Carter fuel pump

[BigBlueIron]

I picked up the Carter M4008 fuel pump I wanted the built in filter since there is plenty of room in this 74 F100 and its out of site for the most part. Two birds one stone kinda solution.   Summit lists this pump at 40gph and Carters website at 35gph. I'm thinking may be border line on this build. Disclaimer I haven't driven it yet so it may be just fine and I'm overthinking it.

 My question is anybody use this pump and actually know what kind of power it will support? Additionally when is it time to upgrade the 5/16" formed line from pump to carb to 3/8" assuming the pump is supplying plenty of fuel for whatever HP, when does the line itself become the problem.

Is there a higher flowing pump with integrated filter? I really don't want to run an inline filter over the front of the engine. If it comes to it I'll probably go with the carter electric at 50gph there is a good spot on the frame where the 2 tanks once switched just a few feet in front of the rear/existing tank.

[cleandan]

I don't know your engine build so its fuel useage requirements are unknown at this time.

Trying the pump to find out if it will supply the proper volume of fuel is easy.
If you want to get fancy with that test, install some gauges so you can monitor pressures (extrapolating that into volume) across the RPM and load range of the engine.

These pumps can be ported a little bit.
It's tricky and requires some patience, but it can be done and it will increase the volume some....not a lot, but if the pump is on the endge of being inadequate I have found porting to work quite well.

The 5/16" to 3/8" line from the pump to carb takes some thinking and testing.
Logic tells us the 3/8" line is better because it can flow more fuel.
But you only need the bigger line after proving the smaller line can not handle the task.

Often the larger line presents other issues, like vapor lock and boiling fuel, because the larger line holds more fuel that does not get used enough to help keep the line cool like the smaller line with faster flowing fuel can provide.

Put the pump on as is and romp around a bit.
Find a long stretch of road, with a hill if you can, to load test the fuel system via a long, full throttle pull.
The track is the best place for this, but there are still safe roads where this testing can be done.

If this is a truck you can hook up a trailer and load test at even lower speeds.
Or you can load the car with friends (sandbags work but they are less fun) and go for some long pulls.

You will feel the engine lose power if it starves enough...it will just stop pulling as if you let off the gas pedal some.

If it is marginal you can get detonation from lean conditions, colorations on the plugs, and a slight surge felt in the seat as if someone is feathering the gas pedal just a bit.

If it is close, but not readily noticeable you will have to read plugs to find out and this can get tricky because it mimics a misadjusted carb as well as a poor timing curve.

In general I think 5/16" line will work up to about 400 hp and 6200 rpm sustained when things are set up right.

There are specific fuel consumption formulas that can help here, but you will have to measure the flow rate of the fuel system (not just the pumps rated flow) in order to use them beyond general ideas.

Last, keep in mind the pump may be able to provide adequately, but you have other issues in the fuel system.
A problem with the fuel pickup sock.
A kink in the line somewhere.
Too many tight bends and restrictive fittings.
Junk in the lines.
Poorly trimmed/finished hand made line ends (some cut the metal line and leave the end as cut) That produces a restrictive diameter smaller than the rest of the line.
Air leaking into the line.
A restrictive filter (clogged or just not good enough)...By the way, the filter cartridge of this pump style is pretty dang good in terms of flow and filtering.

[Barry_R]

Making a ton of assumptions a 35gph volume is only good for around 450 HP.
But...gph ratings on fuel pumps are often "free flow" - meaning with the outlet line open.
Lines, fittings, bends, filters, desired pressure values and such will all reduce that actual volume.

Again - lots of assumptions - the outlet side of a fuel pump line size is less critical that the inlet side size. 
The inlet side is under vacuum - comparatively low.
The outlet side in under pressure which can be comparatively high.
This is why "in tank" pumps on new cars, running with high pressure, can use such small line sizing.

[BigBlueIron]

This was a bench build. You know stuff from under the bench. So its kind of a hodgepodge of parts.

390 block .030 Square decked and align honed.
390 crank cut .010-0.010, FM mains King rods. Had trouble getting end play.
360 rods good prep ARP bolts
Used forged TRW pistons, tops faced, then a step dish added .005 deck height to outer rim. Best measurement guess was around 10cc
Steam engine rings
Balanced by local machine shop.
D2 heads Crafy cnc ported, CJ valves valave job by Blair. Cut on all 3 sides just to clean up.
Fel pro 1020's
Used ED RPM with some port work, blocked crossover (not the best port work but an attempt was made)
Reground and previously ran cam .500 lift, 220/220 flat tappet, 113 sep installed at 107
Comp springs to match, comp retainers/locks
Used rockers OEM non adjustable, pin honed for oversized shafts, heavy wall. Shimmed .045 for better geometry.
Manton 3/8" pushrods, various lengths.
Holley 3310 780CFM (early version) 1" 4 hole wood spacer (to help with heat soak running errands)
Recurved Duraspark with MSD Digital 6
Cheap o Flowtech long tubes, 1-3/4" primary, Full 3" exhaust to Borla straight though mufflers dumped in front of axle.
Used M57A FT pump, 1/4 to 5/16 driveshaft from POP. New pickup tube
Canton screen type windage tray. Stock front sump pan.. Thinking about changing pan to something else. Suggestions?

Compression is a bit lower than the 9.4 to 9.7 goal at an educated guess/calculation of 9.3 but that's ok, just wanted some decent quench. I was trying to be conservative as to run cheap swill 87 octane.. Its a truck and will be used as such.

So whats your guesses on hp??

Barry mentioned 35gph supporting up to 450hp so I should be plenty safe.
 
 I though about making a 3/8 line to the carb but kind of thought it would be waste of effort being the factory outlet on the pump is 1/8npt. Supply side is all 3/8 but it does have to pull from the rear of the truck... Ive kicked around the idea of a new tank anyway, Tanks inc has a solution for an in tank pump for carbs.

No hp goal on this build, just to use some parts I had and make them work together the best I could with the attitude of it will make what it will make. Something a little snotty, fun to drive and dead reliable. 74 F100, C6 convertor 1 step over stock stall 3.73 rear. It's fairly beat up but does have all new floor pans and cab mounts tho, and if never do that again Ill be happy. Just a shop truck. One day when the rust starts poking though some more we might cut it down to a short box and redo the bed sides.

Good suggestion about hooking a trailer up, I do plan on putting a good receiver hitch on it soon as I can build one.

First mock up before cutting pistons and some assembly shots