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Thread: Rear Main Seal replacement - dig me out of a hole??

  1. #21
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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    What do the plugs look like today...the ones in the pic from 9/11 look okay....
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    05-2017 is the current plug pic set (20K miles on'm). I think (famous last words) I changed them last year - but no pix. 1 and 2 look normal. 4 mostly good. 3, 5, 6 - abnormal.

    I was told by a mechanic, on that first set of plugs, what they looked like to him and the reply was "oil fouled". That's my source for my oil fouled statement. Looking at plug condition pictures on the internet they're not dark, wet and oily - but I certainly am burning oil (always carry it and check it / fill it every trip (often it's near the bottom mark of the dipstick and I fill to the top mark). That's in 150 to 200 miles.
          

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    Jim previously posted:
    "Looking at plug condition pictures on the internet they're not dark, wet and oily"

    agreed...you've got some heavy ashy deposits on there, so its definitely not clean full combustion, and a bit of carbon build-up, but not the typical dry black sooty fouling of overly rich and oily, and certainly not the extreme wet oily fouling.....a slightly hotter plug rating might help keep them cleaner and be a good solution to keep it running over the summer. Those old I6 just keep running - rebuilding or replacing is usually based on when you are tired of dealing with a tired engine and not because it blows up....they tend to dye slowly, very slowly.

    May or may not be worth your time and effort - but a combination of a wet vs dry compression test, or a leak down test might confirm how bad the rings are and if the valves are sealing properly. Could also a some issue with valve train wearing and not getting enough lift of the valves (kind of guessing there - but the ashy deposits are interesting). You are right at my limit of knowledge or confidence - but as the plug fouling is not super oily, but combustion is not completely right, I am suggesting something going on with the valves. In reality, its probably a combination of oil consumption from ring blow by and valve issues, and the resulting increased crankcase pressure just compounding matters.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    And a reman long block will tick all of the boxes...

    When doing a swap I'm looking to keep existing setup for replacement (4.2 vs 4.0 and v-belt vs serp) as the york comp setup "fits" this setup. I'd really have to be convinced 4.0 with serp was better before making the change.

    It's unlikely I'll pull plugs this season for any inspection or comp testing. Cyl #1 is difficult to access with the york mounted (something one would think would happen only on a modern, tightly packed engine bay).

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    I love the 4.2, but I'd consider a HO 4.0 with the MPI fuel injection vs the early Renix fuel injection (which is what I think is retrofitted on your existing set-up?)...Are planning on keeping you existing FI set-up or going all new? I am pretty sure you can run later 4.0 heads on a 4.2 (and its a nice improvement), but not sure if that also allows for the MPI set-up - I would guess yes.....but yup, one change leads to another and another like dealing with the compressor etc....For me, in addition to cost, having to deal with different fuel tanks and delivery system is the main block to getting some sort of TBI on the cj5.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    Jim previously posted:
    "It's unlikely I'll pull plugs this season for any inspection or comp testing. Cyl #1 is difficult to access with the york mounted (something one would think would happen only on a modern, tightly packed engine bay)."

    I have to disconnect the v-belt, and disconnect the generator from the bracket, and the remove the PS pump and bracket as a unit to access the driver side valve cover and #1....1957 sbc - but the PS pump and bracket is all custom bubba fabbed (albeit it works and probably better than I can fab), things get odd.....
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    I appreciate the low end torque this motor offers though I wish it didn't run out of breath at the high end (a fresh motor would likely help this condition).

    FINOCJ previously posted:
    "I'd consider a HO 4.0 with the MPI fuel injection vs the early Renix fuel injection (which is what I think is retrofitted on your existing set-up?)"

    I'm told this is equivalent to the Mopar 1995 4.0 setup (I don't know if this is what you'd call early renix FI). I _might_ have the 4.0 head (which I hear flows better than earlier 4.2 heads). Emissions classifies this as 1994 model year. I need to document these major motor parts - what's stock / what do I have (leading back to the question of finding the person that modd'd the jeep - they might be FoCo local).

    I plan to keep the existing FI setup. Intake & exhaust mans stay. Intake is new for injection though I think exhaust is the same - uncertain - it has an exhaust manifold O2 sensor - uncertain if that existed on the carb setup.

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    Jim previously posted:
    "I plan to keep the existing FI setup. Intake & exhaust mans stay. Intake is new for injection though I think exhaust is the same - uncertain - it has an exhaust manifold O2 sensor - uncertain if that existed on the carb setup."

    IIRC, the last version of the 4.2, carb and all, and which went into the last CJs and YJ wranglers through 89 (I think?) had auto-metering carbs for altitude fuel mixture adjustment - so I am pretty sure there would have been some sort of O2 sensor. Based on todays EFI, it was pretty crude, but it worked - I drove my cj7 from the top of Mt Antero (14,000ft) and home to FL and back a number of times and I don't ever remember adjusting the carb - compared to either the Qjet or R2g I have now, it was a complex carb - albeit behind the times as most GMs had gone to TBI in the 80s. Jeep sorta skipped the TBI revolution and hung on to carbs for longer than most, then made the jump straight to EFI (possibly due to AMCs demise in the mid-80s and the Chrysler take-over in the late 80s).

    I haven't messed with a jeep 4.2/4.0 straight six in quite some time...but 1995 would have been the MPI 4.0 HO (high output)....It was like 190 hp when it came out which really does put the early Renix 4.0 and carb 4.2 to shame...A lot of it was head design and multi port fuel injection - and as you want, that kept most of the classic low end torque of the I6, but gave some pep to to the higher end (albeit - its still not a 3000 rpm type motor for extended periods). Guessing some changes were made to the cam as well at the time to take advantage of better flow....
    The old 4.2 was sorta diesel like...relatively low hp, small power band for gas engine, but lots of torque and it just runs even when mis-treated....
    There was a willys wagon for sale around here 3 or so years ago that had a HO 4.0 swapped in - I wish i would have bought that one - it was out of my price range and I wasn't serious about buying yet...The ol wagons came with a flat head straight six (and I kind of wish I had bought one with an original style engine)...but those old L226 just don't have much function in todays driving. Anyway, for whatever reason, while those early L6s were oem, but the later AMC/Jeep straight sixes apparently are a PITA to fit in the engine bay and swap in.

    It'll be fun to see your engine swap take place....There is part of me that debates just dropping the coin for a new sbc 350 crate engine for the wagon....old cars are fun, but more fun when they run like new.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    FINOCJ previously posted:
    "old cars are fun, but more fun when they run like new"

    `was out this morning and a "nice" (worked on) 40's / 50's era "truck" drove by to the stop sign. Stake side flatbed. No paint - all rusted patina look. The sound when it pulled away - modern motor and drivetrain under that old body.

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    Default Re: Rear Main Seal replacement - dig me out of a hole??



    Jim previously posted:
    "The sound when it pulled away - modern motor and drivetrain under that old body."

    I just want my old junk to run like it would have when it was 'new' back in the day....While I wouldn't turn one down if it was done right, I am less interested in an old body on modern frame/drivetrain.
    ___________
    James Orofino
    1970 CJ5
    1958 Willys Wagon

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