2 bbl. Motorcraft & a dwell cam

[Alex Denysenko]

Originally Posted by goinbroke2

just thought of something else, you have 1/4" holes in the plates, i wonder if this is too big and effecting the t-slots. What i mean is, since so much air is going through the plate instead of having high speed air going by the t-slots, i wonder if this is why the fuel is coming out in blobs instead of atomised, which caused you to turn the idle up, which made it worse, so you turned it up more, etc, etc?

Try plates with 1/8" holes and see what happens, you might get some vacuum back and it might clean up the idle so you can use the screws/lower the blade angle closer to the t-slots.

i would say bingo,there be your high idle problem those carbs are very sensitive in that area, they also don't work well with power valves in race applications

[Dave Noll]

Looks like I've got some more experimenting to do.

[Phillip marvetz]

You mentioned the circle track guys turning 7000 rpm. I'm curious what duration cam they use......

[Dave Gantz]

Originally Posted by Phillip marvetz

You mentioned the circle track guys turning 7000 rpm.

Maybe they get to 7000 grand decelerating using the car's weight to push the motor!

[Dave Noll]

Originally Posted by Phillip marvetz

You mentioned the circle track guys turning 7000 rpm. I'm curious what duration cam they use......

When I was involved with that, the cams came straight from the catalogs & dwell cams were unheard of. #'s ? too long ago.

[Phillip marvetz]

The local Cleveland guru we had around here in the 70s always used Schneider cams. It might be worth giving them a call and seeing what they have to say.

[Phillip marvetz]

Just looking at their website they show this one good for 7000rpm. Not a lot of duration there.

Part Number: 0316
Grind Number: 290-0H
Intake Duration (gross): 290
Exhaust Duration (gross): 300
Intake Duration (.050”): 230
Exhaust Duration (.050”): 240
Intake Valve Lift*: .536"
Exhaust Valve Lift*: .536"
Lobe Separation: 110
Intake Valve Lash: .000"
Exhaust Valve Lash: .000"
RPM Range:
3000-7000

[Dave Noll]

Well I futzed with it this weekend & got it to idle better. I tried throttle plates with an 1/8" hole, played with boosters, power valve block, air bleeds, float level & some other stuff. It now idles on the mixture screws w/adjustment, nothing coming out of the boosters. I can idle it down, some, without it dying. It's a lot snappier. But I am back with the 1/4" hole throttle plates. Just gotta get it back on the track & see what I've done to WOT jetting & if that 5800 thing is the springs or carb. Thanks for the input. Appreciate it.

[Mark Yacavone]

Originally Posted by Dave Noll

OK, lotsa input, thanks. Timing is @ 36 initial & 42 total. I bought a box full of these 2 barrel's off E-bay so I have some spare parts. I took all the jets to work & reamed them to between .064" & .070" but I don't know what that would convert to in a Motorcraft jet #.

G.A. - I'm curious what your 2G measures in the venturi & throttle blades.

Ed - Yes it idles best with the mixture screws closed, with the spare parts I've got I might go close up the transition slot too.

Billy - Without giving away secrets, what #'s roughly should the cam have? (or just tell the grinder 6K ?) Going smaller cam would be more palleteable than all the really stiff springs thick wall large dia. pushrod deal. But I'm almost committed to the higher RPM deal at least convertor-wise. I spent the money & got a nice one that will stall 5200 if I get my tune/gearing where it's supposed to be.

When I got the car to the track this year, the motor ran into a wall @ 5800. With what the cam company told me about the profile & the springs I have on it I figured that wall was valve float. Opinion's on if it was the carb ? It's a 1.21/1.68.

David, I wouldn't worry too much about the converter situation. The stator can be changed ,which will lower the stall and change the characteristics of it.
That might end up being the way to go anyway.

[Dave Noll]

Thanks Mark. If that wall is the carb, that's probably the route I'll go.