HELP! Determining timing

[FWBennett]

OK SOMEBODY F#$K'ed up! Now I'm trying to determine if it's me or the engine builder. I bought a longblock from a company that builds lots of motors that I found on the internet. While swapping over my parts (oil pan, valve covers, IP pump.... I pulled off their timing chain set and installed my brand new timing GEARS! I had a BEAR of a time starting it but it FINALLY started - I ran it around the block many times and let it sit for about an hour ideling etc. Then I took it to the shop to have the IP timing set. Now take into account there was more blow-by than I was comfortable and the power was less than exciting, and it was blowing a bit more of black smoke - all this I attributed to the fact that it wasn't broken in yet. The shop set the IP timing, remaked about the blow-by and suggested turning down the IP fuel flow (I'd installed 6.5 injectors and thought maybe they flowed a bit more than the 6.2 block could consume. The shop drove it around a bit at the new fuel setting THEN it refused to start! Plugs were fine, puffs of smoke meant we had fuel, it spun fine cuz it's a new starter - FINALLY he checked the compression - he stopped after 2 cylinders one was 120# and the second was 220#.
At this point I have to take over cuz I can't afford to put his kids through college. He suggested that it might be the timing - he says he's seen them run while being 180degrees out of sync. SOOOooo the question is - did I F'up and turn the cam or crank when I had the chain off (self doubt kicks in!) or tid the builder do a lousy job? Since I'd have to pull the motor and ship it back to the builder for repair/replacement. I need to take the timing cover off - My question is - how do I tell if I've got the timing marks 180degrees out of sync? I understand that the crank turns twice for every one of the cam - how do I tell when the crank is in compression or exhaust stroke?
- Thanks so much!!!

[britannic]

To find the compression stroke:

Remove the glowplug from cylinder #1 (driver's side front), insert a cork/tissue/plug of some kind (don't push it all the way in and lose it in the chamber) and then rotate the engine until the plug is blown out (you can also use your thumb and have an assistant rotate the engine). Now #1 is on the compression stroke.

You can also remove the driver's side valve cover and rotate the engine until the valves close on #1 and the compression stroke begins.

If the timing was off 180*, it wouldn't start at all, since the valve timing isn't symetrical. Is it possible the IP pump has slipped out of adjustment on it's mounting?

The compression issue, may be stuck piston rings- sure sounds like the engine rebuilder needs to overhaul your engine under warranty.

[FWBennett]

Ahhh - thanks for the "cork"/"puff" trick - I was trying to avoid pulling the valve cover cuz ya hafta pull the intake manifold and injector lines B4 U can even get to the valve cover. Hmm stuck rings? on at least 2 cylinders? - I'll keep you posted! I take posession tomorrow. The saga continues.... I was hoping to help the Boy Scouts go on a ski trip at the end of the month - keep your fingers crossed.

[dieselbegreat]

Ah, just one more thought: If your timing gears are out of sync, you will get less compression because the valve timing will be out. Setting the IP timing to compensate will not make up for the valve timing. All cylinders will consequently be low. Is your IP aligned close to the zero mark and straight up and down or is it cocked to one side? If so, how much?

[FWBennett]

When I installed the motor the IP was just a hair to the right (passenger side) of center - it was a #$#^% to get started (took me about a week of after-work attempts)- once I got all the air worked out it would start but with more turns of the motor and with 1/4 to 1/2 throttle (not exactly ideal plus what I considered excessive blow-by) then I took it to the shop to get the IP timing set - I haven't seen the vehicle since, - I take posession tomorrow - I'll report back.

[britannic]

This setting was probably too retarded, hence the hard starting (probably exacerbated by the malfunctioning cylinders?).


Originally posted by FWBennett:
When I installed the motor the IP was just a hair to the right (passenger side) of center - it was a #$#^% to get started (took me about a week of after-work attempts)- once I got all the air worked out it would start but with more turns of the motor and with 1/4 to 1/2 throttle (not exactly ideal plus what I considered excessive blow-by) then I took it to the shop to get the IP timing set - I haven't seen the vehicle since, - I take posession tomorrow - I'll report back.

[FWBennett]

The tow truck delivered the Suburban about 2:00 yesterday. The IP was set just a hair to the driver's side (like 1 or 2 widths of the timing mark) - Yesterday I was able to get the front of the motor removed so today I get to run the cork/puff test and see if in my glee of having a new motor I lost my senses and turned the crank out of sync with the cam.... News at 11:00

[FWBennett]

OK I took the little silicone "plug" that forms when you use the nozzle and it hardens inside and you push out the formed "Plug" into the #1 glow plug hole - spun the motor several times by hand - it never popped, then I made one out of tape - same results, put my finger over the hole and turned it and didn't feel any puff - I don't know if I'm not spinning it fast enough or pressing on the hole too hard???? Anyways I thought I'd pull the gears - spin the crank 360deg.(without engaging the cam then put the gears in (therefore if it was 180deg. out it will be correct) BUT as I spun the crank it came to a stop! I'm assuming that's a valve I'm feeling.
So help me think this through - since it was bought as a long-block (heads on and pushrods etc installed) - I'm thinkin' there's no way I could have spun the crank without the cam and gotten it 180deg. out of sync B4 I put the gears on, because I would have run into a valve RIGHT???
Anybody have any ideas I should try B4 I yank this thing and ship it back?????

[arveetek]

I don't see any way that you could have gotten the gears installed in such a way as to have gotten the cam 180 degrees off. The engine never would have ran that way.

I don't think you can turn the crank over without turning the cam as well, because, as you found out, the pistons will hit the extended valves.

I can't believe that you didn't feel any compression at all, that's just amazing. Did you try any other cylinders?

I would probably reinstall the gears or chain, and then remove the valve covers to see how the valve train looks.

