Elderbrock Heads
Melting Slicks
Joined: Feb 2003
Posts: 2,529
Likes: 27
From: Auburndale Florida
2025 C2 of the Year ('64-'66) Finalist - Unmodified
St. Jude Donor '03-'05-'06-'07-'09
I have been looking at these heads too!!!
I believe one difference is there is no passage in the RPM heads for the heat cross over passage to the intake.
Mark
I believe one difference is there is no passage in the RPM heads for the heat cross over passage to the intake.
Mark
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
I reread their web page and thats about it. I may go with the cross over and block it off to see what happens. I have read conflicting info on that if the choke is not a factor.
Bob
Bob
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
The Performer RPM is available with either straight or angled plugs.
The Performer only appears to be available with straight plugs.
Take note that 0.100" longer push rods are required for stock rockers
on both styles.
.
The Performer only appears to be available with straight plugs.
Take note that 0.100" longer push rods are required for stock rockers
on both styles.
.
Team Owner
Joined: Feb 2005
Posts: 32,519
Likes: 1
From: central America
St. Jude Donor '08-'09
Check out this page for head flow data.
The RPM's flow better at all lifts then the regular performers. If the price is close, then I'd go with the RPM's.
http://purplesagetradingpost.com/sum...fo/heads1.html
trw
The RPM's flow better at all lifts then the regular performers. If the price is close, then I'd go with the RPM's.
http://purplesagetradingpost.com/sum...fo/heads1.html
trw
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
I rec. a reply from Eldelbrock and they are the same except for the cross over. I would guess that there will be a margine of error between test equipment, operator and setup conditions for flow testers
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Nail ur compression before choosing heads.
I imagine u will need the Center Bolt Edelbrock heads with the smaller 60cc chmbers for ur 327" sb.
U will like the increase in compression but do the math before purchase as 10.5 c.r. is safe with aluminum heads.
The higher compression will do u more good than any reduced flow from the smaller 165cc intake runners vs 170cc on the Performers. But the Center Bolts still come with 2.02 and 1.60 larger vlvs so i imagine low lift flow will still be great. Also have X-over port if u need it.
Yes with small c.i. 327" the smaller 165cc runners will be fine but the higher c.r. will get u "up on the cam" faster from start.
Just something to consider w1.
cardo0
U will like the increase in compression but do the math before purchase as 10.5 c.r. is safe with aluminum heads.
The higher compression will do u more good than any reduced flow from the smaller 165cc intake runners vs 170cc on the Performers. But the Center Bolts still come with 2.02 and 1.60 larger vlvs so i imagine low lift flow will still be great. Also have X-over port if u need it.
Yes with small c.i. 327" the smaller 165cc runners will be fine but the higher c.r. will get u "up on the cam" faster from start.
Just something to consider w1.
cardo0
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Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
Thanks casdo0 I have done my homework on the CR. The motor has the TRW 2166 "11/1" pistons .025" deck and the 64cc chambers of the 60899 Edelbrock heads. I should end up with 10.5 cr depending on the gasket. I am confused about the flow of the performer and performer RPM heads. Edelbrock says they are the same except for the cross over but two sources say the RPM ones have more flow. Sifting thru marketing hype, bang for the buck, production tolerences and measurement error is a pain.
Bob
Bob
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Good job - Summit w/s says same. I expected a cast stock low c.r. piston.
Was that a stock piston?
BTW i have heard that Edelbrock has revised thier head castings/porting for the better though i can't seem to access the flow data. But i always heard of good results even with the old design Performers and would have used them myself except that i was afraid to use a steel shim hd gasket with alum hd. That steel shim .015" hd gasket gave me good quench using an iron hd though i gave up some compression (67-69cc chamber hds). But then again i still have stock cast pistons and the lower c.r. with better quench was my conservative choise (World Products SR II's) - well i saved a few hundred $$ too.
But i like the design of those TRW 2166's as something 'bout the vlv chamfers that makes better pwr. I expect the better Edel hds will really wake that mtr up and will take a beating even at hi-rpms.
cardo0
Was that a stock piston?
BTW i have heard that Edelbrock has revised thier head castings/porting for the better though i can't seem to access the flow data. But i always heard of good results even with the old design Performers and would have used them myself except that i was afraid to use a steel shim hd gasket with alum hd. That steel shim .015" hd gasket gave me good quench using an iron hd though i gave up some compression (67-69cc chamber hds). But then again i still have stock cast pistons and the lower c.r. with better quench was my conservative choise (World Products SR II's) - well i saved a few hundred $$ too.
But i like the design of those TRW 2166's as something 'bout the vlv chamfers that makes better pwr. I expect the better Edel hds will really wake that mtr up and will take a beating even at hi-rpms.
cardo0
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Originally Posted by w1ctc
Whats the difference between "Performer" and "Performer RPM" heads?
Their web page dosen't say.
Their web page dosen't say.
GM makes a similar head to E-Tec... called an "aluminum Fastburn" ... last 3 numbers in P/N are 298 ... find it at GMPP site.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Piston clearance?
Well speaking of chamber design w1, with domed pistons u should check for piston clearance on assembly. Take the time and use modeling clay to verify vlv clearance (at least .035" for the valves, some even say .050") but those new chamber designs (vortec chamber)may interfere with domes also. Walmart even sells modeling clay and u will need to assemble head with a sacrifical gasket or else account for the difference in calculating clearance height. 
Just a thought here u may need to do.
cardo0
Just a thought here u may need to do.
cardo0
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
Thanks Cardo0, I hadn't thought of that since my old 452 heads also are 64cc. Better to make sure than hear the sounds of death the first time I turn it over or take it up in RPM.
Bob
Bob