12/2 won't start

[skeeter]

At the time of my last posts, I was getting ready to pour my engine room slab, and concrete block under engine mount. Since then, the slab and block have poured, engine (disasemmbled) was moved into engine room and mounted, room was insulated, wiring completed in house and engine room, and engine was reassembled.  After a couple of diversions recently, I finally got back on the project the last a couple of days, and set out to complete the last few details (heat exchanger/radiator installed (change from my earlier plan), fuel tank mounted and connected) and get this thing running. Well, this morning was it, but after alot of attempts, no go. Using Georges CD and site as a resource, I've rebled the fuel lines (a couple of times), to a point where I'm confident the problem isn't air in the fuel lines. Healthy "clanks" can be head from both injectors. Should I be hearing "Clank"?
  When trying to start-up near side cylinder, with fuel "paw" in down position, and decompressors under both intake valves, I cranked it up to a very healthy speed, while maintaining speed, I remove the near-side decompressor, and continue cranking through compression strokes. Smoke puffs out of exhaust after each compression stroke, but doesn't start. I tried the same with the other cylinder and noticed compression felt alot greater.
  This conceaned me, because when I was reassembling it, I found the head clearance on the far side (from crank) cylinder to be too high, about .095". This, I checked a couple of times using small lead split shots inline with piston pin, torquing head bolts to 170 lbs, then measuring thickness of lead with calipers. I removed two of the paper joint, which got the head clearance down to about .064", matching the other cylinder clearance. This seemed a little high, but at least both match. How does .064" sound to everyone?
  Now, if both clearances are equal, the cylinder compressions should be close. Can I measure cylinder compression directly, and if so, how? Sorry for my ignorance here.  I've owned other diesels (tractors), both never did much beyond normal maintenance stuff, and fuel line bleeding.
  I  was also thinking of pulling the heads and rechecking the spill timing.
  Another thing I tried was to heat up the room. When I was first trying to start it, the room was about 34 deg. F. engine temp measured about the same. Since then I've gotting the room up to 65 deg. F, engine now measures about 50 deg. F. Still no start.
Any suggestions would be welcomed.

[hotater]

Skeeter--

I've never been around a twin, but two singles should count.   

The engine IS cold at 34.  That can cause starting problems, especially if the fuel is the same low temp.  65 is much better.

Check CAM timing first and then the spill timing.  The intake valve should just start to open about 5 deg before TDC and be open .020 or so just past TDC.  If that's right, then go to spill timing.

If you have help and an a separate power source have somebody feed hair dryer air to the intake and it should fire right up.

.065 is still a little high and makes the compression low.  The distance between the top of the piston and the head should be only the thickness of the head gasket at TDC.  THats about .055"....but it should start at .065 without too much problem.

IF you're above about 4,000 feet altitude the head clearance should be minimum for best results.

[dkwflight]

Hi
Pull the intake and squirt some oil into the cylinder. This should help. You might put a squirt of gas in also.
Dennis

[skeeter]

Well, I've haven't gotton started yet, but I think I found and rectified one problem. I adjusted the values the other night in very low light conditions. My wife came in and commented that she had no idea how I could see anything. I engaged my selective hearing and continued what I was doing. Well, that was a mistake, because the tappets were definitely not in the lowest position when the valve were adjusted. After readjustment, cylinder compression now seems about the same, and much higher for the cylinder I was trying to start. I'm still going to check valve and spill timing, before I give it a go, since these were checked in the dark too. Thanks for the input.

[hotater]

Skeeter--
"Suddenly" finding an out of adjustment valve is a very good indicator of the cam being a tooth off.  (I was there in late Nov.!)
 Check the cam first. It'll save you a lot of time in the long run.

[xyzer]

If a cam tooth is off be careful when you turn it over the first time. Off a tooth in one direction no problem just won't start. The other direction and you will get valve piston interferance..at least I did on my 6/1..so crank slowely the first time. Also I have found that bleeding the air out of the fuel system the first time in my opinion is a science in itself. It is like those little bubbles like to stick to things! I'll see in a bit here when I bleed my kit 6/1...maybe I learned a trick or two in the past couple of years!
Dave

[cujet]

While warm air will help the engine start, keep in mind that if the engine and fuel are cold, you are fighting a battle.

One trick I have seen used is to put a light bulb of fairly high wattage under the crankcase. I know it sounds crazy, but over time, this will warm the eng. Especially if the engine is covered in a blanket. An old cold weather aircraft engine trick.

Chris

[skeeter]

Hello everyone. Thanks for the input. Couldn't do anything this weekend due to a last minute little trip this weekend. I'll be at it first thing tomorrow morning. I'll keep you all informed of what happens. Thanks again.

[hotater]

this will warm the eng. Especially if the engine is covered in a blanket. An old cold weather aircraft engine trick.

I thought that was a backyard save the Orange tree trick..

Hey Skeeter, you owe us all a beer for keeping us waiting... tap tap tap.......and posting a delay instead of a smoke report.   

[fattywagonman]

If you have smoke you're getting fuel.. could be timing... listen for the injector and make sure it's right befor TDC. When it's really cold I use a propane torch to heat up the injector and warm up the intake manifold... this usually does the trick...

