free advice needed: fuel pump

[cstanley]

any of you seasoned guys have advice on replacing the stock mechanical fuel pump on a 350? i haven't bought the pump yet, so if there's another good option, please suggest. i'm maintaining the stock tank behind the seat for the time being. anything to watch out for? installation caveats? i have the service manual for instruction, but still soliciting feedback.

thanks, ya'll

colin

[sleepyboy]

Stock fuel pumps are easy to replace. I went with an electric one (Holley) with my in-cab tank. If you are looking for theft protection, you can mount a hidden switch in-line, the thief drives about 20 feet and the truck dies...

[Tx Firefighter]

Get you a new, stock type, pump at any parts store and pop it on. It should take 15 minutes or so.

Only caveat is dealing with the pushrod if it falls down. Personally, I use the long bolt trick, it never fails and only takes a minute or two. Andy did a good FAQ on this very subject. You should read it if you have any apprehension.

[cdowns]

stock fuel pumps are great // not unusual to get 30-40 years out of them //how can you ask for anymore ???

[cstanley]

Originally Posted by cdowns

stock fuel pumps are great // not unusual to get 30-40 years out of them //how can you ask for anymore ???

that's my only aprehension with using an electric. in my mind, mechanical is usually more reliable (esp. with that rats nest i have for wiring.)

[junkyardjohn]

Originally Posted by cdowns

stock fuel pumps are great // not unusual to get 30-40 years out of them //how can you ask for anymore ???

I AGREE COMPLETELY. IT WOULD TAKE ONE HELLAVA LOT OF HORSEPOWER FOR A MECHANICAL FUEL PUMP NOT TO BE ABLE TO KEEP UP WITH THE FUEL DEMAND. YOU CAN ALWAYS GET A HIGH PERFORMANCE MECHANICAL PUMP. JOHN

[cstanley]

does the electric one mount in the stock location, or is it inline somewhere?

[VetteVet]

One thing I do is turn the engine over so the cam lobe that moves the push rod in and out is on the low side. It makes starting the mount bolts a lot easier. On a stocker an electric pump is a waste of money IMO.

[71SWBChevy]

How about a mild build 350? Somewhere between 350 and 400 HP, will a mechanical pump do what I want or do I need an electric pump? Sorry to hijack your thread but this is kinda related.

[cdowns]

Originally Posted by 71SWBChevy

How about a mild build 350? Somewhere between 350 and 400 HP, will a mechanical pump do what I want or do I need an electric pump? Sorry to hijack your thread but this is kinda related.

800hp nextel cup cars use mechpumps

[72 CustomCamper]

Originally Posted by 71SWBChevy

How about a mild build 350? Somewhere between 350 and 400 HP, will a mechanical pump do what I want or do I need an electric pump? Sorry to hijack your thread but this is kinda related.

I have a mildly build big block around 350-400 HP using a stock mechanical pump. No problems...


Chuck

[chevy_fatman]

FAQ is your friend and here's Longhorn man's Small block Fuel pump replacement tips

[71SWBChevy]

Ok i thought i would be ok with the mechanical pump as long as I was sticking with a carb and not going EFI but figured i would check with you guys, thanks for the help. It will be awhile before I am putting a fuel pump on though.

[dwaite72lnghrn]

Mechanical fuel pumps are good. But on my BBC in the 34 years it has been on the road it has eaten 5 mechanical fuel pumps(my dad did 2 and I did 3) in 150,000 miles. If you added an electric fuel pump the long crank starting is gone less wear and tear on starter and engine during cold weather. Since I put the electric on my truck I would not go back. Who needs fuel injection aka tpi when a carb and electric will do the same. just my opinion
yep a electric edelbrock 1791 is $140 bucks but the ease at which it starts is worth it compared to a $40 mech fuel pump.

[dwaite72lnghrn]

Mechanical fuel pumps are good. But on my BBC in the 34 years it has been on the road it has eaten 5 mechanical fuel pumps(my dad did 2 and I did 3) in 150,000 miles. If you added an electric fuel pump the long crank starting is gone less wear and tear on starter and engine during cold weather. Since I put the electric on my truck I would not go back. Who needs fuel injection aka tpi when a carb and electric will do the same. just my opinion
yep a electric edelbrock 1791 is $140 bucks but the ease at which it starts is worth it compared to a $40 mech fuel pump.

[cstanley]

okay, NOW i'm confused.

[junkyardjohn]

Just Put A Stock Mechanical Pump On It & Forget It. John

[Billla]

Originally Posted by junkyardjohn

Just Put A Stock Mechanical Pump On It & Forget It. John

The mechanical is the fastest route for this one, and an electric just isn't required until you're in very rarified air for HP - > 1.5 HP/CID.

If you want to upgrade a bit, there's a middle ground of one of the upgraded mechanical Holly or Edelbrock pumps - they're good for 110 GPH and mount just like a stock mechanical pump. The body rotates to allow positioning of the input/output lines, although the stock hard lines won't line up and you'll need to either put in brass fittings for a soft line or run some braided lines. These pumps are also rebuildable, and I ordered a kit when I bought the pump but it's been 2 years with no trouble at all.

For my 1972, I cut the hardline from the tank just after it reaches the frame rail and put in an Aeromotive in-line fuel filter attached to the frame. I then run -6 Areoquip to the pump (3/8 NPT fittings) and up to the carb. This makes for a nice, clean and very maintainable installation.

[cstanley]

thanks everyone. i'm just going to stick with stock.

[corn]

I always just use an old hacksaw blade instead of the bolt. A LOT faster...corn

[bcolli3]

has eaten 5 mechanical fuel pumps(my dad did 2 and I did 3) in 150,000 miles. If you added an electric fuel pump the long crank starting is gone less wear and tear on starter and engine during cold weather.Who needs fuel injection aka tpi when a carb and electric will do the same

[Green Machine]

I've found that the AC pumps last longer but cost more than the Carter pumps.

[cstanley]

ok, i'm reviving this because of another thought. i just purchased the $12.99 fuel pump from autozone, and got to thinking while i was there. could my fuel problem (see above) be cause by a malfunctioning original fuel cap? it's a '72, so it has all that ECM/smog/fuel return crap, and i wondered if the corroded cap was causing all of this? any thoughts?

[Longhorn Man]

What was the actual fault? You never mentioned it.

[cstanley]

it'll run great for about 4 or 5 miles, then dies. a quick look at the clear inline fuel filter and it's empty! usually takes a few hours or overnight before the fuel starts flowin' through again. every time, always the same. 4-5 miles, sputters and dies from fuel starvation. the last few times it happened at the house, so i quickly disconnected the fuel supply line from the fuel pump, and the fuel flows with strong pressure at that point. i also disconnected from the fuel tank and blew out the line in between with an air hose, and nothing was blocked. so, i get good pressure from the tank until the fuel pump. then, if i quickly plug the line back into the pump. viola! i get flow.

i suspect the fuel pump to be the problem. do they go out gradually, or all of a sudden? this started a long time ago, but was never very frequent. now it is.

i picked up that fuel pump, a new fuel cap, and ordered a new sending unit just in case. i just wish i knew what was causing it.