Mad4slalom
Well-known user
Hi all , seen this pipe mentioned a couple of times, read it can help with fuel evap from bowls when hot. Any thoughts ?
TiA
TiA
Holley query
- Thread starter Mad4slalom
- Start date
Roscobbc
Moderator
The septics will assure us that is a 'Bubba' device. If the carb is in good order, set-up correctly and float levels are correct........the only thing you'll get coming out of those 'vents' is possibly raw fuel in the event of a primary or secondary float needle failure where perhaps a piece of crap get wedged under the needle and allowing the float bowl to overflow and possibly pour out of the vent. Honestly......if the fuel overflow is that bad and you haven't noticed it all the rubber tube will do is make matters far worse and perhaps fill the inside of the air filter, and indeed the inlet manifold with raw fuel...........get a backfire and you are seriously toast.......literally!
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Mad4slalom
Well-known user
Thanks ross
Mad4slalom
Well-known user
Thanks captain, mine is fine for15 mins restarting from hot , 20mins or more and I have to pump gas pedal as fuel has disappeared , motor runs really cool so pretty sure it is not boiling away , presume just evaporating. Carb not hot to touch. Just how it is I guess.
Roscobbc
Moderator
It's worthwhile 'tracing' fuel line to fuel pump/then to carb and see how close to a heat source (exhaust manifold/header tube) it gets. Options (if too close) are to re-route the fuel line - or wrap it with insulation. On mine fuel lines (and break lines) in the engine compartment run sling the top of the chassis........not particularly close to a header tub.......I simply sourced some of that self adhesive aluminium cellular insulation/heat shield materia, cut to length required, then cut that about an inch or so wide, peel-off the backing, slide it under the fuel/or brake pipe and effectively wrap the pipe. Seemed to help mine.
Mad4slalom
Well-known user
Oneball
CCCUK Member
That’s the bubba version of the Holley Off Road Vent Tube. Its purpose is to stop raw fuel splashing out of the float chambers and into the inlet at severe angles of attack and heavy braking. It can help if the fuel is boiling in the float chambers and fuel lines and this expansion is putting raw fuel out of the vents into the intake. If your car won’t start because it’s flooded after sitting it might help but if it won’t start because the fuel has evaporated it won’t.
Mad4slalom
Well-known user
Yes my hood has been “starred” by making contact with the air cleaner wing nut. 🫣
Roscobbc
Moderator
You get over a limited height manifold - carb - air filter 'issue' if you have an 'open' fllter by using a 2" instead of 3" deep element and replacing the stock air filter 'top' with a K & N Airstream filter 'top' to make-up for the reduced filtering capacity.