How much power have you got out of a mechanical fuel pump?

[mc1984ss]

I am in the planning stages of my next big block and have been thinking about the fuel system. It will be a naturally aspirated 502 and am looking for about 550 hp. The block does have the boss for a mechanical fuel pump and that is what I would like to use due to the simplicity and a stock tank. Some aftermarket mechanical pumps claim to handle this power and do not require a regulator. I would like to get by with out a regulator because I dont want to deadhead the pump and i do not want to run a return line to the tank. I am sure others would tell me to just run the bypass regulator and a return line but I do not want to if I dont have to. So has anyone made this kind of power with a mechanical fuel pump and no regulator? If so which one? Thanks in advance!

[Bucky67]

Mc- I am running a 468 BBC in my 1967 Camaro RS/SS. I am running a Holley Mechanical Fuel Pump with no issues. My car was dyno'd on an Engine Dyno, not a Chassis Dyno, putting out 611HP & 618 FT LBS of TQ. I am running a regulator, but no return line. In fact, I am running a stock Polished Stainless Steel Tank. My fuel lines are half Braided Stainless Steel & half Polished Aluminum that I custom bent. I run 6LBS of fuel pressure & I've never once experienced fuel issues once I went with a larger fuel pump. I actually picked this one up straight from the Holley guys on last years Power Tour while we were in Valdosta.

I have my billet fuel filter coming directly off my dual feed line on the carburetor. The regulator serves as a 90 degree turn for the fuel line going to the pump. It's a very clean, professional look and you have the filter and regulator as close as possible to the carburetor.

Some guys will tell you to go electrical, but I like to keep things simple. I'll post detailed pictures is my set-up in the morning.

[CDMBill]

You can supply well more than 550 with right mechanical pump and well engineered plumbing. But, you really need to focus on tank pick up location, line size and avoiding big vertical changes in Line location. You are asking the pump to draw effectively from the Tank at the back of the car, and the float bowls will let you crutch the occasional low fuel levels.

I lke electric return style pumps because of the ease of use and consistency of fuel temp and supply. They are more complicated and expensive. Mechanical can work, go big on the filter.

[yellomalibu]

I used to run this pump http://www.summitracing.com/parts/CRT-M4891/ and was probably just south of 500 hp... I had no issues until my old rusty gas tank clogged it up with rust and killed it, then a second one. I fed it with a 1/2" line. A racing buddy didn't think it would work, but I made the analogy of drinking from a narrow straw and from a McDonald's straw (when they used to have fat straws)... sucking through the larger diameter straw got a lot more volume . My 307 car originally had a 5/16" line.

I have, however, read about people having issues with the really high volume mechanical pumps over on the Chevelle website - mushrooming fuel pump pushrods, so be careful and do research. Perhaps go to the teamchevelle website (sorry Brian) and do a search in the "performance" section. Tons of big inch big, big power, big block guys over there with lots of experience to share.

[oj]

You can return to the inlet of the pump. No reason to go all the way back to the tank, just add a 'tee' anywhere in the line or at the inlet fitting of the pump.

[Monk]

Running an Eddy mechanical on the W motor......647 hp.......3/8 line
and no issues.
Agree with Bill on the filter.

[SpiderGearsMan]

mechanical pumps ? very model t

[Beagle]

mechanical pumps ? very model t

I thought the Model T was a gravity feed? Didn't know they had pumps.

[Barry Donovan]

I thought the Model T was a gravity feed? Didn't know they had pumps.

true. I even tried that on a 1987 1.8 liter..positive rake suspension.

bangshift has a blog post where chad tours a factory. There is a mechanical pump that is not like oem in appearance or function meant for high performance. (I never saw one before, but they do exist, it is in the video)

[Bucky67]

Update W/ Pics

MC1984- Here is the set up that I'm running on Jade. Like I said, I've never had an issue, and that includes launching at the drag strip.

Fuel pump: Holley 130gph Part# 12-454-13
Regulator: Holley Adjustable 4-9lbs Part# 12-803
Fuel Lines: 3/8 Braided Stainless Steel
Fuel Filter: Edelbrock Inline

Hope this helps and gives you some ideas.

[SpiderGearsMan]

thanks beeg ...just bringing up the primitive nature

[Bucky67]

Finally....Pics

MC- I've finally managed to upload some pics for you.... Sorry about the delay man.

Have a good weekend!!

[BluLightning]

I remember that fuel pump!

[mc1984ss]

Thanks to everyone that answerd my question and thanks for the pictures. As far as it being "primitive" I dont care I am looking for a simple, dependable and cost effective fuel system. I want to do it right and I dont want to sump my tank or put in a fuel cell. My block has the boss for the mechanical pump so I dont see any reason to spend more money on a pump or regulator and I also dont want to have to run a return line if I dont have to since I am going to use hard stainless tubing. Thanks again for the help!

[Bucky67]

I remember that fuel pump!

Ha Ha.... I remember changing that out in the hotel parking lot in Valdosta. I'm just thankful that the Holley guys hooked me up. Good times Bob...