Another thing to do is rig up a leak down tester by putting air pressure through the glow plug hole and see where it's coming out. Both intake and exhaust valves need to be closed on this procedure, though. If you pressurize the cylinder and have air coming out the exhaust, then it's probably an exhaust valve issue. Out the intake manifold, again, probably and intake valve issue. If you have air coming out the oil filler cap or dipstick tube, then you have a cracked cylinder wall, broken piston, or broken piston rings.

Something is definitely not right that you can't get any compression. That's why I'm thinking looking at the valve train might help lead to what's going on.

Casey

[FWBennett]

OK - call me a glutton for punishment - I went at it again. Shoved one of those corn starch packing popcorn things in there - turned it and POP it "fired" when the cam gear dot and crank gear dot were at 11:00 - which is about right for the crank cuz it's approaching TDC (12:00) so I thought ah! It is out of whack! So I pulled the gear turned the crank and each time i hit a valve I'd turn the cam enough to get past it - got back to TDC - installed the gears and did the popcorn test again - it poped at the same spot again! Well did I turn the cam soo much that I'm back to where started??? So I did the crank/cam shuffle again paying strict attention this time! And the popcorn POPPED at the same spot! So I said screw it I need to see the valves - pulled the driver's side cover and watched it and it still looks good. Then I got to thinking!!! Is there such a thing as being 180deg. out? OR is that a gasoline issue? If You line up the cam dot (6:00 - straight down) with the crank at TDC 12:00 straight up to meet the cam - then the valves start in the correct spot and so is the crank - now if you rotate the crank again - so what right? it's at 12:00 TDC again and if the cam is still pointing down there's no difference RIGHT? Then you lign up the cam and IP gears and away you go!
Can somebody verify this or am I sniffing too much diesel fuel???

[dieselbegreat]

Jeepers! What does the gear manufacturer say about how the dots are supposed to line up? Do they show a picture? I sure wouldn't put it all back together again until it is verified correct. The fact that it was running already means that it was not 180 degrees out.

As far as your question: TDC on #1 has to be verified with the injection pump set to fire on that cylinder = the compression stroke. Some gear sets even have multiple keyways to adjust the timing + or - a few degrees which can be confusing. And turning the motor with pistons touching valves is just scary.

[arveetek]

The DSG Diesel Pro Dual-Idler gear drive (I'm assuming this is what you have) installation instructions call for the camshaft gear "dot" to be at the bottom, aka the 6 o'clock position, with the crankshaft gear "dot" to be at the top, aka 12 o'clock position. So, when lined up properly, the two dots should be facing each other, with the camshaft dot at the bottom, and the crankshaft dot at the top. However, if you rotate the crank one full revolution, both dots will be at the 12 o'clock position, because the crank turns twice as fast as the cam does.

Since you've got everything out of whack now, you'll need to rotate the crank to get the number one cylinder at TDC, and then rotate the camshaft to get both valves closed ready for ignition. Then install the gears with the two dots facing each other.

Casey

[dieselbegreat]

I second what arveetek says. That done, you can expect that the timing is correct. If you wanted to really verify it, you'd have to get a dial indicator and timing wheel to mechanically confirm valve timing. And a compression test should show good compression uniformly in all cylinders. Uniform low compression or widely differing readings means there's something wrong with the engine.

[Peter J. Bierman]

The popcorn launching at the same spot every time in normal couse thats when your compression stroke starts. What ever you do with the cam, you can't reposition the comp.stroke.
I do think that if you can rotate the crank with cam engaged, and don't hit any valve, your timing is not far off, there is not much room for error in the valve timing with a diesel engine.

It is however possible to have the IP drivinggear out off timing but that would not give weirt compression results, but can cause hard or no start.
But with the cover off it should be easy to see if the marks are aligned.

If you turn the engine slowly and the popcorn shoots out, I dont think you have a broken valve, usualy there is no compression left if that happens, a cracked piston or bad rings can cause low compression, mostly when cranking and building up pressure.

Good luck, Peter

[FWBennett]

I'm convinced there's something wrong with the engine and plan on shipping it back.
My only concern is "Could I have ruined the rings/cylinders" when it took soo long to get it started?"
The block heater from the old motor was gunked up and I didn't have a new one so I put the motor in without one. It took me about a week of after-work attempts - crank two or three attempts till the batteries were down then recharge overnight and go at it again the next day! Till it finally started 4 or 5 days later. With just the starter cranking - does the oil pump still circulate the oil etc?

[Peter J. Bierman]

Yes, normally the oilpump put out enough oil to have the engine lubricated at cranking speed.
The fact that it was a new engine might have caused a delay but if you cranked you battaries flat there should be pressure by the time you did that.
Next to that, a propperly build engine is lubed with special asembling lube to have the bearings protected for the first seconds.
The cylinder wall shoud have been coated with oil when the pistons got in.
If there is a severe problem with the engine, you could not have prevented it.

Peter

[dieselbegreat]

Don't fret about your cranking. The oil pressure would have come up enough to keep everything slippery. Whatever is wrong with the engine is not your fault (we hope :D ). Is your gear installation going to void any warranty with the builder when they find out?

[FWBennett]

Yes The DSG Diesel Pro Dual-Idler gear drive is what I'm using and the crank dot goes up and the cam dot goes down, just like in the picture.
When I ship it back I'll just put the timing gear/chain set back on and swap out the bolts to my girdle kit - there's nothing in the warranty that mentions add-on parts after-all There's a turbo and 6.5 inectors instead of 6.2s etc. I'm wondering if they used the correct head bolts (the problem being in the top end (head gasket?) But then there was the issue of the excessive blow-by which would indicate the bottom end OEY! I'm tired of wrenching - I should be FISHING!!!!