79centurion
06-27-2007, 11:10 PM
Well the 468 is all in and the cam is broken in. I took mine out yesterday to break in the new motor in the picklefork. I went from a pump gas 9.5:1 396 to a 12:1 468. The 468 has a smaller cam(it was for my chevelle, but since I sold the car and the 396 blew up it worked out to go it the boat:D ) but it is way quicker now. The old motor pulled 4,600-5,000 rpms depending on the water conditions. Ran lower rpm with smoother water. Now with smooth water it hit 5,300 rpms. I set the limited at 5,500 for break in and it hits that comming out of the hole with less than half throttle. I only has about 20 minutes on the motor so I will see what hapens after I jet it(running a little lean) and add more timing(only got 27 degress right now) and break it in a little more.
Now for the questions, how much timing do you guys normally run with high compression? This is my first high compression motor. I was thinking 32-33 degrees. In case the cam matters its a hyrolich flat tappet cam with less than .500 lift(Factory 396ci 350hp or 454ci 425hp cam pattern from crane).
Also since this motor build alot of torque and is for mostly bottom end(1500-5500 rpms) it comes out of the water real quick, but it bounced of the limiter at 5,500 alot while it was trying to holeshot. I am not sure if its cavitating or is there not enough rpms between what it runs at top end to my limiter? Basically how much higher does a motor normally rev to holeshot versus its top end? I never paid attention before this motor since the old motor was build to rev 6,200 and never got close except on the bottle.
Dan
Now for the questions, how much timing do you guys normally run with high compression? This is my first high compression motor. I was thinking 32-33 degrees. In case the cam matters its a hyrolich flat tappet cam with less than .500 lift(Factory 396ci 350hp or 454ci 425hp cam pattern from crane).
Also since this motor build alot of torque and is for mostly bottom end(1500-5500 rpms) it comes out of the water real quick, but it bounced of the limiter at 5,500 alot while it was trying to holeshot. I am not sure if its cavitating or is there not enough rpms between what it runs at top end to my limiter? Basically how much higher does a motor normally rev to holeshot versus its top end? I never paid attention before this motor since the old motor was build to rev 6,200 and never got close except on the bottle.
Dan