Allan4

KAAMA, you are right on the 4.470 bore of a 502. A 509 is 4.500, or 0.30 oversized 502 (to get REALLY technical it is 4.466" and .034 over). By the way, can you explain bore notched to me. I am pretty sure I know what you are refering too, but I might be wrong. I'm trying to visualize it (how scaryis that!!??!!) Thanks.

mpjesa, do you know what kind of tq numbers the motor makes??

jpclear

Yep; I need to learn about "bore notching" too!! Who really knows, and where is some good reliable printed info. Or maybe a website or whatever!!?! Where can I get to basics on this ?? --- Jer

KAAMA

Call "JimV" he does this for several of his customers and has dyno'd a 454 with a bore notched block and with all components remaining the same he said he saw a 30hp/tq gain! You can call him. 616-735-0800

Also, Tinkerboater has done this for a lot of local offshore boaters. It's not a difficult procedure---you just have to do it correctly. I think JimV has some pictures on his homepage---I think.

jpclear

Thanks KAAMA; I'll head that way. --- Jer

KAAMA

Find JimV's name within this forum and click on "Profile" when his page pops up then click on his "hompage" address that he has listed. This will obviously take you to his homepage and then click on the word "tech tips" and a picture will pop up showing a bore notch job with some explaination underneath the picture. You have to know what you're looking for to see the bore notch job in the picture---it's right where the deck of the block and the cylinder bore meets. Regarding the flow of the intake valve, it's usually more crittical on the intake side of the bore but it can also be done on the exhaust side of the bore as well.

JimV just made a post in the "I want a little more power from my 572" thread here in the Technical Q & A section. Go find it and it and click on his PROFILE and it will take you where you need to go.

jpclear

Going there KAAMA. Thanks again!! --- Jer

Big Boys Toys

mpejsa,
Take your time and do the research there are a lot of options for you to consider.
One may be to price out a general motors crate motor 502.
The motor does come with steel crank, roller lifters and cam, one piece rear main seal, one piece oil pan gasket, and delivers around 450 Hp out of the box.
Post what you dicide to do.
Good Luck
Brian

Allan4

Thanks Kaama, I'll check it out in a few minutes.....

totalmp

This engine is not used. We are currently taking it down to inspect all components. Upon inspection, it will be reassembled w/ all new rings, bearings, etc. We are a reputable shop and are willing to work with anyone to build the engine that best fits their needs. Our main focus is reliable HP. We will be more than happy to provide references to those interested.

You are the consumer, feel free to ask anything you want, we won't be offended.

Thanks,

Steve

Elite Marine

What is the compression ratio?