[Dick Boneske]

This applies to all carbureted engines, including Tripower cars.

When you drive your car and park it for more than a week, startup takes a long time. This is due to the gas in the float bowl(s) evaporating through the 1/4" vent hole in the top of the carbs and the idle vent on the center carb.

To avoid unnecessary grinding of the starter and discharging the battery each time, some of us squirt gas into the center carb and experience instant startup.

I've been thinking about making a plug to put in the vent hole on my center carb to prevent evaporation. Something like a golf tee would work in the vent pipe, or better yet something resilient that may seal better. I've been wondering if anyone else had done this. It is kind of a PITA to pull off the center air cleaner to install such a plug, but how else could this be done?

For the idle vent, you can simply open the throttle a little after shutoff and lift the fast idle cam to keep the idle vent from being lifted off its seat. That will seal that hole.

Ideas?

[Tom Vaught]

Good Idea, but I can't remember these days where I put my coffee cup, much less remember some plug device to keep the fuel in the bowl longer. Guaranteed the engine would eat my device at some point. This might help though.
Tom V.

[Dick Boneske]

Originally Posted by Tom Vaught

Good Idea, but I can't remember these days where I put my coffee cup, much less remember some plug device to keep the fuel in the bowl longer. Guaranteed the engine would eat my device at some point. This might help though.
Tom V.

Right on!!

[Old Man Taylor]

The other way to do it is to add an electric fuel pump.

[AdamIsAdam]

I don't mind the 5-8 seconds of cranking. I figure it gets the oil circulating a bit before the engine fires up. My battery is strong since it's always on a tender.

But I must admit, it's annoying and even a little embarrassing when the neighbors watch what they think is a hard to start old car. So I too have thought about ways to combat this.

[Jack Gifford]

Originally Posted by Old Man Taylor

The other way to do it is to add an electric fuel pump.

Ditto.

[pfilean]

I didn't like the long cranking so I put in an electric pump. But I didn't want to do the interlock using oil pressure like the new stuff does. So I put it in with a parallel check valve and let the mechanical pump do the run duty and the electrical ran only with a push button. But I thought the check valve was a restriction and put extra strain on the mechanical pump. So I changed it to use a switch over valve like the trucks with dual fuel tanks use. The valves with 3/8 fittings are wired to run only long enough to change from one tank the other and then not use any electricity until the switch says change again. So for one of the valve settings the electric pump runs and then after I release the DPDT momentary contact toggle switch it changes back and has no restriction on the mechanical pump. Works great and unless you look under the car you never know its there.

[Dick Boneske]

Good thoughts. If it was only 5-8 seconds of cranking, I'd be OK with that. It is, however, about 35-50 seconds with my two '64 Tripower GTO's. I'm sure the starter is quite hot by the time the engine fires. Yes, there is oil pressure by that time!!

[AdamIsAdam]

Originally Posted by Dick Boneske

Good thoughts. If it was only 5-8 seconds of cranking, I'd be OK with that. It is, however, about 35-50 seconds with my two '64 Tripower GTO's. I'm sure the starter is quite hot by the time the engine fires. Yes, there is oil pressure by that time!!

Oh my! that's a lot of cranking! I'll time mine next time. I know I never let it crank more than about 5-8 seconds, then I stop, wait 1-2 secs, and crank again. It usually fires by the second cranking burst.

Of course, I'm having my 1/2" fuel system installed at this very moment, so who knows if that will help or hinder this situation! (RobbMc pickup and pump from tank to pump, then 3/8" to carb. Mostly stainless steel lines the full run. 100 micron filter in-line about half way, and 40 micron at the carb.)

But at 35-50 seconds of cranking, I'd definitely be looking at other solutions.

It seems to me that in keeping with the KISS methods, you should start with the vent cap idea first, followed by the "pouring fuel into the vent tube" method, and resorting to the time and expense of electric fuel pump last. Unless this is just the excuse you were looking for to make that upgrade anyway

[pfilean]

But at 35-50 seconds of cranking, I'd definitely be looking at other solutions.

