Edelbrock heads

Good morning all! What is the difference between the BB E series and Performer RPM heads? I believe they have the same port size and location. Is the valve size different? They seem so similar that I can’t understand why they would make both…

Chamber size is one thing. Why not visit Edelbrock's site to review specs for each, so you can evaluate which better suits your needs.

Lesser quality parts (valves and springs) in the E-street.
Edelbrock recommends not exceeding 5500 with e-streets.
I can spin my 440 with 906s to 6500, not gonna go backwards to e-street.

Valve seat material is different too according to Hughes.

ckessel said:

Valve seat material is different too according to Hughes.

Click to expand...

When the E street line was first introduced they came with powdered metal seats(the RPM’s used ductile iron).
The PM seats were pretty miserable to machine, even for Ede, and after a few years decided to go with the DI seats in the E streets.
They’ve been that way for maybe 5 years or so now.

As for the BBM versions, the only difference in any of the parts used are the valves.

The 75cc version is a nice value, whereas the 84cc version is actually a few hundred $$ more than the RPM head.
It does have straight plugs though.

33 IMP said:

Lesser quality parts (valves and springs) in the E-street.
Edelbrock recommends not exceeding 5500 with e-streets.
I can spin my 440 with 906s to 6500, not gonna go backwards to e-street.

Click to expand...

Bingo we have a winner...

IIRC you can get both E-Street & RPM (NOW) in 75cc, 84cc or 88cc combustion chambers
the Edelbrock ports 290cfm out of the box at 0.600" GVL, 2.14" int. & 1.81" exh. valves
are both bigger then the 906's too & the heart shaped combustion chamber,
angle plug design too, blind holes (for intake with s/s helicoils for intake)
blind drilled & tapped in exhaust side, no more water when taking out header bolts
RPM's are far superior to any 50 y/o 906 cast iron head, unless professionally ported
the RPM easily can be even better, if ported,
starts out with 50ccs more volume & 60+cfm more flow, better interior port design
right out of the box
it's if all things equal it's like 40hp bump (to 60hp depending on camshaft)
boost in power "right out of the box" between 906 & a RPM head, if nothing eles was changed

I wish they did the 75cc when I bought mine 12-15 years ago,
I got the RPM in 84cc 'closed' Combustion Chamber, fully ported now
the 75cc would have helped to the boost of compression some, good for quench too
without milling a bunch off
with flat tops w/valve notches
especially if you have lower compression std compression height replacements/pistons,
or a piston that are down in the hole some

BBM E street and RPM heads are both equipped with the same springs, part number 5792.

As I said previously, currently the only parts differences between the two heads are the valves.