PDA

View Full Version : Help, which intake manifold?



sharp67
11-03-2006, 06:07 PM
My engine is almost complete. Im having a hard time choosing the correct manifold. Im being told to go a couple of different directions. I value the opinions and knowledge of many of the members here so I thought I would throw it out there for some feedback. Help. The engine in question is a 383 sb Chevy. Scat forged superlight crank, scat q-light rods, srp flat top pistons. Im running a zero deck, .039 thick head gasket, the new afr 195 heads with a 75cc combustion chamber. the pistons have 5cc valve reliefs. the cam im using is comp cams hydrolic roller with pro magnum roller hyd lifters. 12-432-8. 510/520 lift, 230 236 duration at .05, 110 lsa, intake open 35 close 67, exhaust open 78 close 30. I belive I will be running appx 9.75:1 compression and an effective (dynamic) compression ratio of about 7.74.1.52 ratio pro magnum rockers. tko 600 trans, rear ratio is currently 3.08 but that will probably be changed. top revs will probably be about 6800. The vehicle will be street driven, however im also planning to use it in the silver state classic. so what intake manifold should I use? probably going to run an 850 mech 2nds. Im thinking performer rpm air gap or victor jr. Im concerned that if I use the perf rpm alot of the torque down low will just get burned off because it wont stick. So by going to victor jr I ll move the power up a bit. Thoughts? any input or thoughts on the combination? any help would be greatly appreciated. Thanks Jay.

pdq67
11-04-2006, 02:44 PM
I figure a Stealth should take you up above that rpm. As will both the RPM and 300-36 Holley!! AND I personally like the "muscular" look of the old 300-36!!

And right, a single plane will drop a bit of lower rpm T to save the tires, but it will also pick it back up some in the upper rpm ranges, but who run's in the upper rpm ranges all that much??

And I put a Holley Strip Dom. single plane on my 496 b/c of just your reasoning too!

pdq67

sharp67
11-04-2006, 04:55 PM
do you think the bottom end loss will damage the out of the hole. I figured it might a little but not drastic. what do you think? I was also looking at the motown single plane. On the world products site says this manifold will work great for both low and high end. any thoughts about this one? Im also looking at the weiand team g 7530. it says its good for 2800 to 7200 rpm on summit racings site?

Scott Parkhurst
11-07-2006, 09:11 AM
My engine is pretty close to yours with a couple exceptions (slightly bigger heads, slightly bigger cam, solid roller)...but I went with a dual-plane Air Gap with a Super Sucker 4-into-1 spacer, and I couldn't be happier with it.

Here's the whole story:
http://www.compcams.com/Community/Articles/Details.asp?ID=1945664039

~SP~

6'9"Witha69
11-07-2006, 09:18 AM
I have used an RPM manifold with a 1/2" - 1" spacer for over 6 years on a 500+hp 383. I shift at ~6200. No real need to go much above that even though there is still a little left when she shifts.

Johnny Blaze
11-07-2006, 10:12 AM
I agree with the Air gap and super sucker spacer!

Lowend
11-07-2006, 12:05 PM
I would be looking at the factory Port matched Vic Jr (PN 2900). You will loose a little bit of off the line torque, but that motor is going to make WAY more than the tires can put down anyways.
The extra plentum volume will serve you well not to mention the ports will be better matched to your heads