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Mercruiser 3.7 Build, 1970 Cj5? Big Block Hurricane!

Discussion in 'Early CJ5 and CJ6 Tech' started by 70cj5134f, Sep 27, 2018.

  1. Sep 28, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Mercruiser used many engines, though usually GM based. When most folks hear "Mercruiser", they think of the 3.0/181 and derivatives of the Chevy ll/ Iron Duke. Mercruiser also used the 4.3 Chevy V6 as well as 305 and 350/5.7 small blocks.
    The Mercruiser 470 is a different animal; an "in-house" purpose built marine engine manufactured by Kiekhaefer Mercury that is a 4 cylinder 3.7 liter (huge for a 4 cyl!) alloy block with Ford 460 head. The back of the block is the Chevy pattern, so any V8/V6 (90 degree V) bellhousing bolts up. The rear of the crankshaft may or may not be bored for a pilot bushing, and flywheels can be a Ford or a Chevy part number. My earlier post touches on some other peculiarities.
    As with any engine conversion, there will be lots of fabrication. I have one of these engines set aside with hopes of using in an FC150 because of unique space issues and the ability of bolting up an automatic to the 470 engine. FC's have crazy remote shift linkage that is less than ideal, so a cable controlled automatic has advantages.

     
  2. Sep 29, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    The small,external size, and the large internal size,appeal to me!
    Any idea how much torque?
    I'd like to c a hp, and tq graph.
    Too high compression was mentioned, any idea what it is?
    20180928_111652.jpg 20180928_111621.jpg
     
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  3. Sep 29, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    That's the beast! Sorry, but offhand I don't have specs on these engines. There are several variations, including, as previously mentioned, a 4 bbl version that some sites say is 190 hp. Others with the 2 bbl and milder cam are purported to br 170 hp.
    Yours looks very complete with all the marine manifolds and exchangers. As you can see from yours, some of the main mounts may prove challenging. These engines have been adapted to rat-rod cars, and there are at least two 1950's Anglia's withthese engines about an hour south of me, one sporting a belt-driven GM blower.
    -Donny
     
  4. Sep 30, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Don't think I'll need a blower?
    In stock form it's got 3 times the power I have now with the 134f.
    A stockish build will be great.
    And more power than the cj v6?
    Might go ahead and tear it apart, before I start hunting parts.
    Thanks
     
  5. Sep 30, 2018
    Rich M.

    Rich M. Shoe pusher

    Maryland
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    :watch:subscribed
     
  6. Sep 30, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    I think I'd clean it off and run it before I took it apart. A seasoned motor is a reliable motor.
     
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  7. Sep 30, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Good point, do all fab work and run it as is till something breaks.
    I might address the water to oil thing first?
    More resrarch?
     
  8. Sep 30, 2018
    Danefraz

    Danefraz Well-Known Member 2019 Sponsor

    Chico CA
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  9. Sep 30, 2018
    gunner

    gunner Member

    Washington state...
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    How about a pic of that bellhousing pattern?

    I looked into these years ago for jeep use but came away discouraged. My source of info and speculation by others was on the HAMB/jalopy sites where guys like to get away from the SBC sometimes. But it was real inconclusive. I'd more trust the ECJ5ers to properly explore it.

    As I remember, the adapting issues were: bellhousing pattern, water pump and alternator. It was an unusual engine in its design. It was a problem child as a marine engine- among other things, prone to leakage from coolant to engine oil. Where the 3.0 (181 CID) or 2.5 (153 CID) were stout and reliable, the 3.7 was problematic. Can't take anything away from them in the areas of weight and torque, though.

    Cool that it uses a common Ford head, which can be bought in aftermarket aluminum form for even further weight savings.
     
  10. Sep 30, 2018
    heavychevy

    heavychevy Sponsor

    Danielsville georgia
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    Check the compression, that will give you a good indication of the condition of the engine
     
  11. Sep 30, 2018
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
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    It uses a ford head because it is half of a 460 with alterations. An Aluminum block with a cast iron would be problematic in a car. Remember marine engines run much cooler than car engines, like 50° cooler.
     
  12. Oct 1, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    I'll pic the bell in bout a week, at the beach now for a week, miss my jeep,lol.
     
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  13. Oct 1, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Been researching bell's, which bell do I need for Chevy to a 134f, t90?
    Is mine a t90 or 86?, stock for a 70 cj5,134?
     
  14. Oct 2, 2018
    TIm E

    TIm E Member 2019 Sponsor

    NW Arkansas
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    If stock, yours should be a T90 with the F head. The T86 was put behind the V6 for a short period.
     
  15. Oct 2, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    So let's say it's a 90?
    Now I still c conflicting numbers?
    So I find an adapter that bolts to front of 90 that changes the bolt pattern.
    I find some that say if it's a 134 t90 u must change input shaft?
    Is their not a bell that will do the hole conversion, no other parts needed?
    Right depth and t90 bolt pattern?
    I'm looking for the simplest way(read cheap) of attaching my t90 to a gm bell?
    Behind this 470 merc.
    On the hamb site several different stories?
    I'm trying to keep it simple as I can.
     
  16. Oct 2, 2018
    gunner

    gunner Member

    Washington state...
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    Then you might want to reconsider the 470 Merc. Change one thing and other things change. It gets complex.

    There are two ways of attaching a T90 to a Chevy 90* bell. You can research it on the Novak site. One adapter allows use of the stock input and the other one utilizes the T90J input.The first one is almost 300 bucks but you don't have to dismantle the transmission. This is the one I'll use if I keep the T90 (with the T90C gears) behind the Chevy 153 I plan on putting in.

    You know, with the Merc engine, you may be on the edge of what the T90 can handle long term. These are crazy little engines, producing almost V-8 levels of torque and HP. But we'd all love for somebody to be the guinea pig for a project like this:watch:
     
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  17. Oct 2, 2018
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    Personally, I'd keep the jeep running as-is while building a seperate drivetrain to drop in when it's ready. The path you're headed down now looks like a never-ending project-creep that will keep your jeep sidelined for months, if not years. If you're dead-set on using a t-90, they're cheap enough to pick up a spare to experiment with. If not, build it to fit a better transmission that will bolt to the engine, and spend your time and money adapting it to a D18.
     
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  18. Oct 2, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Oink-oink, I'll be the pig!
    All I require is patience and help from ecj5!
    I'm not exactly OCD, but I like things right,
    Don't have to be pretty,
    But it does have to function.
    I'll research Novak.
    Thanks
    Ps when I turn the first bolt upon teardown I'm starting a new thread.
     
  19. Oct 2, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Ok what are my other trans options?
    I'm not dead set on using the t90, I just have it.
    And yes, I'm keeping the jeep running as is until other drivetrain is ready to install.
     
  20. Oct 2, 2018
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    It depends what the bolt pattern is on the back of the engine.
    :pics:
     
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