Fuel pump requirements

Daryl

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How do I know what capacity fuel pump I’ll need after the engine rebuild and tune, assuming the one I have is the stock, 26- yr old pump? And should I get just a pump or replace with a kit? I’m always pensive about replacing an old component and hoping the rest of the assembly is ok.

Thanks everyone, once again for all your support and input. I appreciate and value it tremendously! Hope everyone is enjoying Memorial Day, and acknowledging what the day is intended for!
 

TrickVert

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There are a number of online calculators. Just search for fuel injector size for horsepower calculator, or words to that effect. You will be surprised at the numbers you get. Most people think they need a huge pump, when a smaller one will do the job, and not over circulate the fuel through the engine compartment.
 

sluggish94

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Most people think they need a huge pump, when a smaller one will do the job, and not over circulate the fuel through the engine compartment.

True.

Every engine is different.

I'd choose a pump that I can grow with based on long term goals.
 

sluggish94

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Long-term is relative.

Each decision made in this entire hobby is relative to each combination.

But it's not a make or break decision here.

155, 190, 255, they'll all work on a H/C/I 347.

255 might be louder under operating conditions.
 

TrickVert

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I think you're missing my point. Too large a pump will simply circulate unused fuel through the engine compartment over and over and over again, causing it to absorb heat. Many people won't have a problem - I didn't until I added the Vortech and it's heat generation - but others, even N/A and basically stock have had issues. This is one situation where if 120 is good, 255 or 340 or 850,000 is not better. Adding a supercharger or turbo setup in the next six months or putting the final touches on that Coyote motor swap? Sure, toss in the larger pump. Otherwise, the pump should be sized adequately for the need, and not excessive to it.
 

sluggish94

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I think you're missing my point. Too large a pump will simply circulate unused fuel through the engine compartment over and over and over again, causing it to absorb heat. Many people won't have a problem - I didn't until I added the Vortech and it's heat generation - but others, even N/A and basically stock have had issues. This is one situation where if 120 is good, 255 or 340 or 850,000 is not better. Adding a supercharger or turbo setup in the next six months or putting the final touches on that Coyote motor swap? Sure, toss in the larger pump. Otherwise, the pump should be sized adequately for the need, and not excessive to it.

Not missing your point.

I understand thermal dynamics.

My suggestion is simply based on wether or not OP potentially sees themselves in search of greater performance in the future, which something everyone in this hobby does at some point.

I'm not here to make decisions for people, just here to extend information relative to the topic and not try and confuse anyone with anecdotal experiences.
 
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Daryl

Daryl

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Trick & Sluggish,
Wow, I appreciate, respect and am grateful for both of your inputs. I think my next step is to calculate what level of fuel pump is best for you my setup and go from there. kudo’s to both of you. Now, let’s see where it take us!!!
 

tvsn95

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My experience on several setups is the 255 Walbro is the way to go, no problems at all. as a plus will support 400+ hp then you get into line size and rails restricting flow.
Just last week I installed a 400L intank pump along with new lines and rails and relay, , this pump is not a complete drop in, Be forwarned,
my current setup is 2 external 255's running 100%. they do add heat but no problems. Remember when you go above a 255 you MUST add in a separate power relay. the ECU/wiring can't handle the current.
 

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