So iam building a 383 stroker motor , it has a brand new set of gm performance vortec heads and the 350 block has been freshly bored and honed, i went with a High Energy 268 Comp Camp, Magnum Roller Rocker tips, Speed Pro Flat Top Pistons and ill be getting a performer rpm intake how much power do you think this motor will crank out at the tires? iam hoping its a nice and high number!! those vortec heads should really help things flow and the reason i got a 268 comp cam is because i thought i was building a 350 until i found out my crank would need some work i stepped up to a brand new scat cast crank with forged i beam rods and flat top pistons - nice big kit! but lets hear some estimates on horse and torque specs - iam more of a body man than a mechanic!!

 

You're using a carb? If the cam is really streetable and the idle and low speed driveability is well behaved maybe 300 RWHP after a lot of fiddling, or premium pump gas, maybe with a bit of octance enhancer. If you go for glory and driveability be damned, maybe 335.

 

woah 335 thats it? i was hoping 370-400 would be freakin nice but how do you figure 335 anyways just curious its a respectable estimate i just would like to know the major things that come into play when you estimate horsepower

 

Hey here are the specs to the cam its fairly mild but i was told thats good becasue then i dont need a stall converter, and it stays aligned with my rpm range 2000-5500 it keeps my max peak at just the right point i guess??
CAM SPECS--INT---EXH
ADV DUR: 268 268
DUR @ .050: 218218
Lobe Sep: 110.0
Valve Lift:.454 .454
I dont know if that will help or anything but those are the specs and i take it its fairly mild but i was reading thatthe Xtreme Energy 268 just a tad bit higher lift pounds alot almost375 horse and 410 torque in an almost identical build ..?

 

I would say around 350 hp..or more..

 

No body will know until you have it together and on the dyno. My estimate was just gut feel and it depends a lot on my definition of "driveability" and that I've seen few carburated cars (including many stock muscle cars of the 70s) that meet modern driveability standards (i.e., perfect under all conditions) -- in spite of the carb I think youcould have 300 RWHP (equivalent to about 350 factory rating or a 365-375 HP crate engine) with near perfect daily driveability (matching a modern fuel injected car under all conditions except warm up), or about 330 (equivalent to about 385 factory) with okay driveability but some low RPM/hot weather driveability issues. You have an extreme cam and so I expect you will get more HP, but end up with something a bit tempermental (that's my experience with carbs).

Good luck

 

I've heard that the Desktop Dyno program is fairly accurate. I had a buddy that built a 347 Ford and ran the program and had the engine dyno'd and was within 10%. I didn't think that was too bad. Of course, the data you get out is only as good as that you put in.