Tell me about my 360...

Engine, Trans & Driveline

  1. westie47

    westie47 Well-Known Member

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    Pulled the drivetrain and pressure washed all the crud off. I found out I have a 76 360 and 727. I tried googling the specs but didn’t come up with much. 8.7:1 compression is about all I found.

    A3E99F4C-7074-4D0E-93F0-3DBD20E9AA1B.jpeg C7591053-5E60-4A06-B31F-5F0672506E13.jpeg 80EE0343-92D0-4CD0-A637-DC9E40C530EB.jpeg 99ED5236-F1C3-4058-9B1A-CF1A75C766F4.jpeg
     
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    • kiwigtx

      kiwigtx International Mod Staff Member FBBO Gold Member

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      More than likely you have a matching set.

      The Crankshaft dampener and torque-converter will have weights for balancing.

      If you try and separate the two for changing either one, you will have to 'recalibrate' for different sized engines.

      There ya go...that's my 2 cents worth. :)
       
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      • westie47

        westie47 Well-Known Member

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        It’s a good thing I marked the flex plate and converter then
         
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        • oldbee

          oldbee FBBO Gold Member FBBO Gold Member

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          Yes, a good first step always. The bolt holes only line up one way but it's better to know before putting together.
           
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          • rumblefish360

            rumblefish360 Well-Known Member

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            The ‘76 - 360 is a low compression smog engine with a lower than stated compression ratio. Take it a part and measure it up, proceed to do the math or go to the Wallace calculators to find the actual static compression ratio. I’d bet below 8.0-1. Other years I have measured come in at + or - 8.7-1 by .1, sometimes, .2.

            The carb up top, if a 4bbl. Will be a TQ with many ports on it for smog purposes and is it NOT very desirable for modifications or performance applications. It will handle very small cam upgrades.

            All of the intake manifolds are an egr design with two floor jets or holes under the carb in the plenums floor. These leed directly to the heat cross over passage. The egr valve controls the opening and closing of the passage way between the head and intake manifold. The EGR’s recirculating, is only happening while at cruise and part throttle acceleration but closed during W.O.T.

            The cylinder heads are the 587 or the 974 and have the small 1.88/1.60 valve size. Chambers are in the 72 cc range or better. CFM flow is in the 180-190 cfm range on the intake and 120 @ best on the exhaust.The flow curve rolls over just after .500 on the intake and the exhaust levels off at .500.


            Pistons are often found to be .100 - .120 below deck height, flat top/dishesd with no valve reliefs.

            The distributor has a lazy slow advanced curve which can be further hampered with the OSCA vacuum operated port. (First seen in ‘73 for stopping the advance curve for IIRC, 15 or more seconds.)

            The engine is externally balanced via damper and torque converter that has weight on it. The damper does not have a smooth back side to it. There is a depression to off set the balance.

            Pistons are cast aluminum and pressed onto the cast in number 645 rods @ the standard 6.123 inches long.
            The crank is cast. Capable of good hp.
            Oil pump is standard.
            Water pumps can be ether 6 or 8 blade. (AC or not.)
            Fuel pumps seem to max out at 5 psi, + or - .5 psi.
            Timing chains are single with garbage material for gears.
            (Seriously I suggest an upgrade there!)
            E58 360 engines step up a little bit in a few areas.

            A move away from the normal 252/252 - 4.10/.410 cam used for 2 or 4 bbl. engines to there use of the 340 cam, 268/276 - .430/.444 cam was employed here.
            The standard 360 - 4bbl. cam is the same as the 2bbl. cam for the ‘74 - ‘75 years, “HP” cams were the 340 cam, but not after or prior.
            ‘76 360’s 2 & 4 bbl. used the 2bbl. cam reguardless. Unless it was the E58 Designation, (again) then the 340 cam was used. Then you got a few more things.
            Rotors were employed on the valve springs, a double roller timing chain was also used and a windage tray.
            If you have these 3 things, you have the E58 engine.

            Your torque converter is 10-3/4 inch.
            A manual trans would have the 10-1/2 flywheel which is weighted via holes semi drilled in the backside.

            I do not know if the trans is a lock up unit but standard gears within should apply.

            Anything else I can help you with?

            Enjoy brother!
             
            Last edited: Feb 10, 2020
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            • westie47

              westie47 Well-Known Member

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              Awesome! Thanks for the breakdown! I haven't broken into mine..yet, but I do plan to replace all the gaskets, take a look around inside, etc. My motor came with an Offenhauser Dual Plane, Edelbrock 1404 carb (500cfm), and headers. I am adding an electronic ignition. I want to put a bigger cam in, without having to start replacing everything in the heads. I will be researching what cams will work, while I'm at it, I will put in the double roller timing chain! I may upgrade to a 700-750 carb, but that's about it. I'm just looking for the lumpy idle and some performance.
              Any other tips or advice would be appreciated.
               
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              • JoePole

                JoePole Well-Known Member

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                Nice work Rumble.
                 
