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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: May 11, 2020 01:19PM

Pics

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: JimBrandberg ()
Date: May 12, 2020 05:21AM

azdave wrote:

"I tested a few more fuel pumps on Saturday. I get the same results after comparing four pumps that as I mentioned earlier, the pressure drops about 1.0-1.5 PSI from when they are cold to when they are hot. No big deal but interesting to note."

---------------------------------------------------------------------------------

Yes. One time I was having a fuel delivery problem and road tested. If I remember right that problem one had even more of a pressure drop. I don't remember what I did about it, I suppose just replaced it. I should have kept a fuel pump journal.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 19, 2020 07:37AM

joelsplace Wrote:
-------------------------------------------------------
> I would rather have a screw type adjuster.


That one sentence has kept popping into my head ever since I read it and made me less interested in completing this project because I could not find a simple solution that met my expectations. Joel is correct of course. Everyone would rather have an adjustment screw for setting fuel pressure and until I could figure out a way to do that properly, I was not satisfied with going further.

Pause 4 months...walk past box of parts gathering dust every day...sigh...

...but now success!

[youtu.be]

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: MattNall ()
Date: August 19, 2020 07:39AM

Great!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: Richard ()
Date: August 19, 2020 08:33AM

I would put one of the temp probes on one of the carbs and recheck the temp vs pressure. The temp variation of the carb is going to be greater than the fuel pump temp variation. The increased temp of the fuel in the float bowl will decrease the buoyancy of the fuel and effect the float level.
The change in pressure may be coming from the carb and not the pump.

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: toms73novass ()
Date: August 20, 2020 04:33AM

Great Job!!hot smiley

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block (Sold)
86' BMW 325es
98' VW Jetta TDI, for daughter
01' Audi Allroad Stage 3 twin turbo
67' UltraVan 211 "Violet"
NFCC, UMCC
Grand Island, NY

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 20, 2020 05:04AM

Richard Wrote:
-------------------------------------------------------
> I would put one of the temp probes on one of the carbs and recheck the temp vs pressure. The temp variation of the carb is going to be greater than the fuel pump temp variation. The increased temp of the fuel in the float bowl will decrease the buoyancy of the fuel and effect the float level.
> The change in pressure may be coming from the carb and not the pump.

Carb temps?
I can check the carb temps vs pump temps when out driving next time just for giggles but I think the carbs stay cooler than most people would guess. My test stand engine is not a good example to draw any temperature conclusions from but those carbs are cool to the touch when the carb mounting base on the heads are running around 200F.

Fuel density affects pump pressure?
In a normal situations, I can't see how fuel density changing the float level would affect the pressure I measure ahead of the float valve but what do I know. I only play an engineer in the internet. smiling smiley

It's only supposed to be 108 this weekend so I might go for a long test drive and see what else I can learn. My A/C is still working on the convertible Corsa clone but my temporary rear window fix melted and came apart in the extreme heat so it's kind of hard to stay cool on the freeway.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 21, 2020 05:13AM

After installing a rev 2 pump on my Corsa clone I got some freeway miles on it driving to work today. No issues this morning but it took a second last night to figure out why I had almost no fuel pressure when I started the engine, regardless of where I set the spring tension.

Note to self: When you only finger-tighten the fuel line feeding the pump it sucks air instead of fuel. D'oh!

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: Wagon Master ()
Date: August 21, 2020 05:28AM

Nice work!
It gives a whole new meaning to "fine thread".

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: toms73novass ()
Date: August 21, 2020 06:16AM

Dave, are you planning on selling your new version or are you going to post a how to on the design? smileys with beer

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block (Sold)
86' BMW 325es
98' VW Jetta TDI, for daughter
01' Audi Allroad Stage 3 twin turbo
67' UltraVan 211 "Violet"
NFCC, UMCC
Grand Island, NY

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: autocomman ()
Date: August 22, 2020 10:34PM

You could just nutsert the top cover for an easy thread in screw. Pretty sweet I have all this to look forward too with a brand new airtex pump. Should I bother installing it as is? Or start swapping parts with the original

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 24, 2020 05:26AM

toms73novass Wrote:
-------------------------------------------------------
> Dave, are you planning on selling your new version or are you going to post a how to on the design?

