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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 27, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    I have at my shop, a supercharged 3800 out of a Pontiac front drive.
    Oldest son bought it while back for a camaro swap that got halted.
    I understand the fuel and wiring challenges, but not the bolt in stuff?
    I've read a tad bout this on other sights?
    I think all the pieces are out their to do a bolt in?
    Is my 90 and 18 and 44 strong enough for 200 hp, 250 torque?
    Also the intake sets off the back of engine some?
    Might hit firewall? Think they make another style for rear drive cars?
    Anyone have experience with these engines?
    Now we ant in no hurry, I already have a this winter build project (455 Pontiac in 1970 amc rebel)
    Maby next winter?
    My 134s all sealed up now, but block was full of cracks around head bolts, it ant going to last forever?
    Also would it work without the charger?
    And what bout weight? Bet it ant much if any heaver than the 134?
    If I'm going to do this, I need to start locating the hard parts!
    Thanks!
    Thoughts?
    Opinions?
    Options?
     
  2. Sep 27, 2018
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    Move along... nothing to see here... :D

    Literally nothing will bolt up.
    If you had the Buick v6 to start with instead of the 134, you'd be a little closer to something fitting, but not by much.

    You'd be ahead of the game if you start with a Chevy 4.3 and build the drivetrain around that. They are cheap, plentiful and easy. Sm465 trans, novak or AA adapter to your t-case.

    Your practical options are very limited without changing out the entire drivetrain.
     
  3. Sep 27, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    ok, thanks
    ill scrap that idea
     
  4. Sep 27, 2018
    Fly Navy

    Fly Navy Member

    Emerson, IA
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    I am certainly no expert but I am using a naturally aspirated 3800 from a Buick Lasabre in my project. Not sure how to put a link to my build (Rebuilding an Old High School Friend!) but it has several pictures that might help. My drivetrain is the 3800 with a T18, D18 and Dana 44 rear & 25 front.

    As far as the T90 / D18 and Dana 44, they will absolutely handle the hp & torque. They handle SB Ford and Chevy power levels and will certainly handle these power levels.

    I did clearance the firewall to clear the throttle body. These intakes are mirror image and can be turned around but that raised too many issues with the front accessory drive and I decided it was easier to leave it as is and clearance the firewall. Being supercharged you won't be able to reverse the manifold but I've seen pictures of elbowed throttle bodies for the supercharged engines that point the opening forward. But I found that putting the harmonic balancer in the same location as the F-head left quite a bit of room at he back of the engine and only ended up clearancing about what you would for the distributor if you were intalling a SB Chevy.

    [​IMG]

    The biggest challenge will be adapting the engine to the transmission. Any 60 degree (GM Metric) bellhousing will work. Transverse mounted engines have the starter on the "wrong" side so you will have to either clearance the bellhousing or get one with starter bosses on both sides. I used a bellhousing from a 83-92 Camaro with the 2.8 or 3.1 V6 because it has the dual starter bosses. I imagine that the input shaft on your T90 will be too long. Not sure what options there are there. I used the shorter Ford input shaft for my T18 but I am not sure if alternatives for the T90 are available... perhaps a spacer could be machined.
     
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  5. Sep 27, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    it was just a thought, probably more work than i need?
    im not really looking for much more hp, but u cant never have too much torque?
    I have another engine I would rather use if fab work will be needed, its a
    mercuiser 470, 4cyl,170hp boat engine.
    it shares the head with a 460 big block ford.
    over 200 torque with mild mods, I think would be realistic?
    it has bell bolt pattern either ford or gm?
    its been used in rat rods before.
    thanks
     
  6. Sep 27, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Now you're talking! That Mercruiser has a Chevy bolt pattern, and may use a Ford or Chevy flywheel, depending whether early or late (early is Ford). You'll need to lose the heat exchangers and front alternator. Is your 2 bbl or 4 bbl carb? Also, the water pump, driven off the cam, is a weak point. It usually leaks where the shaft protrudes. These can be stainless sleeved, or removered and the timing cover plugged, with a remote water pump.
    These are 3.7 liter, 4 cylinders that have huge bores and an aluminum block, and yes, a Ford 460 iron head. I have one set aside for an FC 150 project. They don't like to rev, but sure have lots of torque.
    -Donny
     
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  7. Sep 27, 2018
    mortten

    mortten I can’t put my finger on it

    Peninsula, Ohio
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  8. Sep 28, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Having the 134F now, I'm used too , don't like to REV!
     
  9. Sep 28, 2018
    70cj5134f

    70cj5134f Member

    East Tn
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    Mine a 2bbl. Came out of late 90s boat I think, 470 decal on valve cover.
    U know quiet a bit bout these sounds like.
    Will it bolt to the t90?
    What bell do I look for?
    How do I tell which flywheel to find?
    A friend on mine, he spent a lot of his youth at the lakes, swore these engines
    Were a beast for a 4cyl.
    It would sure look good under my hood!
     