[skeeter]

Yesterday, it came to life. I had pulled heads and rechecked TDC marks, then verified cam timing was correct. Spill timing for the crank side cylinder was retarded by about 10 degrees, reset to 20 deg. BTDC. Far side spill timing was set properly. Also learned that clearing the air out of the fuel lines is not as straightforward as I though. After running for about 30- 40 minutes and roughing in linkage adjustments, I concluded that I have some optimization to do on the governor spring/ fuel rack linkage, since I'm getting around a 5 - 6 hz difference from no load to about 3/4 load. Today, I'm going to spend time runing it and getting it tweaked.

[hotater]

Congrats!!

Governors do a good job in a limited range.  My engine starts out about 21 rpm too high, but once the load is applied it'll stay within one hz of 60 as various household loads are put on.

[skeeter]

Well, I ran "Big Green" for a total of 2 1/2 - 3 hours yesterday. Spent a little time re-polishing governor/ fuel pump linkage, re-adjusting linkage to match cylinder exhaust temps, evaluated load regulation and cooling system. From yesterdays experience, I'm getting a better idea on what I have to do to get it ready for regular operation. One observation concerns starting. Although I'm able to start it fairly easily, it doesn't always start on the first or second compression stroke always. Sometimes it requires a few cranking tries. Earlier in this thread, I mentioned that I had to remove some of the paper joints to get the head clearance down to around .065". The optimum, I take it, is around .050". My altitude here is at 1800 ft. . The temps here during a normal winter (this isn't one of them) will amost always be below freezing, and not too rare to be below zero. For this year, yesterday was a cold day, topping out at 24 deg., while the engine room was 45 deg. or higher.  I know I'm going to have to install glow plug(s), or circulate heated water through it before starting on cold days. Having said that, I'm starting to think that the high head clearance mentioned earlier, is making it a little harder to start then it should. What does everyone think. Is it worth draining coolant and pulling the heads and cylinders? Will I gain anything by removing one more paper joint, resulting in the head clearance going down to about .050". Is it worth the effort.

Observations - Once it reached its operating temp (coolant 195 deg.) it seem to settle into a very rhythmic, steady operation with constant load, almost trance inducing. When warming up their seems to be slight variation in speed and rhythm, causing speed changes, resulting in a couple of hertz "drift". Does this operation seem normal. Overall, load regulation, from noload to full, is about 7 hertz. I suspect I can run with this, but from post here, maybe I can improve this by changing/ modifing spring.
It was slightly "swetting" oil from under one of the decompressors, and the fuel tank (temporary at best) that came with it, more then leaks a little. Fuel filter showed no leaking. Also, found out that engine mounting bolts need to be "tight". Purposely left them loose to see the bounce amplitude. Just kidding on the last part.

Things I feel I need to do immediately are:

1.  Change out fuel tank to install two boat or RV poly tanks, one smaller for diesel, second larger for WVO.
2. Install permanent exhaust system (tested with makeshift out the window). Plan to use y pipe into surplus chevy surburban muffler, then exit out wall and steel siding with double wall vent pipe outlet, then up above roofline line to cap.
3. Improve air flow thru radiator with fan, or (pipedream) mounting in a tilt position to improve convection airflow.
4. Implement fuel heat exchanging, I have a fuel part, a couple of ideas, but nothing concrete.

That's about it. Any comments, opinions, or ideas are welcome.
 

[rmchambers]

sounds like you're well on your way Skeeter.

The fuel tanks on these engines are renowned to be leaky so getting a poly tank or two is your best bet and holds more fuel anyway.

I think there's an O-ring or copper washer in the decompressor mechanism, although I don't quite understand why it would want to leak or sweat oil out unless it's wicking some oil out from the inside.  You will have to keep an eye on it and if it gets worse take the thing apart and see where it's coming from and make remediations for it.

Are you planning on using the engine heat in the house or shed or you just need to get rid of it to keep the engine happy?

I've seen some nice simple arrangements of copper tubing wrapped around the exhaust pipe several times and from there to the filter or injector, once the engine was up to temp and you swapped fuels, that should help warm the WVO up to a nice flowable temperature for injection.

Did fine tuning and polishing the governor parts and linkages cut down on the hunting?  it would make sense that parts that work smoothly would keep a finer tolerance on the RPM rather than rough stuff that you have to overcome friction to get moving and once that happens it makes too much of an adjustment one way or the other and the result is hunting for RPM.

Anyway sounds good what you're doing.  Good luck with it.

[skeeter]

rmchambers  -  I was a little surprise too, from under the decompressor, seems like one of the least likely places to leak. It kind of defies gravity. 

Long term, I'm going to run isolated pipe to my workroom/ office part of the house and install a hot water baseboard heating loop, and maybe run a second line out to the pool to heat it in the summer (keep on my wifes good side). After observing this little "heater" yesterday, I believe its worth while. For now, I just want to keep the engine happy.

Regarding the copper tubing around the exhaust, is this a second, independent, coolant fluid loop, or a tee off the engine coolant system?

Regarding re-polishing the linkage, I didn't notice that much, if any change in hunting. But keep in mind that I had polished these up when I first took it apart. What I did yesterday was to check and touch up, because of what I observed a couple of days ago. I think now, the improvements will come from either optimizing the spring, or maybe modifing/ changing the linkage arrangement. To be honest, at this point I just want to put this thing to work for awhile, and not mess with it too much, if I don't have too.

Thanks for the post.