WMO burns hotter than diesel?

I think I'm finally making some progress on this thing. I'm reasonably sure that this timing chain has stretched a couple of links too long. I'm going to check it today when I adjust the valves.

Yesterday, I advanced the timing on the pump. I don't know where it was, nor where it is now, but I just wanted to experiment. I figured the worst that could happen is that I'd have a car that didn't run worth a crap - wait, I already have that. I moved the pump toward the block about the distance of the width of the nuts on the fuel lines - so about 17mm. I figured that would give me about 5*. I wanted 2* for the liklyhood that the chain is stretched, and another 2* for the oil I'm burning, and the extra 1* because I'm just guessing. Well, I didn't get diesel knock but it's down on power, harder to start, and the engine shuts off instantly when I shut off the key. But it also seems to be running MUCH cooler. It's hard to tell because the temperature had already cooled into the lower 80's by the time I finished and It does OK anyway when it's that cool outside.

Today, I'll adjust the valves, check the stretch on the chain, and move the pump 1/2 way back towards where it was originally.

From experience if its hazing more and harder to start its probably been retarded not advanced, My ford tractor under load ran cooler with retard timing(it lowers peak hp but torque usually isnt strongly effected), advancing it to far will cause harder starts but not as bad compared to retarding the timing. To much advance can blow a head gasket. Ive advanced one to far and in this particular diesel it started easy but didnt run healthy the idle speed lowered and it made more of a grind than a diesel clack. Keep in mind these experiences are based off a direct injection turbo charged diesel. I have no experience with idi.

You my want to research the amount of movement that pertains to degrees of timing for your peticular vehicle. 17mm is quite a bit. I would say even half of that is a lot for the ford idi's.

I know this is not the right way to do it... But I literally just stuck a magnetic dial indicator on the side of the pump and rotated it 2 degrees from where it was. The timing chain had been done about 10k ago, so I was confident no stretch was involved. Made a nice little bump it throttle response, should help mpg and burning alt fuels. Little clackier afterwards. Read that 3 degrees is the rule of thumb before headgasket becomes questionable... I figured I should play it safe since I was not using an exact method.

I marked the pump and engine right next to the easiest to access bolt holding the pump on so I had a baseline mark I could move it back to. Bumping 2 degrees by my method, it was about 1/8" or a hair less if I had to guess. 17mm is almost 3/4"!! Way to much if I had to guess...

JPhauler87, I like your method. 2* is 2* and it doesn't matter how you measure it.

What I had done was to picture a circle. If straight up was 0*, all the way to the right would be 90* (3 o'clock). Then I kept mentally dividing (45, 22.5, 10, 5) and pictured how far that would be. Then I took a punch and made a mark right in the groove between the pump and the motor. I figured that I would just have to line up the two halves of the circle if I want to put it back. As it turns out, I was looking at 3 o'clock as being 45 degrees, so I probably went twice as far as I thought I did. I'm probably 10-15*. I moved it about width of three punch marks at the block. When I started out, the idea was to move the pump while the engine was running. I had read of someone advancing the timing just until he got the "diesel knock" then backing it off a hair. I also read that, if you want to move the pump with the lines still attached, it will require "some force." I think "some force" is a phrase that means "hydraulic ram." It wouldn't budge with a crow bar.

This thing won't heat up unless I do something stupid like let it idle on WMO. I can even drive in the city on WMO and I don't have a problem all the way up to 91* ambient temp. I will back it off about 1/2 way and see what happens, but I won't be able to do anything for another week or so. I'm getting ready to go out of town for a few days.

I also checked the valves out of curiosity. I couldn't get a feeler gauge under any of them. I don't know if tight valves will make an engine overheat or not, but these are more than tight. I'll definitely have to address that.

I also found out why I lost power after advancing the timing. I got a wild hair and checked the throttle linkage. I had heard that the throttle might not open all the way on these things. I've also heard that about numerous other cars and I've never seen it happen. Well, the throttle lever was hitting the top of the pump and it was only opening about 1/2 way. From what the problem was, this thing never opened up all the way. The car is much better now.

I'll probably start with backing the pump off 1/2 way and adjusting the valves and see what happens.

OK. I'm back in town and I've done some testing and checking and this is what I've come up with:
1) pumping D2 into the take is easier than what we're doing.
2) the engine runs hotter on WMO than D2 without an increase in power
3) timing seems to be the easiest way to make the engine happy on WMO
4) cokiong will be minimal somewhere between 15% and 20% RUG (but timing is more important)
5) the engine will run at normal temperature somewhere between 20% and 50% D2
6) the engine likes city driving on WMO and hates highway driving. It will coke quickly on the highway.

I picked up one of those magnetic base angle gauges and checked the timing pump. It turns out that I had added 5* of timing. I split the difference and bumped it back to 3* to see what would happen. It coked the engine severely in one day running on WMO. I also lost about 5 mph from my top speed. Oh yeah, and part of the overheating issue started to creep back in. So today I put it back to 5* advanced and cleaned out the prechambers. I have a slight diesel knock from one of the cylinders if I am idling on D2, but I don't get it with WMO and it goes away with RPM. Power is back and I added more than 15 mph to my top speed over what it was this morning.