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                • wyrmrider

                  wyrmrider Well-Known Member

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                  nice write up rumble
                  OP
                  with that low compression motor you actually want a shorter cam (one that closes the intake earlier the stock cam is really long on the close side) and more lift/ area under the curve
                  a "Bigger" cam, even the 340 cam, and it will die
                  Ones to look at are the 250 Lunati Voodoo and the 256 Howard and a very few others
                  btw Comp cams has nothing in this duration range for a Chrysler till you get to 275 degrees duration
                  lots of threads on low compression 360s
                   
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                  • Don Frelier

                    Don Frelier FBBO Gold Member FBBO Gold Member

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                    I don't think a larger carb is going to do much for you.
                    Do your other stuff and tune the carb you have.
                     
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                    • westie47

                      westie47 Well-Known Member

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                      Would those cams require different valve springs?
                       
                    • wyrmrider

                      wyrmrider Well-Known Member

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                      you might be able to use HP springs however the stock springs will not take much lift and would be too soft
                      and you have to check for keeper (sticking out the bottom of the retainer) to stem seal clearance
                      best to cut for Viton seals (and not the .500 ones the larger ones)
                      and new springs
                      springs need to be located where they sit on the head one way or another (cut seats or inside or outside locators)
                       
                    • rumblefish360

                      rumblefish360 Well-Known Member

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                      I’d replace the springs. The OE are how old now?
                      Springs are cheap.
                      It’ll be worth at best 10 hp up top. But that’s not the draw of why you would do a swap. Overall drivability will improve. A 750, Holley or Carter on this kind of mill is what I’d call equal.
                      IF he has a TQ, I’d call it a mistake to swap carbs.
                       
                    • rumblefish360

                      rumblefish360 Well-Known Member

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                      On cams for a low compression 360, as a basic upgrade that will work, the upgraded spec MP replacement 340 cam, not a OE spec 340 cam, is acceptable.

                      F you don’t have the gear and converter behind it, it’ll suck. Wyrm suggested something seemingly small for a cam BUT they will work excellent with the low compression and make better power over the entire power curve.

                      The older cam designs work really well when the compression is high and the octane is available. Reorganizing the cams ramps rate of lift and altering the events just a bit allows more of the air and fuel charge to be draw in and trapped in the cylinder.

                      As a general run down, if your car has xxx gear, you can use ccc for a cam and if need be, a converter or gggg. Example below, as in a general example. There are a lot of factors involved. But for street driving....

                      Cam @ .050 - gear - converter

                      224 - 230 - 3.55 or better 2500+
                      220-224 - 3.23 - 2500
                      212-218 - 3.23 and up, no converter change
                      Less than 212 use a lower than 3.21/3.23 ratio and no converter change.

                      Real world example; Low compression (7.8-1) ‘78 - 318, 600 carb, Edelbrock dual plane, headers, 2-1/2 exhaust, cam at 218@050-.454/.480 112 lift runs 14’s with a stock converter and a 904 w/3.21 gears on stock tires.
                      (Not very well tuned)
                      And I call that cam a wrong cam to use but it was 100% streetable with the best of 18 mpg’s.
                       
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                      • rumblefish360

                        rumblefish360 Well-Known Member

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                        Oh, I don’t know what Offy you have on there but IMO I’d sell the Offy and the 500 carb off to roll the money over into a RPM (AG or not) and a 750 cfm carb of your flavor.

                        Tell us your goal, wheel and tire size as well as the cars weight. From there, a better cam recommendation can be made instead of generalizing.

                        Also be aware that sometimes, the cylinder head needs modifications to work with some manufacturers springs, which I really suggest replacing. This is not a place to cheap out and save money on ever.
                         
                      • toolmanmike

                        toolmanmike Moderator Staff Member FBBO Gold Member

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                        Oh and have someone like @HALIFAXHOPS hop up your advance curve depending on how handy you are at that kind of thing.
                         
                      • rumblefish360

                        rumblefish360 Well-Known Member

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                        True that one Mike. Between the carb and distributor, there is much power and mileage to be gained or lost.
                         
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                        • westie47

                          westie47 Well-Known Member

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                          I like the idle of that Lunati, plus it's cheaper than the Comp Cam
                           
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                          • westie47

                            westie47 Well-Known Member

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                            I believe its the Offy Dual Port 360 (?), I'm sure it's pretty old. I have a new electronic ignition kit, good coil and plug wires. I'll prob stick with 255/60/15s, or go a bit wider if possible. The book curb weight is 3300 lbs. I want a nice choppy idle and overall power increase. I have a 2.5" dual exhaust with Flowmasters already for it. I won't be racing it. I plan to throw 3.55 or 3.91 in and update the torque converter eventually. I want to do the cam upgrade now, while the motor is out and I am re-gasketing. I'll put the cam in myself but will need to have a machine shop do the springs.
                             
                          • JoePole

                            JoePole Well-Known Member

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                            Do the factory smog heads (587 or the 974) require machine work for replacement springs on the cam type listed above? Maybe like the Comp 995-16? Suggestions? This may be a question for Cam manufacturer.
                             
                          • HEMI-ITIS

                            HEMI-ITIS STREETER on LI FBBO Gold Member

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                            Sounds like a perfect candidate for BOOST!!!:bananadance::drinks::popcorn2:
                             
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