502 mag high pressure line
 

I have a need to extend the pressure lines from the cool fuel to the fuel rail .(cool fuel has to move)Does anyone make any type of 0-ring adapter fitting to go in to fuel rail as the stock fitting does. Has anyone tried cutting existing crimp off of the fitting and re-crimping new hose back on ..When someone is setting up a system with different pump and return style regulator, what is used for the high pressure hose...This is a 502 mag mpi #153???

This is the time to convert it, I wouldn't mess with the stock OE stuff. I used AN fittings and push lock hose on mine, high volume EFI pump, external bypass regulator at the end of the fuel rail and dump the excess back to the tank or filter head.

but how did you get the fuel into the rail without using the oem o-ring fitting? Was hoping someone knew of a merc o-ring to AN or pipe fitting.

I cant remember what the 502 mpi rail feed looked like, mine are 500 EFI intakes, can you post a pic ?? the may make an o-ring to inverted flare fitting

Use the OEM hoses with adapters to AN. Jegs sells them for like $4.

most likely this
http://www.summitracing.com/parts/rus-640940

and this

http://www.summitracing.com/parts/RUS-640930/

exactly ditch the cool fuel and run the return line to the tank. push locks are the easiest way to go.

and ditch the vts tank too while u r at it

Thank you very much .I think that is what I was looking for.

If you can make those work I'd like to see it please!

Says he has cool fuel not VST

2 totally different set ups and systems .

VST junk system -

Gen II cool fuel not that bad to have.

VST was installed topside of engine and a long gone system- cool fuels install bottom side of engine and still around - FYI

If you use those fittings from Summit as I think what you are going to do for the install is hose clamping a longer fuel line to them, if this is correct thinking on my part - then you are not coast guard approved nor is a good & safe position install using them as a high pressure side fuel feed line nor even a low pressure side install.

If I am correct about how that install would be adapted using hose clamps then actually it would be an install that people in the industry would shake their heads at including myself plus it can put liability issues into the mix against the installer.

Also it can personally open you up for liability issues as a non approved install for marine applications especially if you are any sort of a marine business or claim to be however including word of mouth. Just saying and for the better.

What you think I'm trying to do would be wrong ,Bup. I specifically am trying not to use hose clamps .In the back of the fuel rail in front of the distributer is a female O-ring type fitting ,machined in .I was hoping someone knew of an adapter that would go into that hole that would enable me to go to a flare type fitting .Since the original hose was delaminating anyway, I cut the crimp off original fitting and removed hose. I was hoping that I could just have another hose crimped on ..The fitting has three or four minimal lines machined in that would not leave me comfy having a hose crimped/attached to .If there is no adapter made I'm now thinking I will buy a stainless male flare fitting and have welded to the end of existing original fitting. After looking at the adapter that had been referenced here, I don't think it is what I need. Hard for me to believe there isn't an adapter made for this situation ..I have searched and searched and am running out of options

ATI (superchargers ) makes a block off for the return line hole...but that probably doesn't help.

Most people, if looking to add aftmkt lines would drill and tap the holes to take standard pipe thread .

I was trying not to pull fuel rail off engine, but I guess it might have to happen.

its simple, be careful with the O-rings that mate the plenums together, if you tear one, get em at McMasterCar............... merc wants 13 bucks a piece for them

Did I look up that Merc fuel line correctly as It appears that it's NLA. Is that why you are going thru this ?

Please provide pics and part numbers - trying to get rid of the OEM VTS tank on a Mercruiser 502 EFI - not a real 'gear-head' and would like any recommendations - thanks!

I was just saying as it looked like the Summit ones are used in conjuction with rubber fuel line and hose clamps. Thought you mentioned that you might have to go that route with the Summit adapters.

I understand what you are trying to do - totally get it 100 % . I would try an hydraulic hose shop and see about adding length and crimps to the middle portion of the fuel line not the ends side.

No ,Line is still available. This is the cool fuel under the motor and it is having to be relocated because boat is set up with race mounts .I need longer hose to put pump in front of engine .Flame away ,but it is stock 502 mpi's with pumps that work fine ,so I'm just moving stock pump and will return the fuel to the tank instead of filter. That way ,I don't think I'll need water running through it? If stock pump isn't adequate then i'll worry about a different pump and regulator

Bup, the nipple part that looks like you would slip over a line with a clamp, isn't. They where thinking maybe it would go into the female side of the fuel rail with oring.

Cool. Thanks for the info.

Correct. Running return back to the tank should negate the need for for using the cool fuel (water fed) system. Has for the boats I've done this too.

In case you haven't seen it mentioned - thse make it easy to add fuel tank returns into the fuel fill line(s).
http://www.cpperformance.com/c-500-f...s-returns.aspx.
http://www.cpperformance.com/images/.../620-76300.jpg

possible some info help

http://www.arnnworx.com/catalog/inde...d=17&chapter=1

Keep in mind as for relocation and set up that you do want to induce vapor lock / fuel boiling away into the cool fuel. Heat soak boiling the fuel out of the cooler after shut down from drained down heat soak cooling water from the engine side. Very important here.

