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post #3 of (permalink) Old 07-07-2019, 07:46 PM Thread Starter
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John_in_SC's Avatar
Join Date: Apr 2019
Location: Upstate
Posts: 104
Originally Posted by Jsams View Post
Why are your primaries with the PV jetted richer than the secondaries with no PV? Is that a typo?
I see you are in Charlotte. I'm 20 min from Charlotte. Know any CARB jedi knights up there?

Not a typo unlesss I wrote down the secondary #'s wrong when I pulled of the metering plate a week or so ago. I believe we jetted up on the primaries to address a "too lean" at cruise. Not sure what that number was but it was pretty lean. I knew less then than I do now.

Just to update. I let the car cool down.....went to drive it for a cruise but didn't start....empty bowls. Reset the 4 corners back to 1.5 turns out and began to dial it back in. Bottom line - this car won't make 14'ish with the air filter on no matter how hard I try at idle. Best I can get it dialed in at idle now is mid-13's (with filter on) otherwise it will empty the bowls if I try to go leaner. So I accepted this and decided to see what vacuum does at cruise (diff speeds) and WOT. Here are some results

Cruise - vacuum climbs to about 18-19 with AFR in mid high 14's/mid 15's.

Under a load (hills, acceleration) - vacuum drops to 15'ish and AFR richens to 13's

WOT - vacuum drops to less than 4 and further riches to high 11's - mid 12's.

So wondering if this is expected behavior in terms of vacuum. I'm not sure.

Seems somewhat on par for AFR. I'm not sure if I need to go with a diff PV or not yet. I'm planning on dropping in the default jets the CARB came with and seeing how that changes things now that I"m getting more familiar with CARBS.

Or this is just the price we pay for an oversized CARB?


John in SC
Formerly Studiopet_2005
1966 Coupe - 302 with some stuff on it

Last edited by John_in_SC; 07-07-2019 at 07:49 PM.
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