Fuel Pump
 

What power level is the factory 454 Mag (carb) fuel pump good for?

I was going to upgrade to a Holley 130gph mechanical pump to support my blower, but that would save me $150 if I didn't have to switch. Blower is a 250 with twin 850 Nickerson's.

Thanks.

Not enough, that's the one place I wouldn't skimp. I believe 80-100gph.

That's what my gut was telling me.

Good info regarding what the factory pump is good for, too.

I was told the stock fuel system is good for 600 hp, I'm sure you will be well over that.

That's the hope anyway!!

The 525sc used the belt driven merc fuel pump to supply the fuel to the single 1050 dominator on the 177. The 600sc, used the same merc fuel pump, to supply the 420 blower with twin 700 carbs. The 800 and 900sc used a holley 6 valve internally regulated block mounted holley pump. I use those pumps on my engines feeding twin 850 holleys on a 420 megablower. Holley no longer makes them.

For years guys have blamed fuel pumps for being the culprit of their fuel supply problems. Many times, it wasnt the pump that was the problem, it was the rigging. Like the pickup in the tank, line diameter, restrictive fittings, poor flowing filters, and things of that nature.

Tom, if you have Mark IV blocks, I would go with this pump and be done with it. They are much better than the new non 6 valve crappy 130gph holley pumps out today.

http://teaguecustommarine.com/em0011...uel-pumps.html

Google Baker engineering. Just got two pumps from them this past august, they have 1/2 ports.

Google Baker engineering out of Michigan. Just got two pumps from them this past august, they have 1/2 ports.

Yup. The link I posted was for the baker pump, just on teagues site.

Might as well support a sponsor ( I like Teague)

Their pump is a nice, well built piece.

http://33outlaw.zenfolio.com/img/s8/...37157778-3.jpg

Boy does that remind me of the OLD holley fuel pump, that I wish Holley still made.

I'm going to order one of those baker pumps but in 15 psi and use a return regulator to set the fuel psi.

I got one a brand new one from Amazon and it lasted one weekend. Could be just my luck thou I know Mild runs em without issues.
New set up is going to be regulated.

http://33outlaw.zenfolio.com/img/s12...45961115-3.jpg

https://www.holley.com/products/fuel...arts/12-454-25

These are what I run. Pre-set 7.5psi pressure. 170 gph. I still use a regulated return system back to tank.

Is there any good way to bench test these pumps? I have one of the old Holley six-valve versions - was working fine when I took it off my old 454. I did notice that the lever is damn well impossible to push down manually - are they all like this?

Yes. Extremely hard to pushdown.

What he said ^^^

I have a Clay Smith 6 valve pump and it wears down the push rod pretty quick. It to is very hard to push the lever down.

Those the higher psi ones ? Is it wearing the bronze tip?

Yes, I just throw a new push rod in at the beginning of the season. If I let it go too long it makes it too hard to get out. Also I don't want it to dig into the cam.

Wonder how these would hold up

http://m.summitracing.com/parts/hrs-94475

Yeah, I've been thinking about one of those too. FBC, are you using one of the higher quality bronze tipped pushrods? I have read quite a bit about the cheap ones wearing down quickly. I too am concerned about the heavy spring in this pump. I guess that is to keep the rod following the fuel pump lobe at high RPM. I don't want this to turn into an annual headache because it is very hard to get to the fuel pump on my engine when it's in the boat.

I have one of those and got scared to put it in. I was thinking if the end would mushroom out I might not ever get it out with the engine in the boat. The ones I am using now are comp cams #4607.

I had a buddy run one of those comp cams brass tipped ones with a flat tappet cam. He mushroomed it after a couple hours run time and couldn't get it out. So he installed an electric pump. :-(

I have the Comp part to use in this engine. I've used them in other builds without a failure. Perhaps something else caused it to go south? Why use a brass-tipped pushrod with a flat tappet iron cam?

Good Thread! Been wondering what to use here? I like the Specs on that Baker Pump! I havnt used Mechanical pumps in 25 years! Want to put the BEST one in right from the start! I might be wrong....doesn't "CrashCar" have to run Mechanical pumps? If so...what are they using? Baker puts out some NICE stuff...do they offer a pushrod?

Comp said they work with either cam. Obviously not!

Guess not!!

What about the GM Performance one for use with their steel billet roller cams.

ARP makes some GREAT Products....do they offer?

Oh great.. I`m putting in 2 new Clay Smith pumps and now I have to worry about the pushrod?

Tom,

The fuel pump pushrod, like the distributor gear, must be matched to the core material.

Am I correct, you are running a Crane Cam (copper colored between the lobes)? If so it is a carburized 8620 core and requires a compatible material for the pushrod. The Crane part # is 11985-1, available online.

Bob

Bob, what do you recommend for billet cores that you use? Same thing as for the Crane? I'm planning to run basically the same pump as the others are discussing.

I'm wondering if the stiffness of the spring in the pump is a factor in the pushrod tips mushrooming out. It would follow logic that the heavier spring puts a lot more pressure on the rod. I also came across someone discussing the two little "helper" springs that push the arm out to be in contact with the pushrod. Apparently if these are weak it could allow excessive play in the pushrod instead of holding it firmly on the cam lobe. If this happens then it would be easy to see if getting mushroomed out as it gets hammered by the lobe as it rotates. Anyone else encountered this?

Did the 800 and 900SC engines run a billet roller cam, or was it a cast core? If billet, what pushrod was Merc using?

i use the comp cams 4607 with no failure to date.the one bob posted is the same thing just crane,s version.

The 800sc used a flat tappet camshaft, and pushrod part #35377 , which listed for about 25 bucks.

The 900sc, used a solid roller camshaft, and pushrod part #848471, which listed for 66 bucks.

They both used fuel pump part #8M8024635 which listed for 270 bucks.

The fuel pump used on the 800sc, 900sc, was the above part number, but simply was a holley six valve self regulated pump. They still had the holley stamp on them. The 900sc was a 540ci, 8.0:1 static compression. It had a solid roller camshaft, brodix aluminum heads, 10-71 Mooneyham superchargers, LEE intercooler, with twin 1050 dominator carbs on top. It had a wot RPM range of 5600-6000RPM. They used a Thunderbolt capacitive discharge style igntion box on them.

The fuel system consisted of the fuel pump mounted on the block, then to a filter #35-848850A2, then split to the carbs. There was no regulator in the system, no electric pump, no return lines.

We run a pair of 900's with baker pumps. Anything over 5k rpm fuel pressure does drop off. Added electric fuel pumps with no regs and it maintains 12 psi with no issues. It's not a fuel supply issue, 5/8 supply lines with 1inch pickup tubes. If we didn't buy new pumps I would of bought a block off plates, reg, and Aeromarine A1000, no more thoughts of lack of fuel.

What carbs are you using that can take 12psi without flooding the engine?

While I personally have not had this issue, I have read about it, and want to mention. That is, that these mechanical style pumps can suffer from what they refer to as "cavitation" at high RPM. Hence the development of a lightweight carbon pushrod that weighs only 29 grams. I am guessing, that at high engine rpm, the pump spring can be too weak to keep up, and possibly a condition similar to valve float when an engine doesnt have enough valve spring pressure to control the valvetrain. I also guess that the lightweight pushrod, helps take some of the load off the pump return spring, allowing the pump arm to return to the closed position fully on each revolution, so that it can complete its next stroke in a complete manner. Not sure if I am explaining it properly.

http://www.competitionproducts.com/H.../#.VOvwqC7LpE4

Using a bronze-tipped Comp pushrod for one of of your cams, same p/n as used with my SBC cam from years before.