My new engine is a dog!!

Discussion in 'Classic Mustang Specific Tech' started by crushnut, Oct 6, 2004.


  1. crushnut

    crushnut New Member

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    I did do that, i stuck my finger over the #1 plug hole and cranked the engine till if puffed off my finger, then i stuck a small wooden dowel into the hole and turned the engine over by hand till it just barely started to go back down, then i turned it backwards to tdc and the balancer was pretty dang close. Is this not an exceptable way of finding tdc for #1? :shrug: ( i know its kinda hokey, but i dont see why it wouldnt work) I also dont understand how i could of installed the cam/timing set wrong. I lined up the two marks on the gears and both gears only had one keyway, so it could only go on one way. I think the reason my engine is so gutless is the piston choice/cam combination. :notnice:


    If you could do that for me, that would be great :nice: :)

    Much thanks
     
    #41
  2. crushnut

    crushnut New Member

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    I used a Melling replacement timing set for 289/302's.
     
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  3. Max Power

    Max Power New Member

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    Crush, send an email to me with your snailer.
     
    #43
  4. D.Hearne

    D.Hearne Banned

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    Crushnut---- I looked up the pistons that you most likely have ( speed pro part # L2482) and based on their specs( comp height is 1.605) and the specs you furnished earlier,( 54cc chambers, Felpro gaskets, and a 74 302 block w/an 8.229 deck milled .010) I don't think your problem is low compression, on the contrary, your comp ratio should be around a healthy 9.75 to 1 with 289 heads. Your lack of power problem is something else, most likely timing, either the cam or the ignition. Try setting the initial timing at 12 degrees BTDC. If it doesn't respond to that, then look at the advance mechanisim in the distributor. Where do you have the vacuum advance hooked to, full manifold or ported ? 12 degrees initial should be perfect for your motor. Vacuum should be ported on a stock Ford dist. As for it being the carb, if your motor is built right, it'lll even be responsive on the primaries, if it's not then I doubt the carb is the problem. Hell even my 331 six pack in the Ranger kicks butt with only the primary 250 cfm carb , you barely have to give it any pedal to get moving and it'll cruise at 75 mph with only that carb open. Keep us posted
     
    #44
  5. crushnut

    crushnut New Member

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    I found a part# for the pistons it is 272AP
     
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  6. D.Hearne

    D.Hearne Banned

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    You sure about that # ? I went to Speed Pro's website ( actaully Federal Moguls site, they own Speed Pro) and came up with an H273CP # on their hypereutectic flat tops. Either way they still had the same comp height--- 1.605 as the forged pistons, so the comp ratio I worked up wouldn't change.
     
    #46
  7. D.Hearne

    D.Hearne Banned

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    OK I went back and typed in your part # in the search box, and came up with a match. Now for the bad news---- the comp height is even less, by .020 @ 1.585, not good, stand by-----------
     
    #47
  8. crushnut

    crushnut New Member

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    Im stumped, i dont think my timing is that far off. I had it at about 12 btdc and it didnt change how it performed. I am using ported vacuum advance, i also checked my mechanical and it is functioning. What do you mean by if your motor is built right? What could be not right? This is my first rebuild and i bought "How to Rebuild Small Block Fords" by Tom Monroe and did what it said. If the carb isnt the problem what could be :shrug:

    Ahhh!!!, this has me pulling my hair out trying to figure it out :fuss:
     
    #48
  9. D.Hearne

    D.Hearne Banned

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    Your new comp ratio is 8.66 to 1, a tad on the low side, how much overlap does that cam have ?
     
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  10. D.Hearne

    D.Hearne Banned

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    I got to run to my kid's football game now, talk at you later.
     
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  11. mdjay

    Premium Sponsor

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    So, went to lunch and CARB, saw this hot lookin' CARB chick. She was CARB wearing next to CARB nothing and bent over to pick up her CARB purse. All I can say is CARB I saw the crack of Dawn...

    No on the serious side, most of the technical advice here is applicable, but I think it's just choaking with that little carb. Give her some are and gas and see if it comes alive. If nothing else, make sure to check those secondaries on the carb you have. What size jets are you using, needles? Those are real easy to swap on that carb.
     
