V8 fuel pump plate

Discussion in 'Gas Engines' started by sean-nós, Sep 13, 2012.

  1. sean-nós
    Joined: May 2010
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    sean-nós Senior Member

    Back again for more help :D this is my 5lt mercruiser it's a new long block and I'm swapping over a few parts from a donor engine.

    [​IMG]

    The donor engine had an electric fuel pump and I want a mechanical one, I took off the block off plate on the donor to get the push rod and found what looks like a spacer plate like the one below, can some one please tell me if I need this plate with the new pump or is it just part of the block off kit.
    Thanks

    [​IMG]
     
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You need that plate. It goes between the pump and the block. That plate keeps the rod from falling off when you install the pump, it also makes the pump hard to install unless the engine is upside down.
     
  3. sean-nós
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    sean-nós Senior Member

    Thats great gonzo thanks, I wasn't sure if some pumps had a longer arm and needed to be brought out a bit.
     
  4. PAR
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    PAR Yacht Designer/Builder

    Having built a few dozen small block Chevys over the decades, I can tell you that you want an electric fuel pump, not the mechanical one. The mechanical pump works just fine, but is a common oil leak source, plus it steals a few HP from the engine just to drive it. An electric pump is lighter, can't leak and can offer some pressure options (depending on model). Not to mention, it relieves a good bit of pressure from the end of the cam too for some free HP and reduced rotating mass friction.
     
  5. sean-nós
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    sean-nós Senior Member

    I'm not to worried about HP more so reliability as I will mainly be using the boat for cruising the lakes not racing, one of the other reasons Im going for mechanical is the new carb has an overflow outlet and my electric pump has nowhere to connect it unlike the mechanical, funds are very tight on this build so a new electric pump would have robbed me of some mahogany:D
     
  6. powerabout
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    powerabout Senior Member

    The overflow you mention is most likely the broken diaphram pipe.
    Marine pumps have 2 diaphrams and that hose connects between them and to the carb
    If an automotive diaphram splits it dumps the fuel on the ground
     
  7. sean-nós
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    sean-nós Senior Member

    This is the carb I have you can see the pipe at the bottom.

    [​IMG]

    And this is where it fits on the pump on the left.

    [​IMG]
     
  8. powerabout
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    powerabout Senior Member

    I dont think so
    thats looks like an automotive carb
    The marine version of that carb I have only seen the fittign foe the pump in the top.
    Is that low connection below the throttle plate?
     
  9. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    It's hard to tell, as the carb image is too dark to see much, but the lower fitting looks pretty big for a fuel inlet, looks more like a vacuum line from the base plate, but again I can't see anything in this image, so . . . I also don't see "J" tube(s) from the bowl vent(s).

    I would strongly urge you to use both a marine carb and fuel pumps, not automotive, in an enclosed engine box. I've seen way too many come to a loud and violent stop, not paying heed to this warning. Around here it happens several times a year.
     
  10. sean-nós
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    sean-nós Senior Member

    You guy's have me worried now:confused: I will get out today and take some close up photos of the carb on the engine, I haven't got the pump yet it's on order from the marine shop, the two photos above are just ones I got off the internet but I'm sure they are the same as mine. I'll be back soon and hopefully we can sort this out. Thanks

    Ok looks like you guys were right the carb above has the pipe at the bottom and on mine it's at the top "sorry" so hopefully this shows I have a marine carb.

    [​IMG]

    [​IMG]

    [​IMG]

    I had to add a small plate here so the foot throttle would push instead of pull.

    [​IMG]

    [​IMG]
     
    Last edited: Sep 16, 2012
  11. Frosty

    Frosty Previous Member

    The fuel inlet is the big brass nut on the other side seen clearly on your later photos, surely you were not going to connect the fuel to the base plate were you?.

    You have bolts missing from the carb , they are rusty, you have odd bolts with no washers, you have nuts not tightened such at Morse cable lock. You have wrong bolts on rocker covers and things yet un-tightened on the manifold, there is a split pin lying in the manifold off the morse cable and the cable is unlocked---- Is that fitted or just a photo shoot.

    Your HT cables look like you have timing incorrect too.
     
  12. sean-nós
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    sean-nós Senior Member

    The carb is only temporarily in place as I was working out how high to build the hatch and for the set up the foot throttle hence the split pin is out while I adjust the link. There are only two bolt holes in the manifold for the carb and the chrome bolts came in a chevy dress up kit for the rocker covers they seem to work well as I had the engine running fine and have no leaks. The HT cables are disconnected at the moment so they might look out of place. I have a long way to go with the engine before everything is set up right but I will get there, the photos were just to make sure it is a marine carb and to show the overflow pipe that connects to the fuel pump and why I'm changing from the electric pump as it has nowhere to attach the overflow.

     
  13. Frosty

    Frosty Previous Member

    Sean - marine carb is just a carb with a sealed float bowl vented to the inside of the carb throat.

    In the 60's and 70's in Uk there were loads of inboard boats , Alabatross Delta Moon fleet plus the Dateline Bounty and Bikinis that used the old Granada 3 liter v6 ford engines. The albatross was an alluminium 2 seater and a 4 seater built in the Norfok broads with an E93a , 100E and some even had a Coventry climax.

    On Easter Monday on the river Wyre fleetwood there was many boats out on the river. All had car engines,-- there was nothing else, outboards were a bit small in those days. All car engines had car carbs, usually SU--all this marine stuff came from USA. They even stipulate marine starters??? we didnt have them.

    I never ever saw a boat on fire. I would ski on Windermere during the week and even being familiar with Bowness and such I never ever ever saw a burnt out boat, all this stuff came from USA and thats NOT the only way it can be done --not so....

    Maybe distinguishing the cigarette might have been safer.
     
  14. gonzo
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    gonzo Senior Member

    As a marine accident investigator, I have seen many burnt and exploded boats. The physics of combustion are not exclusive the boundaries of the USA.
     

  15. Frosty

    Frosty Previous Member

    But what was the reason of its explosive tendencies?

    Spit back through the carb or a Stereo setting of fire, or wiring.

    In these basic boats of Uk in the 70's there were no cigartette lighter sockets or even electric chokes.

    There was little to combust except fuel in the carb and I never ever saw that.

    There has to be a more detailed reason as to why American boats combust.
     
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