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360 Upgrades

Discussion in 'Intermediate CJ-5/6/7/8' started by 3b a runnin, Jan 13, 2018.

  1. Jan 13, 2018
    3b a runnin

    3b a runnin Member 2019 Sponsor

    virginia
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    Jan 11, 2015
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    I will soon start rebuilding the 360 for my 73 cj5. Trying to decide on the best upgrades for ignition and cam, intake, carb. Engine has an Offy 360 intake with some kind of Edelbrock carb. Does Weber actually make the Edelbrock carb?
    I'm considering a Edelbrock performer cam, with the Offy intake, Edelbrock AVS series 2 carb, with a DUI distributor. Anyone have good or bad experiences with any of these, or think this is not a good combination.
    Thoughts and opinions are appreciated.
    Tim
     
  2. Jan 13, 2018
    Rich M.

    Rich M. Shoe pusher

    Maryland
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    Mar 23, 2008
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    631
    If the Edelbrock carb is a copy of the Carter AFB they are rotten off road even with work.
    Fuel injection, Holley truck avengers, even a good Qjet will serve you alot better.
     
    73 cj5 likes this.
  3. Jan 13, 2018
    PeteL

    PeteL Member 2020 Sponsor 2019 Sponsor

    Hills of NH
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    Bear in mind that fuel was much better in 1973 than we have today, and so engines were higher compression.
    I rebuilt a 1973 360 once and never could get it to run right except on high octane Avgas. But I'm certainly no expert.
     
  4. Jan 13, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    I've built a couple 360's and have always installed an aftermarket "RV" cam (sorry, don't have the specs without digging), and Edelbrock alloy 4bbl intake. Your Offy intake should be just as good, or better. I've used Holley (truck avenger?) carbs with good success. One may have used a Q-Jet. I have always also done a priority oil feed to the rear of the block under the intake. I've had good luck with the stock distributor that uses the Ford type ignition module, and have also used DUI hei type distributors. A good valve job with a little pocket-porting (with the above mods) seems to help wake up these 360's. These engines have nice dogleg exhaust ports, and with the Edelbrock intake, breathe pretty well. The stock exhaust manifolds do fine with these mods, especially with a dual system.
    I have not ever used the Edelbrock performer cam in a 360, but have used several in small block Chevys, and really like them in that application. Great torque with a strong mid-range, and improved top-end compared to stock Chev cams.
    -Donny
     
  5. Jan 14, 2018
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Mississippi
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    Jan 10, 2014
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    I would NOT go with an edelbrock carb. I had a Carter AFB and my buddy has a 1406 on his ford and it's trash off road. Personally I like a Quadrajet, Holley T/A carb or TBI. Check out bulltear for timing covers and such. They make good products for the AMC V8's. Melling MTA-1 is a good RV cam and it requires nothing else to run it. If you'd like to retain the stock distributor you could do a 4 pin ignition module swap in lieu of the stock duraspark module and while you're at it go with a larger cap and rotor and some 8mm spark plug wires.
     
  6. Jan 19, 2018
    nwedgar

    nwedgar Now with TBI!

    Newnan, Georgia
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    I rebuilt mine with the Melling MTA-1 "rv" cam. I also installed Hamilton Fuel Injection kit. I am so glad I did after so many years of fighting carb adjustments. Tons of torque and I never have an issue on cold starts, warm starts, hot engines, angles, etc. Honestly I think the fuel injection has been my favorite upgrade.
     
    timgr likes this.
  7. Jan 19, 2018
    rejeep

    rejeep Well-Known Member 2020 Sponsor 2019 Sponsor

    Rochester, NY
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    keep it simple..

    stock grind or close to it..
    aluminum intake and Fuel injection..
    MotorCraft distributor
     
    timgr, cookieman and sterlclan like this.
  8. Jan 20, 2018
    4wealn

    4wealn Member

    Ontario, Canada
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    Nov 15, 2013
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    My 79 CJ-7 that I rebuilt when I built my other Jeep has a 360, I put in an Edelbrock performer cam and intake and ran it that way for a bit with an Edelbrock carb, it was not that great for off road. I then switched it to the Howell fuel injection and has been great. I am running it with an MSD box, distributor and coil. It works great.
     
