View Full Version : Timing by ear
Since I don't have a timing pointer, I'm going to have to time this by ear. She starts very easy, cold or warm, with only a single battery. When she is cold, she makes a powerstroke seem quiet. It does quiet down slightly when it gets warmed up. I did find that my cold start temp switch is bad and it was keeping the cold advance energized all the time. When it is warmed up, I can run it up to 1400RPM and I do notice a change in the rattle when I energize the cold advance, so I think I'm close. I just think it is very noisy for a 6.5. I was thinking about retarding it by a degree and see what happens.
I have not had it on the road yet - still wrapping up some small details before she is ready to drive. If I rev it (mash the pedal) I get a little bit of smoke, more gray than black.
Exhaust stays very cool, but that may be due to the ceramic coating. I can let it idle and get up to full operating temp and I can still touch the manifolds without getting burned - don't get me wrong, they are hot, but not hot enough to cause any skin damage if I touch them.
Thoughts?
I would make an effort to get your little beastie timed right.
You can get away with the WAG method for a start up and initial run in.
The engine can suffer if you run too much advance.
You need to get the sucker timed with a meter
As I understand it, a meter still needs a timing tab. By the time I realized that I had no tab, the engine was already in. I figured that I would get one from GM and bolt it on - that is when I found that they were adjustable. Short of pulling a head, there is no way for me to find true TDC so that I can install the tab in the correct position.
From discussions in the past, it seems that everyone is timed slightly different anyway, and the best setting is determined more by sound and driveability than anything else.
Hmm it would seem that you are caught between a rock and a hard place.
Looks like at least for now you are going to have to use the seat of the pants method.
The best thing I can offer is you should notice a marked difference in the cackle when the cold advance is unplugged.
If its all warmed up and the CCA has shut off and it still makes a powerstroke sound tame its a good bet you are a tad too far :0)
Robyn
You could also try removing the #1 injector and sliding a thin , long screwdriver down thru the precup slot . As you rotate the crank , the screwdriver will raise or lower . When the piston gets to the top of the bore , the screwdriver will slow down or start to lower indicating TDC . I would remove all the glow plugs and try this slowly to make sure the screwdriver does not get bent .
You could also try removing the #1 injector and sliding a thin , long screwdriver down thru the precup slot . As you rotate the crank , the screwdriver will raise or lower . When the piston gets to the top of the bore , the screwdriver will slow down or start to lower indicating TDC . I would remove all the glow plugs and try this slowly to make sure the screwdriver does not get bent .
That would not be accurate enough. The crank can move several degrees at TDC without the piston moving enough to feel the screwdriver move. Even when checking TDC with a dial indicator you do not try to find where the piston is at the top of the stroke - you go .020 or so on each side of TDC and the center of that reading is true TDC. I'm seriously considering purchasing a dial indicator with a loooonnnnngggggg pin to give this a try. The question is whether or not I would be able to get something into the injector hole and through the precup slot and onto the piston.
Robyn - I do get a difference in the rattle when I energize the cold advance, so I know I'm close. I'm going to pull it back by a degree this weekend and see how that affects it.
Ok , then how about this . Pull the pushrods out of the #1 cylinder and use something to keep either valve open slightly . This will be your piston stop . Rotate the crankshaft as you have stated and divide by 2 to get TDC .
Hi, I am new here but I was thinking about this and it seems you could do the following if you are careful. I may be way off here as I have no real experience with a 6.2 in particular, but here goes. Remove the #1 GP and get close to TDC, just somewhat. pressurize the #1 cyl through the GP hole using compressed air. Remove either valve spring and place an o-ring in the keeper slot on the valve to make sure it doesn't get dropped if for some reason the engine moves. Remove the compressed air from the cyl and place a dial indicator on the valve tip as the valve rests on the piston crown. Then maybe find TDC using the split the diff method described by a previous poster. Reinstall valve spring with compressed air applied etc.
moondoggie
02-19-2007, 15:14
Good Day!
If it rattles like a PS, you're too advanced. Retard until you start getting white smoke on a cold start, then advance back a little.
GET IT TIMED PROPERLY ASAP!
Blessings!
arveetek
02-20-2007, 08:15
I wouldn't bother with trying to install a timing tab. I finally gave up using a meter and set it be ear, seat of the pants, and the boost and egt guages. The diesel rattle should be fairly quiet when the engine is warmed up. Mine rattles a lot when cold with the cold advance energized.
Casey
mstockton
02-22-2007, 22:13
I am without a meter for mine, and I had to time it by the seat of the pants method. I retarded the timing until it started smoking white at idle, then advanced it till it just stops, still may be a bit retarded, but better than it being too far advanced at hurting the engine i figure. Runs great, as soon as I get the rpm up all the rattle disappears, its only rattles at idle, and not near so much as it used to. Running down the highway all I can hear really is the song my 35" muds play.
Timing will definitely get done today. I have not done anything more than pull it in and out of the garage - I know how bad things can be with timing that is too far advanced.
Great info here everyone. Thank you!! I should be able to make my maiden voyage around the block today.
Well, did some adjustments and it is much quieter than it was before. No smoke on cold start though. I started with the lines exactly matched, and now the pump is about 1/8" to the passenger side. I have the cold advance disconnected due to the faulty switch, and it fires up instantly even when cold. I took it out for a quick drive and it absolutely love it. The power is awesome. It was dark and no other cars so I could not see how much smoke I was blowing, if any. A quick 0-70 run got me to 11psi in 1st and 2nd gear, and EGT got up to about 700. 3rd gear boost was still climbing when I realized how fast I was going and I backed out. I am not going to have a problem accelerating to get onto the freeway!
I think I'm going to leave the timing where it is for now. They smog test here in AZ. I might be a little advanced right now, and I would rather have it tested with it advanced.
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