Mis-matched cylinder heights

[1980SC]

I just discovered my 3.0L has some funkiness. Five of my cylinders are height group 6, while one is height group 5.

The five heads over the taller cylinders have been decked, while the head over the shorter cylinder appears untouched.

I know you are supposed to have all the cylinders on one bank in the same height group, but I guess this concoction creates the same deck heights.

I'm not rebuilding this engine now, but I'd like to plan for the future. If I buy a new set of P&C, I should be able to deck that last head, and it should be okay? Right?

I first thought the engine now has higher compression than stock, but I guess it's just like a stock engine that came with cylinders in height group 5.

Any thoughts? Do I have this figured correctly?

-Rob
1980SC euro

[Wayne 962]

When you send the heads out to be machined, they should all come back exactly the same. So, if you use a new cylinder set, then you should indeed be fine...

-Wayne

[1980SC]

Thanks Wayne.

I also see now that I have flat top pistons with a very shallow valve pocket.

Wish I knew what the compression ratio was...

-Rob
1980sc

[350HP930]

This is not a very hard thing to do.

I'm sure Wayne's book probably has some information on how to measure your chambers and cylinders and do the basic math.

I have been too busy to order it yet for myself so someone else will have to let us know if I am correct.

[Wayne 962]

Actually, that's detailed in Bruce's book, so I didn't duplicate it...

-Wayne