248 Camshaft install problem

[award78]

Hey guys, I just installed a s13 exhaust cam into my 95 s14 intake side and I'm having some serious problems. I marked the chain and gears and installed the 248 cam 4 teeth CCW, I double checked. However it idles like crap and backfires sometimes. The idle oscillates between 500 and 1000 rpm. I did retard the ignition timing a bit (no timing light) but it still idles bad and shakes. Is it possible that I slipped a tooth on the lower sprocked while installing. Anybody experience this?

[98s14inaz]

It is either a tooth off or you need to advance your timing. I had a similar issue, I advanced my timing to 20* btdc and it runs like a champ now.

[trahc]

i did mine on a 93 240 sx , i replaced the timming chain at the same time seemed to minimize any problems. i do notice a slight backfire sometimes on decel or shifting. and i drilled the cam gear to try to get timming correct, but i didnt change anything on distrib im still at 15 deg +-2

[CRyan]

Does swapping around the camshaft from the S13 to the S14 KA pick up power? Or what is the purpose? Just out of curiosity - Wish I could help with your problem - but I'm really no good with upper end of engines. . .

[award78]

Is it OK to run at 20* BTDC? Will it knock worse with the 248 intake cam? I have it set at 20* but I do hear a little tapping in the head. Maybe that's normally the way the valves sound.

Oh yeah I reset all the cam timing and installed a new valve cover gasket since I didn't have the original gasket aligned properly when I put it back on and it caused an oil leak and a messed up gasket. Not sure if the bad idle was from wrong cam timing or the misaligned gasket causing a vacuum leak. Anyway it's fixed.

[award78]

Does swapping around the camshaft from the S13 to the S14 KA pick up power? Or what is the purpose? Just out of curiosity - Wish I could help with your problem - but I'm really no good with upper end of engines. . .

S13 cams (most) have 248 duration on the exhaust cam which I used to replace my 232 duration intake cam. Gains a little on the top end with not too much noticable low end torque loss if any. Not a huge gain just helps out a little in the high rpm range. KAs need all the help they can get up there. I didn't feel that much of a difference IMO, but it does feel like it continues to accel past 5500 where as before it kinda fell off.