Author Topic: High altitude carb at low altitude  (Read 1549 times)

Offline Pav8427

  • Carb lover
  • ***
  • Posts: 68
High altitude carb at low altitude
« on: September 16, 2015, 05:12:49 PM »
Hi all. First time post, but I have been visiting for quite some time. A couple of years ago I bought a box stock 79 Hurst/Olds
that had been sitting for 10 years. It wasnt running at the time but since then I have it back on the road with rebuilt Dist,carb and intake gaskets. Of course there were a few miles of vacuum lines and fuel line that needed to be replaced.
To get it running I put a NAPA carb kit. I now know I should have come here for the kit and other stuff.
The car is a California car with the original carb(17059553). I am thinking that I have a lean issue at WOT. I ordered a new secondary cam/spring kit today and hope that helps. The original is not shot, but sloppier than I would like.
The only other issue is a cold start problem that is more of a inconvenience right now.

The info that I have been able to dig up here on this carb is that it is a high altitude carb with 74 primary jets,52m primary rods, K hanger and CV secondary rods. I didnt verified the jets and primary rods, but it does have CV secondary rods with a G hanger.
Being a Cal/high altitude carb now living at around 1100 feet, could that be causing my lean issue?
I was able to scrounge up a couple of sets of primary rods(36B,55M),secondary rods(CP,DP),secondary hangers(J,K) and a set of 70 jets.
While I have the top off to swap the cam and spring, would swapping in a combination of these help the lean issue at all?
Maybe give a little more seat of the pants feel.
It does run decent, just think even a smogger 350 Olds should pull a little harder.
Any help would be greatly appreciated.

Thanks, Doug

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5435
Re: High altitude carb at low altitude
« Reply #1 on: September 22, 2015, 02:42:34 AM »
If you are lean at WOT the problem will be the wrong fuel inlet seat from the NAPA kit.  You need a high flow N/S assembly, none of their kits come with them these days, just the smaller "generic" part......Cliff