Performer heads/comp cam question.
Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Performer heads/comp cam question.
I want to get some opinions on a tentative setup First, a friend is giving me an almost new set of edelbrock performer centerbolt heads not rpm.
Performer heads 165 int runner/ 60 cc chambers /2.02
Performer intake
Stock 1975 L48 shortblock
Small tube headers
Roller rockers
For the cam I am thinking
Comp cam XE256H or XE262H
I am interested in hearing from people that have these heads with a stock L48 and what cam you have with them. What performance gains you noticed what can I expect?
Also does anybody have experience with either of those cams? Looks like more low end torque. I am almost embarrassed to ask but how do they sound? Perform? Stock converter ok?
Finally, if neither of those cams, which would you suggest and tell me about it. I will be using HEI not a real high revving motor.
Thank you for any info you can provide me.
john
Performer heads 165 int runner/ 60 cc chambers /2.02
Performer intake
Stock 1975 L48 shortblock
Small tube headers
Roller rockers
For the cam I am thinking
Comp cam XE256H or XE262H
I am interested in hearing from people that have these heads with a stock L48 and what cam you have with them. What performance gains you noticed what can I expect?
Also does anybody have experience with either of those cams? Looks like more low end torque. I am almost embarrassed to ask but how do they sound? Perform? Stock converter ok?
Finally, if neither of those cams, which would you suggest and tell me about it. I will be using HEI not a real high revving motor.
Thank you for any info you can provide me.
john
Last edited by johnt365; Apr 13, 2007 at 11:26 PM.
Drifting
Joined: Apr 2002
Posts: 1,716
Likes: 4
From: New Baden Illinois
I want to get some opinions on a tentative setup First, a friend is giving me an almost new set of edelbrock performer heads not rpm.
Performer heads 165 int runner/ 60 cc chambers /2.02
Performer intake
Stock 1975 L48 shortblock
Small tube headers
Roller rockers
For the cam I am thinking
Comp cam XE256H or XE262H
I am interested in hearing from people that have these heads with a stock L48 and what cam you have with them. What performance gains you noticed what can I expect?
Also does anybody have experience with either of those cams? Looks like more low end torque. I am almost embarrassed to ask but how do they sound? Perform? Stock converter ok?
Finally, if neither of those cams, which would you suggest and tell me about it. I will be using HEI not a real high revving motor.
Thank you for any info you can provide me.
john
Performer heads 165 int runner/ 60 cc chambers /2.02
Performer intake
Stock 1975 L48 shortblock
Small tube headers
Roller rockers
For the cam I am thinking
Comp cam XE256H or XE262H
I am interested in hearing from people that have these heads with a stock L48 and what cam you have with them. What performance gains you noticed what can I expect?
Also does anybody have experience with either of those cams? Looks like more low end torque. I am almost embarrassed to ask but how do they sound? Perform? Stock converter ok?
Finally, if neither of those cams, which would you suggest and tell me about it. I will be using HEI not a real high revving motor.
Thank you for any info you can provide me.
john
When Chevy Hi Performance did the bench flow tests, the Performer Heads and the Performer RPM heads flowed almost exactly the same. That 60cc combustion chamber will bump your CR up pretty good. Between those two cams, the 262 would be my choice. Neither of them will give you much power over 5000-5200 RPM.
You will also be able to run your stock converter with either cam.
Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
very good question. the heads i am getting are the 6085 which is meant for 87 and up. i will have to buy a special intake to match the bolt pattern but to answer your question... for some reason they say they have 60cc chambers. Summit boasts that they will increase the compression by a point.
Racer
Joined: Feb 2006
Posts: 324
Likes: 0
From: South Elgin IL
Ah, I got it!! You have the Performer Centerbolt for Corvette heads from Edelbrock. They are made for '87-'91 vettes with the centerbolt valve covers and the straight manifold bolt pattern. The Edelbrock part number is 60879 for the complete head.
Performer and Performer RPM heads only come in 70cc and 64cc chamber sizes.
Performer and Performer RPM heads only come in 70cc and 64cc chamber sizes.
