Fuel pump mechanical vs Electric?

I am getting proper PSI from my fuel pump, But I am worried about flow.

I have seen many folks that added an electric pump to the 225, but did most keep the stock mechanical fuel pump?

I am thinking about removing the mechanical pump altogether and going straight electric pump.

I would use http://www.mr-gasket.com/ProductDetails.aspx?MajID=225&MinID=2261&productID=23&txtSearch=1516 to block of the existing pump housing. just to prevent any possibility of future pump failure.

What's everyones opionion?

 

IMO, for a carbureted engine, there's not much reason to change from a mechanical pump. Brand-name mechanical fuel pumps are very reliable, and are quite sufficient for all but racing conditions.

There is a flow spec - but if you have the right pressure, you're mostly measuring the same quantity as flow by measuring pressure.

Electric pumps have their place, for example, in vehicles with persistent vapor lock. For stock or near-stock applications, the mechanical pump is superior. Proven, simple, reliable, inexpensive,

 

another vote here for mechanical
what Tim said

 

Just trying to narrow the options.

Getting good PSI.

Lines are new and clean.

Tank is clean.

idle through 1st and 2nd up to 50MPH Great response and smooth running.

3rd gear, 60mph I loose fuel and get a consitant spiiting and a way too lean mixture.

SO what ever my problems are they are happening under load at above 60 (wish I had a tach for an RPM range) or above at engine full warm up temp.

I am going insane trying to figure this out.

 

hmm
sounds vaguely like Sparkys carb base gasket problem...
you say pressure is okay
how about volume test...pull fuel line at carb, put into container...start engine..at idle speed should fill container fairly quickly (coke bottle sized container), bursts should be short and strong fuel flow.
you could also try plumbing in a vacuum gauge on the other side of the pump; a very high vacumm reading would indicate blockage/restriction.

 

I have tested what bit of flow I can get tested. But when you pull the fuel line on a mech pump to the carb, once the bowls are empty engine dies.

I am getting great flow and PSI at idle. and up reving the engine

Its only under load that I get starvation.

My 225 is modified besides just the 4bbl: bored 40 over, new everything (I mean everything, rockers, Rocker pedestals rods etc), Heads have been milled and a mini port and polish, as well as running a mid range Comp Cam.

Now you did mention vacuum and thats something to look at since I had an oddball reaction with vacuum during retuning.

When we built the engine and tuned the carb in at my buddies shop we where pulling a dead steady vacuum of 14". Now we have had this spitting situation and have been working on it for a while. We rejetted, Jumpered the HEI to verify that it wasn;'t ignition related. and basically beat our heads down.

Saturday at my house tinkering I hooked my Vacuum gauge up, and I was getting 21" of vacuum reading steady with carbed dialed in and rejetted to 53 jets. So I started thinking Power Valve? Could my buddies Vacuum Gauge be bad? or is mine bad. Well mine is a generic 30$ gauge while his is a Snap On who knows how much that Snap on recalibrates for him once a year. But My plans this afternoon where...

Double check Vacuum with his gauge, my gauge and a 3rd Gauge I borrowed from a friend. I was going to quickly hook up an Electric pump as well and see what happens. Also if Vacuum readings where wrong I have 3 new Power Valves to test in the carb based on a correct Vacuum reading.

 

You can get a handle on this by checking the volume of fuel ...

Let's say that the fuel pump pumps 1 cup of fuel every minute. 16 cups per gallon, so that's 1 gallon every 16 minutes, or 3.75 gal/hour. At 70 mph, that will be (70m/h)/(3.75g/h) = 18.7 mpg. Similarly a pint every minute is about 9.4 mpg. So... if your fuel pumps a pint in one minute, you have to get worse than 9 mpg in order to be starved for fuel.

Also, recall that the delivery rate increases with engine speed, so a pint / minute at idle means more fuel at cruising speed. Probably not double the volume with double the engine speed, but more.

No need to hook up the electric pump - just test the volume of fuel being delivered.

I'd guess you are on the right track with the engine vacuum, not the fuel delivery. But you can test fuel delivery easily, as described above.

 

I agree with checking fuel flow.

A little late on this thread but just a thought, I had some similar problems with a 74 waggy that was traced to a nearly plugged fuel filter I did not know was there ( or expected to find ) tucked in tight to the frame rails between the fuel pump and tank.

Some carbs have an integral filter at the fuel inlet fitting or a very fine screen that is inserted in the fuel valve itself, typical on some older YF and MC carbs

 

PSI and Flow are completely different things. I can have a 10000000 psi, but only 1oz flow, Its like a pressure gauge for oil. Its helpful, but not authoratative. I like electric fuel pumps myself, but your engine vaccume is probly your problem. Good solution to your problem is don't go faster than 60 lol.