2 Mallory Reg w/Carbs

[RoninLB]

Finally finished the fuel feed.

Originally the full loop with 1 reg only allowed me to get psi down to 7psi. If a track car I guess it would be ok. For my street car I wanted 3.5psi. The other option would have been enlarging the return line. That'll be later fun.

I used a Mallory by-pass reg as part of a loop with 10psi behind it. I then fed the 10psi to a Mallory dead head routine reg. The feed to the carbs is now 3.5psi. The $20 Holley dead head reg's diaphram left me a little spooked with todays stupid gas. Both Mallory's is a double diaphram designed for exotic gas.

[randywebb]

Pretty complicated looking Ron. What is the advantage over the PMO unit?

[RoninLB]

Randy

It may be complicated for a car but the system is commonly used in industry. The PMO is fine, but it would still have left me with to much psi I believe. I gave it away when I got it because I wasn't wild about it. I had to much psi without any regulators. meaning if I took the fuel pump feed and ran it directly into the return I was getting to much psi. Maybe a return line swelled, who knows. I'll eventually replace the whole return line with an oversized diameter. I'm not wild about PMO's design either. This system feeds a consistant 10psi to the dead head reg under any condition. It's great quality. When I have a good return line I'll only use 1 back-psi reg.

[MotoSook]

Looks GREAT Ronnie! You should have the most stable pressure out there! Finally!

[RoninLB]

Originally posted by Souk

Looks GREAT Ronnie! You should have the most stable pressure out there! Finally!

thanks.

A friend helped me sort out what I had to do. I'm sure I'll get criticed for some reason.. It is a great design.

3 dash psi ga later. 1 before filter, 1 after filter in the by-pass 10psi, and 1 after the dead head in the 3.5psi line.

as soon as this thing is packed up I'm doing a quickie to the 4 corners w/a friend. The game is pack it an leave between the fish migrations. I gotta stretch this thing for 5-8k mi. I'll either wind up w/ confidence in it or it's gonna blow up.

wtf... entertainment

[MotoSook]

I could criticize..it's an over kill

Really, maintaining a constant feed pressure to the dead head regular is the way to go. The arrangement is tested 24 hours a day at more places than you can imagine....and the places that don't follow that arrangement....get tested and retested by techs who get called out at 3AM to go fix it when the delivery can't handle the pressure fluctuation.

Can't wait to follow the thread on The Next Great Ride!

[RoninLB]

Originally posted by Souk

techs who get called out at 3AM to go fix it when the delivery can't handle the pressure fluctuation.

The Next Great Ride!
I could criticize..it's an over kill

good explain.. all I know is that it's the best shot. I even replaced the Holley dead head with the Mallory. Comparing diaphrams is At Least 4to1. Also I have 3x 5#/2.5" $50ga that I'm gonna confirm accuracy with a water tube. They have the screw needle adjustment.

The ride is to see what I'm dealing with. It's all set up rich and stable for Long Island. I'd like to raise EGT 50deg and see what happens. But if i can't drive around Utah it's not doing me any good. If the quickie is ok then maybe I'll start leaning and be able to run ngk BPR 9-ES all winter. I like cold plugs.

it'll be good over kill for my bud who has watched me do these rides over&over over 30yrs. The last time I had a bud along who was pumped up I did 8k mi in 2weeks. His trip is to see everything for 10min and go to the next one. Then he'll return later. He's into fly fishing so he has a few places to eyeball. The ride starts a few hr's west of the Miss R.


wanna come, huh?

[project 911]

Robin,

Really impressive setup. Looks like something out of the space shuttle. I just finished plumbing my new system which is much simpler than yours since I don't have a loop or return line. Since you've put all this thought into yours, maybe you can help trouble shoot a problem I still have. I've got a front mounted pump putting out about 10 psi running to a Mallory Comp 140 filter, Holley reg and into a fuel log with gauge. I have insulated the hard line under the car with thermo sleeve and have the insulators between the intake manifolds and the head. The car runs very cool temps. The problem I have is after shut down the pressure reading on my FP gauge will climb from 3.5 to about three times that reading. This seems to be causing some warm start-up problems. It acts flooded. I can't figure out what is causing this. Would a return line to the tank be warrented? I hate to think of running a new line. When you do this, does the return line need to be regulated too?

Any hints would of course be appreciated.

(oh... 1970 2.2 with Zeniths, headers)

[Fishcop]

I don't have an answer.... But I like looking at your pretty pictures

Is the fuel bar custom?

[project 911]

Thanks John,

I picked up the fuel log on Ebay. It came from someones circle track car and looks to be home made (kind of crude in places). It works great with all the inlets/oulets in the right places. There's even one coming off the back in case I need to do a return line.

Here's a better look at it.

[ozz]

Ronin - Steve - what are you guys using for fuel pumps and where (up front) are they mounted?

thanks!!
Gary

[project 911]

Gary-

I've got my pump located in the bottom of the smugglers box with a good size filter before the pump. I'm using a "vintage" AC pump that is really nice. It sounds like a jack hammer when you first pressurize the system, but only pumps on demand after that so it is silent. I used to have a Facet but it sucked...

[MotoSook]

Originally posted by RoninLB
wanna come, huh?

If the planets align and both my jobs allow...I could use such a trip...

[MotoSook]

Steve B,

You don't have a return line, correct?

[project 911]

Souk-

That's correct. No return line.

[MotoSook]

When you shut down, does the pump relieve pressure? I'm not familiar with your pump, but if it is holding pressure instead of allowing it to bleed down, your regulator is allowing bleed-by and pressuring downstream (carbs and fuel log).

The other potential problem may be your fuel log is warming up after shut down.

I would look to replacing the regulator first. Your 10 PSI pump appears to be adequate, but your regulator may not be sealing off. At 3.5 PSI the regulator should be closed under static conditions. If it is allowing pressure from the pump to your fuel log under static conditions, it should be replaced. During flow (engine running) the leak is undetectable as the leak is not enough to reveal itself.

A lot of systems I design have two regulators in series with the upstream regulator set slightly higher. The downstream regulator is set lower thus it is always operating. During normal operations, the upstream regulator is wide open and sees less wear. But if the working regulator leaks, the monitor regulator will shut things down or take over pressure control at the slightly higher set point. This is critical in a dead end system that can't handle a pressure spike. It can't be set up with the regulators you are using as the monitorign regulator requires a remote sensing location downstream of the workign regulator. It's not applicable to the system you have, but it should give you some insight into what's happening.

I would always carry a spare regulator if you are going to keep your system as it is.

[304065]

Ron, beautiful work. A double loop system. Brilliant.

How about an electric VDO sender with an expanded scale on the small loop? Doesn't the JPI have the capability to display optional inputs?

[project 911]

Thanks Souk,

That gives me some stuff to think about. When I shut down, the guage shows pressure for a about half an hour gradually rising the whole time, then eventually the guage drops to zero. Even after a long drive the carbs and fuel log feel cool to the touch. Is there a reg that you would suggest?

[}{arlequin]

I gotta start designing one of these full loop systems and it's intimidating as hell. Your pictures don't seem to make things any easier...

Great set up though!

[ozz]

Steve,

Thanks for the reponce. I was affraid you were going to tell me it was in the smuggler's box. I've got a battery and the associates cables in there and am loking for an alternative location to put a pump.

Currenty, l I've got a Carter pump that was mounted on the left side of the engine compartment which is giving me fits. Number one, it get's a little warm there and number two, that's an awfully long pull for a pump that is designed to push. Time to find a new pump and location for it.