Do i need a new cam if i turn 5k RPM

A cam would benefit you greatly even at 4k, every bit of air you can get in there helps. I should state then when I turn 5k rpms its only coming off the line, as soon as I am under load I dont have the power or air to turn much over 4k unless its really loose. my truck seems to run best right about 3900.

and trapper, i dont have fly cut pistons, my valve springs are doing a gret job of controlling the valves at 5k so i dont smack a piston. this winter i will however end up with some flycuts and a bigger cam profile when i tear mine down for rebuild.
 
I use a stock cam I come out at 4500 and it holds 4K down the trac , I'm installing 5ks and like to come out @ 4700+ just to see what happens , I think u will b fine , your going to still have a bottle neck no matter what cam u put in it, the head will b the choke u need to look at that first then work yr way down think of it as washing a car start from the top it always looks better :)
 
The Head is a bottleneck for sure. To compensate, you can add a good bit of duration on your cam, this will help quite a bit above 4k but you will lose a little bit of bottom end. If you are not going to daily drive, and you want to open a can of whoop a$$ sled pulling, a cam will be a big part to getting the air through the engine. If you have a ported head that will help quite a bit as well.

Without a performance cam you can turn 5k if you have a bolt on retainer. You won't gain much if any benefit from doing it though. If you decide to turn the big r's, make sure you check drive pressure and keep the charger in its efficiency range down the track.

Zach
 
I left the line at 5k last weekend at Muncie and it really helped keep the rpms up after I left. This is with a stock head and cam. Was def my best pull with the p-pump so far.

Zach I saw you and sled puller down at the end of the track as I pulling off the the track. I was gonna head over there and chat with ya bout a cam for my rig but I never made it over that way.
 
Rods said:
I use a stock cam I come out at 4500 and it holds 4K down the trac , I'm installing 5ks and like to come out @ 4700+ just to see what happens , I think u will b fine , your going to still have a bottle neck no matter what cam u put in it, the head will b the choke u need to look at that first then work yr way down think of it as washing a car start from the top it always looks better :)
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Heres what 4800 rpms leaving the line with a stock cam will do.


Well that and brand new 315/75/16 BFG all terrains on a tigh stick track with a heavy set sled.:bang:bang
 

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That happend wednesday night at the Macon county fair pull. It was in my brothers truck with me driving. Sorry brother!!! The weird part was it happend at 77 ft. The tires were allready busted loose and spinning. I could see it happening if i sidesteped the clutch at them rpm's but i slipped it out to get it going. I kept asking myself is this sob going to release his breaks or not. I felt it go soft but wasnt sure what exactly happend yet and then i heard bang bang bang. I new it was time to stop then. In the video you can watch the wite letters on the tires start slowing down and then finally stop once it pulled the slip yoke apart.

on edit, we wanted the truck to hook up better. I guess we got what we wanted huh.:kick::hehe:
 
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