Revolution Performance Motors has introduced the RPMHemi 4 valve heads for the Evo V-twin and early Twin Cam engines, Twin Cam EFI kits are currently being tested and will be available soon. If someone asks, “That thing got a hemi?” just install these heads and you can say yes. Sweet! The heads bolt directly on to the stock engine, the only changes required are valve clearance pockets must be cut into the pistons and the exhaust must be modified.
RPM has both conversion kits or complete engines in several displacements. There’s also an intake plenum that mounts 2 carburetors, the second CV carb serves as a vacuum secondary for high RPM runs. The heads fit any bore size from 3.5 to 4.25 inches. The hemi combustion chamber and center location of the spark plug as well as less spark advance allow compression to increase from the stock 9:1 to over 11:1. Evo kits start at $2995, Twin Cam kits from $3099.
4 valve heads can dramatically increase engine breathing and with no other modifications, engine horsepower and torque increase by 15 to 20 percent, with gains everywhere in the RPM range but it’s especially dramatic above 4000 RPM. Modified engines will see even bigger gains. Engine height is 1/4 inch lower with the 4 valve heads than with the stock configuration.
These 4 valve hemi heads seem like a pretty nice setup, either alone or as the first step before further modifications, and they would seem to be just right for a big twin powered sport bike or cafe racer. It will be really interesting to see some back to back performance comparisons.

 

i'll take one!

 

hmm anyone wanna buy some slightly used stock heads???

 

Impressive.

http://www.rpmhemi.com/

http://www.rpmhemi.com/conversion_kits.html

http://thekneeslider.com/archives/20...nes/#more-1740

 

imagine dropping this on top of a 127....i think i just wet my pants...lol

 

so they have some in testing for efis? wonder if they need a motor to tes them on.Naturaly Im just now getting motor backm together and new toy out.**** back to shop to start tearing back down

 

It's never ending ain't it[:@]To late in the mod season for me maybe next fall.

 

way too cool. Might have ta have a set.

 

I wonder of their heads will hold up any longer than their over rated Nikasil jugs. I have heard horror stories about Rev Perf's warranty program and how they treat their customers when their products fail.

 

NICE