Holley carb issues

[pkonopasky]

2 diferent carbs and same issues..... is the timing ok?? what distributor are you using? are the spark plug wires good?

I am using the MSD offroad ignition system, brand new wires and plugs, and we have the timing around 20 advanced

[SPONSOR]

Membership in the largest desert racing community has its advantages - Participate in Forum Discussions - Send and Receive Private Messages - Maintain Public Photo Albums - Access to Groups - User Profile in our Social Network - Increased Access to more Sub Forums - Reduced Online Advertisements Join our community today

[pkonopasky]

OK, which accel pump cams are you using and if you have 2 UMP's, whats the plemun on top of the carb look like?

The carbs are straight out of the box, nothing changed.

[Zambo]

Get rid of that little intake hat and put a real air cleaner on it! We had the same problem with our stock full, that little hat just doesn't hold enough air for immediate demand when you need it.

Also, how much vacuum is your motor making? A 383 with a big cam might not make much vacuum, and you're running vacuum secondaries. I'm not that smart with carbs but I think most desert racers would run mechanical secondaries, I know I do.

[partybarge_pilot]

Get rid of that little intake hat

X2, those with the offset inlet create a swirl over the top of the carb that screws with the highspeed air bleeds. Get the larger one with dual inlets. Dynoing a 430SBF with one of those versus a 14" air cleaner lost us 75HP. The larger dual inlet plenum was about the same as the 14"...........

[partybarge_pilot]

Also, I think those come with the red cam. Run the brown or yellow.

http://www.holley.com/data/Products/...mpCamGraph.pdf

Edit, if you put on the DP, run the pink cams...........

[12LaPaz]

Check the screen IN your fuel pump.... take off the bottom plate

[pkonopasky]

Get rid of that little intake hat and put a real air cleaner on it! We had the same problem with our stock full, that little hat just doesn't hold enough air for immediate demand when you need it.

Also, how much vacuum is your motor making? A 383 with a big cam might not make much vacuum, and you're running vacuum secondaries. I'm not that smart with carbs but I think most desert racers would run mechanical secondaries, I know I do.

Before messing with the air cleaner I'm going to check the fuel pressure next weekend and check that off the list. It does open up the secondaries well though! I'm going to have to figure out a different way to do the intake it that's the problem though

[pkonopasky]

X2, those with the offset inlet create a swirl over the top of the carb that screws with the highspeed air bleeds. Get the larger one with dual inlets. Dynoing a 430SBF with one of those versus a 14" air cleaner lost us 75HP. The larger dual inlet plenum was about the same as the 14"...........

Where do you suggest to get a dual inlet plenum? Would that be a good route to switch to?

[pkonopasky]

Check the screen IN your fuel pump.... take off the bottom plate

I'll pull it apart before I take it out next! Thanks!

[partybarge_pilot]

Where do you suggest to get a dual inlet plenum? Would that be a good route to switch to?

The UMP one is bigger, could be bigger still.....