  9. Jan 21, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    JMO - I'm not a performance expert, but I have been around these engines for a while - so this is just a collection of my thoughts. A 360 is quite strong when not strangled by emissions controls, and is a lot of engine for a CJ chassis... IMO. The main advantage of a 360 over the factory 304 is that the price/performance is excellent as long as you are happy with the big gain the stock (or mild) 360 provides over the 304. The 304 and 360 have the same crank, with the 360 having a larger bore. The larger bore has three effects, as I see it. First, more cubic inches. Second, the higher stroke ratio moves the "natural" torque peak to a higher RPM. Third, and significantly, the larger bore accommodates larger valves and provides improved breathing. The heads are quite good and you don't need to do a lot to the induction side. The pre-1980 cast iron exhaust manifolds are quite good for iron manifolds, and a smart choice for a Jeep when paired with a free-flowing dual exhaust. I'm not a fan of headers for Jeeps - they are hot, fragile, noisy, leaky, and not durable - strictly race car tech.

    If I were going to run a 360, I would first measure its compression and oil pressure. A seasoned engine does not start losing a lot of power until it's really worn, so it's important to assess the condition of your engine and thereby avoiding an unneccesary rebuild. The main issue these engines have is low hot idle oil pressure. There is plenty of discussion of this topic on all of the Jeep and AMC forums.

    The factory 2V manifold is said to be very restrictive, but there are two factory iron manifolds that you might consider. Just adding a 4V carburetor increases the HP of the 360 from 235 to 285, a 21% increase. That's a lot. AMC used the Motorcraft 4300 4V before 1975, and the 4350 model thereafter. The 4300 is the familiar Holley square pattern, but the 4350 has a unique pattern that looks like the Rochester Quadrajet pattern, but is different. The later manifolds will only work with the 4350 or must use an adapter to square pattern. These later manifolds should sell for near scrap prices, if you want to cut costs. Try the Wagoneer forums if you are interested.

    The old hot rod maxim tells you to focus on "the 4 Cs" - cam, carburetion, compression and cubic inches. I'd think the main issue with getting a lot more power from a 360 would be compression. Ideally you'd replace the pistons to get higher compression, but this is comparatively expensive. So you're pretty much limited to cam and carburetion. If you want to get a wide range of opinions and decide for yourself, the Wagoneer forums have thousands of threads about this topic. Search at ifsja.org (the oldest forum) or fsjnetwork.com ...
     
    Last edited: Jan 21, 2018
  10. Jan 21, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    I see you have an intake manifold and carburetor, so please overlook those comments in my post above.

    IIRC the Edelbrock is the same grind as the MT-1. If you replace the cam and timing gears, read up in the Wagoneer forums to avoid defective parts.

    I too would spend the additional money and install one of Bill Hamilton's TBI systems rather than buy another new carburetor. Hamilton also supplies a Motorcraft distributor that works with spark control from the TBI computer.
     
    Last edited: Jan 21, 2018
  11. Jan 21, 2018
    wheelie

    wheelie beeg dummy 2019 Sponsor

    York, PA
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    If I may butt in with a question........Tim........you suggest using the 1975 and older 4bbl manifold, correct?......vs the later 4 bbl manifold? Am I understanding correctly?
     
  12. Jan 21, 2018
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    It's not relevant to the original poster, but I was suggesting a factory iron 4V manifold as an alternative to an aluminum aftermarket manifold. You mean '74 and earlier? That manifold is a conventional square pattern and your AFB, Edelbrock, or Holley, will bolt right up to it. The '75-up wide-pattern manifold will work with an adapter, but without an adapter the later manifold only fits the 4350 that Jeep provided. It's pretty close to a Quadrajet pattern, but not close enough to work. Just as an aside, I have made carburetor adapters and it's not hard if you have a drill press, a die grinder, and a suitable slab of aluminum. I expect you could make an adapter to one of the later manifolds to mate a Rochester throttle body, or a Rochester Quadrajet, or even a Holley or Edelbrock if you had the later manifold. There is (or was - don't know) an aftermarket square pattern adapter from the 4350 wide pattern to the Holley square pattern. Anyway, these later wide-pattern manifolds are boat anchors, and you should be able to find one for almost nothing.

    This is of interest to me because the 2V manifold that my J20 has is what you would usually pair with the 2V Rochester throttle body. I would expect the iron 4V manifold to breathe better than the restrictive 2V manifold, and it would probably be worthwhile to adapt the throttle body to a 4V manifold. If you are going to adapt a manifold to the throttle body simply to eliminate the 2V manifold, it may as well be a cheap manifold.
     
    Last edited: Jan 21, 2018

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