750 holley 3310-2 question

[Black_Sheep]

Good info for verifying Holley factory configuration

https://documents.holley.com/techlibrary_carb_numerical_listing.pdf

 

[33 IMP]

I can't recall. Does a 3310-2 have a metering block or a metering plate on the secondary side? Original 3310 had blocks on both ends.
And agree with above. Bad pv or you're well into the transfer slot at idle. Use the screw (that's missing) to open the secondaries a bit.

 

[padam]

3310-2 has a plate

 

[Canadian1968]

this right here is a PERFECT example of then an wideband 02 sensor is SOOOOOOOO helpful.

 

[velrob]

When did the problem you discuss in your first post occur, relative to your quoted statement above? Before or after? Why did you “…change everything “?

The carb was pretty bad it, came off the car when I bought it. So I cleaned it up and replaced everything

 

[velrob]

The wrong power valve does NOT cause a rich idle! A leaking PV will!

Do NOT drill holes in t/blades until other possible causes have been ruled out.

That cam in a 383 is going to NEED about 25* of timing at idle. Possibly more; less than that can cause your problem, which is likely the pri blades open too far. Increasing idle timing from the generic factory setting will increase idle rpm; this, in turn, will allow blades to be closed further so that the idle cct works as designed.

I was wondering if that would cause the issue as well. Right now we are at 11 timing. I'm going to try raising it to 18 initial timing

 

[BSB67]

The carb was pretty bad it, came off the car when I bought it. So I cleaned it up and replaced everything

You really didn’t answer the questions.

If you give us some detailed history, it would help.

 

[velrob]

The carb was pretty bad it, came off the car when I bought it. So I cleaned it up and replaced everything

Sorry I read your post quickly

This is a rebuild on the motor and carb. We are just tuning it for the first time. Besides the break in we ran it one more time to try to fix the rich problem and stopped after that when we saw the needles didn't do anything fully seated and kept running

 

[BSB67]

Sorry I read your post quickly

This is a rebuild on the motor and carb. We are just tuning it for the first time. Besides the break in we ran it one more time to try to fix the rich problem and stopped after that when we saw the needles didn't do anything fully seated and kept running

Okay. So this is a totally redone motor that has never run right, and you believe that the carb is the problem.

You have a lot going on there. I would try to find a known good carb just to get the motor running and eliminate one variable.

If not, here are my top picks:
1) PV/gasket not installed correctly,
2) leaking needle and seat
3) float too high
4) intake manifold vacuum leak, or other

It could be other non carb items too.

 

[velrob]

Ya I may buy a new carb. I'm gonna take a look at the power valve and if it's obvious I'll try that and if that doesn't work I'll try increasing my timing

 

[Geoff 2]

Post #19, Black Sheep.

With the utmost respect to you, this is where ignorance sets in. My car, when it was idling on the showroom floor, idled with 26* of idle timing.
It had a cam that had 25* less duration than the XE 268cam....
See below about idle timing. It changes with cam duration.

 

[Geoff 2]

Just to add.....
I just finalised carb tuning today on a 440. Sol roller cam, 10.5:1 Trick Flow heads, headers, M1 Single plane intake. 850 TQ carb. Best idle was with 44* BTDC.

 

[RemCharger]

Tq on on a trickflow head lol. Yall really did run out of money lol. Good luck