Hey all,

So I'm rebuilding my 302 (mild rebuild, just intake, cam, exhaust) and have my block all torn down and am ready for the machine shop. I planned on taking some measurements before I send it out in order to avoid unnecessary machining, like checking my head and deck for flatness and bore diameter/shape. (I have a buddy who is a machinist) But upon inspection, the block looks to be in great shape and want to know from you guys if this is a good idea or to just send it in. (Block is from a 94 mustang with 30k miles, pulled after oil pump failure fried the bearings). What do you guys think? (Note that there is glare on the bores from oil, its not wear.

 

So without a response I went ahead and got my buddy over here to take some measurements. I looked at purchasing mics and dial indicator, but for decent tools I would have spent more than I was looking to save by avoiding unnecessary machining costs. Plus this guy has been an industrial machinist for decades and brought his personal tools.

The Crank:
Haynes listed connecting rod journals between 2.1228-2.1236

We measured 2.123 Assuming the crank was made correctly and not over-sized, I now know that it is at least within the wear limits. The larger outside diameter the less suspected wear. Check

Allowable out of round is 0.0006 per linear inch. My journals varied in roundness about 1 notch on the dial indicator, which is less than negligible.

Main bearing journals should be 2.249-2.2482. I was at no less than 2.2482

The block:
Bores are to be 4.0004-4.0048 Mine were right in the middle at 4.002
and less than 0.001 our of round. Good sign.

I skipped measuring the main bearing inside diameters because by previous owner has been a low mileage stock engine, and the main bearings showed minimal wear.

Head warpage limit is ).006 overall

With a machinist flat bar (his weighted 20#!) and feeler gauges we verified deck flatness across the cylinders middle, inside and out then across each bore left and right. I was able to barey get the smallest feeler 0.005 under the bar in a few spots, so is within limits.





In conclusion the block appears to be in great shape. I will have everything hot tanked and magnafluxed. I will have the machine shop verify but should be able to get away with just a bore hone, cam bearing install, and crank polish.

I'll let you all know how it goes!