Seems like there have been a lot of "Smoking" post lately so I might as well get mine in too.. I've got an 8V71T in my MC-9. The other day I went out to start it to make a short trip. The engine spun over several times without firing. I noticed in my mirror that it looked like a huge cloud of white / grey smoke floating around at the exhaust. It didn't look like your regular smoke since it seemed to hug the ground like fog instead of thinning out real quick. I spun the engine over again and the smoke just poured out and it still didn't fire. I walked to the back of the bus and it looked like a fog was coming out the exhaust tip. While at the back of the bus, I could smell a strong diesel fuel smell in the smoke. It fired on the 3rd try and the smoke cleared up almost instantly. I made my trip with no problems and no signs of smoke while idling or driving... only while trying to start it. I let it set 3 days and went out to start it again and it is doing the same heavy diesel smell smoking and not seeming to fire. It will eventually fire after several attempts and once again the smoke clears out as soon as it starts. The temps were around 48 to 50 degrees both times. Can a diesel flood?? If so, what would cause it to flood??? Any other ideas???
Jimmy
has happen to me when I last fueled in summer then started in cold weather.In our part of the country they go to a winter blend Oct 1st each year. Like you once started it quit. Haven't noticed problem when the tank has the winter blend in it. FWIW Bob
That is very common for these old engines in cool weather. The white smoke is from unburnt fuel. You may have also noticed that initially the engine wasn't sounding as smooth as usual, then it smoothed out and the white smoke stopped, in your case "almost instantly". In some cases it can take a little longer to smooth and clear.
Only takes a few degree drop to affect the smoke on a 8V71T as they are lower compression than N/A
good luck
You have explained exactly what happened the first time I had to start my 671 in 29* weather when I first got it, even to the number of tries!
I smoked out a whole RV park, they even allowed me to return the next year!
I suspect my 671 was tired and was part of its being hard to start.
The 8V71 in my 4107 starts right up in weather down to the 20s but it is fairly newly O/H.
my 8v71 does the exact same thing on cooler days, but just like ole faithful when she fires she runs smoke free from there on.
Great... Sounds like I don't really need to worry too much then. I had never seen that much smoke coming from anything that wasn't running. Merry Christmas to All...
Jimmy
Jimmy what you saw was SOP for those of us who occasionally have to start a diesel in a lot colder weather than what you were experiencing. What I generally do in that situation is to crank it a few turns and then let it sit. The technical term is "heat soaking". Let it sit for about a minute and then try it again. If it doesn't light right off let it sit again. The absolute worst thing you can do is grind it over for long periods. All that will do is get you acquainted with how heavy your starter really is. In cold weather everything is working against you:
- compression is down
- oil is thick so its harder to crank
- battery efficiency goes down so it doesn't spin as fast
Jimmy -
As mentioned above, "heat soaking" is a good way to get the DD to fire in cooler weather. 5 - 10 seconds on, 30 -60 seconds off, repeat.
Or, a couple of hours of having your block heater plugged will make it a happy camper, too!
FWIW & HTH. . .
;)
I'm with the last suggestion. Block heaters are great. plug it in an hour before you want to leave. Starts right up, but the smoke will still be there, just not as long. mine really smokes when cold.
i find the block heater works best, but a shot of ether will help if the block heater didn't or momma wants to leave sooner. just a quick shot, don't soak down the filter. mine kicks right in, but stay upwind to avoid the smoke.
Yours does not sound unusual.
Quote from: white-eagle
... but a shot of ether will help if the block heater didn't or momma wants to leave sooner. just a quick shot, don't soak down the filter. mine kicks right in, but stay upwind to avoid the smoke.
Yours does not sound unusual.
Warning, stupid question ahead: where do you put the ether? I am not a diesel guy and have no bus yet. On an older gas engine I would expect to take the air cleaner off and put it in the carburetor, but no such thing with fuel injectors. What would I be looking for? If you are talking about putting it in where the air filter is, does it matter which side of the filter you put it in?
