400 BB Mopar dyno test
I've been running stock rockers for years now. Id like to see what the rollers would do to that engine with no other changes.
IMO, not much at all. The upgraded rockers show themselves right well with a high performance build of some stoutness rather than a OE re-build to moderate performance builds.
The upgraded rockers are accurate, less flexing and deliver the cams timing events and full lift as spec'd to the valves.
The OE rockers are a known flexing part with less than accurate ratio. Some have been found to be in the 1.40-1.43 area. Add the years of use and abuse, the ratio can drop.
Lift has a direct impact on HP
If your engine is dead bone stock, the return per dollar spent will be pitiful and low.
ou812;
I was just wondering out loud for a guesstimate. I do have a 400. I will be looking to a basic inexpensive rebuild with something in mind like what you did above. A bowl porting would be added.
Making use of what I have on hand, the only *performance parts* I have on hand are;
Aftermarket TQ
Holley Street Dominator
Headman E-lete (SP!) headers.
All of which cam with the engine.
The engine is a '78 P code. Not much to it considering the year it was produced for. Smog ridden equipment, broom stick cams and a D.O.A. compression ratio that can be run on yak urine.
I'm not sure exactly where I want to go with the build as of yet. There is no rush in doing so. (Other targets in my sight now)
The 400 is in a '71 Duster w/a 727, 8-3/4 rear. The gear ratio is yet to be decide, but, 3.55's are about where I want to be.
Cam wise (Also yet to be decided) would be something to be of an upgrade over the Road Runner cam. Considering that cam size, the intake duration being thought about wouldn't really be much larger at all. If at all. IIRC, it would be close to the Thumpers intake duration. But that is about the power band I'll be looking at.
All points headed towards a true street driving car.
Thanks Brian.
