502 or 454 how to tell ?
 

I've come across a ski boat with a big block in it and the owner said he's not sure what the engine is. Is there a way to tell just by looking at it?

Down on the side of the block about in the middle will be 7.4 if it is a 454 or 8.2 if it is a 502.
Eddie

Thanks,I'll check that.
Bill

I looked at the block and no 7.4 or 8.2. It's a gen4 bowtie, in the back corner is 445 high performance. on the right side is the chevy synbol. The owner said it's a 454 and another guy who worked on it 10 years ago said it's a 502. Just looking for some info.
thanks

My gen IV 502 has the bowtie also but that just shows it's a GM performance " bowtie " block i think it could be either a 454 or 502 still . the dealer i got the boat from had it listed as a 454 , got her home stood on my head to see the merc s/n tag to find it was a 502

look for the casting numbers and go here http://www.mortec.com/

this site is an excellent source of info on heads and blocks

BBC numbers http://www.mortec.com/bbc.htm

My 502 is this one

10051107...454...............4-bolt, Bowtie, MkIV, 9.8" deck, siamesed bores, 4.25" semi-finished bores, can be bored to 4.50"

454 has a fuel pump mount and the 502 does not.

The markIV 502 has a fuel pump mount!!

that depends on the engine generation

If some body bored the block ,,,it could be anything !!!

They where stock 454's and then what ever u made them !!!

Chevy gen 4 block !!

Mine is a 510 ci !!! so basically 8.4 liter !!

either way ,,bowtie gen 4 is ok ,,because u can bore out to 4.600 + !!!
Stock is i think was 4.350 or so ?!
Plenty of mat. to work with !! In case it ever break's.

I think the biggest u can go on a Gen 4 bowtie short deck (9.800) is 598 CI !!!!:eek:

Man, I know less than I thought....time for me to quit talking.

Thanks for all the input ! I ran the numbers and its a Gen IV 502. All my stuff is gen VI so I didnt get it. If any one is looking for this type let me know. It was a crate motor and has never been apart,I got it started and it ran fine. The boat is junk. It has trans too.
Thanks again
Bill:ernaehrung004:

You can run all your gen 6 accessories. Just install a fuel pump block off plate. The gen 6 engine does have some improvements to the castings affecting oiling and cylinder cooling I believe.

Ill look into this a little more.I just hate to pass up a good deal on a big block. I think you talked me into it !! Yep Thanks