Thanks,
Mike
Ether isn't the nicest thing you can do for your Detroit. If you need to leave earlier, it will be much happier if you turn on the block heater sooner.
In 7+ years of ownership I think I've fed our noisemaker ether maybe twice. Diesels tend to get addicted to ether if you use it enough ........... but enough with the thread drift, that's a subject that gets well thrashed out - check the archives. As to where you put it, you can dump it in ahead of the air cleaner but on my bus there is a port directly into the intake after the cleaner. Heat, good batteries and time are your friends - ether is not your friend.
I have found that you can avoid a lot of the white smoke if you start from the back, and hold the engine stop lever closed while you do the "heat soaking" spins. The heat is derived from compression, the white smoke is from unburned fuel, so if you activate the engine stop lever you inject no fuel and compress only air. I then roll off the stop lever while cranking and usually it starts up smooth.
Didn't think of this myself, got it here from the masters!
Brian
Very little ether in today's starting fluid not like it was in the past when it was 90% and fwiw your 2 stroke mechanical has a starting aid adjustment (pita to set) the DDEC's do it by electronics
good luck
luvrbus,
I have a 6V92 and only below 20* does it need more than that first start.
BUT what is the "starting aid adjustment" you spoke about.
Frank
When the engine is stopped, the governor puts the fuel racks in the full fuel position. On non-turbo engines, the racks are at full fuel while cranking and go to idle position as soon as the engine is running. On turbo engines there is a starting aid screw to limit fuel input during starting. When you are looking at the governor, it's on the upper right hand corner facing you. I have no clue how to adjust it, I'm just reading the manual... It does say for natural engines back it out all the way to defeat it. Prior to 1974, turbo engines had an internal starting aid device.
just reading the manual on Christmas Eve, so I don''t have a life... ;D
Brian
With the turbo engine from the factory, you have 17 to one compression pistons-compared to 18.7 to one on non turbo'ed engines. Hence you won't create quite as much heat when cranking when it is cold-the results-unburned Diesel fuel in the form of white smoke. One of the ways to start a cold 2 stroke engine is to start it from the rear. What you do is to turn on the ignition, then hold the stop lever on the governor in the stopped position with your finger then start cranking the engine (while watching not to get entangled in the fan belt). After 5 seconds of cranking and continuing to crank, slowly release the stop lever on the governor and the engine will just come up to speed. This works because the stop lever not only stops the engine, but it retards the timing in the injectors facilitating better starting in cold weather. I do it all the time with my 8V-71 turbo. Good Luck, TomC
Quote from: TomC on December 24, 2010, 10:42:34 AM
With the turbo engine from the factory, you have 17 to one compression pistons-compared to 18.7 to one on non turbo'ed engines. Hence you won't create quite as much heat when cranking when it is cold-the results-unburned Diesel fuel in the form of white smoke. One of the ways to start a cold 2 stroke engine is to start it from the rear. What you do is to turn on the ignition, then hold the stop lever on the governor in the stopped position with your finger then start cranking the engine (while watching not to get entangled in the fan belt). After 5 seconds of cranking and continuing to crank, slowly release the stop lever on the governor and the engine will just come up to speed. This works because the stop lever not only stops the engine, but it retards the timing in the injectors facilitating better starting in cold weather. I do it all the time with my 8V-71 turbo. Good Luck, TomC
Stupid question... but where is the stop lever on the governor located???
Quote from: Highway Yacht
Stupid question... but where is the stop lever on the governor located???
Yacht the only stupid question is the one not asked!
If you'll look directly between the fan belt on you MCI there on top of the engine there is a little air cylinder that pushes out on a lever. That lever is the shut down lever and it won't push out without air, unless you manually push it.
;D BK ;D
Quote from: Busted Knuckle on December 24, 2010, 04:23:57 PM
Quote from: Highway Yacht
Stupid question... but where is the stop lever on the governor located???
Yacht the only stupid question is the one not asked!
If you'll look directly between the fan belt on you MCI there on top of the engine there is a little air cylinder that pushes out on a lever. That lever is the shut down lever and it won't push out without air, unless you manually push it.
