Pat McPherson

Having this discussion with a couple of guys at work...
Assuming the same induction, heads, and valve-train.
Would a 454 that was bored and stroked to 496 make more low end torque than a stock 502?
Are there any advantages of a stroker 496 vs. a stock 502 for a boat application?
Thanks, Patrick

H2Xmark

good question, I would think that in a low to moderate horsepower engine it would be very minuscule, low rpm engine you would want longer stroke for better torque, high rpm engine a bigger bore and shorter stroke would help, maybe someone will come up with a good answer to this, connecting rod length also makes a difference on this too

mcollinstn

Short answer - the stroker motor should make more torque at speeds under 2500 rpm (assuming all other factors such as compression ratio, camshaft, carb size, etc remains constant).

4.25 bore combined with the valve sizes necessary for 500hp, you end up with the flow path from the valves being cramped by the bore surface itself. The 4.57 bore of a 502 automatically provides for a more efficient flow path.

Which is better for a boat?
In reality there are too many variables to consider, especially when you factor the different types of boats into it.

force 320

At this time you have 496 posts, I would go with IT

cuda

Now there's an eye for detail!

deboatmon

Would not the answer to that question depend on the bore to stroke ratio ? If they were the same as a standard 502 and all other things were equal or similar I would think the performance characteristics would have to be very similar. Changing the bore to stroke ratio would change torque curves and other things. But, depending on exactly which block you have it's not likely that you can attain the same bore in a 454 block as in a 502 block.

Ric232

Ken,

Yes, it would depend, but the standard 454 to 496 conversion consists of a 0.060" overbore and stroke increase from 4.00" to 4.25".

Pat McPherson

Hey Guys,
That is quite a omen that I would ask this question with my 496th post.
I really don't have any plans to turn my 454 into a 496 stroker at this point, maybe I should...
The question just came up in a discussion among the boys.
Thanks for the answers.

dyno

If you are going to spend money on cranks why not get the added CI ???? If you dont need cranks then stay with a 454.....you can convert your 454 to 496 way cheaper than buying the 502 outright. Or If you have a buyer for the 454's the choice is yours....rotating assemblies are $2k for Eagle stuff......

Big Block Billy

The cost of and even being able to get a 502 block for a reasonable price and using a 4" stroke crank and stock (JE) pistons is probably more than boring a 454 and using a kit to make a 496. There are many options, of which all parts should be balanced. I was going to build a 496 with a 4.25 stroke Lunati crank and some milled down forged pistons With resized rods and arp bolts I actually have all parts. If you could get a 502 block you could put a 4.25 crank in it and make the bore 4.5" and have a 540. I really feel that the way to go is availiable on e-bay in the form of a brand new 540 Dart marine block, eagle crank and rods, Basically a full short block for $3899 from Dynoflo. Try to buy the parts seperately and realize the cost. A 572 to 598 avail for apx. the same price. This is what I'm going to start off with next season. All of these shortblocks come fully assembled and balanced to within 1 gram. Put your tin ,valvetrain, heads, and intake, etc on, and instant motor is what you have. Anyone need 454 mag parts?,...I should have just saved my money and got a bigger and better motor. Most people know the difference between the blocks, if not ,I'm sure there are many threads on here. BBB