Sleeve o-rings, important?

[Crazcnuk]

Wondering if those viton o-rings, in the gasket kit, that go around the base of the cylinder sleeves are important?

I put the block back on, got it past the tensioners, cam chains etc, slid it, very gently onto all four pistons and realized I had forgot to put those o-rings in!

[3Phase]

Wondering if those viton o-rings, in the gasket kit, that go around the base of the cylinder sleeves are important?

I put the block back on, got it past the tensioners, cam chains etc, slid it, very gently onto all four pistons and realized I had forgot to put those o-rings in!

If I remember correctly: the last time you were putting the jugs on your engine a irreplacable piston ring broke and you acquired a new boat anchor....

Man, that's a tough call. You really should use the Viton o-rings but you might luck out with some Yamabond case sealer. I'd just pull the jugs and put on the o-rings but then I'm a complete moron! :biting-nails:


Regards,

Scott

[Ken Talbot]

I'm sure I read somewhere that you're not supposed to use them anymore. Not sure if they are only for the earliest models only, not to be used on later models, or just what. I'll try some searching.

[Crazcnuk]

The boat anchor is still in the trunk of my car, there were a number of issues going on there.

I have the o-rings, but last time I got the barrels on perfectly, thie first time, I had to take it off, and broke the ring on the 2nd attempt. Those rings are irreplacable, at the moment.

If they are not needed I would just as soon leave them out, but I will put them in if they are necessary.

[TopCatGr58]

Hey Cnuk,

I hate to be the harbinger of possible bad news, but ALL of the fiche I checked, from the 79 to the 81's show the cylinder O-rings. It was the cam chain well seal on the early models that were not needed/required in the later models with the newer head gaskets.

HOWEVER, as has been stated before, there isn't any major pressure around the base gasket area to blow oil up there. I would think that along with the base gasket, a good layer of Yamabond on both sides would be adequate to make a proper oil and AIR seal, making the O-rings redundant!?

Also, I remember doing my top end rebuild, I didn't get a complete gasket kit, just the head gasket from the Wiseco kit, along with new valve seals, and I had pulled my jugs to be rebored, etc. I didn't replace the O-rings, but I don't know IF the machine shop would have removed the OEMs for doing the boring. But I didn't put any new O-ring on it. and I don't even remember there being a base gasket? Of course this was some 9 years ago, so CRS may be setting in some, but my engine has been running just fine for 9 years that way, no leaks around the base gasket area!! YMMV!
T.C.

[Crazcnuk]

I'm just not sure what those o-rings are supposed to do...

As you mentioned there is no pressure there, the sleeves are locked in place by the cylinder head bolted on top.

The old o-rings on this one were really soft, almost melted by the gasket remover I used. I have the ones that came with my gasket set, but they are on the other barrels I tried to use originally.

I don't have any Yamabond, or anywhere here to get any. I do have loctite high temp gasket maker.

[3Phase]

I'm just not sure what those o-rings are supposed to do...

As you mentioned there is no pressure there, the sleeves are locked in place by the cylinder head bolted on top.

The cylinder sleeves are cast iron and the engine case is aluminum. The expansion and contraction rate is significantly different between the two so it's difficult to get a gasket to make a reliable seal. If the piston rings are in good shape there isn't any real pressure at the cylinder bases but there is probably at quart of engine oil in a air/oil mist being hammered around at high velocity by the crankshaft.

Without the o-rings in place, oil will be forced up around the cylinder bases and fill the empty o-ring groove, then wick through the base gasket.

The old o-rings on this one were really soft, almost melted by the gasket remover I used. I have the ones that came with my gasket set, but they are on the other barrels I tried to use originally.

I don't have any Yamabond, or anywhere here to get any. I do have loctite high temp gasket maker.

High-temp Loctite would work. They used Viton o-rings because they're durable and it's faster and easier to install o-rings in a shop or on an assembly line. You'll have to clean the o-ring grooves with acetone or some other cleaner that removes any trace of oil and won't leave any residue. Lay a narrow, gapless, bead of Loctite that's a little larger than the diameter of the original o-ring around each cylinder base and wait for it to set up before seating the jugs and tightening down the cylinder head.

Whatever you do -- be careful!


Regards,

Scott

[Crazcnuk]

I just took the block off and put the darn o-rings in.

