Does the 502 415hp have Cast Internals?
 

I have searched the internet and can not find my answer. I found a pair of new ‘Base 502 415HP’ engines at a reasonable price. (Actually everyone that sells them are pretty close in price)

I am trying to decide to build a pair of 496’s or buy crate. I am leaning to building, because I can put forged everything in and some nice heads for the same price.

I can tell you from experience all 502 mercruisers come from the factory with forged crank, rods, and pistons, if its from an aftermarket rebuilder who knows what they will use

mrfixxall
 

their all forged! Eagle engines has new 502 415 hp for 5600.00

call victoy marine. He has brand new from merc ones on the shelf with tins for a fair price.

He advertises here on the board.

Yes, they are all forged internals.

Looks like I will have to do some more research then:drink:

Why does it only make 415hp:rolleyes:

That is the way the mpi is set up from the factory. The original carbed 503 was only 385 I think.

The exhaust on a factory 502mpi is very restrictive. That is all the power you are going to get out of it.

If you upgrade to a nice header, then there is no reason you can't do a cam swap, and a few other things and get around 550-600HP out of those engines.

A compresion increase wouldn't hurt those things either.

If you want a recipie for a nice 525hp 496, I just built 2 of them and they dynoed very well.

Just a reminder Merc rates them at 415HP @prop shaft. Motor itself puts out more than that.

How about those 496 recipe's!! Weighing options of building 496's or 468's from 454 mags.

My 502,415 HORSE block was junk i am going with a dart 540 and header and new cam shaft but i am told i am limited on horse power because of 502 MPI.

How much HP do you want? The 502 Mag MPI can make 550 easy HP.
I have a friend who did a 502 in a 272 & it runs really well. Close to 70 if not 70 I think.

That is true about the intake. It is a limiting factor in making hp. What is wrong with the block that is junk? I have seen some really bad blocks that could be saved. About the only thing that is usually non-repairable is a freeze crack.
Even though the intake is a hp killer, it will still make 550+ hp NA with a little work. It all depends on how much hp you want to make as to if the intake will work for you.
Eddie

502MPI/EFI are good candidates for prochargers. I had a Baja 272 502 EFI with procharger ran 78 best speed, 76 with a load.

Im going to do a 502 crate engine this winter 415hp and was wondering what the best intake, carb set up would be. I already have brandnew eddie marine headers and long risers. looking for 450-475. Anyway to do this without touching heads, dont want to pull heads off a brand new motor.

Call Bob Madero. his handle i rmbuilder here n OSO.

Tell him what yuo are doing and he will send you cam to install. No reason you can't get 550 out of that engine and those heads. regular 800 carb and a single plane intake of some sort. you will need to change the rocker studs and add roller rockers. Other than that, it is pretty simple. I am finishing that exact thing right now for a customer.

Good luck