Cylinder Spacers

[jimbrandberg]

I've been philosophically opposed to cylinder spacers to use small cylinder tops in large head registers but maybe I'm wrong. Racers did it all the time to use full fin cylinders and 140 heads together.
It came up now because I find myself with '60 full fin cylinders bored for new EM .030 pistons only to find the '63 turbo heads have been opened up to accept '65 cylinders.
I do have another pair of '63 heads but have to wonder how many '63 turbo engines I want to put together.
I assume when using small cylinder tops in large registers you use large head gaskets and the spacers fit only against the outside diameter, not up against the head gasket surface? I seem to be getting in trouble when I assume.
Jim Brandberg
Isanti, MN
CorvairRepair.com

[66vairguy]

I've been philosophically opposed to cylinder spacers to use small cylinder tops in large head registers but maybe I'm wrong. Racers did it all the time to use full fin cylinders and 140 heads together.
It came up now because I find myself with '60 full fin cylinders bored for new EM .030 pistons only to find the '63 turbo heads have been opened up to accept '65 cylinders.
I do have another pair of '63 heads but have to wonder how many '63 turbo engines I want to put together.
I assume when using small cylinder tops in large registers you use large head gaskets and the spacers fit only against the outside diameter, not up against the head gasket surface? I seem to be getting in trouble when I assume.
Jim Brandberg
Isanti, MN
CorvairRepair.com

I do have one of the early 65 cylinders that came from the factory with the outside "band" or spacer. It was basically a 64 cylinder with the band to fit the 65 head. The band is ON TIGHT! AFAIK the 65 and newer style head gasket was used. When it comes to adding your own spacer/band I can't say what head gasket to use, but I assume the wider/later gasket must be used so it does not go off center in the head.

Just me, but I would not use a 0.030" bored cylinder on a turbo motor. Over the years folks have reported issues with cylinders bored 0.030" or greater on turbo engines. Just what I've read.

[Frank DuVal]

Yes, factory banded 64 cylinders to use with 65+ heads. Lon sold me some years ago, as he had run out of normal cylinders for a while to recondition.

Factory boost maybe OK, aftermarket high boost maybe not.

My 60 over cylinders, well..... . still haven't found an engine to build with them. Maybe a stock power 140 HP.

[Nashfan]

I ran .040" over 64 cylinders on my turbo at far higher than stock boost without issue. I later converted to the 65 and later style cylinders when it was convenient to do so, but that was for "extra" overkill. My recollection was approximately 18-20psi, although it was only for short hits of boost.

[joelsplace]

Definitely LM head gaskets. You will see the need when you lay one in the head. If they used EM head gaskets the spacer would have to sit proud on the cylinder enough to center the gasket without interfering with the crush.

[jimbrandberg]

The .030 cylinders I'm using are '60 full fin.

Steve Goodman told me the GM replacement cylinders for 65 and later were often '64 cylinders with a spacer pressed on. He said it was hard to tell if you didn't know to look for it. The picture I saw of Otto ones did not look deep enough to go the entire depth of the cylinder top.

Jim Brandberg
Isanti, MN
CorvairRepair.com

[Dennis66]

I have one of those jugs from an engine I did years ago. Didn't know about it at the time and thought it had been sleeved. "Who sleeves a replacable cylinder?" We bought another cylinder (it was the only one on the '65 Greenbrier that had the spacer. Dennis

[jimbrandberg]

I'd love to see a picture of a cylinder with a GM sleeve, and/or a picture of what an Otto spacer looks like on a cylinder and/or a picture of what hose clamp or other metal spacer looks like.

The person selling Otto spacers lately has 3... nothing's ever easy...

Jim Brandberg
Isanti, MN
CorvairRepair.com