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-   -   Fuel pump? (https://forums.maxperformanceinc.com/forums/showthread.php?t=873476)

dhcarguy 05-02-2024 10:57 AM

Fuel pump?
 
will adding 1 or 2 gaskets between pump and block lower fuel pressure?

Thanks, Dave

steve25 05-02-2024 11:25 AM

Can't say for sure, but in theory the thickness of the gasket used will reduce pump arm travel.

Do you know for sure that your fuel pump eccentric is bolted on correct?

What Carb are you running and are you having issues with flooding out?

Schurkey 05-02-2024 04:12 PM

I'd expect that would lower volume, but not pressure. May be so slight that you'd never notice.

Pressure is set via the internal spring.

dhcarguy 05-03-2024 09:41 AM

I have a 65 with TriPower. For years ,I dealt with the air horn gaskets oozing fuel and sometimes the throttle body gaskets also. I finally installed a Holley 804 fuel regulator. Before I did, I temporally put an in-line pressure gauge. My pump was putting out 6 psi. That was my problem. I took the car out yesterday for a long ride. Temp outside was 80*. When back home, I opened the hood , and there was NO gaskets oozing. I did set the regulator to 3 psi.
The reason I asked about adding gaskets to the fuel pump was because of talking to an old-timer mechanic, He said I could have done that instead of going thru trying to get everything installed in such a limited amount of space.

Dave

dhcarguy 05-03-2024 09:46 AM

3 Attachment(s)
Quote:

Originally Posted by dhcarguy (Post 6501479)
I have a 65 with TriPower. For years ,I dealt with the air horn gaskets oozing fuel and sometimes the throttle body gaskets also. I finally installed a Holley 804 fuel regulator. Before I did, I temporally put an in-line pressure gauge. My pump was putting out 6 psi. That was my problem. I took the car out yesterday for a long ride. Temp outside was 80*. When back home, I opened the hood , and there was NO gaskets oozing. I did set the regulator to 3 psi.
The reason I asked about adding gaskets to the fuel pump was because of talking to an old-timer mechanic, He said I could have done that instead of going thru trying to get everything installed in such a limited amount of space.

Dave

Here is pics of what I did

78w72 05-03-2024 09:48 AM

Im not familiar with tri power carbs... but 3psi seems very low for any carb, is that what the pressure is supposed to be at? maybe something else is causing the fuel seepage?

dhcarguy 05-03-2024 09:54 AM

Yes, the expert Tripower guys, (Dick Boneske and Mike Wasson among others) told me TriPower carbs can only withstand between 3 to 4 psi.

Dave

steve25 05-03-2024 11:30 AM

With only 3 psi to feed even just one Carb no less 3 would not run the motor to full throttle and expect nothing less then the motor falling on its face within 4 seconds.or by the time you get into high gear.

blueghoast 05-03-2024 04:50 PM

Quote:

Originally Posted by dhcarguy (Post 6501301)
will adding 1 or 2 gaskets between pump and block lower fuel pressure?

Thanks, Dave

NO

GT

Formulajones 05-03-2024 05:07 PM

Quote:

Originally Posted by steve25 (Post 6501506)
With only 3 psi to feed even just one Carb no less 3 would not run the motor to full throttle and expect nothing less then the motor falling on its face within 4 seconds.or by the time you get into high gear.

I tend to agree. Shucks even our air cooled VW has more fuel pressure than that and those webbers aren't known for wanting a bunch lol.

I'd like to hear from some of the tri power guys that actually run their cars at the track and what they are doing, because even a spirited drive on the street with 3 psi I would expect that to fall flat on it's face.
Quite a few tripower cars in the PS drags, I can't even imagine they are running such low pressure??

steve25 05-03-2024 05:14 PM

1 Attachment(s)
This photo should be self explanatory and to me and maybe many others brings into question how any 2 bbl could provide the needed fuel to a motor at full throttle above 3000 rpm.

dhcarguy 05-04-2024 06:41 AM

Interesting, When I get a chance, I will run my car at full throttle and let you how it does. Hate to think I did this for nothing

Schurkey 05-05-2024 01:57 AM

3 psi is probably insufficient.

The gaskets aren't soggy because the fuel level is too low.

What you have going for you is that there's three needles 'n' seats instead of one. More-or-less triple the valve area, so low pressure may still generate adequate volume. I'm still suspicious, though.

steve25 05-05-2024 07:01 AM

Just like any carb that has its float setting too high and or the float not set right to compensate for todays fuel and it’s expansion rate with heat , you will see the air horn gasket get wet and at that point you might see fuel dribbling out of the booster ring.

In short this is not a condition that is seen only Rochester 2 bbl carbs.

I also need to ask if you in fact do have the right air horn gasket?

chrisp 05-05-2024 07:55 AM

Needle & seats not sealing & floats too high/ fuel boiling / need to retighten throttle body & airhorn screws/ stock float heights are for stock sitting cars / i run 6 psi for 15 years & trouble free

Skip Fix 05-05-2024 10:55 AM

"how any 2 bbl could provide the needed fuel to a motor at full throttle above 3000 rpm."

Back in the day NHRA, IHRA and AHRA had 2 bbl Stock classes-maybe even SS that could sure scream

Formulajones 05-05-2024 11:28 AM

There are still many sanctioned 2 barrel racing classes around the country. My concern is trying to run them with just 3 psi fuel pressure. I'd still like to hear from those that race, or even some spirited driving with high gear pulls that are actually getting away with that. I can't imagine that would work out too well.

Dragncar 05-06-2024 04:03 PM

I little off topic but I just worked on a 2GC engine yesterday. This family friend, 93 year old man need help moving his Willy's Jeep with a 265 sbc in it. So I went to check it out, get it moving and it had a 265 with rams horn manifolds and a sock 2 barrel 2 GC carb that had a fuel leak. Had not been started in years. If fired up with carb cleaner, good sign. Fixed the leak and it ran just fine, glass packs, sounded GOOD.
Would not come up much in RPM but it was enough to move it. No brakes so that was interesting.
The install was pretty clean, he has had it for years and wants to sell it to me. Might do it but I am 6' and the seat does not go back far enough to get the steering wheel off my lap. Getting out in a hurry would not go well. Has a roll bar and my foot hits it getting out.
He also has a Honda Trail 90 in great shape. I am getting that for a track bike ! That thing makes me feel like a kid. Ran them all the time in the 70s-80s.

Skip Fix 05-06-2024 06:50 PM

Yea 3lbs seems awfully low to me even for a stock pump to put out.

dhcarguy 05-08-2024 09:57 AM

Quote:

Originally Posted by chrisp (Post 6501798)
Needle & seats not sealing & floats too high/ fuel boiling / need to retighten throttle body & airhorn screws/ stock float heights are for stock sitting cars / i run 6 psi for 15 years & trouble free

Hi Paul,
What do you set your float levels and drops. I have mine set at 1 3/4" drop and 21/32" level. I use the floppy disc type seats(not sure what they are called) supplied by John at Pontiactripower.com.

Dave


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