E85 with Mechanical Fuel Pump

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100VALIANT

100VALIANT

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My engine is going to be around 500-525 hp with 11.0:1 compression and Aluminum heads. A bit too much for California 91.
It'll be 90% street driven so I am thinking about going to e85 but it would be nice to use a mechanical pump like the Carter M6270 to avoid wiring and a battery disconnect when I do make some passes in it.
The Carter is a 120GPH pump. Taking out the 30% loss it'll be closer to 80 gph. I am using a RobbMc fuel pick up with -08 pick up, a -08 PTFE hose and would thread an AN in to the Pump. I know it's only a 1/4 NPT inlet. Has anyone seen this or done similar?

1688048166473.png
 
I calculated 550hp on e85 and got 61.6 gph Using bsfc averages for fuel.
Gasoline .45 - .50
E85 .63 - .70
Methanol .90 - 1.0
I used .70
In my opinion you’re cutting it too close for comfort. You’ll be pulling fuel a long ways through a filter and those pumps are rated at free flow. Any idea what the flow rate is at 7psi? And no way in hell I’d try to do it through a 1/4” outlet.
 
TT5.9mag said:
I calculated 550hp on e85 and got 61.6 gph Using bsfc averages for fuel.
Gasoline .45 - .50
E85 .63 - .70
Methanol .90 - 1.0
I used .70
In my opinion you’re cutting it too close for comfort. You’ll be pulling fuel a long ways through a filter and those pumps are rated at free flow. Any idea what the flow rate is at 7psi? And no way in hell I’d try to do it through a 1/4” outlet.
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I can see where it may be too close.
Kind of a bummer that no one makes a better mech pump for SB Mopar. You can get a 170 and 190 for the other guys.
 
Just fyi we run an 11.2:1 small block 410 ford in one of our race trucks on 91 Cali piss gas. It can be done.
 
100VALIANT said:
My engine is going to be around 500-525 hp with 11.0:1 compression and Aluminum heads. A bit too much for California 91.
It'll be 90% street driven so I am thinking about going to e85 but it would be nice to use a mechanical pump like the Carter M6270 to avoid wiring and a battery disconnect when I do make some passes in it.
The Carter is a 120GPH pump. Taking out the 30% loss it'll be closer to 80 gph. I am using a RobbMc fuel pick up with -08 pick up, a -08 PTFE hose and would thread an AN in to the Pump. I know it's only a 1/4 NPT inlet. Has anyone seen this or done similar?

View attachment 1716108293
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Honestly, 100% straight forward here, run the proper electric pump with a return to the tank. I know it’s expensive, a PIA to install correct and nicely, BUT, in the end, you’ll thank me and be very very happy.

Personally I don’t know of a mechanical pump that is 100% OK with E-85. There are electric pumps that are. Food for thought.
You’ll forget about the price when the quality and longevity last longer then the memory of the price you paid.
 
rumblefish360 said:
Depends on dynamic compression.
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Depends on a lot of things. Mostly temperature, air and coolant. I could run 14:1 on 87 octane if I never put a load on the engine, or yanked all the timing out of it. In my experience inlet air temp is a major factor.
 
rumblefish360 said:
Honestly, 100% straight forward here, run the proper electric pump with a return to the tank. I know it’s expensive, a PIA to install correct and nicely, BUT, in the end, you’ll thank me and be very very happy.

Personally I don’t know of a mechanical pump that is 100% OK with E-85. There are electric pumps that are. Food for thought.
You’ll forget about the price when the quality and longevity last longer then the memory of the price you paid.
Click to expand...
I hear ya. My other higher HP cars and boats have all had mechanical pumps. I just like the idea of no buzzing, less electrical and no disconnect hanging out back.
 
Alky is MUCH more liable to vapor lock and boil that straight gas. I would go electric, and the pump belongs at the tank.
 
100VALIANT said:
I hear ya. My other higher HP cars and boats have all had mechanical pumps. I just like the idea of no buzzing, less electrical and no disconnect hanging out back.
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Why does an electric pump need a disconnect at the back? I never use one unless the battery is back there.

Find a used Mallory 250 pump, but their 4 port return regulator and hook it up.

NO HOLLEY ****.
 
Rat Bastid said:
Why does an electric pump need a disconnect at the back? I never use one unless the battery is back there.

Find a used Mallory 250 pump, but their 4 port return regulator and hook it up.

NO HOLLEY ****.
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I may be wrong and I think you are correct. I think a disconnect is only needed when you move the battery to the trunk.
 
100VALIANT said:
I may be wrong and I think you are correct. I think a disconnect is only needed when you move the battery to the trunk.
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It would probably be wise to wire in a crash switch, but I'm not sure they are required, either
 
67Dart273 said:
It would probably be wise to wire in a crash switch, but I'm not sure they are required, either
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Im not sure on that either but I’ve been using an oil pressure switch that won’t let the pump come on until there‘s oil pressure. And it turns off the pump when there’s no pressure.

Then I wire in a push button switch so with the key on you can bypass that low oil pressure switch, prime the carb and crack it off.

There is another switch that some guys recommend and I can’t think of the name of it now. I looked into it and I like the low oil pressure switch better.
 
Rat Bastid said:
Im not sure on that either but I’ve been using an oil pressure switch that won’t let the pump come on until there‘s oil pressure. And it turns off the pump when there’s no pressure.

Then I wire in a push button switch so with the key on you can bypass that low oil pressure switch, prime the carb and crack it off.

There is another switch that some guys recommend and I can’t think of the name of it now. I looked into it and I like the low oil pressure switch better.
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That is pretty bad ***. What oil pressure switch have you been using?
 
100VALIANT said:
I saw that one but it is only 110 GPH. It would be about 72GPH after the loss.
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That's 1/4" NPT on the pump in Your original post, ....NOT the passage....LOL!!!(directed at 1st response)
You can get a fitting for a 3/8" steel line with 1/4" male NPT no problem. I've gotten some fittings that were smaller than the tube ID(5/16"+), I just drilled & honed 'em up, but 3/8" line will deliver what You need if the system is done correctly no problem.
E85 does require pushing the flow close, the outlet isn't the challenge tho', yeah inlet will need to be free of restriction...a pusher pump or just going to electric is the best policy...I understand, I've lived with the whining-growling etc., it can be annoying..
I vowed to mount the next one in a foam-lined cage with some ventilation slots & EFI hose connections..
 
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