Pre pump filter for EFI
 

What is tranditionaly run pre-pump? The AZM setup I have came with a Mallory carburator fuel filter after the fuel pump. I can put the 5 micron efi filter into the mallory housing, but that leaves the pump unprotected. In an old boat with an old fuel tank, I figure that could cause problems. But putting the Mallory filter in line before the pump could really restrict flow.

What is normal for an EFI system on a boat? Two separate filters? One course filter before the pump and a finer one after?

Any thoughts or advice would be appreciated.

I run 2 filters, a low restriction filter before the pump. I found a glass filter with AN fittings that disasembles. Then after the pump I run a High flow/High pressure aftermarket fuel filter/water separator. I got the housing from EMI and I use a Wix high pressure water separator fuel filter. I use the Holley MPI kit 1000cfm trottle body with 42lb injectors. Hope this helps.

You should have the water seperator/filter before the pump. That filter is not made to have pressurized fuel running through it and it could be dangerous. Those filters get rust in them from water and could get a hole in them from excessive rust. You will then pump pressurized fuel into the bilge. I run the water seperator first, then the pump, and then a high pressure filter after the pump to catch any parts if the pump fails. I use one from Aeromotive. I think it is like 50 micron. It is made to catch the larger pieces to stop them from going into the fuel rails and injectors. It will handle like 100 psi. Hope this helps, Eddie.

ANy idea if any of the off the self water separators will handle the flow of 600hp on the vacume side? The ones at West Marine say they're only good to 200hp.

Anyone know a part number for the water separator on an old carbed HP500?

Go with what Mercury Racing uses -- a Ramco water/fuel filter/separator then the pump then the smaller 10 micron filter. The second filter should be changed very often -- depends largely on how long the boat sets between use.

A Ramco filter is the only prefilter that can keep up with a Weldon pump which is found on all 850's, 1075's & 1200's.

I am not using the stock filters. I am using High pressure filters. They are like $60 a piece. I am not using the stock mercury water separator/fuel filter. Be sure to keep the low pressure filter as low as you can in the bildge along with the pump. Then run the output of the pump to a High flow High Pressure Filter Separator. I have had this installed on my boat this way for 8 years. The filter will not rust. You should change your filter every year or 2 anyway. This is assuming you do not have a pump in the tank. You need to have the pump as low as you can so it can draw the fuel from the tank.

8 whole years ??? If I had been only doing it that long I would be listening to all of Eddie's dumb comments. But thats just me. :rolleyes:

OK, I edited my first comment. This is not my post. I am not a marine dealer. I do all my own wrench work. I installed my system acording to manufactures recomendations in 2002. I am just trying to put somone on the right track. I was told at the time this is the best way to do it and it works. I am just giving my advise. He probably thought I was using the stock mercury setup. My only concern with running the separator before would be additional restriction before the pump.

Any idea where to buy one? I did a search and came up empty for anything Ramco marine. I'm guessing it's probably pretty pricey. I looked at the high capacity stuff CP and Hardin sell and it would seem I'd be better off buying two normal ones and running them in parallel. That way a prefilter change would be $18 instead of $50

What does that mean? What makes my comments so dumb???

Eddie, you have always been willing to help and might I add, with good info. I do not get the above comment from P31 either. thanks !

Thank you. I'm not sure what it means either. I don't know if it was meant to be sarcastic. I certainly hope it was, or we are going to have some problems.
I have done EVERY boat's fuel plumbing the way I described and it has worked flawlessly. Several pleasure boats have been well beyond 1400 hp. I will not give a customer a boat with a filter that is seeing pressurized, unregulated fuel. A Weldon pump can make over 80 psi unregulated and a water seperating filter was never designed for that. I have also worked with several boat manufacturers and I have yet to see one of them plumb the water seperator after the pump. Merc. also puts the filter before the pump.
Eddie

That by no way was a shot at you eddie !!!!!! You had to have read the comments that have since been deleted by some know it all. I think it is great that you take the time to share your wealth of information with all the members on here. :ernaehrung004:

P31 was defending you. I edited my post after reading it over I added more detail. If your way works then stick with it. I am using High Pressure aftermarket water separators. I have been using this setup on my personal boat since 2002. They have a petcock on the bottom and the filter can be drained. I have never had any rust ever accumulate in my filters. The comment you made about rusty filters kind of irritated me. I have never tried to be a know it all. I just give comments on my experience. Were do you locate the water separator and pump?

Sorry JeffP31. I wasn't sure what it meant, that's why I asked. It makes sense that posts were edited, that is why I wasn't sure what was meant by it. Again, thanks and sorry.

jeffswav, why would a comment about rusty filters annoy you. I have seen more that I can count. They may have been older filters that were run in salt water, but they were full of rust, both in the filter and all around the top. What you are using is fine...a HIGH pressure filter/seperator that is made to handle the pressure. Someone could misunderstand that and try to use a standard filter in that way, which is not made to be pressurized. If your way works, then use it. I was just relaying the way I do it that has worked for me. There is more than one way to skin a cat.
One other added benefit of having the filter first is that it acts as a reservior for the pump to draw from. I try to use at least a one quart filter. It will absorb any pulses and keep the pump primed at all times. I try to mount them as low and as close to the tank as possible. I want the pump and filter no higher than the top of the tank. None of these pumps are very good at pulling. Pumps are made to push fuel, so the closer they are to the tank, the better.
Eddie

I just took it the wrong way. Glad we cleared that up. I can see were a engine builder would rather do it your way. If the owner fails to maintain the system you may be held liable. I change my filter every other year, and empty a couple of times per season. My boat is run in fresh water and stored in by building. Some boats must be difficult to install a large separator so low in the bildge. I have a small inline filter just after the tank, then a short hose to the pump, then up the the separator in the stock location.

Unfortunately, not everyone maintains their boat like you do. Liability is the biggest problem since most do not maintain their boat like they should. Sometime it is tough to get a large filter down low. I will go to a smaller one if I have to in order to keep it at or below the top of the tank. I would rather have a smaller filter below the top of the tank rather than a larger filter above the top of the tank.
Eddie