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12 Hole Booster Holes?
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Author:  Ken0069 [ Sat Jan 15, 2011 7:05 pm ]
Post subject:  12 Hole Booster Holes?

Is it possible to increase the .058 hole in the 12 hole booster to something near .080? Using Mlayton's 40% theory my .235 banjo would need those 12 holes to be .080 each? :-k

Author:  shrinker [ Sat Jan 15, 2011 7:15 pm ]
Post subject:  Re: 12 Hole Booster Holes?

Yeah, you can add more holes or increase the size etc or make your own booster inserts with a larger back side channel. Whatever you need. Check and calculate all dimensions of the fuel flow pathways.
Making the booster holes more area will alter the tune on the emulsion and the main jet.

Author:  mslayton [ Sat Jan 15, 2011 9:15 pm ]
Post subject:  Re: 12 Hole Booster Holes?

I already installed my inserts so I can't check the spacing, but the holes would begin to be close together. It is a billet piece so it would be much stronger than the stock cast parts so I'd imagine it would holdup when you install them. Your best bet might be the slot approach jmark is using. You could have three larger slots while still having a decent amount of material between them.

Author:  jmarkaudio [ Sat Jan 15, 2011 9:50 pm ]
Post subject:  Re: 12 Hole Booster Holes?

That is why I used billet inserts, cast may break when pressing in if you drill too much.

Author:  ron [ Tue Jan 18, 2011 9:41 am ]
Post subject:  Re: 12 Hole Booster Holes?

Ken0069, I have some notes of a couple of sets of inserts from QF that i measured up, one set was a green 17 hole insert for e85. There are 12 lg holes at .070 and 5 sm at .040 with a .218 pin. The other set was a blue insert for meth, it had 8 holes at .090 with a .230 pin. These are the inserts you would get in a kit from QF.They like to add 5 extra holes on the e85 inserts for more area rather than opening up the 12 holes. This is how QF must like to add area with e85.

Author:  Ken0069 [ Tue Jan 18, 2011 11:19 am ]
Post subject:  Re: 12 Hole Booster Holes?

Ron you say they have a .230 pin? I'm going to assume this is the booster pin and if so is that ID or OD? If that's ID it's about .005 short of what I was looking to try as I have successfully drilled a banjo out to .235. My other meth carbie has .213 pins and they are way too small but that .230 looks like QF has found the same problem I have!

I want to be able to run a .225 jet I'm thinking the .230 pin at the other end of that circuit would be too small too. I'm also looking at doing something besides that pin deal to hold the banjos in place, which may include cutting off the outer support leg?

Just imagine the possibilities! :-k

Author:  ron [ Tue Jan 18, 2011 12:18 pm ]
Post subject:  Re: 12 Hole Booster Holes?

Ken0069 Wasn't sure so i called and talked to QF about there largest id pin, a .218 id pin is what they use and it is a .235 od.

Author:  jmarkaudio [ Tue Jan 18, 2011 2:49 pm ]
Post subject:  Re: 12 Hole Booster Holes?

Those 5 small holes on the 17 hole are probably located at the main passage exit in the banjo, trying to enhance fuel dispersion at low airspeed, atomize the fuel better. They use those on the 1450 carb they build. Might help on gas, not sure E85 would like it, might be worth trying in addition the slots on mine. New 9x19 lathe came in today, I'll get a puller made for the inserts and try some things after I see where I am at with the AFR and fuel curve.

Ken, if you have a lathe I've thought about threading the main body and making removable pins. Sort of like BG uses on the Demons, but instead of threading the booster for a nut use a thread in pin.

Author:  Ken0069 [ Tue Jan 18, 2011 8:20 pm ]
Post subject:  Re: 12 Hole Booster Holes?

BLP booster numbers 5102/5104/5108 all are listed as billet .500 hole but they don't say what the difference is between these part numbers???? Anyone know what the difference is?

Author:  mslayton [ Tue Jan 18, 2011 9:18 pm ]
Post subject:  Re: 12 Hole Booster Holes?

I just bought the 5102's which are .500 ID with .050 flat bottom. The 5104's are a tapered bottom and the 5108's are a tapered bottom for Alcohol.

Author:  Ken0069 [ Thu Jan 20, 2011 4:44 pm ]
Post subject:  Re: 12 Hole Booster Holes?

Went to place an order today with BLP for 5 banjos, 4 boosters and two sets if intake gaskets for my SBC and shipping was $21??? DAYUM!! Dropped the intake gaskets off the order and it was STILL $21 shipping!!?? [-(


FYI, I called about those 5108 methanol 12 hole boosters and they have .078 holes in'em, which is within .002 of the size I want to use in this alky carb. The 8 hole 5108 boosters have .096 holes. If I can open up the 12 hole booster to .080 then I get almost the same area as the 8 hole one with the .096 holes.

Author:  ajcasini [ Fri Mar 25, 2011 4:46 pm ]
Post subject:  Re: 12 Hole Booster Holes?

I like the 12 hole boosters. I drill them out to .068 - .070 and seem to work the best so far.

I also have a set of the QF 17 hole boosters but have not run them to this point. I basically bought the kit as I was going to try a 3-circuit conversion with the kit but after doing some numbers I felt as though I could not get enough fuel through the main wells.

If any of you guys want to experiment with these blocks let me know I have them.

AJ

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