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Did I fint TDC right? need asap for pump timing

2K views 20 replies 6 participants last post by  GAmes 
#1 ·
after doing many searches for the best way (without specialty tools) to find the engine's TDC I found and used Rbratby's (forum member) method which consists of
I use the valve drop method. Remove valve cover #1. Break the nut loose on the intake valve. Turn the set screw down 2-3 turns. Bar the engine over until the piston contacts the valve. Be careful on that step so you don't bend the valve. Mark you vibration dampener. Bar the engine over in the other direction until it contacts the piston again. Mark the dampener again. Measure the distance between the 2 marks. Take half the distance and mark it. That is tdc. Loosen the set screw so you can bar the engine over to the compression stroke and not contact the valve
I just finished it and just wondering if I found the center between those two points correctly. Would TDC be between the two points the long way or short way? One section between the marks is about 215* on the dampener and the other is 145* (approximate).
 
#3 ·
X2 on 180* for TDC. That is TDC on exhaust (overlap). You gotta spin the engine over 360* to get on TDC compression. Then your set on engine timing.
 
#4 · (Edited)
There is a chance that the cam has pushed the valve down the way you did it.

I pull #1 valve cover and turn the motor over backwards till I see #1 intake valve opening, then I loosen the exhaust valve adjuster and tighten it down to zero lash and give it 2 ½ turns or rounds. Then I turn the motor over in the normal rotation till the piston tags the valve, with a TDC pointer in place and pointing to the damper I make a mark on it. Then I loosen the exhaust valve and turn the motor say ¼ turn past the first mark going in the normal rotation. Then I tighten the exhaust valve adjuster the same amount as I did the first time so the relation is the same, once this is done I turn the motor over backwards via the alternator till the piston hits the valve once again. Now I make another mark as I did the first time. What I did was find a relationship between either sides of the upstroke, now with the two marks made I measure the distance and divide it, that is TDC.
 
#5 ·
THIS is how you find TDC right here! :thumbsup:

There is a chance that the cam has pushed the valve down the way you did it.

I pull #1 valve cover and turn the motor over backwards till I see #1 intake valve opening, then I loosen the exhaust valve adjuster and tighten it down to zero lash and give it 2 ½ turns or rounds. Then I turn the motor over in the normal rotation till the piston tags the valve, with a TDC pointer in place and pointing to the balancer I make a mark on it. Then I loosen the exhaust valve and turn the motor say ¼ turn past the first mark going in the normal rotation. Then I tighten the exhaust valve adjuster the same amount as I did the first time so the relation is the same, once this is done I turn the motor over backwards via the alternator till the piston hits the valve once again. Now I make another mark as I did the first time. What I did was find a relationship between either sides of the upstroke, now with the two marks made I measure the distance and divide it, that is TDC.
 
#6 ·
From your post I understand how the cam could have negatively affected my results (not how, more like why, I saw the push rod move it I just didn't realize it mattered [read: idiot]).
I'm just confused by what you mean when you say to loosen the exhaust valve adjuster and then tighten it down to zero. Is that what I did earlier when I broke the nut loose to be able to adjust the set screw? and when you say 2.5 turns on the exhaust side do you mean to cw or ccw?

I get what you are saying just don't quite understand how to apply it...
 
#9 ·
I'm just confused by what you mean when you say to loosen the exhaust valve adjuster and then tighten it down to zero. Is that what I did earlier when I broke the nut loose to be able to adjust the set screw? and when you say 2.5 turns on the exhaust side do you mean to cw or ccw?

I get what you are saying just don't quite understand how to apply it...
Loosen the nut and take the .020 (or whatever you really have) lash from the rocker, IOW snug to the top of the valve. Make a mental note (or mark) where the slot in the adjustment screw is. Tighten it (CW) 2 1/2 turns. I do the procedure twice for verification. I use a piece of 1 inch wide masking tape on the damper for the marks. Once I have verified the exact TDC I paint a reference mark on the ESS and the damper with a fine tipped brush. You will need that during the timing process. Do you need those instructions?
 
#10 ·
if you just leave the adjuster down without backing it off and rotating the engine so that it arrives back on the base circle, your'e likely to have piston to valve contact while the cam is lifting, and your piston will be stopping at a different height.

you want to pick an arbitrary piston height which is done by dropping the valve 2 turns or 3 turns. then the center point between those two marks on the balancer will be about as close to TDC as you're going to be able to achieve :cool:
 
#12 ·
That is just great man! thank you tons. I read your first reply and had questions but your following posts cleared it all up. I'm finding TDC so I can properly time my pump. I really appreciate the input.
 
#13 ·
if i take my pump to TDC and my motor to TDC will it really be 0* timing?
I really am sorry if it seems like I'm asking a lot of stupid questions. I'm just tired of working on my only mode of transportation for two weeks and broke after all of it.
everyone told me when I bought the truck that I was buying a mistake but I loved it. I still love it despite what everyone says about it being out of commission. I love it, but I just can't handle much more.
 
#14 ·
if i take my pump to TDC and my motor to TDC will it really be 0* timing?
The IP pin is a timing pin, not a TDC pin. In other words, with it engaged it will be a stock timing for that pump. You really need to invest $30 in a factory service manual.
 
#17 ·
for its intended use, the geartrain pin is accurate enough. I hear ya on the pump plug though, that thing is a bytch to deal with on these dodges. much easier to work with on an industrial app where you can actually see WTF is goin on!
 
#18 ·
Russian. There are two TDC's one on valve overlap and one on compression. The valve drop method is to find TDC on valve overlap, you'll need to spin the engine another 360* to get it to compression, which is what your IP is timed to.

I didnt see anyone mention that? Though id throw that out there.
 
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