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twistedjack

changing valve springs??

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I am in the process of installing a 4" inline pacbrake I bought off ebay. I got the inline style since twins are in the near future. Anyway the question is I am finding conflicting information on the proper procedure to swap the valve springs. Last thing I want to do is drop a valve. So how do you tell you are at TDC and not BDC before I break things loose? Cause unless I am mistaken both valves can be closed at the bottom of the compession stroke on its way up to fire. BD and pacbrake have diffrent instructions, I have read that one procedure is wrong as well as the re-torque procedure so what is the RIGHT way to do this:wall:

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the way I DO IT i LOCATE no. 1 tdc. then chang e no 1 spring. then I follow the firing order (153624) next compress no. 5 ex. valve w/your spring compressor,don't remove keepers yet. valve will drop down , then turn engine clockwise w/ barring tool 60 degrees or untill valve raises to max. now you can change that spring and go to no.3 and so on. 60 degrees times 6 is 360 degrees,one complete revolution. hope I did'nt confuse you more than you already were. Harold

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Hey Harold,

How do YOU re-torque the head bolt? Some procedures say 90ft-lbs then 90 degrees.....YIKES others say just re-torque to 120 ft lbs. What do you think?

Edited by MUDDY

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I'm not Harold but when I re-torqued my studs I was told by Pat @ Big Twin to do in increments. I started 50-100-125x2-150. Although bolts will be different then studs. I have always heard/done increments.

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I agree with Harold! Only thing I might add is like when you first go to say #5 and turn it 60 degrees to get the piston to push the valve shut; make sure you do both valves on #5 while you are there (I read it fast but I think that might not be in there and I can see a guy missing it when he is in the thick of it!).

Are you working on your '94? If so, I have the FSM for a '93 and could look up the procedure for you if you like. It should be the same for a '94 I would think. (We need to add all the FSM's to our 'arsenal'!)

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the way I DO IT i LOCATE no. 1 tdc. then chang e no 1 spring. then I follow the firing order (153624) next compress no. 5 ex. valve w/your spring compressor,don't remove keepers yet. valve will drop down , then turn engine clockwise w/ barring tool 60 degrees or untill valve raises to max. now you can change that spring and go to no.3 and so on. 60 degrees times 6 is 360 degrees,one complete revolution. hope I did'nt confuse you more than you already were. Harold

ditto, fastest, easiest way I've found to do it...also, any and all cylinder head initial torque or retorque must be done in increments. Final torques on everything I've seen as far as heads go has been a 90 degree turn. But then again, those were initial torques, not a retorque. I can't imagine a 90 degree turn being wise on a retorque unless bolts have been backed way off....Just my opinion.

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