TPIFormula

Well I work for autozone and had a few mins between shoopers so I did a little looking around for a higher flow fuel pump that cam factory in the 93 Chevy Caprice police car 350TBI..... I made a few comparisons just in case to make sure most TBI's cars/truck shared the same fuel pump wich they do, 4.3/5.0/5.7/ 454TBI's but then there was the special police option on the caprice and for their 350TBI, yes they use larger injectors, but the fuel pump has a higher PSI of 15-25PSI Compared to our 12-17 PSI, and the caprice pump flows 45-55 gallons per hour compared to our35 GPH.

Caprice part numer for the fuel pump is, master/airtex E3268.

Both pumps are identicle in measurements and hookups...

I posted this b/c I was wondering is this worth swapping over stock esp if you are using larger injectors and a larger motor, for example, I am swapping my 4.3TBI in a S10 to a 355TBI using 350 inject instead of the 4.3's

hope someone can chime in!

Travis

89IROCZ28

iTrader: (14)

Nice ... and it's only a couple dollars difference in price. $51 vs $54

TPIFormula

YUP! just wondering if it is useable and possibly not hurt anything, Im sure if your running a AFPR this pump would take the advantages of that

89IROCZ28

iTrader: (14)

It's probably not needed for a stock 305. But, when you start making other modifications, sooner or later you're going to need more fuel to take advantage of the upgrades to make more hp. Especially, for a punched out 350 w/ an aggressive cam and larger injectors. Those trying to get 20 psi or more won't be able to do that w/ the stock pump.

I don't think it's overkill. In fact, it seems just the ticket for those of us starting w/ upgrades in the way of headers and mild cams. And, if you need to replace the fuel pump for any reason, why not upgrade it for a couple bucks more? The fuel lines and components should handle the potential increase in pressure - keeping in mind, pressure is controlled by the regulator. The only item that would raise any concern for me is the regulator diaphram. But, we're still talking about a relatively small increase in pressure over stock. I wonder if there's even a difference in the diaphram for the police option or 350 TBI? Does anyone know? Can you look that up and tell us what you find?

It sounds like a good alternative to an overpriced 'high performance' pump when it's not really needed.

TPIFormula

I'll look into that today when we have our "slow period" from open to 6 on Sat we are slammed! after that till 9 We are so dead! even compared to week nights, guess everyone is out partying lol!

I'll let you know

TPIFormula

The fuel pressure regulator equals the same part number so no difference, now what caught my eye was a fuel pump for a 95 454 TBI had 40 GPH but at a higher 45-50 PSI rating this might be overkill

89IROCZ28

iTrader: (14)

Nice. Someone running a TBI will be able to make use of that pump. What's the mfr & part number?

I think this could be good TBI sticky info. Make up a chart w/ "mfr / part #/ psi range / gph" and send to the forum moderator for consideration.

TPIFormula

just might have to, I'll get the PN for the 454 pump

Ronny

iTrader: (1)

I ran TPI pump on stock 350 vette for a while. I noticed no diff in performance(or insignificant minor diff) from prior pump that apparently was up to snuff. I swapped due to mods coming later. Check price of TPI pump?

Kevin91Z

iTrader: (1)

If you're going to the hassle of swapping your fuel pump, use the Typhoon/Syclone/LT1 fuel pump. Its rated at 60 PSI and 45 gal/hr or something like that.

The fuel pressure regulator will cut that down to the 15 PSI for TBI with no problems. And, you have extra capacity for swapping to a multi-port setup like a TPI or LT1 later on.

ownor

iTrader: (5)

would the FP used in the SyTy be the same as a LT1 fuel pump?

according to my calculations a 45 gal/hr rating would come out to about 280lph if you want to compare it to say a walbro or similar.

i remember some members on here having problems with the walbro255 because it was actually flowing too much. i dont know what the usual pressure output should be on these though, anyone?

i'm just asking if this particular pump Kevin mentioned wouldn't be too big for the stock FPR and fuel lines (especially return) as well.. just a thought, let's elaborte this

Ronny

iTrader: (1)

It has been reported the Walbro 255 needs a larger return line to function properly. 190 series may be a better choice.

Kevin91Z

iTrader: (1)

Ok, so 45gal/hour is too big. Its probably around 35gal/hour then. Sorry, I mispoke.

But the Sy/Ty/LT1 pump I mentioned IS a direct swap that will work with TBI engines.

ownor

iTrader: (5)

okay that sounds about right btw i also found a lot of the walbros (at least the 255, the failing ones are p/n F20000169 or so) are failing after a few thousand miles or a couple of months on a lot of people.. i'll get a link to the thread that was started on here some time ago.
is the Sy/Ty the same as a LT1 pump?

89_RS

If you're all looking for an aftermarket 255lph fuel pump other than the Walbro's, how about the Granatelli pump from Jegs:

http://www.jegs.com/i/Granatelli/467/GM722-2/10002/-1

Damon

I believe the later TBI motors, just before they went to Vortec/multi-port engines DID run at a higher PSI than earlier TBI setups. I think they upped the pressure considerably but cut down on injector flow rating at the same time, netting out around the same max HP potential in stock form.

In any case, you can use a considerably larger AND/OR higher pressure pump than stock and the TBI will just regulate it down to the same pressure at the injectors anyway. Plenty of guys have used stock TPI and LT1 in-tank pumps with the factory TB setup.

FYI- I have a 255 LPH in-tank pump in my heavily modified 1990 454 SS truck and the stock sized lines (3/8" feed, 5/16" return) have no problem keeping the pump's pressure down to 6 PSI to work with the carb. If there is a problem getting the pressure low enough it's probably a restriction in the regulator built into the TB, not a problem with line sizing.

va454ss

iTrader: (1)

Correct. The 94 and 95 454 TBI motors ran at 30 psi. I believe they used a V6 injector. I've heard this was to thwart a vapor lock issue.

ownor

iTrader: (5)

so can i just take a 93-97 LT1 genuine delco pump to get the job done for me? i couldn't find any # for these pumps.. any1 with p/n or specs here? i would like 30psi and enough fuel to feed about 300fwhp.

ownor

iTrader: (5)

ok i found a p/n and also some specs for the TPI pump:
ACDelco EP241 50psi 24GPH (about 160lb/hr)
i think it was used in the early (85-87? maybe even 85-92) L98 vettes and f-bodies. thomas1976 is also running it, maybe he will chime in here and give us some comments on this.

thomas1976

Hey ownor,

ACD#EP241 TPI fuel pump: Its around 100$, phisically almost identical to tbi pump, direct replacement no modifications needet, new strainer was not included.

I hope it will last wery long

redbird92'

iTrader: (1)

Whats the part # for the 454 pump and is identical in size to our 305 pumps


GREAT THREAD!!!!