I’m baffled (1 Viewer)

[mrtodds77]

I have a Holley 350 2 barrel on my 1969 FJ40. I tried to take it over the Miller Jeep trail in SoCal but my pig just kept flooding and stalling whenever it got on an incline. I eventually had to get towed out.

I read up on the issue and found out I needed to baffle my carb. It seems silly to me that Holly would not design this into all their carbs. The carb floods on any incline. I could be in any car in SF and hit an incline and the car would flood as well. Not to mention if you have an electric fuel pump it would just keep gushing fuel out and it would be a major fire hazard.

I know I should probably get another carb but for $30 I thought I would try to baffle it and see what it does.

 

[mrtodds77]

So here is my off-road kit. 1 baffle whistle, 1 spring loaded vale and needle, and one slightly longer vent tube.

 

[lcwizard]

I haven't had a carburetor on a 40 since 1990 but in the 70s and 80s I tried Holley, Carter and Weber. Holley made an "off road"
kit that extended the vent tube and included a float bowl baffle. I don't know if it's still available but I know the Holley never worked as well as the stock carb. It wasn't even in the competition. I started throw GM injection on in 1990 and never looked back.

 

[brian]

Holley is a name in muscle and stock car racing....not much in the way of inclines and off chambers in those worlds.

 

[mrtodds77]

I put some marine JB weld on the baffle to keep it sealed and in place. It says it is petroleum resistant. We’ll see.

Getting the old vent tube out was the hardest part. I couldn’t get a grip on it with my vice grips or my needle nose pliers. I carefully ended up using a reverse drill but inside the tube to get it lose. After it was out I blew out the vent and tapped in the new longer one with my hammer.

 

[mrtodds77]

The spring loaded needle valve was interesting to install. I had to take my float valve cover off twice to to this right. You have install the needle with the float upside down so you don’t lose the spring. I took care to notice how many threads the old needle had exposed so I could adjust this one the same.

 

[mrtodds77]

I still had a problem after the install. When I turned on my key and electric fuel pump I kept getting gas flowing out my main shaft onto the headers. I didn’t think that was safe.

I had to adjust my float down a little more to stop the flow of gas. I think the float was always too high but installing the baffle kept the vent open which allowed the gas to keep coming.

I think I am much safer now. And hopefully ready to OFF-ROAD!

 

[Downey]

mrtodds, the Holley 350 float bowl baffle and chimney kit have been in my ebay store forever, see ebay #254041028091, especially pay attention to the 3 drawings with the photos. This is a 1,000% cure all for the Holley's:
1. Use JB Weld to install the whistle tube, it seals around the edges.
2. Make sure you don't have a blown power valve, common Holley problem.
3. Check ebay for a Holley #125-207 (extremely long shot), it's a dual stage high altitude power valve, and boy does it work- - -I had a screaming hot rod at 8,000 ft.

 

[mrtodds77]

Thanks Downey. I thought you went out of business. I read some of your old posts about this solution. I may not have purchased your kit but I did get one similar.

Glad to know you recommended using JB weld to attach and seal tgbecause that is what I did.

 

[mrtodds77]

Downey, I think my power valve is ok. But I will do some tests. Do you know of a good test to determine this?

 

[lcwizard]

You still won't win a rock crawl competition unless your Holley logo is followed by the word Sniper. A great carb like the aisin will
get you over 75%. A Rochester, or modified Carter and Holley might work 60% of the time. Rochesters ( original quadrajet )
because of their needle and jet design handled bouncy inclines better than the Holley or Carter. Edelbrock bought up the Q-jet design but for some reason I don't think they run as well as the originals. Then again it may be I've gotten used to fuel injection

HOLLEY 2 BARREL OFF ROAD CONVERSION KIT, AED BG DEMON GRANT QFT CARBURETORS | eBay

Fits Holley model 2300 performance 2 barrel carburetors such as 4412, 7448, etc. and most similar AED, BG, Demon, Grant, and QFT carburetors.

www.ebay.com

 

[Downey]

The spring loaded needle valve does nothing for most off road/off camber/incline angles. They are primarily intended for float bowl "bounce" on studder bump flat dirt roads (which Baja is full of, ala south of San Felipe). I believe a slightly better choice than Wizards choice above would be to use my ebay #254041028091(listed in my post above) because it includes the float bowl baffle, and a much taller vent chimney. Then if you are lucky enough to get ahold of a Holley #125-170 high altitude dual stage power valve, then you have solved all of the Holley float bowl issues, plus set the carburetor up for fantastic running in 5,000 to 10,000 ft. altitudes.

So, I've said before, and I'll say again; the only guys who didn't like a Holley 350 in off road terrain didn't have their float bowl set up properly for off road use, and those who did loved their Holley- - -easy deal.

 

[yotadude520]

The spring loaded needle valve does nothing for most off road/off camber/incline angles. They are primarily intended for float bowl "bounce" on studder bump flat dirt roads (which Baja is full of, ala south of San Felipe). I believe a slightly better choice than Wizards choice above would be to use my ebay #254041028091(listed in my post above) because it includes the float bowl baffle, and a much taller vent chimney. Then if you are lucky enough to get ahold of a Holley #125-170 high altitude dual stage power valve, then you have solved all of the Holley float bowl issued, plus set the carburetor up for fantastic running in 5,000 to 10,000 ft. altitudes.

So, I've said before, and I'll say again; the only guys who didn't like a Holley 350 in off road terrain didn't have their float bowl set up properly for off road use, and those who did loved their Holley- - -easy deal.

I'll second this. Any carburetor that's going on a 4x4 or crawler needs have the float lowered 3-6mm to account for angles. Did that in my 1980 pickup and it never stalled going up steep obstacles!

 

[Downey]

Downey, I think my power valve is ok. But I will do some tests. Do you know of a good test to determine this?

Yes, slowly turn in your air/fuel mixture screws, if power valve is good engine will start to die, if power valve is blown engine will just keep running since it is not shutting off the flow of fuel. 1992-older Holley power valves could blow out with an engine backfire, 1993-newer power valves have been improved and won't blow out if engine backfires.

 

[mrtodds77]

On the needle valve, I was suspecting that it would do little in an off-road rock crawl world. But it may help in some situations in the future so for a few dollars it couldn’t hurt.

I did find a power valve 125-170 on eBay for about 45. I do want to go off road at altitudes like rubicon so I may install that as well. Is the install straight forward? Or do I have to take everything apart?

 

[Downey]

You merely unbolt the float bowl (4 screws), pull off the metering block from it's dowl pins, then unscrew the old power valve, install new power valve with new washer gasket, then possibly need new gaskets when re-installing the metering block, float bowl, and 4 screws.

 

[mrtodds77]

I checked my manifold vacuum and adjusted my HG until I got to 18 HG. It was only 1/2 turn up from closed on both idle mixture screws. So I think that means I need a power valve that opens at 9 HG. The 125-170 power valve recommended by Downey has the first stage open at 9 HG so that sounds about right.