I had been running 15% RUG / 85% WMO and was having trouble with overheating and coking. So I increased my RUG to 20%. It seemed to help with the coking some. When I first bought the car, I was running 50% D2 / 50% WMO. I think that coked the prechambers pretty badly before I even had a chance to understand what was going on. It seems that a clean D2 tank for startup and shutdown is essential - not for "flushing" the fuel system, but to de-coke the engine. Whenever I run D2 in the city for a while, there is more power and less smoke as the prechambers clean out. Since there is no such thing as an "Italian tuneup" for a 240D (considering you're full-out at every light) It appears that the high revs and changing RPM under full load is important for de-coking. The truck guys seem to have success with 4* advanced timing and the occansional Italian tuneup when they start to smoke.

I have started adding D2 to my fuel at 20% to fight the overheating. While it has made my fuel very thin and very easy to process, it really doesn't seem to be helping much with the heat issue. More timing made a bigger difference than more D2. I plan to take care of the issue with a bigger radiator. I ordered an aluminum racing radiator that is the same size as the stock one. It will also end up being cheaper than adding more D2 in the long run. It was $120.00, or about the price of 35 gallons of D2.

So, It seems that a little timing, a good radiator, and 15%-20% RUG seem to be the keys to successful WMO,

I have a pretty good theory on the higher temps with WMO. I have two Common Rail Cummins that I run waste oil in at 70%. The radiator is huge so I don't really see a difference in Coolant temps, but there is a much higher EGT reading with WMO, along with some lost HP.

This weekend I installed one of those Vegatherm heaters inline before the injection pump, it appears to heat the WMO to about 100* before it hits the engine. This alone killed the smoke (haze) issue I was having, and dropped the EGT's 200* and put them back to where they should be. Not to mention the HP came back.

My theory is when the WMO is cold it is not burning fast enough / completely and is causing higher temps in the cylinders. With a small radiator you would see it in the coolant gauge.

I know that WMO burns slower than D2. Slower burning fuel will retard the effective timing of the engine for the same timing on the pump. Once I gave the pump 5* of advance, my problem was solved. I can tell the difference in the timing, too. I get a "diesel rattle" on D2 and it goes away when I switch to WMO. Retarded timing will heat up the best cooling system and it is a perfect explanation for why I saw instant heating of the head without any increase in power.

Any updates on the glow plug issues?

Yeah, I'm pretty sure it's the timing. I started another thread for the glow plugs. Yesterday, I finally got my new glow plugs (champions) and they don't fit. The body is too short so, by the time they seat, they're buried into the head. They might work with a thin walled socket but I just see myself inviting trouble like that.

Anyway, when I took out the old glow plug from cylinder #1, it was eaten all the way down to the body! And I haven't used any propane. I'm going to try backing 2* out of the timing today and see how the engine reacts. I'm also planning to pull one of the injectors to see how the coking is coming along.

Major point of chemistry might be overlooked here.

The carbon chain which is burned produces heat energy... if you burn No2 diesel, you get *** number of heat units [BTU's] per volume of fuel. WMO, because of it's chemical composition, has a much longer carbon chain. When it burns, if it burns completely, it will produce more heat energy [BTU's] per the same volume of fuel, compared to No2 diesel.

Injector coking in engines that burn WMO or Veggie is the residue from incomplete combustion, which translates to mean the combustion temps or oxygen supply is not sufficient to burn all the available carbon in the fuel.

Heat is what you want to produce power. Controlled heat is what you want to preserve engine life. It is a balance act that is played out every time you start an engine.

Thanks G. Mann, but It's not being overlooked. One of the results of burning the longer carbon chains is a slower burn rate, which was covered in post #38. There are also additives and such in WMO that you don't find in D2. After all, they DON'T want that stuff to be able to burn. It;s not just carbon that was coking in the prechambers. It was also something white. And carbon isn't white. Advanced timing solved the issues with it.

I backed the timing off to 3* and the car is running better and the heat issues don't seem to be creeping up like I was afraid they would. There are other issues with the car, though. I'll cover that in a bit... I pulled the injectors and there was no sign of the coking that was there a couple of weeks ago. Timing seems to have fixed it. 5* is too far. 3* seems to be working for now. We've had some cold fronts so the temps are down in the 80's, so I'm not sure what it will do on a warm day.

I've hurt cylinder #1. It has 80 psi of compression, the valves are still in adjustment, there is a bunch of unburnt fuel in the prechamber, the valve cover spits like a volcano if you open the cap while it's running, and #1 comes back in if you get the RPMs up. Sounds pretty concrete to me - it's a piston/ring issue of some type. I'm also not going to fix it. I'll run the car like it is until it dies. Then I'll get my truck.

No good! How many miles are on the motor?

Eh, who knows? The odometer says 190,000, but I fixed it 3,000 miles ago. Who knows how long this thing went with a broken speedometer cable? It's no great loss to society. Truth be told, I never should have bought this thing to begin with. It was a total junkyard candidate. The most pressing issue has been the rust. This thing was a northern car at some point in its life, so it's almost rusted in two. I've been hoping to get 600 gallons of oil through this engine before the car comes apart. Oh well, I did about 110 gallons so far...