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  1. #1
    Junior Member
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    New ATK replacement 5.9 motor en route along w/ a few other goodies

    My niner' been down for months now (as well as my wheeler 4.0/ 4.7-4.9L stroker build w/ custom manual swap before 1 tons/ 7-9" LA's.) I bought a cheap 04' subi as my DD until I could fund one of my builds (to my defense I'm putting myself through Hi perf. auto during the day..6am till 230-3.. then working full time from 3-330-12-1230am during the week so cash and time haven't been on my side BUT brand new ATK 5.9 replacement motors shipping this week...sooo I'm pretty sure I'm gonna throw order 2 Edelbrock RPM heads bc a. it's take 10mins to install a/ the Mopar Perf. valve cover's that I already have, along w/ my DT header's and Kolak 3" exhaust once I drop the motor into place .I'm still heavily considering a Comp cam/valvetrain, gettin myself into a little more debt & biting the bullet on an intake mani. to simplify life slightly. Also, I reeeally need to replace my torque converter bc after rebuilding my 46re to a race trans.a. my 190,xxx motor couldn't keep up w/ the harder pulls and shifts...I can't make up my mind whether to go w/ a low or high stall..any input would be greatly appreciated!! Also since my current motors' seized and I can't crank it by hand I'm not even bothering w/ sending it in/ getting rejected for accord charge...although it'll work out in my favor bc once I have machine shop I'll be able to bore out/stroke that one to (hopefully) a 410ci and have that motor completely built/tested/dyno'ed etc; swap in the new stroker motor and flip the basically new "stock" ATK motor for a decent chunk of change; also that way I won't be w/out a vehicle for more than a day max! I'm completely open to any and all critique/ suggestions or insight how to go about it better! Thanks guys!

  2. #2
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    Living off top ramen now basically but the debt will be worth it in the end lol.

    Think you should definitely do the cam, can keep stock rockers if on a tight budget or throw on some chevy rockers if you go with aluminum heads. People don't like more than .520" lift on stock rockers but some have gotten away with much more. Don't know if this is correct but I think going with aluminum on stock compression would hurt performance. I think IMM is best bang for buck, but EQ is pretty damn good too with potential down the road.

    We're stuck with a single 3" and tri-y headers. I think it's best to build for torque. Or peak power at 5-5.5k rpm. Plus it would make DD nicer. I personally hate loose torque converters. Stock is borderline too loose for me haha, mercedes is sweet. Maybe a tight high stall for fun launches? 408+ down the road would make me want to stick with a lower stall even more.

    I don't know where you live but if you don't have smog inspections I think turbo is the best budget performance way to go. But for N/A budget I'd add EQ heads, comp cam, air gap and Rolf's 53mm TB. Rolf's M1 ends up costing over $200 more I think, but better mid-top performance.

    Played with comps cam finder tool quite a bit. Their 20-604-9 210/220 112lsa cam made the most power up to the 220+ duration range. I used IMM iron heads and 1.7 rockers but lift didn't make a huge difference. Ended up going with a custom 212 110lsa .564" lift w/1.7rr single pattern from Oregon Cams per IMM's advice with using their heads for my setup.

    Stock bottom end, think the short duration really helps build dynamic compression with our 9:1 engines. All this is just speculation/months of research. I've ordered all my parts, sitting at the shop. Last thing left is the cam coming on Tuesday. Going to get started this weekend and hopefully have it back on the road by mid May.

    Planning on running a 408 ATK stroker when the stock bottom end finally dies.

  3. #3
    RallyJeep GO
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    Jan 2010
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    Rochester, NY
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    Keep in mind, the Edelbrock heads have 58cc chambers instead of 62cc on all of the iron heads, so they'll bump compression a bit. I had my IMMs shaved for 60cc chambers when I got them. Haven't needed aluminum for ping resistance, although the weight savings would be nice.

    Exhaust wise, no need to be stuck with a single 3". Just gotta make a custom setup from the headers back and not use the Thorley y-pipe. For mine, I'm planning to go dual 2.5" off the headers (run next to each other, both on the pass side) and either continue that all the way out the back or merge it to a single 3.5" depending on what will fit best over the rear axle.

    Currently I'm running with a 3" and even with my tiny cam (Comp 20-744-9, 206/212, 112 LSA, .512" lift at the valves with 1.7 rockers) peak power is a little past 5k I think and it spins to 6k very well with a pretty slow drop-off. I let it shift at 5700.
    1998 ZJ 5.9 Limited - Deep Slate
    Mods: Big trans cooler, 231 swap, Indy MA-X heads prepped by IMM, Comp 20-744-9 cam, 1.7 HS roller rockers, 52mm TB, Airgap manifold, DT headers and full 3" exhaust, SCT tune homebrewed by me, Martin Saine valve body, B&M tranny pan, magic suspension made from unicorn tears, power steering cooler, lots of lighting mods

  4. #4
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    Definitely post pics if you get the exhaust figured out please. Going to throw the jeep on the hoist tomorrow and do some head scratching. The exhaust rattling has left me with mush for brains. Tried using band clamps, they don't hold for long lol.

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