Reply With QuoteWithout flow numbers it's hard to select the cam you want. If you can come up with even comparative numbers, it would help, otherwise, you're just guessing. Chris Straub is the guy to talk to about selecting the cam.
I am looking for help on picking out a cam for my 421.
65 421 ~ 60 over so 433 ci. 9.78 to 1 comp 750 dp( coming soon) 1.92 in take, 1.66 ex. 1.65 to 1 harland roler rockers. its going into a jet boat with aggressor bronze 1.5a ( will probly be cut down to A but still free impeller is a free impler) orignal torker edelbrock intake.(or should I go to a duel plane?) blue printed and balanced. nicson logs with elbows What I am looking for is something that will be able to pull a skier np and still give me a good ammount of top end. I have been looking at the comp cams spec sheets--all that did was give me way too many choices :hammerhead: from what I have been told by some old time poncho guys that the motor will make between 400-450.
here is the spec sheet.
http://www.compcams.com/Technical/Cu...ML/210-217.asp
or should I give comp cams a call and have them make me a custom cam????? its really not that much more vs 1 of thier stock cams ( unless you go wild)
Any help you can give me would be most helpfull. heads are going to the machine shop moday. They should be back end of the week or earily the fallowing.
Without flow numbers it's hard to select the cam you want. If you can come up with even comparative numbers, it would help, otherwise, you're just guessing. Chris Straub is the guy to talk to about selecting the cam.
I have some #s that are are from a pontiac mag that may or may not be close. They might be helpful.
Lift int flow ex flow
.100 63 35
.200 111 66
.300 136 85
.400 142 98
.500 145 106
.600 149 110
those # came a page I ripped of of a mag some where for a 65 389 gto or 421 ho(mine)
assuming that the tests were done by some 1 that knew what they were doing and all the heads are very close they should be "close" pretty much all of the 62-65 heads had close flow #s. other then the SDin 63. in 66-69 they went to larger vavles so the #s went up. atleast according to the page I have.
Is that helpful??
Based off what you have posted your going to need something around a 12 degree split at .050". To feed 433 CID those flow numbers are terrible. Camshaft wise it will need a pretty good size stick to make this thing work.
Look at an Erson TQ-50. Ran one in my 455 Pontiac with logs for a while and it worked well. It is somewhat patterned after some of those OLDS jet boat cams. Interested why you have chosen the 1.65 ratio rocker arms. M/T
Sure miss my SWTD......
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