how much cam with performer rpm heads?

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shoebox1.1

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if i were to be able to get RPM heads it sure would be nice to be able to run the springs on them. i cant find any information about the springs other than 600 lift max. how much cam can be run with out of the box heads?
 
Call Summit, speak to one of their sales reps and they will get you the exact specs for the springs. I have the same heads, and bought them fully assembled, and couldnt use the springs, and later decided to swith to 10 degree locks rather than the 7 degree's that come witht the heads. i am running Comp's XE285, which is a 545 lift, and yes the springs on the heads are good to 600, but what about the spring pressure, and how well it controls the cam. I would suggest get the heads bare, and buy the matching springs for your cam, better fit, and they would be designed for your specific cam.
 
Ahh yes, thats the book i had looked at to determine pressures. If i remember correctly, the seat and open pressures were off from what my cam needed...
 
If you get sneaky, you may be able to get an inner spring to boost seat and open pressure. You need to have an idea regarding desired camshaft to get a good answer.

Get with a good machinist that knows these heads and they can guide you. The advertised max lift is a joke with these, they won't handle an aggressive camshaft with that lift.

ou812, Brian, on this board is a good guy to talk with.
 
I am faced with same dilema have eddy heads really dont want spend any more on them other than mild port and gasket match. I believe I will run the .525-.525 solid lifter comp cam. I hope the springs that come with the heads I believe they are #5767 will support this cam.Thanks Kevin.
 
i talked with eric at muscle motors and i mentioned the comp 250 .525 110 solid cam and he said those springs would probably be ok for it. he said those springs are 130 on the seat and that he recommended their edelbrocks that have 10deg locks and a 5 angle valve job= 18xx.00 bucks. thanks for those links!
 
Kevin D. said:
I am faced with same dilema have eddy heads really dont want spend any more on them other than mild port and gasket match. I believe I will run the .525-.525 solid lifter comp cam. I hope the springs that come with the heads I believe they are #5767 will support this cam.Thanks Kevin.
Click to expand...


shoebox1.1 said:
i talked with eric at muscle motors and i mentioned the comp 250 .525 110 solid cam and he said those springs would probably be ok for it. he said those springs are 130 on the seat and that he recommended their edelbrocks that have 10deg locks and a 5 angle valve job= 18xx.00 bucks. thanks for those links!
Click to expand...

Hummm, strangley, I have the same lift cam but the duration is 248* @ 050. Reguadless, I have not yet opened it up for a run. I think it'll be OK since the spring pressures of the Edelbrock heads and the recomended one via Comp Cams are close.

This is half the issue. The other half is total lift of the cam. Kowing the springs are goof for a .575 lift, then yeilding before that is good.
 
Just a guess but i would think .600 lift max like it says.
 
FYI, I had the locks and retainers swapped out for 10° on my RPM heads still using the the springs they came with. I plan on running the XE274H comp cam (0.488"/0.491" 230/236 @ .050"), the springs comp recommends for this cam are comparable to the eddy ones.
 
mr plink whats that cam supposed to do with these heads on a 440? i think i remember articles somthing like 530 horse with that cam and these heads??
ive pretty much decided to get the heads bare and build them. the UD cam i want calls for dual springs 140 seat and 330 open so that what i want to run. thanks for all the inputs!
 
I had my Edlebrock heads #60179
Looked over by a local machinist, that others had suggested before installation. They checked out good.
He recommended with those springs
Not to exceed over .530 lift
 
I am currently running a .557 purple shaft solid with 906s. The cam was selected specifically to use the edelbrock springs when i do my A to B test with ootb rpms.
After lash, and minus the poor rocker ratio of the old iron adjustable rockers, i have about .520 lift at the valve.
 
WOW! Way to go digging up this old thread. (2010!)
It’ll probably help someone out.
Ledhead said:
I had my Edlebrock heads #60179
Looked over by a local machinist, that others had suggested before installation. They checked out good.
He recommended with those springs
Not to exceed over .530 lift
Click to expand...
 
rumblefish360 said:
WOW! Way to go digging up this old thread. (2010!)
It’ll probably help someone out.
Click to expand...

Yeah a 10 year old thread from a guy who wanted to know how big of a cam he could run with valve springs that were rated for 0.600 lift. Hmm, paging Captain Obvious to the forum please. Captain Obvious, we need you to explain how big of a cam you can run with springs rated for 0.600 lift. Would it be 0.600 lift? Is that the answer?
 
rumblefish360 said:
WOW! Way to go digging up this old thread. (2010!)
It’ll probably help someone out.
Click to expand...
I just happen across this article & curious how much peak lift stock Eddie RPM's would handle? I don't live on here. Didn't know how old post was. Added my 2 cents because rating is .575 , machinist said .530 at best. So much for ratings, what else is inaccurate? Not a Guru, just thought the inaccuracy was note worthy.
Sorry that my ignorance caused you
to want to exploit it.
 
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Ledhead said:
I just happen across this article & curious how much peak lift stock Eddie RPM's would handle? I don't live on here. Didn't know how old post was. Added my 2 cents because rating is .575 , machinist said .530 at best. So much for ratings, what else is inaccurate? Not a Guru, just thought the inaccuracy was note worthy.
Sorry that my ignorance caused you
to want to exploit it.
Click to expand...
Your over reacting to nothing but the words you mistake for a jab at you.

FWIW, just about everyone gets this “poke” of a joke when they dig up an old thread, myself included. When I wrote “It’ll probably help someone out”, I wasn’t kidding.

Another FWIW, glad your reading back that far. IMO, I thought it was cool. But yea... you got the :poke: anyway.

One last thing, your ignorance? I don’t see any of that posted. What I saw was a good move. You stated, “He recommended....” which says to me you sought advice and from a person that knows something. And that’s smart. An honest question answered by someone you trust now forwarded to a like person that posted the question.

Now to search for an old thread and dig it up! :poke::poke::poke:

(Did you laugh at the last sentence with the poking icons? I hope so! Or I might recommend a trip to the Doctors office located within the walls of the nearest comedy hall!)
 
Hey Rumble, your right I took it the wrong way. My apologies to you.
With all that's going on in our country,
Covid, Government, "Defund Police" my emotions can be 40 amps on the head of a pin. So.... :poke::poke:back atcha :thumbsup:
 
The OP could have been curious about the same thing I am, which resulted in me finding this thread as well.
My questions is this - how much lift can the RPM heads handle - regarding the retainer to guide clearance (not the factory valve spring lift limit, which is stated obviously in the marketing material.... Ya know?

So if anyone has an answer to that one, lemme know and :poke: at ya all....
 
Physically able to handle........I've run as much as .815" with the stock exhaust valves and guides......using seals, springs, retainers and locks for the big roller cam. I don't think they'll flow too good up there without some porting. But.....I don't recollect ever tesing the stock OOTB exhaust port at .800"
 
shoebox1.1 said:
if i were to be able to get RPM heads it sure would be nice to be able to run the springs on them. i cant find any information about the springs other than 600 lift max. how much cam can be run with out of the box heads?
Click to expand...
I ran the 292/292/.508 FTH with 1.6 arms so .542 lift
later
I ran a 270/276 Hughes FTH at .538/.549
Both of these went to 7000 and beyond at 1/2 turn preload on the Hughes circliped lifters.

Btw the alloy heads worked awesome at 195psi on pumpgas.
 
What was your calculated compression ratio on that setup?
 
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