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  12. crushnut

    crushnut New Member

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    It is whatever Edelbrock puts on a 500cfm Performer w/manual choke, I havent changed anything yet. I already havd a 14x3 inch K&N open element. I wish i could change the carb to see if that is the problem, but i dont know anyone who i could borrow one from, and i dont really have the cash to buy a new one :(
     
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  13. crushnut

    crushnut New Member

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    rbhom figured out the cam has 61 degrees of valve overlap. Apparentley too high for such a low compression engine. What are all the ways you can increase compression fairly easily :shrug:
     
    #53
  14. kndyblucapri

    kndyblucapri New Member

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    cam timing and stuff

    well if you have all the cylinders firing ignition timing is fine what i would check first is cylinder leakage with a cylinder leak down tester check, compression, and make sure your cam is timed right if it's not your engine is gonna be what it is a dog. o and get a better carb like a 650. cam timing is your most important thing that is if the motor was assemblied right. then worry about ignition timing
     
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  15. mdjay

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    Well we could go around and around on the jets with your carb and it still wouldn't be enough. With everything said about the cam issues and overlap, these are issues that will make a difference in the overall output. So changing the cam may be a consideration. However, I would still bolt on another carb and see what happens. The carb you should have on that engine is a 600-650 tops. I suggest a 625 road demon #4282010ve with vacuum secondaries. These are nice carbs and whatever ends up being the case with the cam timing etc, you will still need the bigger carb, so get a good one!

    http://store.summitracing.com/default.asp?target=esearch.asp&N=100&Ntk=PartSearch&Ntt=4282010ve
     
    #55
  16. Mosse

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    Yes, it is true that edelbrocks have secondaries opening mechanically, but there is secondary flaps also, which are opened by vacuum. I have 600cfm carb with my similar engine, but351, and I think it is small for me. The engine goes lame in 4000rpm. Of course I´m running stock -69 heads so thaya re also the reason (should have ported them...)I´ve read that edelbrock 500cfm equals 450 holley, so it is a bit small? Correct me if I´m wrong, I´m not a carb exp. Good way to check that you have all the 8 mugs playing, is to spray water to headers(if you have ones) when they are worming up. No need for infrared thermometer, which ofcourse works also. If you have opportunity to get it to dyno some where, the graph would tell a lot of motors possibilities.
     
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  17. diablopony

    diablopony Member

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    I've been following this post because it sounds very familier. I put in a new FR motor a few years back. I installed the motor, set everything up as speced and had a big turkey. I spent a year attempting to get the motor to run right. I got a lot of great advice, like you are getting on this forum, but was not making any headway. Finally my neighbor, seeing me wing a 1/2" box wrench out of my garage, suggested I take it to a dyno tune shop in town. $400 and 2 days later, I had the car I'd been looking for. It runs smooth, but goes like a scaled cat when you hit the gas.

    I've upgraded the carb from an Edlebrock to a Holley which I again had dyno tuned. The result was even bettrer. For me, I do all the basic labor but get the experts, with their tools, to do the tune. In the end, I still have my hair and a car that is a blast to drive.
     
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  18. crushnut

    crushnut New Member

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    Too give you guys an idea of how not fast my car is, today i did a 0-60mph run and it took 8.4 seconds, on wet pavement :rolleyes:

    Besides having the heads milled down what are some other ways to increase compression in an engine?

    Thanks again
     
    #58
  19. D.Hearne

    D.Hearne Banned

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    Only way to increase it on your motor now is to mill the heads and or use thinner head gaskets to get the compression back up where you want it.But this will also require milling the intake to fit it afterwards. I think if I were you though, I'd contemplate a different cam , one that'll work with your comp ratio. From what I've heard something like Comp Cams 268H is what you want, it's designed to work with low compression motors like yours.I'd also use their timing set to insure it's timed correctly if you can't use a degree wheel to check it. As for those who still insist he needs a bigger carb, that's not the case. If it's a dog from off idle, then a larger carb will do nothing to help. Even with a too small carb, the motor would be responsive ( if the motor is set up and tuned correctly) from off idle to what ever rpm the carb would run out of breathe at. From what Crushnut says, it's a dog from the get go, so the carb size isn't the problem. Like I posted before, my 331 stroker with a 3x2 Holley intake and carbs, is a terror off the line , even just using the primary carb, and that's only 250 cfm's worth of carb. :D And Crush, I'd also go back to your machinst that recommended those pistons to you and give him a swift kick in the pants, he ain't got a clue as to what a Ford needs. :rolleyes: At least give him a bag of dog bisquits to feed his future dogs. :D
     
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  20. crushnut

    crushnut New Member

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    What is the most you can have the heads milled before running into issues with the intake not lining up? .040? what about thinner head gaskets also?
     
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