Piston identification

[OEM1984CJ7]

I bought the AMC 304 I have from an older man that had it built about a year ago and never started it. I pulled the oil pan off to check the cylinder walls and they look good but wanting to try and find out how far it was bored. Can I tell by the new pistons how far? There are 4 numbers stamped on the inside lip of the bottom of the piston 8890 in block style lettering but I don't see any other markings. He said he thought .30 over but not sure. Any way to measure the cylinders without special tools?

thanks.

 

[jasonmark1993]

You'll need a micrometer to get within .030".

Generally the pistons have the size stamped on top, so maybe you can google the numbers you got off the bottom and find something that way?

Are you just curious or is there some reason you want to know?

 

[Casuall454]

Preform a mic on the cylinder wall, attached is a engine bore and stroke chart.

Hope this help you out.

 

[CJ]

Umm... I take it that if you pulled the pan to check the bore diam. the heads are still on. You can't use a bore gauge or a caliper if the piston / rod is in the way. I can't remember if the piston skirt is exposed on the down stroke - but if it is - just mic it out. Unfortunately you will need a 3" - 4" mic or a good set of calipers.

 

[OEM1984CJ7]

I believe I can measure one of the piston skirts sticking out. Its really no big deal, main thing I wanted to make sure the motor was built and in good shape before starting. I will try to measure and let you know what I find out. I just didn't know if you could tell by numbers or not.

 

[tarry99]

Not so sure there is enough room to get a mike or caliper up there. Maybe some outside dividers?

 

[jasonmark1993]

I tried searching with that number but came up empty.

Did see one link with a set of AMC 304 pistons but it listed all oversizes available.