Reply With QuoteI would talk to an engine builder who does boat motors that use I/Os.I am pretty sure they use a different set up vs jet or light v drive.
Got my cam in the mail today.What do you guys think.How about the overlap and cam size.The cam is for a 11 to 1 comp 565" chevy going in a 22' daytna sterndrive boat.How much rpm will this idle at?What about reversion with lightning headers--water jacketed.
This is the cam card.
duration at .050 is 262-272
lobe lift-- .4100
lobe seperation--114
timing events at .050--open/close intake--19/63
open/close exhaust---72/20
seat duration at .020--296/306
gross valve lift--697-697
valve lash hot .029 intake--.030 exhaust.
This is a custom grind solid roller from bullet cams.I kept the lift down for spring life.The rockers are 1.7.Where will this cam make power at.The carb is a 1195 king demon and the intake is a brodix hv2001.
I would talk to an engine builder who does boat motors that use I/Os.I am pretty sure they use a different set up vs jet or light v drive.
I think on a bravo type drive you want it to idle under 1k no more than that
I am going to guess that cam in a 565 will peak power somewhere around 6,400 RPM maybe a bit higher. I doubt whether you will spin it that much but there are other considerations.
Some of the big name sterndrive engine builders use a cam that is bigger or peaks power higher than where it is actually used. I cannot speak for them but I think some of them do that to limit the torque a bit to save the drive. Cannot put engines out there and expect to sell a lot of them if they kill the drive instantly. Also sometimes a cam that is a bit big for the application will make more power at 5,300 RPM than a cam that peaks power at 5,300 RPM. Just for example.
As far as the selection. I would probably run a 110 or 112 LSA cam on an N/A deal but 114 will not kill you.
Are your lightnings reduced water versions? It should idle 800 -900 RPM.
They actually wanted the cam on a 112 lobe seperation but i was worried about reversion.My headers are not the dry ones.I am going to run another water dump to help get rid of the water.
The reduced water lightnings have a 1/2 NPT bung where the water enters the exhaust to dump overboard. the outlets in the exhaust stream are only 3/16" and there are only about 6 of them in each header. You might be able to do that yourself.
What cylinder head is on the boat? Cam seems big to me unless it has OEM type heads.
Chris
The heads are dart cnc ported 355 pro-1's.I would of been better off with a smaller head but this is what i already had.Dont you have a cam program?Let me know what you think it should be?Im sure i will be playing around with it some.The bore is 4.600 and stroke is 4.25".Thanks
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