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too much horsepower take II

Discussion in 'Early CJ5 and CJ6 Tech' started by dunl, Jan 25, 2010.

  1. Jan 26, 2010
    Corveeper

    Corveeper Member

    Chanute, Kansas
    Joined:
    Jul 29, 2005
    Messages:
    817
    Ah, got’cha. Thanks.
    Didn’t someone here have a 2.3L Pinto motor in their Jeep?
    That’s an interesting swap.
     
  2. Jan 26, 2010
    duffer

    duffer Rodent Power

    Bozeman, MT
    Joined:
    Sep 17, 2009
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    4,420
    Almost? Just about any aluminum headed small block Chevy, be it a 262 or 434, will come in within 5 lbs (the weight of the 12 pack stashed in the bed) of the F head. Any of the aluminum block versions will be 80 to 100 lbs lighter.

    The 134's were very good motors for their day but one must remeber where they came from: the 1926 Whippet, with the same 3.125x4.375 bore and stroke. The F head conversion was certainly an improvement but these engines are still based on 1920 design. I got pretty tired of replacing rings every 50 to 60k. If I ever get to my 3A project, it will go back together completely stock but it not something I plan to either wheel or use for a daily driver-for which my minimum remains the 225.

    As to the OP, I am very doubtful that you can pull anything close to 400 hp out of any of the V6's and still have any useful bottom end torque. For that, there is little substitute for a healthy displacement and a relatively long stroke-just not as long as 4.375. In my experience, for off road use, the bottom end torque is where it is ALL at and if that is what is desired, there is no reason not to install a V8. Same $ to build (or in the case of a sbc-probably cheaper), about the same work to install, a much less stressed motor, and better all around driveability.
     
  3. Jan 26, 2010
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
    Joined:
    Mar 4, 2003
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    5,461
    I have gotten well over the 200HP mark with a 225 (would have to do some looking for the dyno sheet) built for the Pikes Peak Hill Climb (the one I am running is rooted in this). I still believe in the principle of building in a snap point. That way you can know where things are going to break and make them easy to fix/less expensive. Mine is the U Joints (I hope) as I have not snapped anything yet with the current setup. I run the 225, SM465, D18 w/OD, 4.88s D30 front D44 FF back with OX lockers on 33s. This allows me to run 60 - 70 no problem but I have @ 80:1 crawl when I need it.

    I am going to go FI, but still don't see any problem with strength. It's all a puzzle and depends on how you put it together and use it.
     
  4. Jan 26, 2010
    Patrick

    Patrick Super Moderator Staff Member

    Los Alamos, NM
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    Yeah, ALMOST.
    If you say a SBC with aluminum heads weighs within 5 lbs. of an f head, a SBC with iron heads(as the majority are) would weigh more.:rofl:
     
  5. Jan 26, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
    Joined:
    Nov 25, 2006
    Messages:
    125
    Back on topic once again (I'm not going with a flatfender, nor a V8, so I'd like to concentrate on the V6...:tea:)

    The rig is a 1948 CJ2A. A V8 will entail firewall cutting. I'm not hoping to do that. The reason I want to go with the 4.1 is to get things up and running again quickly, and as the 3.8 was in there already and the 4.1 is just an overbored version, I'd like to go with that. Plus....how many people use 4.1 V6's in their jeeps?

    As for not getting anything close to 400hp, this is the engine that powered the legendary 82 Buick Grand National. We're talking 125-140hp without a turbo, intake mods, etc.

    http://www.turbobuicks.com/articles/4point1ForCheap/

    More low end torque would be ideal, but if I ever do a diesel, it will most likely be a VW 1.6 with a lot of thought. Either that, or a Wrangler of some variation with the OM617 Mercedes diesel I have sitting in the garage. :)

    Warloch, your point about snap-points is excellent. No sense in breaking a locker when you can build in a safety point elsewhere.

    I guess what I am trying to say is that I WILL be going with the 4.1 V6. I'd like some more power than stock, but not enough to kill the jeep. I do try to keep off the skinny pedal, which is pretty easy to do with a sm420. I'd just like to tweak this engine enough to get some more juice, but I don't want to be racing any Grand Nationals with it. R)
     
  6. Jan 27, 2010
    DrDanteIII

    DrDanteIII Master Procrastinator

    Milford NJ 08848
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    Mar 21, 2007
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    1,516
    Well if you are looking for mild hop ups for the 4.1V6, then you could use pretty much the same basice mods that the Dauntless guys suggest. Maybe a nice carb and a mild cam and you'd have more than adequate power.
     
