? And no fire ring on the head gasket?

[ellis93]

Yep,but they do something a little different. Being wet sleeved they cut the grove in the thick cylinder sleeve. Same thing in principle.

[RCCUMMINS89]

Different material maybe? That would be my bet.

[ellis93]

Don't know...I just pull the heads (three of them) and replace stuff