I hope to sell a few pumps tested ready to go and plus few kits too. It's an easy idea to copy for those who would rather make their own. Most of what you need to know has already been revealed. I'll show the adjuster design in a few days when I get some good pics. I spent the weekend laying fence block since it was only 109. smiling smiley



autocomman Wrote:
-------------------------------------------------------
> You could just nutsert the top cover for an easy thread in screw. Pretty sweet I have all this to look forward too with a brand new airtex pump.

I did the nutsert trick back in May and variations on threading the lid but strangely enough, I didn't like modifying to top cover or having a screw protruding out the top.



autocomman Wrote:
-------------------------------------------------------
> Should I bother installing it as is? Or start swapping parts with the original

I can change a pump pretty quickly these days. No harm installing your new pump first to be sure you have a good one and then do the mod later.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: autocomman ()
Date: August 24, 2020 01:26PM

I will, swapping it out isn't too bad. I would love to see how you set it up Internally with the screw.

The inability for companies to build a pump that works right seems to be every increasingly hard. I've had more pimps now on various things totally outa wack. My bro has a triumph spitfire with a 1300, new mech fuel pump, 6 psi...SUs are very unhappy with that as they love to be at 1.5-2pai. had him out a dead head regulator on. Guess we will see how long it lasts

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: joelsplace ()
Date: August 24, 2020 09:35PM

Have you decided how much you want for the kits?

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 25, 2020 08:13AM

autocomman Wrote:
-------------------------------------------------------
> The inability for companies to build a pump that works right seems to be every increasingly hard.

I think pump reliability has improved recently looking at eight pumps I have purchased since last fall. For better longevity, it seems like the pump diaphragm would last longer if you only ran the required fuel pressure instead of the 6-7 PSI I find on new pumps. Whether that means a 10% longer pump life or a 10-mile longer life I don't know. smiling smiley



joelsplace Wrote:
-------------------------------------------------------
> Have you decided how much you want for the kits?

Not yet. I still have to decide how much loss I will accept on machining the riser rings. grinning smiley The rest of the parts are common hardware bits with very little labor needed to modify and assemble them.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: Wagon Master ()
Date: August 25, 2020 08:46AM

azdave Wrote:
I think pump reliability has improved recently looking at eight pumps I have purchased since last fall.


I am just looking for a replacement pump and willing to swap in my old spring to lower the pressure. Where are you sourcing your pumps, E-bay, Amazon, Rockauto?
Thanks for all your efforts to improve the hobby.


'29 Ford Model A Tudor
'61 700 Lakewood 110 4 speed
'69 Monza Convert. 140 Auto.
'70 Dodge Challenger R/T 440 4 speed

Been aircooled since 1973
Northwest Ohio

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 25, 2020 09:44AM

Wagon Master Wrote:
-------------------------------------------------------
> Where are you sourcing your pumps, E-bay, Amazon, Rockauto?

When I started this little project I bought three different brands of pumps from RockAuto to see what would arrive. They were all very clearly made by the same company but with different packaging. The casting marks/blems, date code tags etc., were all identical. The packaging indicated they were manufactured in Mexico but the pump lid was stamped with "Made in USA" just like back when they were actually made here.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: joelsplace ()
Date: August 25, 2020 05:42PM

Is that a part CNC equipment could crank out cheaply? I have a friend looking for some work. If you aren't that interested in making them he might be.

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 27, 2020 05:40AM

joelsplace Wrote:
-------------------------------------------------------
> Is that a part CNC equipment could crank out cheaply?

There's a good pic or two of the spacer ring earlier in the thread if you want to ask him out of curiosity. I don't expect enough demand to bother bringing in an outside vendor.


So here's where I am now.
Pic #1 show what I believe will be the final kits parts.
Pic #2 shows my solution for the hidden adjustment mechanism.
PIc #3 shows the stainless screw hidden under the lid.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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Re: Adjustable Pressure Mechanical Fuel Pump Experiment
Posted by: azdave ()
Date: August 27, 2020 05:40AM

More pics.

Pic #1 assembled.
Pic #2 Allen wrench to adjust
Pic #3 Parts used to add a pressure gauge (temp or permanent) on the pump output.

Dave W. / Gilbert Arizona
65 Corsa 140/4
66 Corsa 140/4
66 Corsa 140/4 w/factory A/C
66 Corsa 455 Toro V8
65 Monza Convertible 110/4
66 Monza Convertible 140/4 A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5



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