Wonder why Holley would use a #55 power valve in the primary and use 101 jets on all four corners??
LIST 80532
When I bought the carb I plugged the PV and put 98 jets in. I'm raving in Vegas in a few weeks and and figured I'd jet down some for the high altitude.
Looking up the factory specs on the carb reminded me about the PV I took out and got me to wondering why I went down on the jet after plugging the PV.
Car always had safe EGT's at sea level...
I'm kinda confused about where I'm actually at right now.....

quote:

Originally posted by imakehp:
Wonder why Holley would use a #55 power valve in the primary and use 101 jets on all four corners??
LIST 80532
When I bought the carb I plugged the PV and put 98 jets in. I'm raving in Vegas in a few weeks and and figured I'd jet down some for the high altitude.
Looking up the factory specs on the carb reminded me about the PV I took out and got me to wondering why I went down on the jet after plugging the PV.
Car always had safe EGT's at sea level...
I'm kinda confused about where I'm actually at right now.....

Dave,

I don't know the D/A range you normally run in. This time of year in Vegas the D/A will range from 1,000' to 2,000'. I've been following it from Nellis AFB the tracks neighbor, for the past couple weeks.

If the motor was happy with the current carb tune, I wouldn't worry about it. My opinion is leave it alone, get some test hits & if it's that far off; make appropriate changes.

2BKing

dont change unless you put in bigger jets

Hello Dave, if you are confident it isn't running lean in SoCal, I would leave the jetting alone for now. As David Reher wrote a few years back:
"In this age of digital everything, carburetors have an undeserved reputation as low-tech devices. In fact, a racing carburetor is a very ingenious system. A carburetor responds to differential pressure, and therefore it self-compensates for changes in barometric pressure. The gas in the float bowl is always subject to the prevailing atmospheric pressure; the jets deliver fuel in proportion to the differential between the pressure in the float bowl and the pressure in the induction system. So when the barometric pressure falls, as it does so dramatically in Denver, there is less pressure differential and therefore fuel flow is reduced accordingly."
Here is a link to the full article, as it appears on the RM website:
https://rehermorrison.com/tech...o-live-with-bad-air/

What Jim said.... Ive had 3 Reher engines, dyno tuned at their shop. The first 2 I rejetted for our colorado air and all I accomplished was slowing it down.
I never rejet. Ive run the same jet in Phoenix as I do in Denver and all is good....