It is best to remount the Gen II cool fuel assembly as low as possible - the bilge area is the coolest section of the engine compartment hence why Mercruiser mounted the GEN II cool very low like they did.

the negs are from Mercruiser install is - it makes it hard to get access to it on many apps.

I was surprised at the hose shops that won't touch it once I mentioned gasoline.

Where are you planning on mounting the pump and cooler

Says will mount it in the front of engine.

If all possible mount it low. I would try a real hot rod shop who does and makes their own AN fuel lines and or crimped fuel lines.

I would adapt from the middle unless the fuel line ends are not in good shape for whatever reason. I did this before but mounted it all further away from side of the engine to the outside portion of the stringer.

Initially I was going to just have a hose shop add line in the middle with crimped on double ended barbs.When I cut the heat insulation off one hose, the hose was delaminating...That's when I cut the crimps off the ends and checked (barb) on tube fitting ...It is almost nothing .The old crimps were a tight,trapped fit on the tube and crimped to the hose. Hose couldn't blow off .I did talk to a friend today that does welding for some of the "hot rod shops".When I asked him about welding a fitting on the end of a tube(original tube/fitting). He said he does them quite a bit for custom stuff .I am trying to go the path of least resistance ,but have legit uscg approved type setup. Beyond that...If I mounted the hi pressure pumps below fuel level on the rear tank bulkhead would I still need low pressure pumps?

Have to ask as you posted " If I mounted the high pressure pumps" - ok now I have to ask what set up do you have with more than 1 high pressure fuel pump ? or is this a typo error ?

You need the boost pump / aka low pressure fuel pump for the stock GEN II OEM cool fuel.

do you have a year model and engine serial number so I know what you have here ?

I just assumed he had two engines.

It is twin screw boat .Serial is OK 153 something .You answered my question about low pressure pump.thanks

See I am not so bad to you Motor and I understand now with being twins application,

I never said you were bad to me .All I said was "why not join the site" .It does make it a lot easier to use and doesn't cost much .You wouldn't have to clear your PM inbox everyday ,which you probably have to do now .

Went from VST to cool fuel Gen 1 with return back to the tank during last rebuild, it doesn't use the low pressure feed pump. Was thinking of doing the same thing and replacing the current cool fuel with after market high pressure pump. Don't know if Merc added the boost pump because of the 1/4 ID fittings feeding the high pressure pump or some other reason. My lines from tank to pump are 3/8 ID to reduce the restriction

Was nt sure if you were asking as you already have the low pressure fuel pumps installed wanting to get rid of them or you are looking to install them to help with vapor lock issues and feed the high pressure fuel pump. Anyways Merc always recommended the kit after the fact. Just wanted to make sure about your question.

http://www.amazon.com/Mercury-Mercru.../dp/B005IGSW0G

502 High pressure line
 

Motor, I'm just reading this thread. Mine is 1998yr cool fuel also. Will have to look up what Gen# it is. I had severe vapor lock issues. Both motors.
It's mounted port side low where yours is behind an offshore front engine mount steel plate.

What had been happening I think was when the eng mount plate was installed they had to move the cool fuel box rearward, to make room for the mount plate...the two fuel lines were short and thus pretty tight up against the BOTTOM OF THE OIL PAN. So tight there was no room to insulate or pull them away from the pan. It boiled the fuel out EVERY time i stopped for a while.

3 years ago, i just added extensions in the middle of the two hoses to make them longer to move them a little to get an inch clearance between the pan and the two supply and return filter hoses, And put 2 small pieces of that alum foil covered plastic bubble sheet stuff between the lines and the oil pan. PROBLEM COMPLETELY WENT AWAY. I also put a small sheet between the port side of the block and the cool fuel box and wrapped the fuel filter but these two steps may not be necessary.

Never a VL issue again. The whole time the hot pan had been boiling the fuel.

What I am doing right now is making a couple brackets and moving the pump even more forward so that the two lines that come off the front of the cool fuel pump turn with the tubing 90 degree elbows, are all in FRONT of the steel plate and not crossing it between the pan and the plate under the pan.

NOTE: I did have to cut a big hole in the steel plate for the fuel pump to fit in, but pump and other stuff is now easier to reach and get out if needed. I still was able to use the std pump and attached fuel cooler. Don't need to go back to the tank this way.

By the way, to answer about longer hoses needed. I made a flat plate bracket and just lowered the filter on the front starb side of the motor so the std length hoses would reach.Wrapped the hoses in this foil bubble wrap also. Its HOT down here on the gulf coast in August, still no more vapor lock.

If you wanted to move just the pump, and do away with the cooler by going back to the tank that would probably work also, but as i recall.... you might need a new pumps with the right hose fitting

Very curious what you did. Let us know.
Cap'm Kurt
Lake Charles, La

PM if you need.

I have adapted a 6an compression fitting on that 3" tube by sliding on the female nut and using a brake line flare tool to flare the line, then just screw on your new hose with new flare fitting.