Performer RPM ?

[Sonny's at Work]

I have a RPM manifold/w1406 and I am not to crazy about it myself (PO installed it). I would have gone with the regular performer/performer air gap if I had to do it again. I have a 350/700R4 w/3.73 and I rarely see over 4,000rpm. Most of my driving is around the 1500-2200 rpm range. Look for a combo the suits the majority of how you plan to drive the truck.

Sonny

[Ole Blue 68]

Thanks John, I've seen a couple posts on the site that didn't have good things to say about Comp Cams so I'm staying away from them.

Originally Posted by 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

[Ole Blue 68]

So you think its the intake and not the carb? You're the first person I've heard from who disliked the RPM intake but i've seen tons of posts from people who didn't like the 1406.

Originally Posted by Sonny's at Work

I have a RPM manifold/w1406 and I am not to crazy about it myself (PO installed it). I would have gone with the regular performer/performer air gap if I had to do it again. I have a 350/700R4 w/3.73 and I rarely see over 4,000rpm. Most of my driving is around the 1500-2200 rpm range. Look for a combo the suits the majority of how you plan to drive the truck.

Sonny

[400ex]

My .02..

No experience with edelbrock cam. But I have been running a 625 cfm Carter for a couple of years (which is basically the same design as an Edelbrock carb) with a Comp Cams XE274. Motor was built by a professional and dynoed at 390 hp. I 've got around 10,000 miles on it and it runs great. No its not the fastest thing in a truck but it does move and somewhat quickly.. I am pleased.

[70rs/ss]

What you need to do is search the flow rates on your heads. If your heads stop flowing air at .400 lift, then why put a .425 or .450 lift cam in it. You cannot pick a cam by its advertised RPM range, as this is an estimate. There are websites that post common chevy heads and their flow numbers. carcraft.com has flowed many different heads and created a chart. Without the cfm flow numbers you are guessing at best when it comes to picking a cam. Scoggins Dickey has some flow numbers for popular SBC nad BBC heads. Flow numbers usually start at:
.050 lift 25cfm
.100 lift 50cfm
.200 lift 65 cfm
.300 lift 74 cfm
.400 lift 85 cfm
.500 lift 86 cfm
.600 lift 83 cfm

Look for the most cfm and then look at the lift, if the max cfm is at .500 lift and it is 2-3 cfm lower at .400 lift, then it is obviously better to go with .400 lift as it is easier on valve train. If you want you could go with .450 ish and not really lose anything. This is the ONLY way to pick a cam, period. Once you know flow numbers you can pick the lift and have a good performing engine. If you ar e sreious, find someone with a flowbench and have you heads flowed, if you have paid for port work and they didn't flow the heads, how do you know they helped the heads? A flow bench is the only way to verify how the heads work, new perf heads all list those numbers upfront, even the out of the box Vortec heads offer flow numbers. without knowing how much air your heads move you are guessing (at best what cam to buy) and more often than not we buy cams that are too big (too high of lift) and that hurts performance. I'd put a well matched small cam combo against the same motor running a too high lift cam any day, because the motor that has the correct cam to match the flow characteristics of the heads will flow the correct amount of air and not slow it down by opening the valve to far, and it will not wear out springs, etc from excessive lift. My .02 cents, but if you do not believe me, look into the cam manufactuers sites and talk to a tech, if they know what they are doing they will tell you the BEST way to pick a cam is to know the flow numbers and then the other stuff, ratio, trans, stall, etc. Good luck

[sweet n rare67]

Well, I have The Performer RPM cam and Performer EPS Intake and reworked heads. So far I like it pretty good but I have had No Street time on this setup so I will see. I didnt know so many people hated Edelbrock Cams.

[Sonny's at Work]

I have a friend who has the same carb, but has the performer on a sbc and his powerband seems smoother (he has about the same cam I have). I don't like the carb either. It's too sensitive to environmental changes and here in Georgia the humidity fluctuates like crazy. I haven't found a happy medium yet either. I will be pulling the truck in the garage here very soon to begin the restorodification process. One of the mods I want to do is install either a TPI, LT1, or LS1 so I won't have to worry about it anymore.

[Ole Blue 68]

Hey 70 RS/SS, good info. I've got a pair of 487 heads that came with the engine that are currently in the machine shop. I couldn't find flow numbers for that particular head but I did find some info on 882 heads which has similar specs to the 487 head. It says the 882 heads max out at .600 lift.

[Ole Blue 68]

Neither did I! I was just looking at them since they're made by the same company.

Originally Posted by sweet n rare67

Well, I have The Performer RPM cam and Performer EPS Intake and reworked heads. So far I like it pretty good but I have had No Street time on this setup so I will see. I didnt know so many people hated Edelbrock Cams.

[Green Machine]

If you could open and close the valves instantly, then it would make no sense to open the valves past max flow lift. However that clearly is impossible. If your cam lifts the valve .400 then it is at that lift for perhaps only 10 degrees of crank rotation. During the other 250 degrees or so of travel the valve is either opening or closing and is not at max flow.

If you lift the valve .500 then the valve will see .400, go past, back down to .400. It then might be at max flow for 50 degrees of crank travel. Its called the area under the curve and will give you better power.

[Novaguy73]

Originally Posted by 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

I would stay the hell away from the comp XE line specifically. Go over to the chevelle or camaro borad and just ask. Some people swear by them, some swear AT them.

