Box Stock

thoughts on a cam grind

subbietjw said:
I could do a 3 angle valve on the lath.. That should help at the low lift area?
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You can modify the valve on the lathe, the seat will require at the very least individual angle cutters but better yet a system that allows you to machine a radius as well as angles ( i.e. serdi, newen, dcm etc). The flow bench is a vital tool here as there is no hard/fast rules and the port design tends to dictate the seat geometry. When I develop a valve/seat set I used a 2 piece valve with a removeable head for easy modification, and I might go through 25-30 iterations before nailing the geometry down. The short turn should have a fairly flat floor for the best low and mid lift flow ( D shape ). Size your intake throat for about 200-225 ft/sec mean port velocity at about 500 rpm below your max track rpm.
 
Because I'm pore an work for a job shop machine shop I'd just have to set it up on the lath an see what looks good... But I could lap the valve an seat with some dicam an see what I have to work with... A more layed back angle should allow more threw at low lift.. An leave the standard area there.. I think it's what a 45*
 
To do the valve... The only way I could do the seat here it would have to go into a cnc mill.. But the valve I can do
 
alvin l nunley said:
"EASILY"? That's the tough part, now isn't it. I'll be real interested in seeing how others approach that. I think I could come up with a couple of methods, but none of them would be easy.
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I'm bored too Al. I thought the whole system had crashed for a couple of hours this afternoon. I kept refreshing. Nothing. I thought about getting on this running nascar thread and asking who the heck is Joe E to get a response. I haven't kept up and really don't know. Abilities and knowledge runs the gamut here. I've cranked a few handles and pushed a few buttons but you just never know what is what here. Take Care...:)
 
To the original poster. There is power to be had in all the high tech tools like flow benches and countless hours of experimentation but the majority of power can be had from simple common sense. Trust yourself. Work your valve down, do what you can to enlarge your seat ID and go from there. It sounds like you have the equipment you need at your disposal but don't over think it and make it more of a chore than a pleasure. Keep thinking and trying new things. None of us has all the answers, even if we try to pretend we do. Take Care and have fun.
 
subbietjw said:
Even with the black mamba Jr I have now. I think the 37 lbs springs would be a better fit over the 26lbs springs isky calls for... In my build the cam will run 6500-6700 but the springs go soft after 2 or 3 days..
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Something is wrong then. I run 26lb springs for a long time, turning 8400..with a mamba cam.
 
M.D.racing said:
To the original poster. There is power to be had in all the high tech tools like flow benches and countless hours of experimentation but the majority of power can be had from simple common sense. Trust yourself. Work your valve down, do what you can to enlarge your seat ID and go from there. It sounds like you have the equipment you need at your disposal but don't over think it and make it more of a chore than a pleasure. Keep thinking and trying new things. None of us has all the answers, even if we try to pretend we do. Take Care and have fun.
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Since when is developing a race engine a chore????? :)
 
makoman1860 said:
Since when is developing a race engine a chore????? :)
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I know it should never be a chore. I've just seen many dwell so intently on the dark secrets(real or not) that they forget to have fun as they try new things and learn. Frustration takes many out. My post wasn't directed at you. You sound like you are in real deep in the knowledge pool. Take Care.
 
I get what you are saying. I think the frustration comes in more when you cant measure what you have done. Trying to develop a race engine without tools like a dyno or a flowbench or good software is about as frustrating as it gets, mainly because you dont know if what you did helped or hurt. Luckily there are those that do have access to that equipment and usually if they are really at the top of the ladder they will freely tell you all they and the industry have learned about a specific application. I think they do this because they have nothing to prove anymore, and its literally just fun to them. Of course you have to weed out the industry and field professionals from the "internet experts"..............
 
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