Cylinder group height's??

[RetroSC]

Not knowing cylinder's had group height's I purchased two used 2.0 biral cylinder's. It appears these are group height 6 where my four original are group 5. Can't determine any measured differences between the set's, so what exactly do the group height's mean and can I mix the 6's with the 5's?

I'm guessing the differences are incredibly small, but may cause a problem with even torque across the cam towers if the group's are not all the same. Are 5's and 6's close enough to not worry about?

[ChrisBennet]

I think 6's are higher than 5's. If so, I'd have the 6's machined to match the height of the 5's you already have. I wouldn't mix them as is.
-Chris

[Don Settergren]

Couldn't you just machine one 6 down to the size of the 5 and put then on one side of the engine? That'll save you a couple of bucks...

[Jos]

For your car (upto 1972) the height of the group 6 cilinders is 82.225 to 82.250 mm. The group 5 are exactly .225 mm lower (with the same deviation). I would take of .225 mm (almost a 1/100th of an inch) off from the bottom (surface that meets the crankcase) to prevent problems with the seal between the cilinder and the cilinder head. Or buy a third 'group 6 cilinder' and keep these on one side of the engine.

[Henry Schmidt]

Any good machine shop can match your mismatched set. If they machine all six, you can achieve a tolerance closer than factory spec. Oversided base gaskets can make up the difference for the material removed.

[RetroSC]

Thanks for the info everyone, I'm on the right track now.