Billet Meter blocks for 850 DP... your thoughts?

mbaird said

Thx...
this is going on a fairly mild 5.9 with a 221/229 @ .050 cam and Brians IMM ported EQs.
It is a bit of overkill but this is more of a learning experiment .
I am having trouble cleaning up the 1800-2400 rpm range with the current 750 VS aand I bought these blocks cheap so I thought it would be fun to try them out on the 850.

Click to expand...

That makes sense. The RPM range you are having issues with is because you are at the end of the transfer slot, and the main is delayed by a small MAB. I have fought this before, especially on TR stuff and/or stuff with lower gear ratios.

It finally dawned on me that Holley and all the clones are using a MAB that is too small to DELAY the booster because the rest of the tune up is so wacky.

FWIW, a smaller air bleed DELAYS the mains starting, and makes the fuel curve richer at RPM.

A larger air bleed STARTS the mains sooner, and makes the fuel curve leaner at RPM.

Holley carbs are notorious for being pig rich on the bottom, lean in the middle and pig rich on top. Been that way since I started driving in 1980.

Why Holley sends out a tune up in their carbs like that, I can’t say. But that is the defacto tune up they and most every clone I’ve seen is done.