[Novaguy73]

Originally Posted by 70rs/ss

What you need to do is search the flow rates on your heads. If your heads stop flowing air at .400 lift, then why put a .425 or .450 lift cam in it. You cannot pick a cam by its advertised RPM range, as this is an estimate. There are websites that post common chevy heads and their flow numbers. carcraft.com has flowed many different heads and created a chart. Without the cfm flow numbers you are guessing at best when it comes to picking a cam. Scoggins Dickey has some flow numbers for popular SBC nad BBC heads. Flow numbers usually start at:
.050 lift 25cfm
.100 lift 50cfm
.200 lift 65 cfm
.300 lift 74 cfm
.400 lift 85 cfm
.500 lift 86 cfm
.600 lift 83 cfm

Look for the most cfm and then look at the lift, if the max cfm is at .500 lift and it is 2-3 cfm lower at .400 lift, then it is obviously better to go with .400 lift as it is easier on valve train. If you want you could go with .450 ish and not really lose anything. This is the ONLY way to pick a cam, period. Once you know flow numbers you can pick the lift and have a good performing engine. If you ar e sreious, find someone with a flowbench and have you heads flowed, if you have paid for port work and they didn't flow the heads, how do you know they helped the heads? A flow bench is the only way to verify how the heads work, new perf heads all list those numbers upfront, even the out of the box Vortec heads offer flow numbers. without knowing how much air your heads move you are guessing (at best what cam to buy) and more often than not we buy cams that are too big (too high of lift) and that hurts performance. I'd put a well matched small cam combo against the same motor running a too high lift cam any day, because the motor that has the correct cam to match the flow characteristics of the heads will flow the correct amount of air and not slow it down by opening the valve to far, and it will not wear out springs, etc from excessive lift. My .02 cents, but if you do not believe me, look into the cam manufactuers sites and talk to a tech, if they know what they are doing they will tell you the BEST way to pick a cam is to know the flow numbers and then the other stuff, ratio, trans, stall, etc. Good luck

Im going to have to disagree if i read your statement correctly. The way i took it was you say that Lift is the most important factor in picking a cam. I saw nothing about adv duration, .050 duration or Lobe seperation. Id say first and foremost that I agree that you dont need .600 lift if your heads dont flow up there. Its pointless and probably hurts performance.
But simply put Advertised duration is also a huge factor. This is what will determine your cylinder pressure for a given static compresson ratio. too big a cam and your motors a slug down low, too small a cam and you have detonation issues and a cam that is far from optimal. Lobe seperation is important to say the least. If you want a scavenging effect, a peaky HP/TQ range and an idle like a pro stocker {My Nova} you go with the tighter 106,107,108 somthing around there. Now if you get in the 112,114 range you will have a broader power range a smoother idle and are better suited to run a power adder. These are other things to take into concideration way before you pull your heads off and have them flowed.

As a side note, IMO most manufacturers lie about head flow but without flowing them all this will be your best bet if you want to pick a cam based on that. I have found through study that AFR and Brodix are the only 2 companies that dont inflate #'s, Brodix is actually conservative. Hence the reason i chose their race rite 200 heads for my nova.

[Ole Blue 68]

Must...stop....reading.....Getting....dizzy.....Too...much...information....

Just kidding...

I'm going with the Lunati. If it sucks, I'll pull it.

[crazy longhorn]

My only complaint on the XE series cam is that its noisey(a common complaint). The XE 268 runs like "stink"in my 383 (pretty fair idle too) I still say that if it needs to "tick" , it should be a solid cam........& the next 1 will be in my old Chev Can you say Iskenderian? L

[Novaguy73]

Originally Posted by crazy longhorn

My only complaint on the XE series cam is that its noisey(a common complaint). The XE 268 runs like "stink"in my 383 (pretty fair idle too) I still say that if it needs to "tick" , it should be a solid cam........& the next 1 will be in my old Chev Can you say Iskenderian? L

Crazy...according to a very well known cam grinder that im not going to disclose, that tick is the sound of your valve slamming shut because of the terribly aggressive ramps....just a heads up

[crazy longhorn]

Originally Posted by Novaguy73

Crazy...according to a very well known cam grinder that im not going to disclose, that tick is the sound of your valve slamming shut because of the terribly aggressive ramps....just a heads up

Yup, Im not confused about that......the fast ramps do make power, but at the expense of the valve train pcs! Many perf cams I have run are somewhat noisy, but nothing like the XE series. I ran an Engle in a 455 olds, that was planted in my longhorn ( in the early 90's), & it was a tad noisey, but it ran d@mn good Some of my Ford buds also claimed the cams were noisey when you got in the .500 + lift range on some cams. I think Comp pushed the envelope a tad far on the XE cams, & they are not forgiving for any other minor valvetrain problems that you may not notice with other cams that are less agressive. L

[RPMkid]

Just to throw in my two cents.

I have a 78 305.It's .030 with stock type replacement pistons.(Guy built it and didn't like how it ran.Built a new engine and sold me this one.(882s +stock cam=sucks.

Now the engine has Pro ported 461 heads,The lunati bracket master cam 2 that you just listed,Performer RPM,HEI,hedman 1 5/8 headers,1406 carb,

The truck is a 69 longbed with a 3 speed on the column with a 3:73 rear.

This truck runs really good!

I also ran this exact same cam along with the intake and headers on a 350.Torque out the wazzoo.

I think it is an exellent cam.Idles are 750RPM's with a slight lope.You can tell its not stock.I have also ran a comp 270h.And it sounded more like a race cam.But it didn't make power till around 2500RPM.

I would use the cam you have.Swapping a cam out isn't that hard to do.No reason to not use it.I know the edelbrock markets their cam and intake as a combo.Which it is.But if put it togother with the wrong engine.(Low compression)It won't run as good as if the proper cam was used.

What I'm trying to say is just try it out!You'll like it.