I can't see oil wicking through the gasket, if it could do that, the gasket would be pretty much useless.

The iron/aluminum thing plays in it I am sure. However, the iron sleeves are kept very hot by the combustion process, while the aluminum is being cooled by airflow. This should keep the aluminum pretty tight on the sleeves.

My thinking is that the space between the sleeves and the block will change at certain times, warm-up, cool-down, etc, and oil may be able to get in between, if the orings aren't there. Any oil in the space in between would be prone to baking and may build up after a while causing issues later on?

[3Phase]

I just took the block off and put the darn o-rings in.

Nothing broke! Yay! <wiping forehead>

I can't see oil wicking through the gasket, if it could do that, the gasket would be pretty much useless.

The iron/aluminum thing plays in it I am sure. However, the iron sleeves are kept very hot by the combustion process, while the aluminum is being cooled by airflow. This should keep the aluminum pretty tight on the sleeves.

My thinking is that the space between the sleeves and the block will change at certain times, warm-up, cool-down, etc, and oil may be able to get in between, if the orings aren't there. Any oil in the space in between would be prone to baking and may build up after a while causing issues later on?

base+gasket+leak+evo


Big Boys do it without o-rings




Regards,

Scott

[Crazcnuk]

A lot easier installing the barrels when you still have the chamfer in the bottom of the sleeves, AND your not fighting the flu at the same time.

These gaskets are in a constant oil bath, all the time.

Oh, and you can't compare these to Hardleys....ewwww

[3Phase]

A lot easier installing the barrels when you still have the chamfer in the bottom of the sleeves, AND your not fighting the flu at the same time.

Seriously, I felt bad after reading what happened.

These gaskets are in a constant oil bath, all the time.

Oh, and you can't compare these to Hardleys....ewwww

Harley-Davidson, Yamaha, Suzuki, Honda, Kawasaki, Victory, Volkswagon, Porsche, Corvair, Ford, Pratt&Whitney, Rolls-Royce, whomever. It's an engineering problem not specific to any make, model, manufacturer or number of cylinders but it's easier to illustrate it with one cylinder!


Now it's time for me to flush the neutralizer out of the gas tank and see how it looks.


Regards,

Scott

[Crazcnuk]

"Harley-Davidson, Yamaha, Suzuki, Honda, Kawasaki, Victory, Volkswagon, Porsche, Corvair, Ford, Pratt&Whitney, Rolls-Royce, whomever. It's an engineering problem not specific to any make, model, manufacturer or number of cylinders but it's easier to illustrate it with one cylinder!"


So how do you explain all the other paper gaskets that are in oil, like the clutch cover? Not just subject to oil spalsh but actually living in oil all the time.

[3Phase]

So how do you explain all the other paper gaskets that are in oil, like the clutch cover? Not just subject to oil spalsh but actually living in oil all the time.

The engine case, base gasket, o-rings, cylinders, cylinder head gasket and the cylinder head are like a Slinky or a stack of dishes in a spring-loaded restaurant plate dispenser. The grade of steel in the cylinder head bolts determines the quality and strength of the spring/Slinky and the torque determines the amount of stretch and preload.

Every time a cylinder fires the cylinder head tries to explode upward, slightly stretching the springs/cylinder head bolts as it tries to go up and the bolts relax when it comes back down. As each cylinder fires, it sets up a rythm: the cylinder head, gaskets, o-rings, cylinders and the case all fractionally relax and try to separate and come back together thousands of times per second. If there were no locating pins the gaskets would get scrubbed to oblivion as the head and cylinders wandered around one another.

The clutch cover and its oil-soaked friends do try to twist and move around but they are not subjected to the same type of explosive, cyclic loading. The small locating pins and bolts are sufficient to keep the covers in place and the oil inside the engine.


Regards,

Scott

[Crazcnuk]

Cool, kind of nice to be able to visualize the processes.

I was going to put Form'a'Gasket Copper on that base gasket. Good idea?

We take a lot of this stuff for granted.

[3Phase]

I was going to put Form'a'Gasket Copper on that base gasket. Good idea?

We take a lot of this stuff for granted.

Up to you, really. I used #2 Permatex on the base gasket on mine. It'll probably require a jackhammer to loosen the jugs they ever have to be pulled again.

Yes, we take a lot of things for granted.


Regards,

Scott