Hello from Germany

[cycleguy55]

Originally Posted by Max Power

I think that this is the place for very good engine advice.

I have a 351W with a roller cam and ported Performer RPM heads that makes 355 rwhp behind a c6 tranny.

Here are the specs. The heads originally had 170 cc intake runners but after porting, they have either 190 or 195. I don’t remember exactly. they also upgraded the valves to 2.02 on the intake

My heads flow this

lift. intake. exhaust
100. 79. 61
200. 162. 121
300. 180. 168
400. 241 178
500. 264. 196
600. 275. 205

My current cam is a hydraulic roller (std base circle) with 236/240 dur at .050 and 540 of lift on the intake and 560 on the exhaust on a 108 LSA

I have an air gap intake, wide ratio gearing, 3.73 rear gears and a 3000 stall converter.

so I am now ready to stroke to a 408. I can either get new heads or electric power steering but not both. I NEED the power steering so I am going to keep my current heads for now. I have seen that enginefactory.com sells a 475 hp 408W using performer rpm heads (the 190 cc intake runner version) and an off the shelf comp cams XE roller.

Comp has suggested a cam for me to use in this set up with the following specs.

hyd. roller with 242/248 dur at .050 with 584/579 lift on a 108 lsa.

can anybody help me understand what the curve would look like? I don’t want a car that is a dyno queen that makes peak hp at a high rpm. I want something like the 408 that engine masters built with the 165 afrs that had tons of torque across the board. I am more of a bottom of the page than a top of the page guy.

If I can get closer to 400 hp at the wheels than I am now, I would be thrilled. Maybe better heads when the money allows but not in the cards for now. Can you guys opine what you think the power curve on a 408 with these heads and cam might look like? thanks.

You currently have 1.011 RWHP/cu in. All things being equal, increasing your displacement to 408 CID will give you 412.6 RWHP. All things aren't equal, of course, but even with your existing heads and cam you'll be very close to 400 RWHP. If that's not sufficient you can easily change cam and/or heads at a later date, as long as you have sufficient valve to piston clearance - which you should probably check and measure when putting in the stroker kit.

As noted by olddog your torque curve will shift to a lower RPM, so it seems you may well meet both torque and RWHP goals merely by increasing displacement. Go ahead with the power steering.

[Max Power]

Originally Posted by cycleguy55

You currently have 1.011 RWHP/cu in. All things being equal, increasing your displacement to 408 CID will give you 412.6 RWHP. All things aren't equal, of course, but even with your existing heads and cam you'll be very close to 400 RWHP. If that's not sufficient you can easily change cam and/or heads at a later date, as long as you have sufficient valve to piston clearance - which you should probably check and measure when putting in the stroker kit.

As noted by olddog your torque curve will shift to a lower RPM, so it seems you may well meet both torque and RWHP goals merely by increasing displacement. Go ahead with the power steering.

thanks for the tips. I guess I could up the stroke and see how scary the car is after and then decide whether to get a new cam.