I have the maintenance manual and instruction for adjusting the rocker arm to valve clearances. I don't have the special turning tool but most importantly, I can't find which direction to turn the engine for adjusting the valves. When I adjusted the clearances on my boat engine, the direction of rotation was very specific. Hoping that someone can give me more info of the valve adjustment process.
The front and back cylinders are on the same "throw" and the middle two are the same, so when the front has a valve open you adjust the back valves, and when one of the middle ones has a valve open you adjust the other middle one. This applies to every inline 4 I've seen, but somebody will correct me if I'm wrong. Turn it the direction it runs, and double check all the valves with a second rotation. I always turn engines over by grabbing the belt and fan, and turning it a bit at a time, then let the compression leak down, then turn again. I suppose it's technically possible to start an engine that way, so make sure it's off, and you're not superman, and OSHA's not watching.
I'd like to see you try that on a 3412 Cat
The way I was thought years ago for engines you don't have specific spec's for is about the same but goes by "Valve Over Lap" As Demer says the cylinders are in pairs. So when both the rockers are tight for say #4 then you set the valves on #1 then when both on #3 are tight then set both on #2. If you know firing order just start with #1 and go through the order. Unless you are working on a Detroit as they do things different , but that's not a concern here huh:cool2
If it was trashed enough for me to get my mitts on it, then I'd bet I could. And, obviously you're right, that applies to inline 4 CYCLE engines, and valve overlap (TDC) is the right way to do it.
Yeh, but if it was that bad why waste time setting the valves? I know some management guy thinks that because some book says "Adjust Valves" every so many hours that will cure everything. Just because there is more smoke coming out the crankcase breather than the exhaust stack is not a reason it needs a major overhaul!:Banghead And as long as you are getting paid by the hour and the check don't bounce go for it!:salute
The engine is on the stand and I was trying to avoid installing the starter till I reinstall in the frame. Sooo ... if someone can tell me which way a 4-390 Cummins in a CASE 1840 turns, I would appreciate it. Thank you.
Clockwise. There should be a timing pen located right below the injection pump. It pins on the cam, so when falls the engine is at top center compression number one. Adjust intake and exhaust on Cly one, intake on two and exhaust on number three. Pull timing pin so tip does not break off , mark balancer and rotate engine 360 deg. Then adjust exhaust on Cly two , intake on three and intake and exhaust on four. Intake .010. Exhaust .020
Thanks for the info. Just to clarify, is that clockwise from the back, facing the fan?
Looking at balancer from front of engine. Having the rotation right normally is only ness for injection pump timing because your are taking out the gear lash. In my opinion there is not enough gear lash as the cam turn of the crank gear to affect valve adjustment.