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Author Topic:   Alcohol Bypass
chomme
Dirt Freak

Total posts: 308
posted November 27, 2005 03:47 PM  
I dont know about the one you got but the BG is a good unit. I got one and it works very well. I put mine on the back side of my fuel rail and had just enough room to put the return to the cell under it.

NJantz
Dirt Forum Champ
Total posts: 763
posted November 29, 2005 08:11 AM  
On my KSE we had the same problem. Tried about everything and finally put on the BG Diaphragm bypass and got her tuned into shape. On my buddy's car he's got a Ron's pump and runs the BG piece.

brownstone
Dirt Freak

Total posts: 291
posted November 29, 2005 08:58 AM  
I run the Rons pump and it works good, but I have never had any luck with the pop off deal, we switched to the BG valve and have not had any trouble in years. Pitch the pop off, and buy the $60 BG valve and problems will go away.

nine finger
Dirt Forum Racer

Total posts: 93
posted November 29, 2005 04:27 PM  
it probably has a 070 jet in it will probably have to go to a 090 to drop the pressure. as long as it will idle dont worry about the fuel pressure being to low at idle. less than one pound is usually where were at with the 090 jet.

jhswords
Dirt Roller

Total posts: 9
posted November 30, 2005 06:21 PM  
quote:
Originally posted by brownstone:
I run the Rons pump and it works good, but I have never had any luck with the pop off deal, we switched to the BG valve and have not had any trouble in years. Pitch the pop off, and buy the $60 BG valve and problems will go away.
i am runnig alcohol for the 1st time this comeing year what is a BG valve


rocket36
Dirt Freak

Total posts: 228
posted November 30, 2005 08:57 PM  
BG (barry grant carburation) diaphragm bypass valve. it is a pressure regulating valve that is placed in the fuel return line (usually on the back of the fuel log). contains a small jet that controls fuel pressure at idle and a diaphragm on an adjustable spring to allow you to set a different fuel pressure (and control it) at wide open throttle.
kind of a constantly variable device to regulate fuel pressure which allows it to be matched to pressure requirements throughout the rpm range.
they are most commonly used with belt drive & direct mount rotary pumps.
once they are set, they are pretty much hassle free, and the carburetor maintains good response right throughout rpm range.
Barry Grant, BP, & Holley all make similar products.
We run a Holley diaphragm bypass in conjunction with a BP belt drive pump on our late model and have an engine running in a limited sprintcar running a BG bypass with a hilbourn direct mount pump.
Avoid the poppet style bypass deals and leave the pill returns for constant flow injection.

Kromulous
Dirt Forum Champ
Total posts: 822
posted December 01, 2005 09:52 AM  
Pay close attention to your fuel line sizes. Thats where alot of problems come from i believe.

We run -10 on supply, and -8 on return.

Ultra high HP, 800-900 plus i would run -12 and -8 respectivley.

Most will say -8 supply and -6 return will suffice, but i dont buy it. We dont aim to suffice in racing.

Also were running the BG Diagrahm Bypass valve, works great with a BG Pump, or Ron's.

Krom.

[This message has been edited by Kromulous (edited December 01, 2005).]

[This message has been edited by Kromulous (edited December 01, 2005).]

chomme
Dirt Freak

Total posts: 308
posted December 02, 2005 02:31 PM  
Thanks for all your help. I'm tossing the rons pill bypass...and have a new BG here, however, I also found I had one of the Willys load sensitive bypasses (same as a bg, just has the vacuum line to open the bypass quickly on decelleration) and am going to run that. I called Willys, for like $14 or so, they are sending me a new diaphragm, spring, and three new air bleeds to set the pressure. Thanks much!

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