I never actually timed it but I know it was too much time. By the time I could get it started the battery cables would be so hot the insulation was starting to melt near the crimp at the terminals. Just normal parts store 4 ga crap. I was sure I was just ruining the starter. So I had new cables made from 2 ga welding cable. Much better now but I will still hit the electric primer pump for a bit before I hit the starter,

[Tom Vaught]

I have posted my deal with the electric fuel pump and the 3/8" orifice electric check valve,
similar to pfilean's deal, several times.

My deal, you turn on the fuel pump, watch for fuel pressure on the gage to stabilize, give the engine two pump shots with the double pumper carb, wait about 5 seconds and then turn on the key. fires right up because I use a old Holley 850 DP carb with a mechanical choke. Just bangs away at 5" of vacuum on the gage.

Tom V.

[barrierblue66]

Originally Posted by Dick Boneske

Good thoughts. If it was only 5-8 seconds of cranking, I'd be OK with that. It is, however, about 35-50 seconds with my two '64 Tripower GTO's. I'm sure the starter is quite hot by the time the engine fires. Yes, there is oil pressure by that time!!

I'm with Adam. Both my 4 barrel and tripower cars never take the 35-50 seconds. Definitely around that 10 -12 second mark, stopping in between if a really long time sitting but I like to use my cars alot. The 4bbl does start a bit quicker.

Ken

[ho421]

Adding an electric pusher pump (with a bypass) was one of the best decisions i made. So easy to start with minimal cranking and the pusher is ON when i want to "give'er the beans"

[1stgenbird]

My 4 bbl starts up pretty quickly but my tripower taked a lot of pedal pumping and cranking.

[Dick Boneske]

Originally Posted by 1stgenbird

My 4 bbl starts up pretty quickly but my tripower taked a lot of pedal pumping and cranking.

The evaporation rate would be about the same, due to the vents in the airhorns, but the Tripower has about three times the volume of gas with the three float bowls. It takes more time to get enough has into the center carb for the accelerator pump to function.

A Quadrajet would take less time than a Holley or Carter AFB for the same reason--the Quadrajet has a tiny float bowl compared to the others.

With the comments so far, I'm leaning toward squirting gas into the center carb vent tube after turning the engine over 'til there is oil pressure. A bottle like restaurants use for ketchup would be just right--with the pointed nozzle--and it's red for safety!!

[Tom Vaught]

I rebuild carbs for people occasionally in my driveway I like Metal Cans for gasoline so I painted a squeeze lever oil can "RED" (The rest are silver) and when I do a carb rebuild I give the vent(s) a few good squirts with the oil can and one or two pump shots and the engine will fire right up.

Not a big fan of large fuel cans next to my house. Gas for my lawnmower, etc stays in my shed.

Tom V.

[michaelroy]

Mr. Vaught could you give me more info on brand, vendor, and install location of your elec. pump.
Been using the squirt method and it's difficult if you are alone. Usually end up pouring rather than squirting.
Than you sir and thanks Dick for the interest.

[AdamIsAdam]

This thread may help:

http://forums.maxperformanceinc.com/...5&postcount=10

the full thread link is: http://forums.maxperformanceinc.com/...ht=pusher+pump

[Dick Boneske]

The squirt method can be done two different ways--pertaining to the center carb of Tripower.

If you squirt gas into the airhorn where the venturi clusters are located, it runs past the throttle plates and the engine will fire instantly. If you squirt gas into the vent tube at the front of the airhorn opening, it goes into the float bowl. The accelerator pump will work with only a small amount of fuel in the bowl if you're using a Pontiac center carb (some other Rochester carbs such as Chevrolet have a different supply source for the pump). This method will give quick startup, but not as fast as if you squirt directly into the venturi area.

Please read the letter I posted here from the July issue of "Muscle Machines" magazine. This is about a '68 GTO with a Quadrajet. Read about the extent this guy went to fix a problem that cannot be fixed. I see so many Tripowers with Teflon tape wrapped around the inverted flare nuts--which does absolutely nothing.

[AdamIsAdam]

Has anyone tried using one of these check-valve fuel filters for the carb? Would that really help prevent the bowls from emptying the gas?

https://quadrajetparts.com/short-pap...8f31c3bf094c34