  10. Sep 28, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    There's a couple of styles of adapters for the GM pattern to the T-90 using a GM bell. Lots about it here - Novak Conversions :: Chevy Donny says it's a Chevy bolt pattern, so that's where I'd start. Get out your tape measure and figure it out.

    It's an unusual swap, so you'd be mostly on your own regarding parts and fitment. If you need more advice, the 4.3L Chevy has been done many many times, and you could expect a lot of specific advice.

    Realize that even the native Buick/Jeep 225 V6 was adapted-in to the chassis, so there's very little that you can save from the F134 setup. The T-90 was never offered with the V6. '50s Studebakers used the T-90, and back in the day there were quite a few conversions using the Studebaker 6s. But putting any inline 6 into the CJ's short engine compartment creates a different set of problems due to engine length.
     
    Last edited: Sep 28, 2018
  11. Sep 28, 2018
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

    Tantallon, Nova...
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  12. Sep 28, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    Well, depends on what "mostly" means. A more selective search on ECJ5 shows 2 posts, both by Donny - site:earlycj5.com mercruiser 470 - Bing Maybe there are more threads that refer to that motor less specifically.

    There's also the GM 181 (3.0L) industrial motor, which is sold under the Mercruiser name for marine use - I presume that's where most of the hits in Howard's search come from. The 181 is a bored and stroked (?) Chevy 153, which is part of the Chevy third-generation 194/230/250 engines. Indeed, the 153 is exactly 4/6 of the Chevy 230. Both the 153 and 181 have been done a lot, and you'll even find build threads for those motors. Chevrolet 153 4-cylinder engine - Wikipedia
     
    Last edited: Sep 28, 2018
  13. Sep 28, 2018
    Danefraz

    Danefraz Well-Known Member 2019 Sponsor

    Chico CA
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    We had a merc inboard in the mid eighties.

    It was a 4L volvo 4 cyl.

    I think.
     
  14. Sep 28, 2018
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    Hmmm...
    I wonder if that would make a good jeep engine?

    :whistle:
     
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  15. Sep 28, 2018
    Danefraz

    Danefraz Well-Known Member 2019 Sponsor

    Chico CA
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    It was a good little beast.

    We had a ~16ft fiberglass hull (Marlin). That motor was awesome for water skiing and day cruising. Lots of torque.

    Do to HP, those of us in the 200# range had to know how to single ski- otherwise, you would just be a human torpedo. I could pop right up.

    Iirc, 4000 RPMs was operation limit we self imposed (or the throttle did).

    It didnt like to troll much, would load up at idle, but was fine above 1000RPM. Ran like a scalded dog across the spectrum when you would pour the coal into it.

    It would run all day on a tank (20g IIRC), vs my buddie’s 454ci jet boat w/40g which got us 4 hours...
     
  16. Sep 28, 2018
    Danefraz

    Danefraz Well-Known Member 2019 Sponsor

    Chico CA
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    I also think it was standard rotation.
     
  17. Sep 28, 2018
    Muzikp

    Muzikp Active Member 2020 Sponsor

    Sacramento Ca.
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    A supercharged 3800 only has 200hp... really? Is this the same motor that's in the Buick Grand National?

    [​IMG]
     
  18. Sep 28, 2018
    Danefraz

    Danefraz Well-Known Member 2019 Sponsor

    Chico CA
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    I had to hit the wiki to read more...

    Buick Regal - Wikipedia

    that's an interesting rabbit hole.

    I don't know on the actuality of the facts presented there (that's a mouth full)... but it seems very interesting.

    1987 was the magic year where they cranked up the performance..
     
  19. Sep 28, 2018
    Rich M.

    Rich M. Shoe pusher

    Maryland
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    I think any of those powerplants would be cool. Personally on anything other than a stocker I wouldn't futz with a T90. YMMV
     
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  20. Sep 28, 2018
    Mike C

    Mike C Member

    Austin, TX
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    Feb 19, 2007
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    The circa 1980 ish CJ that came with the Jeep 2.5 motor used the 60 deg gm bellhousing pattern and is a good choice for adapting trans to the FWD GM motor. Not sure how it compares to the Camaro/S10 V6 bellhousing.

    There is a LOT of misinformation about the early GM 4 bangers out there. The Iron Duke 151 really muddied the waters. Especially the first couple of years that use the same distributor as the 153. I'm still playing around with them but haven't gotten started on my install yet. I have figured out how to get a large cap HEI on the 153 using the '76/'77 151 setup. Also found my '95 3.0 LP forklift motor has a one piece rear seal. That made finding a rear sump oil pan a challenge... also it is still a zero balance flywheel unlike the small block setup that went to an external setup when the ditched the rear counterweight. I used a one piece rear seal SBC flexplate and elongated the two holes that are on the same bolt pattern and I removed the counterweight. Bolted up great. Next step is to trouble shoot the LP motor on the test stand using HEI instead of governor electronics that was on it.
     

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