Performer RPM ?

[Ole Blue 68]

Is anybody out there running an RPM Intake and Cam combo? If so, how do you like it and how is the idle? Rough for street use?

[Ole Blue 68]

Nobody's running this combo?

[Ole Blue 68]

Guess not... alright, here's the specs on it. Anyone care to weigh in on it?

Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-6,500 RPM
Intake Duration at 050 inch Lift: 234
Exhaust Duration at 050 inch Lift: 244
Duration at 050 inch Lift: 234 int./244 exh.
Advertised Intake Duration: 308
Advertised Exhaust Duration: 318
Advertised Duration: 308 int./318 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.510
Valve Lift with Factory Rocker Arm Ratio: 0.488 int./0.510 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash (in): 0.000
Exhaust Valve Lash (in): 0.000
Computer Controlled: No
Lifters Included: Yes
Lifter Style: Hydraulic flat tappet

[JAKES 68GMC]

ttt

[see ten]

I personaly run the performer on both of my trucks. I just thought that they were more suited to the RPM range I would be running.

[72MARIO]

I have the RPM intake on my 355 with the 327/350 Hp cam. It works great.

Not sure on the cam in that kit. Just make sure you have the power in the range where you will be driving most of the time. It's no good it your making 375 hp at 6000 when you cruize at 2000 and make 150 hp in that range.

[Ole Blue 68]

Well that was my concern since the performer's range is supposed to be idle to 5000 but I figured the rpm should be ok since its range starts at 1500 and even though I don't have a tach, I know i spend a lot more time at 1500 then i do at idle.

[72MARIO]

It's the cruize speed that matters you want the truck to have power starting around 800-1000 that way you have the bottom end power you most likely need.
Unless your using 4:11's and running in the 1/4 mile at 6500rpm, the Performer setup is better for the street. We all want to say we have a massive cam and 500 HP but at what RPM ? The key is getting the power in a range where it actually get's used.

All I have is the intake on my motor the cam is mainly what controlls what rpm the power is made. Low end power is best for economy and driveability.

[Ole Blue 68]

Good point Mario. The other thing I would be concerned about would be whether my 600cfm carb would be enough with that combo or would i need to bump up to a bigger carb.

[72MARIO]

500cfm is enough for a 400hp motor jetted correctly. A 600cfm will be fine. You can go bigger but it's not necessary. If you put in a huge cam (Which work great at high RPM that's what Race cars have them and sound that way)
You might need to increase the jet size.

[Ole Blue 68]

Yeah this is true. Well I reconsidered on that RPM cam and I'm going to go with the milder Performer cam instead. Thanks for the good info!

[MrC1]

You didn't say what size engine this is for.

Either way those duration figures are a bit stout. Normally big block truck engines run about 220* of duration and the SBs a little less. The lobe separation isn't bad, however.

I'd check out the Edelbrock dyno sheets for the different combos. Look carefully at the torque curves. You're going to want as much down low as possible with the flattest curve you can get.

You could also plot the combos in Dyno 2000 or something similar to get a better idea.

[Bowtie67]

The Edle cams are old school, go with a Comp Cam, Crane, Crower etc. the RPM cam unless you have some good CR it will run just OK, till I meet up with you at the light and leave you like you have an old Iron Duke 4CYL..

[Novaguy73]

Please post your combo in detail here include your compression ratio.

Both edelbrock cams are crap in all honesty ill give a reason why. With the RPM you have 308/318 degrees of advertised duration. You really need at least 11:1 maybe 12:1 compression for that to work worth a hoot. Then the .050 duration is only 234/244. That is a TERRIBLY slow ramp and you would be leaving alot of power to be had. If you want me to explain this in serious detail i can.

Call up a few major cam companies and get some responses on your combo. But i will guarentee you that youde be leaving TONS of torque and at least 20 hp and some gas mileage on the table by running an old ass Edelbrock cam.
Call Crane, cam motion, erson, bullet, crower, howard, isky. Actually i would call Lunati about their new Voodoo cams. Harold Brookshire designed them so you know they are good. He used to own Ultrdyne cams and designed comps HE line 20 yeas ago. Call Lunati for sure....but DONT GET THE EDELBROCK CAMS....

