Engine Bore Measurements.

I finally got my f-head torn down, after measuring all the bores to see how bad they are, I'm rather surprised to find what I think is a block that doesn't need bored. But i find this idea crazy for a 60+ year old engine so i wanted to make sure I'm understanding the specs right.

I measured all 4 cylinders on top, middle, and bottom, from side to side and front to back. all my measurements only range .002" ranging from 3.125 to 3.127". I've rechecked twice because I questioned the results. if I'm understanding the manual, tolerance is .005, so I should be able to use standard rings and pistons. Is this correct?

The motor isn't original to the jeep, numbers point towards a 54 build, but I don't see anything that would make me thought it was a rebuild, rather than just a junkyard motor.

 

If there is no ring Ridge or taper run it!
It might have sleeves

 

I'd at least give it a quick hone just to get a good finish on it..

 

Over the years I have come across a couple that were still standard bore in good enough shape to just need to be honed. Both of them were military engines in civilian Jeeps. Surplus engines were available up through the late 60s at least, Sears even sold them, so I suspect the two I encountered were those.

If the bores measured as described and are within tolerance, hone the cylinders and go with that.

 

Thanks guys, I think thats what I'll do, hone it and move on. I just couldn't wrap my head around the idea that a 60+ year old engine could still be a standard bore with no signs of a rebuild. I thought for sure I had to be missing something.

 

Someone gave me a L134 at the Willys Reunion before last, and when I tore it done I found it was still standard bore, though there was some rust in the cylinders which will require it to be bored. So there are some still out there that haven't seen multiple rebuilds, and this L134 is 70+ years old.

Consider yourself lucky.