422 dyno fail

PRH said

I thought after you had your motor off the dyno you discovered something that was the likely cause of the lower than expected power?

The top end of the run on the last sheet from the OP had the bsfc numbers in the .7 range.
In 32 years, I don’t think I’ve ever seen them that bad....... not without a plug wire off or something like that.

Poor bsfc numbers are simply the result of using a lot of fuel....... and not efficiently converting it to hp.

Click to expand...

We did a dyno test of a BB Mopar years ago, trying to push limits of the NEW beehive springs...after a 15 min. convo with Billy Godbold at Comp, we tried some solid FT lobes with the beehives...during break in...2500rpm the bsfc's were way out to lunch...so we pulled the intake off and the lobes were all going bye bye.
Changed springs, new cam (same specs and lobe family), during break in bsfc's were normal...break in was successful! Added the inner springs and away we went. After looking at our data, and the materials, Comp said the lifters were not staying in contact with the lobes...yeeeeah.

Most of our sb mopars with ported heads (not factory heads mind you) will have BSFC's in the .400 to .450 range with DP intakes and 750-950 carbs.
Our race stuff will see the BSFC's in the .385-.400 range.
The BB we tested, once tuned at WOT made BSFC's in the .440 range.