Twin Cam starting issue vs compression releases

Discussion in 'Engine, Fuel and Exhaust' started by Mixer08, Aug 16, 2010.

  1. Mixer08

    Mixer08 Member

    I'm going back together with my twin cam that I have just bumped up to a 106 Stroker. I had previously kicked up to a 95 kit and starting having problems then with the starting. At time when you hit the starter it would make a bad noise which was the starter gear not engaging or hitting ring gear. I think that was caused by the timing being just a bit off due to the hot set up on the motor. I also went through a couple batteries due to bad slow starting. But I think that was mostly due to my ground that kept loosening, it hards to believe that a loose ground could cause that much problems, even when it seems tight. Now with my main question, I'm curious if I have made a mistake not putting compression releases in the heads before going back together.
    Any thoughts...
  2. Jack Klarich

    Jack Klarich Expert Member

    Your starter would thank you and last longer, the grounds would not get so hot as your demand for more cranking power would be down
  3. Hoople

    Hoople Account Removed

    I take it by "timing" you mean spark timing? If so, your spark timing has no effect on starter pinion to ring gear engagement. The pinion is suppose to engage the ring gear before it starts turning. If it starts turning first, I would expect a terrible noise regardless of what your spark timing was.

    Without making a few measurements like cranking cylinder PSI or current draw of the starter motor, you don't know where you really stand or what is causing the problem if there even is one.

    The intake valve closing point (degrees) determines to a large degree what your cranking compression will be. If you have a radical cam, it may not be that high. Lots of factors go into your final compression ratio.

    I would take some measurements.
  4. Mixer08

    Mixer08 Member

    Not real sure what is making the crazy loud noise but it does not happen often, and usaully if I let off and hit the switch again it does not do it again. But the gear is a bit chewed on the ends. And the cams are S&S 585s.
  5. kykool1975

    kykool1975 Member

    Personally I would have put compression releases on anything 103 and above. I have heard too many guys say that a simple kick back sheared teeth and ripped out the starter clutch. At about $200 a pop that ring gear gets real expensive! A simple compression release would have saved them hundreds if not thousands before the fixed it with a compression release. DEFINATELY A WISE CHOICE!