Cam choice help
#13
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Just found the original spec's for the cam that was in the motor.
Duration @.050; Intake .234* /Exhaust .238*
Lift;Intake .271 / Exhaust .282
With 1.7 rockers isnt that (?) Lift; Intake .461 / Exhaust .479
Duration @.050; Intake .234* /Exhaust .238*
Lift;Intake .271 / Exhaust .282
With 1.7 rockers isnt that (?) Lift; Intake .461 / Exhaust .479
Last edited by f_inscreenname; 12-24-2006 at 03:44 PM.
#14
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Location: claymont, DE, USA
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For nat. asp motor, a 110 LSA is ok in the 218 range. When you get in the 220's a 112, 230's and higher you need a 114.
Now, that statement is very general. The biggest thing to worry about is valve overlap vs water in the exhaust, because LSA and duration directly affect overlap. If water in the exhaust is not an issue, then you run a cam that gives peak performance and that will let you idle at the dock.
So just because you have wet pipes doesnt mean you must have a 114 LSA. Just to give some ridiculous examples; Crane cams 964021 has a 110.5 LSA but both the intake and exhaust valves are closed for 23.5 degrees of crank rotation. How? Duration is only a 192/203.
On the other hand I run a Lunati cam thats a 252/263 114 the valves are open for 29.5 degrees of crank rotation. I wouldn't dare put that in anything but "dry" pipes.
Oh, and just for the record, a 109 intake centerline is very popular. Usually is a good all around install.
DAVE
Now, that statement is very general. The biggest thing to worry about is valve overlap vs water in the exhaust, because LSA and duration directly affect overlap. If water in the exhaust is not an issue, then you run a cam that gives peak performance and that will let you idle at the dock.
So just because you have wet pipes doesnt mean you must have a 114 LSA. Just to give some ridiculous examples; Crane cams 964021 has a 110.5 LSA but both the intake and exhaust valves are closed for 23.5 degrees of crank rotation. How? Duration is only a 192/203.
On the other hand I run a Lunati cam thats a 252/263 114 the valves are open for 29.5 degrees of crank rotation. I wouldn't dare put that in anything but "dry" pipes.
Oh, and just for the record, a 109 intake centerline is very popular. Usually is a good all around install.
DAVE
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I used the 230/544/109(lunati#LUN-00024LK from summit racing $136.88 with lifters) cam in a 454 oval port open chamber flat top cast pistons motor that came from a 1974 car.Very low compression motor,maybe 8.0 to 1.With it I used a weiand single plane xcelerator intake,750 vacume out of the box holly, basset wet headers and new rings and bearings.It pushed a 23 daytona v-drive to exactly 80(75 with old glenwood logs) with 15 pitch prop and 1.14 gears turning 5200 rpm.Don't know if it made any power after 5200 but it did pull nice from idle on up.If it was getting water in the motor I never new it.I have no idea how much power this low performance/low $ set up made(350-400?).It was easy to drive and idled nice and strong with only a mild lope at 600.I,m not a motor man but this cam worked GREAT for me.Of course every boat and motor is different.I think this cam is a good candidate.Hope this helps