engine help

[jdf]

hey guy's here is what the better half gave to play with 489 here what's in it
10.5 to 1 forged piston
steel crank
eagle rods
pro 1 alum. 315 heads
com cam 612.612 lift 252 262 110 lobe this cam was ground for nos
tunnel ram 2 hdp 850's
msd ing
18 gears in the box
11.25x 15 prop
what do you guys think and what would you change

[Carnivalride]

hey guy's here is what the better half gave to play with 489 here what's in it
10.5 to 1 forged piston
steel crank
eagle rods
pro 1 alum. 315 heads
com cam 612.612 lift 252 262 110 lobe this cam was ground for nos
tunnel ram 2 hdp 850's
msd ing
18 gears in the box
11.25x 15 prop
what do you guys think and what would you change
What kind of boat is it for, flat, runner, semi-v? How heavy, whats the intended use?

[beaverfab]

With 18 gears and 15 pitch prop you should turn 7,000 + you might need more gear or prop. just my .05$ j.j. My cole with LS7 2-4's 16 pitch 18 gears 6800 rpm 84-86 mph. :supp:

[jdf]

sorry it's going in a 5/8 runner 78 dimarco it had a ls 6 motor and it turned around 6800 at about 90

[MandDPerformance]

Turn it 7000+. you will probably be over carbureted on the low end but she will have plenty to rev. i hope you have decent valve spring pressure. roller cam or flat tappet?
What would I change. Probably the prop. 11x15 or 11x16.
What kind of gas you plan on running? This will greatly affect the timing you can run. This can actually result in 25 plus horsepower.

[jdf]

Turn it 7000+. you will probably be over carbureted on the low end but she will have plenty to rev. i hope you have decent valve spring pressure. roller cam or flat tappet?
What would I change. Probably the prop. 11x15 or 11x16.
What kind of gas you plan on running? This will greatly affect the timing you can run. This can actually result in 25 plus horsepower.
hyd roller and going to run the good stuff

[MandDPerformance]

Never mind on the 7000+. Keep it under 7000 with a hyd. roller and gear it accordingly. Good gas. Set timing at around 38 to 39 full advance. It would be ideal if the dist. or mag. is locked out, "fixed".
Being a hyd. roller with those big carbs. I'm going to say you're over carbed all around. You can make them work but better performance can be had with smaller carbs. You will never get to the RPM range with that cam to benefit from the size of your carbs. This is mainly because Hyd. lifters require a much lighter valve spring to work properly which in turn means valve float at a much lower rpm. My $.02.

[jdf]

thanks for the help ..as for the cam that's what i have now, it had isky z-89
soild lift