What to expect out of mild build 360

Mopar Performance Issues

  1. NormalPcGamer

    NormalPcGamer Member

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    Hey, I'm looking for other people with a similar build as me so I can sorta gauge how the engine is running.

    Car is a 1975 Plymouth Valiant

    1978 LA 360 .030 over, flat top pistons, unknown compression ratio
    U cast heads 2.02" int 1.60" exh
    Comp XE268 cam specs
    Edelbrock 750 carb #1407 set up to #9 on the Edelbrock calibration kit
    Vac advance (ported vac source) distributor 19 deg at idle 38 total at about 2750
    Hooker headers to dual exhaust
    NGK RN14YC spark plugs

    other things
    3.23 suregrip in the 8 3/4
    1973 904 transmission
    25" tall tire


    I don't know what I should be expecting out of this setup. I've owned this car for about 3 years (2 of that with the stock 318) but now I've swapped this engine in and its hard to tell if its actually running how it should be. I've never driven or really even been a passenger in any other car around this era (I'm only 21) and my other car couldn't be more of an opposite comparison (2013 Focus ST). My dad and I have been chipping away at everything that's been breaking on this car over the last 6 months or so but now its starting to run good enough where I can start fine tuning the carb and timing.

    I'm trying to absorb as much information as I can so if you've got a similar set up, post as much information as you can, as in, carb size and jets/metering rod settings, timing, HP/TQ numbers, 1/4 mile times, videos of the car driving, tuning tips/tricks, anything I can use to compare my car with so I can get it running as best as I can.

    Thanks!
     
  2. mopowers

    mopowers Well-Known Member

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    Are you planning to take it out to the track any time soon?
     
  3. 318willrun

    318willrun Roadkill '80 D150

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    Should run very low 13, and with no wheel spin and tuned proper, maybe a high 12 in the 1/4 mile.
     
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    • j par

      j par Well-hung Member

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      First welcome to the team..:D..
      Just so you know from my experience if it's a well-tuned 360 4 barrel with headers and a decent cam, 25 inch tires and 323 gears... It should start idle and run smooth and have no hesitations, coughs, or giddy-ups...
      In other words from a dead stop in drive you should be able to stomp it to the floor and without hesitation it should burn the tires seriously... :thumbsup:
       
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      • RustyRatRod

        RustyRatRod Weenie idiot loser. FABO Gold Member

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        Run a compression test and post up the numbers. We can come real close to telling you what it should make.
         
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        • NormalPcGamer

          NormalPcGamer Member

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          I'm gonna try to this year if I can find a trailer to take the car, closest track is about an hour and half away.


          Yeah I finally took the carb apart to rejet it last weekend and it was set up as lean as it could be. I have the tuning kit for it so I set it back to stock settings and that was the first thing that completely changed how the car drives, and after a little more adjusting I was able to get rid of the off idle stumble I've heard about the Edelbrocks. although I haven't driven it that much since because I've been having some overheating issues, still running the stock 22" rad.
           
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          • NormalPcGamer

            NormalPcGamer Member

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            145 psi on all cylinders
             
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            • RustyRatRod

              RustyRatRod Weenie idiot loser. FABO Gold Member

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              That's low. Was the camshaft degreed? I'm guessing it was installed dot to dot. You could add a lot to that if you went in and degreed and advanced it some.
               
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              • j par

                j par Well-hung Member

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                sounds like you're doing the right thing for now just driving it and letting the little things pop up and fix them as they come along. I would be getting the overheating problem fixed...
                It could be anything from a pluged thermostat to a bad tune...
                 
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                • NormalPcGamer

                  NormalPcGamer Member

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                  Yeah its dot to dot. I think the engine could take more timing because we can't get it to ping but instead it will start to stumble, like its starts to fire on the next cylinder. is there any way I can get more timing in it without taking the front cover and degreeing the cam?



                  The overheating problem has been coming back and biting me all year, I've replaced the coolant hoses, added a electric pusher fan, put the shroud back on and even bought a 6 blade fan to replace the stock 4 blade from the 318 and nothing has helped, it would be running at 210-230 after 20 mins on the highway. I've got a 3 core aluminum rad and 16" fan coming on Monday that should fix all those problems though
                   
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                  • j par

                    j par Well-hung Member

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                    The only thing I can think of to add to that is making sure your bottom hose isn't collapsing under RPM..
                     
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                    • RustyRatRod

                      RustyRatRod Weenie idiot loser. FABO Gold Member

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                      You can get more ignition timing. But it needs more camshaft timing. Don't let it intimidate you. It's an easy job with a lot to be benefitted from. You could be talking about a 50 HP change with both camshaft and ignition timing.
                       
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                      • NormalPcGamer

                        NormalPcGamer Member

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                        Yeah I may attempt to do that when winter comes along, the only reason I'm concerned is because when my dad and I were rebuilding the engine we accidentally stripped the threads for the balancer bolt so we just loctited it in there with whatever threads were left. But if its gonna give me some good gains it might be worth it to try
                         
                      • RustyRatRod

                        RustyRatRod Weenie idiot loser. FABO Gold Member

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                        They make these new things. Maybe you've heard of them. Heli Coils. I think they've been around since the 1930s. LOL At any rate, that will fix your problem if it's the crank threads that are messed up. It could be the bolt itself, which is an easy fix. Either way, it's very repairable, so don't let that slow you down.
                         
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                        • RustyRatRod

                          RustyRatRod Weenie idiot loser. FABO Gold Member

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                          • B3422w5

                            B3422w5 Well-Known Member

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                            3.23 gears and stock convertor it isnt going to run anywhere close to real low 13’s. Maybe real high 13’s if i had to guess.
                            Back in 1972 i had a 69 340 swinger. Headers and 3.55 gears. Ran 14.23
                            This should run better than that no doubt. I will say 13.70’s- 13.80’s
                            This all assumes he has a stock convertor
                             
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                            • 318willrun

                              318willrun Roadkill '80 D150

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                              I just ran 13.5's with 2.76 gears, stock converter, AND a stock 360. He has more bore, more cam, more compression, better heads. I'm sure low 13's won't be a problem, maybe he'll go high 12's.
                               
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                              • B3422w5

                                B3422w5 Well-Known Member

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                                What is your combo and car weight? Impressive
                                 
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                                • 318willrun

                                  318willrun Roadkill '80 D150

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                                  Car weighs over 3200 lbs with 1/4 tank of gas, no spare, without driver. Stock smog heads, stock dished pistons, stock crank, stock rods, how about I say stock long block with a .427 lift / 204@050 cam (less than a factory 360 4bbl). 750 Holley DP on a eddy intake. Headers/duals out the back.
                                   
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                                  • j par

                                    j par Well-hung Member

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                                    Unbelievably impressive...:poke:
                                     
                                  • B3422w5

                                    B3422w5 Well-Known Member

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                                    Very impressive. Hard to believe that could run better than a 340 with x heads and more gear.
                                     
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                                    • j par

                                      j par Well-hung Member

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                                      Is your home track like straight downhill....?
                                       
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                                      • B3422w5

                                        B3422w5 Well-Known Member

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                                        Unbelievably impressive indeed.
                                        Raced a TON of smallblocks since the early 70’s, takes something going on to get in the 13’s, at least in my experience.
                                         
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                                        • 318willrun

                                          318willrun Roadkill '80 D150

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                                          LOL... Cordova Dragway. Flat and asphalt, 600 ft above sea level.
                                           
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                                          • j par

                                            j par Well-hung Member

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                                            He's an expert tuner...
                                             
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