According to Edelbrock's "packages", the RPM cam and RPM intakes are supposed to go together.
Overall performance is not a whole lot different between the two, but Air Gap tends to keep a denser fuel charge in warmer weather. Not a bad thing unless you're "fat" already. RPM has similar runners and plenum. If you have an electric choke, there's not much reason NOT to run Air Gap. If you need a "hot" choke, you can't use Air Gap.
The idea ("air gap") has been used since at least 1953 in Studebakers, and Pontiacs also have a similar deal. Blocking the crossover effectively makes either an "air gap" (no heat). BBDs are loosely similar.
If you want more lower-RPM performance and not so much over 5,500, use Performer. The same "rules" apply to Performer "Air Gap". Advancing that cam 4 degrees and using Performer is a very effective way to make strong towing and "truck" engines. The cam is a little 'big' for fuel economy, though, and it can be compression-sensitive (detonation).
Thanks for your reply... there are several features on the Air Gap that I don't need, such as the rear water inlets, the nitro bosses... stuff id just have to plug.
Compression sensitive got my attention! i'm running a very nice set of 186's with 2.02/1.60's, guide plates, screw in studs, very nice port and polish job on them. they are the 64cc chambered heads, and i know im pushing the compression issue, i want to run it on pump gas (super).
My plan is to try and get some relief from the pistons... D dished or just dished, havent talked it out yet??
Also what does advancing the timing on the cam 4 degrees do? will it help elimanate the detenation problem that may come with high compression? dont know if its going to be a problem yet for sure, but i know it's possible. should i advance it anyway? Ive read before that the Performer RPM Cam is kind of soft on the bottom end and it seems to me that advancing the cam 4 degrees might be the way to go from the get go.
Any thoughts? Anybody...
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