noobie question about cams

[chmercer]

what would stop somone from swapping cams between an sr20, ca18, ka24, etc? i am just wondering what is the physical difference between these cams that makes them incompatible?

i know between sohc and dohc the sohc cam would have 2x as many lobes, but what is there to stop somone from swapping various types of dohc cams between inline 4 motors.

(i know **** about suspension and even less about motors, please forgive my noobie question )

[karay240]

The only thing that's swappable b/w the KA & the SR is the injectors. Nothing else, as far as I know, will swap over. Not exactly about the injectors on the CA, but doubtful that anything else will work either. I've heard of some shop (can't remember who) who was trying to fit the sr crank into the KA, but I have not heard anything since about it. My guess is that it didn't work. Very unfortunate IMO 'cause that would have been the ultimate motor. It'd be like a SR but w/o head and block problems. . .

[chmercer]

is it just that the camshafts between motors are physically longer or somthing is the reason they are incompatible?

[karay240]

the cylinder pitch (the distance b/w each cylider) is different as far as I know. Plus the SR uses rocker arms to activate the valves, whereas the KA & CA have direct acting cams. They're totally different motors, though

[Chingon]

i think this may be due to the displacement of the engines. 2.4l, 2.0l, and 1.8l have different travel and bore and stroke, so i'd guess the valves would have different measures.

[Hijacker]

each cam is ground differently, but it's the pitch angle amd style of activation (as mentioned earlier) that defeat the point of swapping the cams.