Is this a good start?? Timing Question

Discussion in 'PSI Superchargers Tech Questions' started by Scotttrod, May 5, 2014.

  1. Scotttrod

    Scotttrod Member

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    Ok guys, first I would like to say thanks for the help and advice already given. I have been hot rodding for years, but my learning curve has been steep on this blown alky screw stuff. I appreciate all the patience when you guys could have told me I am out of my league or disregarded me as an idiot.


    Thanks to Will for the site, I have almost always been the buyer and the seeker of advice, it has been valuable, I will gladly pay the $5 fee to sell stuff when the time comes.

    Ok, so for the question.....

    I am getting the parts and machine work together for the motor (again) and found a small sheet of paper from the previous owner about the timing setup he ran, it said "27 max, likes 26 degrees" This was a C rotor 496, Veney 179cc head, 10.87 compression, 4.310 bore, 4.25 stroke, C rotor with 44 mag and waterman pump at the time, running 90 to 128 over. Lenco/clutch.

    On the overhaul, I found the crank cracked and replaced it with all the other usual parts. The new stroke is 4.5 making it a 526 cid, and with THE CORRECT ROD LENGTH (most of you have seen the thread and my huge mistake I made measuring for new rods :rolleyes:) 10.7 compression (for real).

    Is 26 degrees a good starting point for this combo? I have read and re-read Mike Canter's methanol plug reading document and will read again before shaking out this motor to sneak up on things instead of my typical blow-up style that I have been using in the past.

    Also good shift RPM? Two speed Bradco 400 1.4 first with 4.29 rear and 34.5 tire.

    Thanks again and hopefully will be racing for real here soon.

    ScottRod
     
    #1
    Scotttrod, May 5, 2014
  2. Mike Canter

    Mike Canter Top Dragster
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    Since you are just starting out I would recommend no more than 25 degrees until you get comfortable with the tuneup. As far as shift rpm it depends on how fast you want to go and how often you are going to check your valve springs. My recommendation would be to start off with a shift point around 8800 rpm. Were you thinking of going that high or higher? Not sure about your gear ratios. Seems to me you are going to have a hard time pulling a 1.4 first gear with a 4.29 rear gear. What car is this and how much does it weigh?
     
    #2
    Mike Canter, May 5, 2014
  3. Scotttrod

    Scotttrod Member

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    70 Camaro, 2900 lbs

    Was thinking 8500 RPM, 8800 sounds good. Ultimate goal is 3.99999 1/8 and to qualify for a Pro-Mod license, not wanting to save the world..

    Lots of suggestions have been made to go with 5.0 gearing

    Thanks
     
    #3
    Scotttrod, May 5, 2014
  4. Mike Canter

    Mike Canter Top Dragster
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    If you go with 5.0 gear then you are going to turn high 9000's and into the 10,000's. I think you would do good running a 4.56 with your first gear and the RPMs you want to turn.
     
    #4
    Mike Canter, May 5, 2014
  5. Scotttrod

    Scotttrod Member

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    Many thanks

    Thanks Mike,

    Also have a Rage pump coming, too many scary stories with the Enderle 1380.
     
    #5
    Scotttrod, May 5, 2014
  6. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    gear

    Mike -

    I don't know that he would turn that many rpm's. A competitive PX car will turn that kind of rpm (10k +) when they are going 200-210 through the traps in the 1/8, but you are talking about a 2300 ish lb car going 200+.

    Scott's car is 2900 lbs and won't be making the power of a competitive PX car (at least at the start). I would say with the weight and the lower hp he would probably be in the mid to low 9000's. And that would be a good lap for him, probably well into the 3's.

    Sometimes lugging a motor can be harder on parts than revving it.

    Thoughts?
     
    #6
    Will Hanna, May 6, 2014
  7. Mike Canter

    Mike Canter Top Dragster
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    I agree with the lugging being bad thats why i think the 4.56 rear would be a good in the middle starting point. Not sure he wants to pay the $1000+ for a 5.00 gear
     
    #7
    Mike Canter, May 6, 2014
  8. M Tigges

    M Tigges TAFC

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    4.500 stroke

    Our Veney Motors ran well shifting @ 9500. should run great at 8500. but beware of 10,000 rpm. you will be exceeding the bolt stretch strength on the deceleration on the shifts. 12 to 15 runs on rods max! 25 to 26 degrees. long dwell with 4.50 stroke cant light it to early.
     
    #8
    M Tigges, May 6, 2014

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