;D BK ;D
Ok...thanks BK...I know where that is. I did not know that was the governor tho.. I thought the shut down lever only cut off the air intake and I had no idea it would retard the timing to the injectors... I will give it a try..
Jimmy
Just plug in your block heater. Problem solved.
Jimmy, you're leaving out the "low" temps of our NC nights....That's the problem! Temps lately about 20*. This is a faux paw of the 'bama folk. Little mistake on perception of the Global warning thingy....good luck. Those engines soak up the teens degrees and it takes a day in the sunshine to un-freeze the engine. Call me if you need information on installing a block heater if you don't have one. You need one. I installed a block heater into my 6V92TA and had excellent results. Cranks clean and ready to go. Even the heaters are cooking! sucker used to smoke up the barn...big time! Looked like it was on fire for a bit.
The cold diesel smoke (unburned fuel) really doesn't mean a thing. As long as it clears within a minute or so. Cold diesels are not efficient.
As someone said (Tom, he's the turbo guru), if you have a 'real' turbo engine, it has 17/18 to 1 compression ratio, which means harder starts in cold weather.
8V71NA's have about 21/1 compression. The NA's will (generally) start better in cold weather because of their higher compression.
A block heater will solve all of your problems. If you don't have one, get one. They are not expensive, and if you wish to crank it during bitter cold weather, a block heater is your friend.
On the downside, a very well worn engine will smoke like H and take forever to clear up. Bitter cold weather will screw all over worn diesel engines. But it will eventually run normally. A block heater bring will them back to life fast!
It's past my bedtime, and I've maxed on adult Christmas beverages. Some guy in a red suit was supposed to drink these things...but nooooo. Here I sit. Now I gotta get rid of them! ::)
Jimmy give me a call sometime at 704 650 0235. I'll be available anytime other than Wed AM and Thursday AM. I change hats and become Mr. RN on those days. Otherwise I'm retarded from work and almost always looking for someone to eat lunch with!
I'm only half hour from you. I'd like to see your coach up close! We may have spoken in the past....need to get together and compare ideas!
Merry Christmas to you dudes! JR
Yes JR.. We spoke a few months ago. I'm the one who works in Monroe. I've been meaning to catch back up with you to see your bus to gets some ideas and advice but was waiting on it to get a little warmer. I will definately give you a call once it does warm back up. I'm still early in the learning process. As far as the smoke, she clears up almost the second she starts. It is definately a "real" turbo 8V71. Detroit says the serial number tells them it is a 1987 8V71T surplus Military Tank Engine. Don Fairchild was nice enough to also run the numbers and said it was a 350HP engine with the N-90 injectors. I do not have a block heater yet but will put that on my wish list.
Hope you are ready for the SNOW!!!!!.. Sounds like it is on the way for us later today..
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi783.photobucket.com%2Falbums%2Fyy114%2FHighwayYacht%2FMC-9%2FParty021.jpg&hash=524fb04a2063e9e1c63cc356f26dfc5da0465862)
H-Y just so you know some of the military 8v71T were 15:1 compression and a real bear to start around 0 degrees with your's blowing that much smoke at 50 degrees you probably have the 15:1
good luck
Compression ratios on various 2 stroke engines. 53 series Natural were 21 to one; Turbos were 18 to one. 71 series Naturals were 18.7 to one; turbos were 17 to one. 92 series Naturals were 19 to one; turbos were 17 to one. Higher the compression-easier it is to start when cold. I retained my 18.7 to one Natural pistons, but only used 75 injectors and a waste gated turbo from a 12.7 liter Series 60 to keep boost down to around 15 psi. Good Luck, TomC
Thought I'd throw my 2 cents worth in, not only cold conditions, unburnt fuel, LOW CETANE will also make it smoke!
Steve 5B....... MERRY CHRISTMAS EVERYONE..........
I am now officially stuck in my chair...ate too much! Gads. Fortunately, the laptop is within reach!
