Bridgeport with carbs, 8,500 RPM What are fuel pressures i can expect?

**Valero2.5** · 07-31-2015, 07:55 AM

I have purchased a Bridgeport with some mods to internals, allowing it to run into the 8's Rpms, my question is he gave me a Holley electric fuel pump and i think he said idle pressure should be 2-3 lbs and what about flat out? i want to buy a gauge to monitor that i have fuel pressure to prevent a meltdown so any tips, pictures showing how anyone rigged their Bridgeport fuel pumps would be much appreciated. i am going to use old barrel fuel line fitting at motor and want to know hose is safe from blowing off and fuel spraying all over! i was thinking of putting pump and connections in an enclosed plastic battery box since i have had TWO bad fuel leakage issues in other boats and it was not fun. i can take pics of actual pump? Many guys say disconnect the neautral safety switch and start in gear to save beating up gears, regular lower with a Bobs Cone. with fuel pump i cannot depress choke to stall and shift, plus owner said shut down a few seconds to relieve pressure on carbs. Its been many years, 1992 since i ran a Bridgeport and dealer rigged it, this time i am on my own and want to do it right. Thanks guys! JIM

**Ira Tindale** · 07-31-2015, 05:07 PM

Ran a 2.4 to 8600 regularly running a Holley blue set at 7psi.

**Dave Strong** · 07-31-2015, 07:26 PM

Pretty much the same as a 245hp 2.5 , mine had a Holley Red can't remember what the regulator was set to. As was said 7psi max and good needles and seats will be fine.

Dave

**Dave Strong** · 07-31-2015, 07:28 PM

Pressure is less important than flow, red or blue will flow enough for what you need.

Dave

**powerabout** · 07-31-2015, 08:01 PM

how about dead head ( in the photo) or have the regulator on the return line?

**rankink** · 08-01-2015, 06:49 AM

Are Bridgeport different when it comes to fuel pressure? I ask because I thought I have read most mercury carbs need to be at 4-4.5 lbs at idle.

**2Fast2Pass** · 08-01-2015, 06:56 AM

Get rid of all the square 90's and replace with mandrel bent fittings. Flow is much better!

**Valero2.5** · 08-03-2015, 09:30 AM

Any pics any guys can send of how they have set up their fuel pumps to flow good, and does it matter if pump mounted in ski locker below the fuel tank? Jim

Originally Posted by 2Fast2Pass

Get rid of all the square 90's and replace with mandrel bent fittings. Flow is much better!

**johnmiffco** · 08-03-2015, 11:03 AM

holley red pump will flow all the fuel needed for a stock to mild ported v6 merc
2.0,,2.4,,,,2.5 don't matter all pretty much the same
as far as 6-7 lbs fuel pressure on the seats at idle
holley red is preset at 7 lbs
that holley blue will flow lots more fuel than motor can ever use
fuel pressure is fuel pressure at idle or wide open if pump flows more volume than a motor can use
if set at 7 it is 7 at idle or 8,000 rpm
pressure will only fall off if pump flows less than a motor uses,,,,,,,,,

**Brad Zastrow** · 08-03-2015, 11:05 AM

I am not sure how you can regulate a fuel pump to have lower pressure at idle nor would you want to. Pumps need to maintain a steady pressure at all times. Flow is the concern as you need enough fuel to keep up with engine. Too much pressure and you blow out the seats and flood the engine. Engine will only burn what it needs even at idle.

**Dave Strong** · 08-03-2015, 11:23 AM

7psi is a good press, if it blows the seats off at that press then you need to work on the carbs.

Dave

**Valero2.5** · 08-03-2015, 01:41 PM

Originally Posted by johnmiffco

holley red pump will flow all the fuel needed for a stock to mild ported v6 merc
2.0,,2.4,,,,2.5 don't matter all pretty much the same
as far as 6-7 lbs fuel pressure on the seats at idle
holley red is preset at 7 lbs
that holley blue will flow lots more fuel than motor can ever use
fuel pressure is fuel pressure at idle or wide open if pump flows more volume than a motor can use
if set at 7 it is 7 at idle or 8,000 rpm
pressure will only fall off if pump flows less than a motor uses,,,,,,,,,

Thanks, i did not buy this pump and got some hints from previous owner, so you say run 7psi and good to go, where is best place to put the gauge and any you recommend, i saw one at auto zone for 0-15 psi. I was thinking installing in splash well for easy viewing right before it goes into motor? sound good? JIM

**johnmiffco** · 08-03-2015, 02:45 PM

regulator needs to be mounted where ever u have the least vibration
is best to rubber mount the regulator to keep pressure more accurate
as bouncing will make it fluxuate
as why most on stock to mild motors run the red,,,no external regulator
u can mount guage where u want on motor on 1 of the plugs on the wh carbs'
use the other port on the regulator
or cut in a tee in feed line to carbs

**Valero2.5** · 08-04-2015, 07:48 AM

Originally Posted by johnmiffco

regulator needs to be mounted where ever u have the least vibration
is best to rubber mount the regulator to keep pressure more accurate
as bouncing will make it fluxuate
as why most on stock to mild motors run the red,,,no external regulator
u can mount guage where u want on motor on 1 of the plugs on the wh carbs'
use the other port on the regulator
or cut in a tee in feed line to carbs

Everyone left info, but i appreciate your more detailed info since last time dealer set up my Bridge and this time i must do it, do you know why the previous owner said shut fuel pump off 5-7 seconds before engine to reduce pressure in carbs, what in carbs cannot be under pressure? my last Bridge was an EFI so this is all new to me, any tricks on how to shift into gear? he said CLE or Bobs normal lower cannot take the clunk of big 30" props, with a lower RPM and what RPM idle you recommend? thanks, JIM

**rankink** · 08-04-2015, 07:55 AM

Shifting into gear by cutting engine, shift into forward or reverse, then start engine in gear. Same thing in reverse for taking out of gear. I have a sportscaster and CLE