Pcm need to be tuned for 1.6 RR's?

[paxton350]

just picked up a set of comp magnum 1.6 rr's... does the pcm need to be tuned for these i mean im sending it out anyways to pcm forless for a bunch of other things but should i make mention of these too? what kind of gains do you think i could see on my particular setup with these? maybe 5-10hp? thanks,

-chris

[fastTa]

Yes, mention it too him. He will need to make some changes especially on the idle and PE tune.

[SteveH95Formula]

If you don't already have one I'd suggest an LT4 Knock module if you are going with 1.6 RR. They do make a bit more mechanical noise that maybe picked up by the knock sensor.

[paxton350]

Yes i do have an lt4 knock Steve. For the install on the rockers are you supposed to bring each cylinder to TDC by turning the balancer then go zero lash an half a turn back? also how do you know when each cylinder is at TDC i know when #1 because of the mark on the balancer... am i just going to have to judge the pushrod/rocker height of each cylinder? thanks



-chris

[Kevin - Blown 95 TA]

They fire at 90 degree intervals and the firing order is 18436572. Just remember, it's OK to adjust the exhaust valves when intake valves are just closing, adjust the intakes when the exhaust valves are just opening. there's methods of doing a bunch of valves at once, but doing them individually keeps you out of trouble. Doing them while they're running is better, but it can make a mess unless you can keep the oil contained.

[fastTa]

Yes i do have an lt4 knock Steve. For the install on the rockers are you supposed to bring each cylinder to TDC by turning the balancer then go zero lash an half a turn back? also how do you know when each cylinder is at TDC i know when #1 because of the mark on the balancer... am i just going to have to judge the pushrod/rocker height of each cylinder? thanks



-chris

You don't neccesarily need to have each cylinder at TDC, you just want both lifters to be on the base circle(heel) of the camshaft so that both the intake and exhaust valve are closed. When you are bumping the motor over or turning by hand, you will see the exhaust valve open and then the intake valve open. Right after they both close, both the I and E will be on the heel of the cam. Now you R&R the rocker arm on that cylinder. For now on each cylinder's rockers, just tighten down the adjuster nut until you cannot spin the pushrod anymore.

You can start with #1 at TDC then turn the crank 90 degrees then do #8, then repeat through the rest of the firing order(18436572), but it is easier to do it the way I described above.

Once you have all the rockers snugged, now you can set the pre-load. You can do this without the motor running and it will appear to work out OK, but it will NOT yield as accurate a result for setting proper pre-load as if you have the motor idling to obtain working oil pressure to keep the lifter properly pumped up in order to find an accurate zero lash. Trust me, don't let anyone tell you otherwise.

The adjuster nuts are 5/8". With both valvecovers both still off, go ahead and start the motor and allow it to idle for about 30 seconds. Now starting with #1 and then working your way around(doesn't matter where you start), back off on the adjuster nut just until the point where you hear the pushrod making contact with the rocker arm and then slowly re-tighten the adjuster nut until the rocker quiets down. You are now at zero lash. Take not of where your ratchet handle is oriented. Now tighten the adjuster nut another 135-140 degrees.

As long as you don't rev the motor, you won't get hardly any oil anywhere. If you get a little on the manifolds, spray them off with carb cleaner.