[Ole Blue 68]

Alright here's the juice on the engine. Short block (010 casting), 350 bored over .60 with new speedpro pistons/xrods, new crank and a lunati cam. The problem is the guy I bought it from doesn't recall what lunati cam it is so I can't look up the specs and I'm pretty sure it's not a voodoo. This things been sitting too long for it to be a voodoo.

A guy I know's got a garage and we're gonna drop it in there but I won't know how the lunati's gonna be until the engine's built and in the truck. Unless somebody else knows where I can get numbers off of a lunati cam, I just don't trust it.

[Bowtie67]

Originally Posted by Ole Blue 68

Alright here's the juice on the engine. Short block (010 casting), 350 bored over .60 with new speedpro pistons/xrods, new crank and a lunati cam. The problem is the guy I bought it from doesn't recall what lunati cam it is so I can't look up the specs and I'm pretty sure it's not a voodoo. This things been sitting too long for it to be a voodoo.

A guy I know's got a garage and we're gonna drop it in there but I won't know how the lunati's gonna be until the engine's built and in the truck. Unless somebody else knows where I can get numbers off of a lunati cam, I just don't trust it.

If you can take out the cam, look at the back of it and there is usually a stamped code for what the cam # is..and then you go to their sight or call them to find out the specifics of that cam..


Novaguy73: Harold Brookshire is no longer with Lunati.

[Novaguy73]

Originally Posted by Bowtie67

If you can take out the cam, look at the back of it and there is usually a stamped code for what the cam # is..and then you go to their sight or call them to find out the specifics of that cam..


Novaguy73: Harold Brookshire is no longer with Lunati.

Yeah i know, but he still designed the Voodoo line....any idea where hes at now?

[Ole Blue 68]

Thanks bowtie, the engine's sitting in the bed of my pickup so I can pull it.

Originally Posted by Bowtie67

If you can take out the cam, look at the back of it and there is usually a stamped code for what the cam # is..and then you go to their sight or call them to find out the specifics of that cam..


Novaguy73: Harold Brookshire is no longer with Lunati.

[Ole Blue 68]

Ok, I pulled the Lunati cam and here's the specs on it based on Summit:

Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-5,200 RPM
Intake Duration at 050 inch Lift: 218
Exhaust Duration at 050 inch Lift: 218
Duration at 050 inch Lift: 218 int./218 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 284
Advertised Duration: 284 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.458
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.458
Valve Lift with Factory Rocker Arm Ratio: 0.458 int./0.458 exh. lift
Lobe Separation (degrees): 110


As a comparison, here's the Edelbrock specs again:

Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: Idle-5,500 RPM
Intake Duration at 050 inch Lift: 204
Exhaust Duration at 050 inch Lift: 214
Duration at 050 inch Lift: 204 int./214 exh.
Advertised Intake Duration: 278
Advertised Exhaust Duration: 288
Advertised Duration: 278 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.420
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.442
Valve Lift with Factory Rocker Arm Ratio: 0.420 int./0.442 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash (in): 0.000
Exhaust Valve Lash (in): 0.000
Computer Controlled: No
Lifters Included: Yes
Lifter Style: Hydraulic flat tappet


They both seem pretty tame. Which would you guys go with?

[crazy longhorn]

Forget about the edelbrock cam....let me say that again...FORGET ABOUT THAT EDELBROCK CAM! It is old school as allready posted. i have the complete EDEL package.....less the cam. the heads & intake rock. I run Edel rpm heads, intake, used the timing set......tryed the carb(didnt like it), it was not a Holley! My 383 runs an XE 268 comp, & it runs decent......I reccomend (on a 9.5 to 10 to 1 motor), the XE, or XS 268(solid), or an Isky solid, or lunati "voodoo" in the same range.......crazyL

[Ole Blue 68]

Got it, no Edelbrock!

How about the Lunati (non-Voodoo), worth a shot or should I look at the Voodoo. Keep in mind, I already have it since it came with the engine.

[crazy longhorn]

I would give it a shot,the specs dont sound bad on that Lunati cam , for a perf /driver. You can always upgrade later, if you want more.... L

[Ole Blue 68]

Thanks CrazyL!

[72MARIO]

I also did not like there 1406 carb on my 84. I love my Demon it's like a holly but diffirent.

[junkyardjohn]

BEFORE YOU INVEST IN COMP. CAMS , MAYBE YOU SHOULD TALK TO SOME OF THE MANY MANY PEOPLE WHO'VE HAD THEM GO FLAT IN LESS THAN 1000 MILES. JOHN