Expected HP for stroker motor?

[wp29p4a]

What would be a ball park estimate on horse power and RPM's expected if someone were to take a 400 ci hp engine and stroke it to 500 ci, with .540" lift on the cam? Single 800cfm carb. Stock ratings are 250HP @4800 rpm's

I was curious if this type of performance upgrade would be a 100 hp increase or more?

[DynoDave]

Not sure how to home in on an accurate answer here.

What heads are you planning to use? Intake?

Do you know what you final static compression ratio and dynamic compression ration will be? Reusing a stock lower end (Pistons down in the hole?)?

Headers and exhaust?

You mentioned cam lift, but no other data. A quick search on Summit shows me two Comp Cams (for example) both featuring lift in the .540 range, but one is 286/294 (advertised) duration (power band from 2500-6200) and the other is 292/300 (advertised) duration (power band from 2800-6400). You'll probably want some better heads to take advantage of those cams, or at least some reworked stockers. Cams in this range usually are recommend with more rear gear, a higher stall speed converter to get you into their power band at launch), an external trans cooler to deal with the extra heat from the higher stall converter, and often times more compression. Cam can also "behave" a little bigger in a small cube engine (think 318) or a little smaller when feeding a larger cube engine. So lots of variables.

With the proper supporting parts, you could easily make more than 350 horse. Without those supporting parts, I'm not sure where you'd land. Indy Cylinder Head has several 500 cube big blocks in the 500+ horse range with their aluminum heads and other components.

[wp29p4a]

I was trying to keep it simple, not worried about accurate, just ball park. It has stock 400ci hp heads. The stroker kit came with new pistons, rods,,,Well,,,everything. Everything except the cast iron block, heads, intake and exhaust are new. It has 2.5" exhaust out the back, stock hp exhaust manifolds, with a little port matching.

It's been done and in the car for 10 years, I'm just starting to drive it now to break it in and get everything adjusted. Now that I have almost everything working perfectly, it is amazing to drive. It feels like twice the horse power I started with. It has way more than enough power, even at 5000' elevation, to bark the tires hard going into 2nd gear, and drifting is not a problem.

[DynoDave]

Gotcha. Sounds like a sweet engine. I would guess you easily have an extra 100 horse, and a lot more torque to get that car moving. Whose stroker kit did you use?

[wp29p4a]

It was a company called Speed O motive, in So. California. It's a 4340 steel crank with Keith Black pistons.