351w w/2bbl - running lean 6k+

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351w w/2bbl - running lean 6k+

Unread postby nm12oval » Sun Jul 21, 2013 4:28 pm

hello Mike

what no place for racers like me?

i run lean 6000+ rpm
351w+.030, 8.5 compression, 2100 -1.23 2bbl. no butterfly

any thoughts?

1/2 mile asphalt oval

Paul
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351w 2bbl., C4, 390 open rear
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Re: 351w w/2bbl.

Unread postby decipha » Sun Jul 21, 2013 8:25 pm

Hey Paul !

There's a racing results section at the bottom of the index page
viewforum.php?f=15

have you tried rejetting it?

whats the full carb specs? and engine specs as well, do you know about how much power its making? Do you have an electric pump? what size? also what pressure are you running?
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Re: 351w w/2bbl.

Unread postby decipha » Mon Jul 22, 2013 3:13 pm

nm12oval wrote:what no place for racers like me?


done!
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Re: 351w w/2bbl.

Unread postby nm12oval » Tue Jul 23, 2013 1:55 pm

OK

351W Stock, 8.5 compression, stock dished pistons (70's) about 29cc
Cast iron 2bbl. intake (70's)
87 Fox exhaust manifold
2100 2 bbl. carb., 1.23V (about 358cfm) No choke plate.
1" 2 hole spacer.
92oct. gas
manual fuel pump

I hit just over 6000rpm. (twice A lap, lol)
Allu Radiator, twin core racing.
factory elect fan., 3/4" hole restrictor

:?
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351w 2bbl., C4, 390 open rear
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Re: 351w w/2bbl.

Unread postby decipha » Tue Jul 23, 2013 3:46 pm

whats heads and cam do you have in it? i need to have an idea of about how much power its making before i can recommend any carb adjustments
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Re: 351w w/2bbl.

Unread postby nm12oval » Tue Jul 23, 2013 5:59 pm

Hello

Heads are GT40p's
Cam stock lift. about 234* duration. .447I .472E

Carb uses Holley style jets. I have 76's in.
Power valve of 4.5
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351w 2bbl., C4, 390 open rear
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Re: 351w w/2bbl.

Unread postby decipha » Wed Jul 24, 2013 10:58 am

I would guess that engines only making about 290rwhp

you must have a motorcraft carb, you either have a fuel supply issue or you need a larger needle and seat 1.35-1.4 would be typical
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Re: 351w w/2bbl.

Unread postby nm12oval » Wed Jul 24, 2013 2:05 pm

decipha wrote:I would guess that engines only making about 290rwhp

you must have a motorcraft carb, you either have a fuel supply issue or you need a larger needle and seat 1.35-1.4 would be typical


Hello

I'd be lucky to have 290rwhp

Yes, A 1963 2100 2bbl. carb. 1.23V (358cfm)

larger needle and seat 1.35-1.4??
:?
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351w 2bbl., C4, 390 open rear
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Re: 351w w/2bbl.

Unread postby decipha » Wed Jul 24, 2013 4:01 pm

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90 (4x 5spds) - Dante, Ruby, Daja, Ava
91 4r70w - Skarlett
92 (2x) 5spd & auto - Bianqa, Andrea
93 auto - Danika
94 5spd Rionda
95 auto Aisha
Vehicle 2 Information: Others:
00 Lincoln LS - Luanda
98 Camaro SS - Bounquisha
02 Harley F-150 - Sasasha
03 Marauder - DyShyKy
00 Explorer 5L - Bernyce

Re: 351w w/2bbl - running lean 6k+

Unread postby JETFAST » Thu Feb 04, 2016 4:34 pm

This is an old topic, but I will add my 2 cents regardless.

If you have enough fuel pump The needle and seat need to be .110 or larger. As you go up on the needle and seat you need to reduce the fuel pressure. those classes usually dont allow a regulator. you need the largest volume pump with the lowest fixed psi. The carter pump is what i recommend and use.

if you have enough fuel volume then the issue is the needle and seat. I run .150 SS for this exact reason.

It's not as simple as just changing it out.

as you go up on the needle and seat orifice, (say .110-.150+) the trickier the float adjustment gets, and the less fuel pressure is needed, or you will sink the float, trying to close the needle on the seat, the float displaces fuel, the needle then doesn't have full travel, and the higher fuel pressure across the seat causes turbulence and bubbles. Bubbles are bad! You only have one fuel bowl, so it needs to stay as full as it can, as long as it can, with the least amount of white wash and bubbles as possible.

The larger the seat, the lower the fuel pressure needs to be, to keep the float and fuel level high and the bowl full, and offset any chance of bubbles in the fuel bowl. These Carb's pull vacuum at wot, and usually pull over extra fuel out of the pump shot, without a siphon break in the circuit. This usually causes a rich condition in most cases I deal with.

The power valve is very important too. 4.5 is a good spot to be. Some times i set them up with a 3 or 3.5 to aid in high speed lean out. i'm my throw down stuff I block it.
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