Racer
Joined: Feb 2006
Posts: 324
Likes: 0
From: South Elgin IL
Found this:
Performer Centerbolt
Designed for 1987-95 Chevy 5.7L engines originally equipped with centerbolt valve covers (except Corvettes; see Performer Centerbolt for Corvette below)
1987-95 intake manifold bolt pattern
High-velocity intake runner works with either T.B.I. or Tuned Port Injection systems
Maintains stock compression ratio when used with the recommended head gasket
Accepts stock centerbolt or Edelbrock aluminum valve covers #4246 and #4247
STREET LEGAL PERFORMER CENTERBOLT
Chamber Size Intake Port Size Valve Sizes (in/ex) Bare (single) Complete (single)
60cc 165cc 2.02"/1.60" #60849 #60859
Performer Centerbolt for Corvette
Designed for 1987-91 5.7L Corvettes (except LT1, LT4 and LT5 Corvettes) originally equipped centerbolt valve covers and the early style "straight" manifold bolt pattern
Also fits 1986 Corvette convertibles originally equipped with aluminum heads
STREET LEGAL PERFORMER FOR 5.7L VETTES
Chamber Size Intake Port Size Valve Sizes (in/ex) Bare (single) Complete (single)
60cc 165cc 2.02"/1.60" #60869 #60879
Performer Centerbolt
Designed for 1987-95 Chevy 5.7L engines originally equipped with centerbolt valve covers (except Corvettes; see Performer Centerbolt for Corvette below)
1987-95 intake manifold bolt pattern
High-velocity intake runner works with either T.B.I. or Tuned Port Injection systems
Maintains stock compression ratio when used with the recommended head gasket
Accepts stock centerbolt or Edelbrock aluminum valve covers #4246 and #4247
STREET LEGAL PERFORMER CENTERBOLT
Chamber Size Intake Port Size Valve Sizes (in/ex) Bare (single) Complete (single)
60cc 165cc 2.02"/1.60" #60849 #60859
Performer Centerbolt for Corvette
Designed for 1987-91 5.7L Corvettes (except LT1, LT4 and LT5 Corvettes) originally equipped centerbolt valve covers and the early style "straight" manifold bolt pattern
Also fits 1986 Corvette convertibles originally equipped with aluminum heads
STREET LEGAL PERFORMER FOR 5.7L VETTES
Chamber Size Intake Port Size Valve Sizes (in/ex) Bare (single) Complete (single)
60cc 165cc 2.02"/1.60" #60869 #60879
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
I would go with a XE 268 H for that setup! I think the 2 you have listed are too low in duration for your compression ratio and too low of lift for your runner size. A little more duration and lift will help fill the cylinder better with the small runners and give you a noticable power inrease thoughout your RPM range, not just up top.
Last edited by 63mako; Apr 14, 2007 at 02:23 PM.
Drifting
Joined: Apr 2002
Posts: 1,736
Likes: 37
From: Stockton Ca
I have it
My 74 has TFS heads CC 218-224 HR w 1.6 rrs, stk rams horns. 280 rwhp 315 rwtq The ex is a big log jam.
A bit flat under 2K, big block mid range!!!
Headers should add 20-30 hp/tq I can't wait
Ricisan
A bit flat under 2K, big block mid range!!!
Headers should add 20-30 hp/tq I can't wait
Ricisan
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Melting Slicks
Joined: Sep 2002
Posts: 2,783
Likes: 2
From: Engineers do it better.
I ran 211 rwhp with HE260H cam, stock L48 heads, TH400 and hooker headers with stock muffler and stock bottom end. It was good for the money spent...around $500.
But now with the parts in my sig, I got 250 rwhp and that's without dyno tuning. I think there's at least 20 more in there.
For the parts you mentioned about, your cam choice is too small.
PS. stay away from Comp cam XE series
But now with the parts in my sig, I got 250 rwhp and that's without dyno tuning. I think there's at least 20 more in there.
For the parts you mentioned about, your cam choice is too small.
PS. stay away from Comp cam XE series
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
w/ those 60cc heads & GM 10105117 gasket ... OE L48 will make about 9.7:1 scr w/ approx 0.053" quench (decent).
2 good cams w/ above are either:
Comp 275DEH (not an XE) ... or very similar ...
Speed-Pro CS1062R
2 good cams w/ above are either:
Comp 275DEH (not an XE) ... or very similar ...
Speed-Pro CS1062R
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
I'm using the XE262 and my only regret is not going with a roller retro fit. Go ahead and bite the $500 bullet, get an XR264HR10 and be done with it. You'll be happy you did in the end. God bless, Sensei
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
I'm using the XE262 cam (383 engine). Its OK but you could benefit from the XE268, even in a 350. BTW - make sure your oil has enough zinc in it, to avoid flat lobe problems. I'm using Valvoline Racing Oil (it says "Not for street use on the label).
