Is this cam too big for my combo?

Discussion in 'Classic Mustang Specific Tech' started by 68stang351, Dec 9, 2003.


  1. 68stang351

    68stang351 Founding Member

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    I came across a cam today for a price that I couldn't pass up. If anything, I can sell it for a profit. I really would like to put it in my car though. It is a Comp Cams custom grind 284/296 duration with .512/.513 lift.
    Is it too big? See sig for combo.

    It's a roller cam, and if I put it in I'm also buying Comp roller lifters and valve springs.
  2. brads91

    brads91 New Member

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    Im no expert on mustangs but that cam doesnt seem to big for your setup. The duration is slightly on the higher side but not bad. The lift sounds pretty good. I went with a Lunati .510/.512 with 274 duration in my efi 302. It runs well with no big loss of driveability.
  3. D.Hearne

    D.Hearne Banned

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    That cam will work fine but I'd get a bigger carb. What's your rearend ratio? I'd also get roller rockers too
  4. 68stang351

    68stang351 Founding Member

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    3.55's. Yeah, I wondered about the carb too. I bought a 600 because it was the right size to buy at the time.
  5. D.Hearne

    D.Hearne Banned

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    You mean it was the right price.. Lotsa people go with em cause they're generally the cheapest and they work on just about anything, from 4 cylinders to big blocks, it's just that anything more than a modified 302 can use a bigger carb. Your motor would be able to use a 650 -750 carb.
  6. D.Hearne

    D.Hearne Banned

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    The 3.55's are also a good choice.
  7. 68stang351

    68stang351 Founding Member

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    Sometimes I see a lot of people overcarb their motors waaaay too much, and didn't really want to do that myself.
  8. D.Hearne

    D.Hearne Banned

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    With a vacuum sec carb, you really can't over carb it, unless the secondaries are tuned to open quickly.
  9. Edbert

    Edbert Founding Member

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    I did not see anything about your heads in the sig. Are they bone stock? What year?

    That cam is a LITTLE on the big side for stock heads with low compression chambers. At least the 351 has bigger valves, I'd say it is definitely too big for a stock 289/302 head.

    I have PerformerRPM heads on my 351 (2.02i and 1.60e) and I'm using a smaller cam, it is a 226/234 (274/282) and .506/.506 lift hydrualic roller
  10. D.Hearne

    D.Hearne Banned

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    There's nothing wrong with using a big cam on small heads. The performance gain may not be as much as you'd realize with better heads, but you will still see some improvement.
  11. Edbert

    Edbert Founding Member

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    Up to a point right? Theres a threshold somewhere in there when a cam is too big for a head that you'll actually see a decrese in overall performance right? I'm not trying to argue anything with regards to his specific cam here but there is such a thing as too much cam just like there is for too much carb. You should size and match all of the components together, from the oil pump to the air cleaner (top to bottom).
  12. D.Hearne

    D.Hearne Banned

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    You'd have to go to a cam that's got a .600 or more lift and a 310 degree diration ( advertised)to overpower a stock head. Sure you should size a cam to an application, but very few people can afford all the components at once. Piece by piece and step by step is the way probably 75 % on engine upgrades happen. I ran a B303 roller with stock E7 heads and there was a big difference in performance. The B cam's specs aren't far off from the cam he was going to use. And his 69 Windsor heads probably flow better than the E7's.

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