IrocManiac

Ok my friend just dropped a new motor in his truck it is a 350 with the 90 model 350 truck heads. We are converting it to Carb and he picked up a Holly 600 and an Edelbrock Performer manifold. Aproximately how high should you put the redline on this motor to get the most effective times. I think about 6,000 rpm is about what they carb and manifold could handle right now and still be effecient. Then if we ported and polished the manifold does 6,500 sound about right???



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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

FastBroker

You should use Performer RPM manifold if you are looking for high rpm HP/torque. You didn't mention a cam and stuff and if you need to be emmissions legal. Performer only really good to 5000rpm, pushing past there is possible, but manifold won't produce power up there like an RPM manifold (or equiv)

Polecat

true....I would be safe to say that 5000 is the highest I would pull that motor too.

Good luck!

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350 4 bolt main, Speed-O-Motive 383 stroker kit, re-sized rods ground for clearance,Hypereutectic pistons,9.8:1 compression,HPC Coated RPM intake, Speed Demon 750 cfm carb,World Products Sportsman II heads,2.02/1.60 valves, K-Motion springs, Comp Cam 1.6 roller rockers, Lunati adv.292/230@.050 with .512 lift,Crane pushrods,Proform HEI and MSD6A box,HPC coated 1 5/8 headers, 2.5" exhaust with 40 series mufflers,TH350 with B&M 3000 stall, Powertrax NoSlip Locker, 4.11 gears.

Jester

We can't really tell you the mechanical redline of the motor...we didn't build it. But the Performer will not pull hard past 5000, if yo wanna go higher you'll have to at least upgrade your induction.

ChrisFormula355

Manifold type really has LITTLE to do with the actual safe redline of your motor. That depends on your valvetrain, bottom end, rotating assembly, CR, cam specs, ect.....Just "porting" the intake won't do **** for your redline, but if you plan on BUILDING a motor to rev over 6 grand, the only way to go is Super Victor single plane or a similar 180 degree style intake. Dual planes can only do so much at high RPMs. Its been proven on the dyno time and time again that a Super Victor intake is worth a good 15-20HP over an RPM above 6 grand on a healthy small block, hence the reason I'm swapping on a Super Victor intake real soon
Chris

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Nice car: 1988 Formula 355, mildly ported/polished Vortec heads, RPM intake, Comp Cams Extreme 268 cam, 650 Holley double pumper, 5-speed/3.73 Richmond gears, and N02 on the way
Old 1/4mile: 13.5@105mph

Evil Car: 78 Pontiac Grand Prix, 500inch caddy motor, edlebrock intake, 600 holley, B@M TH350 tranny, 16inch Iroc-Z rims, blacked out chrome, soon to run 10's...

There's no replacement for displacement!

FastBroker

Yeah, but remember, the low-end will suffer more than is gained with a single-plane manifold. Will suffer a lot, too and make stop sign driving more intolerable than any dual plane intake. If you want PURE power, single plane is obviously the way to go. But for my money and driveability, I feel that an RPM manifold with properly gasket-matched heads is FAR better for total performance. The dual plane will get out of the hole a little quicker because of better low-end, too. And remember, when they got that (slight) HP/Torque difference, they were probably tweaking the setups several times on a dyno to get it right, which we can never do. without tuning perfectly, you could actually have more power than w/single plane.

I have used several single planes on peoples cars... Some a VERY happy, some are very SAD and most are in between. You have to trust me that with a carb, bigger cam and single plane, your low-end will be hurt compard to identical setup w/RPM type manifold. If you daily drive more than you race/go fast, use the dual-plane, please... With only a 268 Comp Cam and Vortec heads, you will probably not gain much. Get a bigger cam if you are going to use the single plane and kiss low-end goodbye, especially with a DP carb.

[This message has been edited by FastBroker (edited September 21, 2000).]

IrocManiac

Hey guys thanks for the reply. I know what the mechanical redline of the truck is capable of I just wondered what you guys would set the shiftpoints at with that carb and manifold setup. It can safely rev to about 6000rpm mechanically but because of breathing issues and your help witht he carb and manifold we are probably going to port and polish the manifold and gaskets and set the redline to 5250 or 5500 and experiment with that. Any more info would be greatly appreciated guys. THANKS!!!

------------------
TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

FastBroker

If those '90model heads are "swirl-port", I would get some other heads!. Swirl-ports don't like much advance and can't rev worth a darn. Even ported, they are terrible!!!!! Ask around...

ChrisFormula355

Thats just the problem though. I can SPARE some low end right now, and along with the intake I shoulda said that I would be getting a bigger cam and porting the heads if time allows. I highly doubt I'll be lacking in torque even with the bigger cam, and single plane intake, right now it will easily smoke the tires in 1st 2nd and 3rd with 245 Eagle GS-C F1's and a working posi. THe extreme energy series comp cams make LOADS of torque, despite their high durations.
Chris

EDIT: I shoulda said 360 degree, not 180 degree intake in my first post, a 180 would be a dual plane,

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Nice car: 1988 Formula 355, mildly ported/polished Vortec heads, RPM intake, Comp Cams Extreme 268 cam, 650 Holley double pumper, 5-speed/3.73 Richmond gears, and N02 on the way
Old 1/4mile: 13.5@105mph

Evil Car: 78 Pontiac Grand Prix, 500inch caddy motor, edlebrock intake, 600 holley, B@M TH350 tranny, 16inch Iroc-Z rims, blacked out chrome, soon to run 10's...

There's no replacement for displacement!

FastBroker

I'm with ya' W/bigger cam and porting/gasket matching, you will be ok AND you already know low-end will suffer a little. You should be happy w/what you get.