Mechanical fuel pump for a 512 / 650hp

[OzCharger69]

Hello all,

I'm currently running a 3/8 steel line and a Carter pump on my 383. Towards the end of the year I'll have a stroked 440 going in. Does anyone run mechanical pumps on higher hp motors? I do have an Edelbrock high volume pump with 3/8" ports sitting on the shelf.

I read the Carter M4862 is a good one but has 1/4" ports. I would prefer to stay off electric pump if at all possible.

Thanks for any advice

 

[Ironbuilt]

You can keep your mechanical pump, and run 3/8" line.
https://www.summitracing.com/parts/hly-12-440-11
https://www.summitracing.com/parts/sum-g3118

 

[Steve009]

I debated this for a while too. BBM have very limited selection for mechanical pumps that have large size fittings and high volume. I went with the edelbrock rpm as it was the only one with 3/8 inlet. You have to think that you can have as big a line as you want but if the inlet is 5/16”, that’s the restriction. I’m building a 470 stroker and hope for around the same HP numbers as you. I’ll see how it goes. Let me know if you find a better mechanical option. I know BBC have super high horsepower mechanical pumps. Too bad not for BBM.

 

[Ironbuilt]

I debated this for a while too. BBM have very limited selection for mechanical pumps that have large size fittings and high volume. I went with the edelbrock rpm as it was the only one with 3/8 inlet. You have to think that you can have as big a line as you want but if the inlet is 5/16”, that’s the restriction. I’m building a 470 stroker and hope for around the same HP numbers as you. I’ll see how it goes. Let me know if you find a better mechanical option. I know BBC have super high horsepower mechanical pumps. Too bad not for BBM.

It doesn't matter the cubic inch, if the motor is carbureted, it will never need more than 9 PSI.

 

[OzCharger69]

Thanks all for the responses. I was under the impression that pressure and volume are totally different and not mutually exclusive. I plan to use a fuel regulator. I read that the best pumps are the Clay Smith ones but I'm not sure they make them anymore.

 

[67charger383]

I mean QFT makes a mech pump that runs at 80psi and 110gph
https://www.ebay.com/itm/132985796902?hash=item1ef6923926:g:ksAAAOSwLMFch6NK\
Should be fine for what your doing

But seriously just run a electric pump. I like my old Mallory pump

 

[66Satellite47]

It doesn't matter the cubic inch, if the motor is carbureted, it will never need more than 9 PSI.

It's not the PSI that matters, it's volume the pump can deliver to the carb. Positive displacement pumps mounted at the engine are suspect to suction limitations. That is why electric pumps near the tank have been used for high power applications. They push the fuel to the carb(both pressure & volume), not suck it to the mechanical pump where the volume and pressure are given to the carb. Pumps that are suction limited have problems.

 

[hunt2elk]

I am having no problems running a Carter 6903 with 3/8" line on both my BB strokers. The one made 590hp and 605 ft.lbs. Also remember that very little time is spent at WOT on a street car.

 

[diesel_lv]

Is this car going to be spending a lot of time over 5k RPM? If not, then a mechanical is just fine. If you're looking to spend time doing dyno shootouts then you need to build it for race. I built my 496 for driving and very low end torque, no "need" for anything other than a mechanical fuel pump with a carburetor, the hp I have is a byproduct of the torque. I did not build it for a hp number, built it for tq n to be a "driver".