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Anybody else using the RobbMC Performance fuel pump (PN 1000) with the new Edelbrock 6102 heads? This post is partially soliciting the experience of others and suggestions on the approach I'm taking, and to share my experience with anyone else who may be interested in the combination.
I'm fitting mine up and planning to use the stock alternator brackets for the passenger side installation. The pump body can be rotated to any position by loosening the 6 bolts enough for the clamp ring to slide around but there are still some minor issues with clearance to the heads. Fittings on the top outlet (1/2") of the pump had clearance issues so we're planning to use the side outlet (3/8") with a 90 degree elbow at the pump and another at the filter. Had to rotate the pump body to position the elbow with clearance to the block.
The pump was a tight fit to the head in it's out of the box orientation and had to be wiggled into position so the fastener could clear the corner of the head's inset. I'm not sure why the head design created this downward facing point when a slight modification would have provided some obvious clearance for a pump's horizontal surface. After rotating the pump body a bit as mentioned above, it's obvious that the pump isn't going to sit flush on the block mating surface unless I do some clearancing on the head. I'm assuming there's plenty of material in that area so removing 1/8" of the point to clear the pump won't be an issue.
I'd rather avoid the 90 degree elbows, but things are a little tight. So one elbow out of the pump, some AN-6 line and another 90 degree into the filter which is connected to the carb lines. A 45 degree AN-8 fitting into the pump's side inlet should be enough to keep the fuel line out of the way, Fuel return line is AN-6.
It would probably be easier to use aftermarket alternator brackets, which isn't out of the question yet. I think that would allow a straight line into the top outlet but that point on the head will still need clearancing.
Last edited by VI Cutty; March 30th, 2024 at 12:46 AM.
This is 100% the reason I just installed an electric fuel pump and was done with it. Been there, done that. Turn the key, two pumps and it fires right up.
So I get that I probably should have gone with an electric pump, but at this point I have a bunch of cash invested in this one and I'd like to make it work. It seems like it will, although I'm sure those 90's aren't ideal. Does anyone see any issues of concern or suggestions based on my current setup and plan forward?
Also, if I throw my hands up in frustration at some point and switch to an electric pump, ,what specs should I be looking for as far as PSI, gallons per hour, etc? 461 with QFT 850 SS carb.
Need to know hp to recommend the right size pump. Engine ci doesn’t really matter.
And I got your pm.
Not sure how much you can take off there, I’ll look at a set I have here and let you know.
But can you notch the cover of the pump as well? How much material do you have on that?
Putting aside bracket and fitting clearances, and rotating of the pump body, it looks like there's a slight clearance issue no matter how you slice it.
I'm making an inquiry to RobbMC regarding how much material I can remove from the top of the pump, it looks a bit of chamfering there is pretty feasible. Also waiting for Mark to get a chance to reference his heads for material thickness. Perhaps even a combination of the two will get the job done.
Well shiznit, something for me to look forward to. Same heads, same pump for my build. Please add information on the results or direction you went with, email reply will also work.
My engine is at the builder still, so I have a little while to get to the point you are. Thanks.
Well shiznit, something for me to look forward to. Same heads, same pump for my build. Please add information on the results or direction you went with, email reply will also work.
My engine is at the builder still, so I have a little while to get to the point you are. Thanks.
Robb (RobbMC Performance) advised me that I could safely remove 1/16" from the pump cover. Bernard Mondello told me I could remove probably up to 1/2" on the head (much more than would be necessary). He also said he has other customers with this combination who don't have any problems. I'm not sure why mine would be any different but it didn't matter how I positioned the pump body there just was not enough clearance.
The pump body can be rotated to any position be loosening the six screws to the clamp ring (four on top and the two lower side ones). Turning the body will introduce new interference points depending on the orientation. In the end, I found my position as shown in the photo which allows me to use the side outlet. I found the top outlet didn't give me a good angle to get the fuel line to the filter, and was completely unusable with the stock alternator brackets I'm using. The outlet is rotated slightly into the corner of the block to provide clearance between the 90 degree outlet fitting and the block. I removed a slight amount of material from the fitting too. I used a hand file to remove material from the pump, after a lot of fitting to see where it needed to come off.
The corner on the head slopes down towards the back of the recess. Before removing any material, there was contact at the front of the point preventing the pump from being anywhere close to properly seated. Getting to the back is a difficult angle. Bernard recommended a carbide bit on a Dremel for the head, which worked great. I had a flexible extension for mine but even using that I had a hard time getting the bit where I wanted.
In the end I was satisfied with the amount of clearance I got. More might have been better but this is enough for now, after re & re'ing the fuel pump a few dozen times. First photo was one of the in progress efforts. The back corner was the bane of my existence.
This is the end result.
I used a 45 degree for the inlet and a 120 degree hose end for the return line. AN -8 for the fuel supply and AN - 6 for the return line. I'll post more photos of the end result in my build thread.
The 90 degree outlet fitting feeds the line straight up to the Holley filter and into the carb easily.
Lots of clearance to the belt.
Last edited by VI Cutty; April 17th, 2024 at 06:01 PM.
I just ran a 483” FE Ford on the dyno, 633 hp and 650 lbs torque with 2 625 cfm Holleys. The first runs used the dyno electric pump then we switched to the stock AC 4918 mechanical pump. Horsepower, torque and afr numbers were unchanged. Do you really think you need that huge pump?
Last edited by Fpcopo; May 14th, 2024 at 08:46 AM.
I just ran a 483” FE Ford on the dyno, 633 hp and 650 lbs torque with 2 625 cfm Holleys. The first runs used the dyno electric pump then we switched to the stock AC 4918 mechanical pump. Horsepower, torque and afr numbers were unchanged. Do you really think you need that huge pump?
No idea if I need that much pump...but it's the pump I've got now!
If you’ve got it you might as well use it.👌. I used to worry about having big fuel lines and lots of pump capacity, then I saw that all the Mopar hemi super stockers had 5/16” fuel lines from the factory. I was at a car show and asked Tom Hoover the main Chrysler drag engineer about it. He said they tested fuel lines up to 1/2” and found 5/16” lines provided all the fuel the hemis needed. He said why carry the extra weight and expense of the larger lines. This was in the early Seventies so I know engines are putting out more power now. Interesting nonetheless.
March 30th, 2024, 12:42 AM
