Am I over cammed ?

Discussion in 'General Maverick/Comet' started by duramax59, Jan 19, 2017.

  1. duramax59

    duramax59 Member

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    Looking for opinions, this is a new build about 1 hour run time and went down the street once with it open headers.
    My goal was to have a healthy sounding engine and to be drivable and may be take it to the track a few times.
    So it does sound good but I think it may be to radical for my needs.
    So here is what I have
    Engine- 331 Stroker -compression approx 9.75
    Cylinder heads- Pro-maxx Max 175- 60cc- 2.020 intake-1.600exh-intake port volume 175cc-flow 266@600 lift
    Intake- Edelbrock Performer RPM
    Carb-Quick Fuel-HR 680VS
    Cam-Comp Cam Magnum 290HR-Retro Fit-Duration 290-Duration @.050" lift 230-Valve lift I & E .544
    lobe separation 110*- intake center line 106*
    MSD ready to run dist and coil
    Headman headers-88300-1 5/8" tube-3" collector
    Torque converter 10"-stall 2800-3200 rpm
    Trans rebilt with shift kit
    Rear end 3.55 traction lock
    Rear tires 255/60-27" tall

    Also has an old set of Southside lift bars on it and Alston subframe connectors
    So thats about it so let me know what you think-Thanks

    IMG_20160819_132704.jpg
     
  2. Krazy Comet

    Krazy Comet Tom

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    Ummm dats real purdy...

    It no doubt depends on what one expects but a 230* @ .050 would more than I'd want for a mostly cruiser... Even with advanced base timing, modded dist curve, carb tuning and the stall converter you have it's apt to be a bit "jumpy" at idle and low cruising speed...
     
  3. duramax59

    duramax59 Member

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    Thanks Krazy. I really need to drive the car to see how it will react and if I can live with it but I have no exhaust for it and the weather is iffy around here for now. I may have to wait till spring to get exhaust done.
    Is there enough room to pull the cam without pulling engine ?
     
  4. maverick306

    maverick306 Member

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    I have a 349 with the 282 Comp Cam it's 232/240 lift 566/576 3000 TCI converter 389 gear 26 inch tall tires I like the thumb
     
  5. duramax59

    duramax59 Member

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    Thanks-So how is your car to drive on the street
     
  6. groberts101

    groberts101 Member

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    That's a sweet little motor you put together.

    IMHO, the static compression is just a tad low for that cams duration. Next size down would have been closer.. 2 sizes probably perfect. BUT.. the extra bit of stroke, tighter lob sep, dual plane manifold and smaller cross sectional area of those cylinder heads easily compensates for much of that shortcoming. Plus you could easily tune that for regular fuel if need be. I myself wouldn't do it due to the slight power losses that come from an ignition delay(detune).. but some are concerned about fuel costs and availability.

    Personally speaking, with the engine still out on the stand, I'd just move the cams ICL up on a 104 or 102°(2 - 4° advanced) to pump up the meat of the power curve by building cylinder pressure sooner. Then go enjoy the hell out of it through the mid-range. At least till the cam starts signing off harder around 6,400 rpm(depending on valve spring rate). The car is light but the gears you're running(trans AND axle) with 27" tires still need torque to get the car rolling along to quickly reach the meat of this cams power curve. My guess is that the true stall speed will be on the lower end of those spec's due to this cam being softened up a tad by the current static compression ratio. So, advanced cam timing will also help the engine to "come up on the converter" quicker, a bit higher rpm and hit it harder overall. More cylinder pressure, more manifold vacuum, more torque, more throttle response.. more fun.

    Just be aware that the tuneup changes when advancing the cam and PTV clearance needs to be checked depending on where you were at with PTV clearance in the first place. The intake PTV clearance gets tighter with cam advance.
     
  7. duramax59

    duramax59 Member

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    Thanks for your input but the engine is in the car and I have been using 93 octane fuel. What if I were to change out the rear gears to say 3.80 or just change out the cam. Changing out the cam is more work but what else have I got to do.
     
  8. duramax59

    duramax59 Member

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    When I took mine out for the first and only time it did not puck and fart it ran very well it actually scared me a little. So use to driving newer cars with no power. So maybe it's just me. Does your car give your eyes burning feeling when running in garage?
     
  9. groberts101

    groberts101 Member

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    And just to clarify.. i was responding to the question of whether or not the cam was too much or best tailored for this specific engine and chassis combo. Not so much relating to the cam choice based on any individuals power threshold. Far too subjective based for anyone here to accurately answer a question like that.

    The combo of parts needs to work together for best results. Otherwise.. it's even more crutches and bandaids than we're already forced to apply to any conventional 2 valved 4 stroke.

    What is the static timing set at? How much mechanical advance and @ what rpm is it all in by? Vacuum advance canisters hose running to full manifold vacuum?.. or ported/timed source on the carb?

    What is the manifold vacuum @ idle?

    New carb?.. spec's? How many turns out are the idle screws currently set at?
     
  10. Miguel Arzola

    Miguel Arzola Member

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    Nice engine clean work, like the A/C comp,installation
     
  11. Hotrock

    Hotrock Rick, an MCCI Member Supporting Member

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    No it does not make my eyes burn when running in the garage, but I will say my wife doesn't like it very much.
     
  12. maverick306

    maverick306 Member

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    IT drive fine to me I would like more thump I just be happy with for now. I don't have have to turn it 7500 to get all about 6200 and it's good. I have had this combo for 3 years about 15000 miles.
     
  13. rotorr22

    rotorr22 Member

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    It is supposed to scare you a little bit! You put together a potent combination and it sounds like you got what you asked for. Get an exhaust on it and I'm confident you will perceive it a bit differently. If you don't have sufficient tuning knowledge, take the car to a good chassis dyno shop and get it tuned. Thereafter, drive the snot out of it and get to know your car. If you are like us, you'll be craving for more power pretty soon.
     
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  14. duramax59

    duramax59 Member

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    Thanks to everyone that responded, for now engine is on hold till exhaust gets done-mufflers have been ordered.
    Thanks again
     
  15. maverick306

    maverick306 Member

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    I was a little scared to when the front wheels came off the ground at the drag strip with slicks.
     

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