  7. Jan 27, 2010
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
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    12,529
    In this case a good RV style low end cam, a good flowing tuned exhaust system, and a good fuel induction system should be all you need. A little bowl and port cleaning IF you have the heads off at some point is a good thing as well.
    Most 4.1's came with a small Rochester Quadrajet. The only thing better would be fuel injection imho if the Q-jet is working correctly.
    My 231 ef with the stock but tweaked Dualjet 2bbl, headers, mild RV cam, and some mild head work chassis dyno'd at 220 hp, runs on pump gas, is dependable as the day is long, etc. etc. Works great in mud, sand, trails, and even ok on rocks.
    This makes a good balanced package for a Jeep. I ran the 25 front and tapered axle rear for years with this motor with few issues except when the driver decided to hammer away at the throttle:)
     
  8. Jan 27, 2010
    Dummy

    Dummy I kick hippies

    Escondido, CA
    Joined:
    Dec 5, 2004
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    646
    The 225 odd-fire in my '71 CJ-6 had more than enough power for hill climbs and freeway driving. It was stock with fenderwell headers and a rebuilt factory 2GC carb. Driving up Hwy 395 in CA to the Rubicon I just put the NV3550 in Fifth gear and left it there. Had enough beans to pull the rig at 75mph up those grades w/out downshifting and delivered 17-18mpg while doing it. Gotta mention gearing and tire size comes into play. I had 4.88s and 31s. Figure similar performance with 5.38s and 33s, but with the Dana 20 you won't have the overdrive option. You'll be happy with the 4.1L and a mild RV cam. Even better if you can find some inside-framerail headers and run 'em into a single 2.25- or 2.5-inch muffler.
     
  9. Jan 28, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
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    Nov 25, 2006
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    I have 3.54 gearing and 34" tires, so that doesn't help. I might look into downsizing the tires some too....they were a really good deal, so I grabbed them, and they fit fine. :)
     
  10. Jan 28, 2010
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
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    You'd be much better off re-gearing the axles. Those gears and even a 32" tire don't go well together with a V-6. 4.27 gears down to 5.38's depending on if you have, plan to run an overdrive. 4.27-4.56 without and lower with. I have 3.73's in the Daughter's Jeep with 225 and 31" tires and works well on the street. I definitely wouldn't go any taller on the gears and if it was going to see off road duty regularly I would've gone lower.
     
  11. Jan 28, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
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    Nov 25, 2006
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    I will probably change them out at some point in the future, but as for right now, I'm going to keep them. On the other hand, maybe selling them with the ARB lockers in them might be worth it to someone.
     
  12. Jan 28, 2010
    JohnnyCommando

    JohnnyCommando Blue Tarp Station, proprietor

    Eureka, CA
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  13. Jan 28, 2010
    (0llllll0)

    (0llllll0) Mr. Willys or Wonty

    Utah
    Joined:
    Oct 3, 2004
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    I've been running a "56" willy with a 4.1 bought used from some unfinished jeep project.... LOL
    I have 5.38 gears, sm465, D-18 with overdrive, run 33" tires, dana44 rear dana 30 front with e-lockers, has a carter afb 4 bbl on it now. Been using it for three years, runs good at low RPM's but has a vibration when reved up.
    It's licensed for the road but I trailer it to trails so can't comment on highway use.

    I'm going to go to TBI before Moab this year. right after I get rid of my engine vibration! I think it has the wrong flywheel on it now, I just put the one on that came with the box of parts with the engine.
    I was told the oddfire FW weight was 90 pounds and the one I put on never weight 90 pounds more like 50, now I hear the oddfire FW weights 55 pounds and only seems like 90 when it falls on your toes!

    Anyway I'm going to pull the FW and have it balanced, put it back on and see if thats whats wrong, then put a new harmonic balancer on also.

    Then the TBI.....

    "Willys or Wonty" will be done.............LOL
    Cam
     
    Last edited: Jan 28, 2010
  14. Jan 28, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
    Joined:
    Nov 25, 2006
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    So I'm being told on the Buick forum that the transmission (sm420) will not be good for the V6 engine....due to "The shifting, clutch press/release, load/unload of the engine."

    Anyone want to comment on a way around this?
     
  15. Jan 28, 2010
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Mar 4, 2003
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    Umm - they got rocks in thier heads???? I run a SM465 and don't have any issue. IF you have an issue it would be as Nick pointed out - axle ratio. I love mine with the 4.88s.
     
  16. Jan 28, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
    Joined:
    Nov 25, 2006
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    Beats me.....these things never came with a manual? He mentioned the manual having a blow-off valve.

    Edit: he said it would NEED a blowoff valve.
     
  17. Jan 28, 2010
    Patrick

    Patrick Super Moderator Staff Member

    Los Alamos, NM
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    A manual transmission?
     
  18. Jan 28, 2010
    dunl

    dunl Member

    Sylvan Lake, Alberta
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    Nov 25, 2006
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    See edit above....."needs" a blow off valve.
     
  19. Jan 28, 2010
    Patrick

    Patrick Super Moderator Staff Member

    Los Alamos, NM
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    The transmission?

    I hate to be this way, but someone has no clue what they're talking about.
     
  20. Jan 28, 2010
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    This is a normally aspirated 225, right? To me, a blow-off valve is something for a turbocharged engine.
     
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