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awr68
09-12-2004, 11:08 AM
Ok, it's time to figure out what parts I'll be using for the fuel system. I have a '96 LT1 for my '68 camaro (hope for about 400hp when done)and Matt is building me a fuel tank. I plan on using an inline fuel pump and filter as well as a regulator (w/ gauge close to the motor). I've been doing a bit of research this week and really only came up with Holley and Aeromotive. I know there must be more options out there but I just can't seem to find them. Know of any other brands I could be looking at? Like most of us I don't want to spend more than I need to, but on the other hand I prefer quality parts...

Also, what kind of flow/pressure numbers will my motor require? It is basically a stock aluminum headed LT1 that will have a Hot Cam upgrade, headers, electric water pump, 58mm TB, ect. but in the future I may add a SC and do a 383 rebuild when the timing is right and not having to redo the fuel system at that time would be nice. Thanks!!

nancejd
09-12-2004, 11:23 AM
I think the LT1 fuel pressure peaks at between 42 and 44 PSI at WOT, at least that is the stock unit. I think if you had a pump that could supply at least 50 PSI you'd be doing pretty good.

Fuelie Fan
09-12-2004, 12:27 PM
Fuel pressure is determined by the regulator, not the pump. Deadheaded, I would not be surprised if the LT1 pump could hit 80 psi.

Stock pressure is supposed to be 43.5 psi.

required flow rate = HP *BSFC

Your engine: HP =400, BSFC = 0.50 lb_f/hp*hr (usually a good estimate)

Therefore, you need 400(0.5) = 200 lb/hr AT 43.5 psi. MANY companies will confuse buyers by providing open flow rates, ie unrestricted (zero psi).

Conversions
lb/hr to gal/hr: divide by 6 (33.3 gal/hr for you)
gal/hr to L/hr: mult by 3.79 (126 L/hr for you)

Factor of safety: I would aim for a FOS of AT LEAST 1.2. THerefore, your pump should supply at least 150 L/hr at 43.5 psi. Becuase, even with a brand new fuel filters (of which you should have two by the way, one before and one after the pump) you will have pressure drops. This means that instead of only having to supply 43.5 psi upstream with an inlet at atmospheric, perhaps your pump will have a 2 psi upstream restriction and must supply 47 psi to overcome the post filter pressure drop. And, this gets worse as the filters age.

Inline pump: If you're having a custom tank made, why would you still select an inline pump? I would reconsider. In-tank pumps are quieter, have a longer life, more reliable, and greatly simplifies fuel line routing. I think the only advantage to running inline would be if you needed a mammoth pump for a 1000hp engine, becuase those may be hard to find as an in-tank, but you are not in this situation.

awr68
09-12-2004, 08:25 PM
Thanks for all the info!!! Very good reading on a topic I know very little. Actually after looking under the car and seeing the lack of good mounting points for a inline pump I'm heavily considering a in-tank pump now....

andrewb70
09-14-2004, 05:55 PM
I have a Holley 255L/hour in my GTO and I have never had any issues. I have a pressure gauge mounted in the car and I have never seen any dips in pressure, even at WOT. I have 500RWHP, so you should have no issues.

Andrew

mike67cam
09-14-2004, 06:26 PM
I believe the Holley pump is made by Walbro. The 255 L/hour in-tank should be more than adequate. I had Rock Valley install a Walbro pump in a reproduction 67 tank and it works great. :icon996:

Mike

censo69
09-15-2004, 06:12 AM
Ok not to highjack your post but my question has to do with fuel systems. Im looking for a sumped bolt in tank for my 69 camaro any recomendations and contact info?

gc427
09-15-2004, 07:23 AM
Vince, a Rock Valley/DSE tank seems to be the best bolt in tank that is available. Stainless steel construction, plus can be built for internal or external mounted fuel pump. IMHO Weldon makes the finest electric high pressure pumps, regulators, and filters on the market, they are able to withstand use for racing or street driving. Just my 2 cents, George.