Jimmy, if you're trying to start the coach to move it, or for some other reason, go for it. Otherwise, I'd let it sit. Unless you plan to run down the highway and place a load on the engine long enough to bring the oil up to normal operating temp, cranking it just to see if it'll start is not especially good for the engine. It'll never warm up idling. Sitting over the few winter months won't hurt the engine...not as long as water isn't dripping onto the engine from rain and snow. If you just gotta crank it without a block heater, charge the batteries up fully and crank it in 4 second bursts with a little rest between. That'll 'heat-sink' the combustion chambers and it'll light up eventually. This is rough on starters...40 wt oil is like sludge (not really, but it's pretty heavy) in our recent arctic temps. A work light placed beneath the oil pan will warm the oil. You gotta watch that...work lights get hot. And, while not the best of ideas, if you just gotta start it, a shot of ether should do the trick. If all that fails, you can punch a few air holes in a big coffee can full of charcoal, light the charcoal :o .....nevermind. Don't do that.
If you buy a block heater, buy a unit designed for an 8V71. Don't dink with oil pan mats, dipstick heaters, or coolant hose heaters.
It's much better to warm the coolant with a properly designed block heater than to heat the oil.
My 6V92 required that the coolant be removed when installing a block heater. Someone can clear this up, but I believe some '71s use a pipe plug style heater which could be installed without draining the coolant. It'll get messy, but it can be done.
'92 series use a plate style heater that' situated on side of the crankcase behind the dipstick.
You probably know this, but don't be tempted to change the 40wt to "winter" or multi-viscosity oil. 40wt is correct for your use. Even in the winter.
Give me a call at 704 650 0235 about anytime.
Oh well, back to watching the snow fall! JR 8)
Quote from: 5B Steve on December 25, 2010, 11:11:48 AM
Thought I'd throw my 2 cents worth in, not only cold conditions, unburnt fuel, LOW CETANE will also make it smoke!
Steve 5B....... MERRY CHRISTMAS EVERYONE..........
Unburnt fuel is what make the clouds of white smoke during and following cranking attempts. Rough idle right after startup also adds to the unburnt fuel smoke. Often as not, only a few cylinders light in a really cold engine...smokes until all cylinders light up.
While not beneficial, white smoke that clears up once all cylinders are running following a cold start doesn't indicate a problem either.
JR
71 and 92 series take the same block heater goes on the right side just above the oil pan 4 bolts and the system needs to be drained
good luck
The 92 series in many RTS's, including mine, have a connection to the transmission cooler connected to that port. So on mine the block heater is in a pipe threaded port in the end of the cylinder head (it might be right below the head, without going out to look at it, but that is the general area). It's a little slower heating like that but it works like a charm.
Kat's make block heaters that will work about anywhere on a engine even on the freeze plug for good heaters I like the 1500w it doesn't take long
www.warehouseautoparts.com (http://www.warehouseautoparts.com)
Hey guys where can I find a block heater for a '64 8v71? Even in central NC they are great to have. ( former road driver)
The electric block heater for the 8V-71 goes on the right rear of the block at the square plate with 4 bolts holding it. Problem is-this is also where the coolant line for the transmission is taken from. When that is done, there is no other place on the block to put an electric block heater. Other options would be an inline heater on that same coolant line from the transmission cooler, or what I did last weekend-put a 500 watt halogen light under the oil pan for about 2 hours. Good Luck, TomC
Quote from: NJT5047 on December 25, 2010, 07:27:45 PM
You probably know this, but don't be tempted to change the 40wt to "winter" or multi-viscosity oil. 40wt is correct for your use. Even in the winter.
Actually the book says to put 30W in for colder temperatures (can't remember exactly how they define "colder"). I don't like doing that and its not necessary if you can properly warm the block up prior to starting but as somebody has already pointed out, with temps in the 20s (F), 40 weight oil is like molasses.
You guys are diehards. Using straight Rotella, etc., 30w or 15w-40 is much better in freezing temps than straight 40wt. Your engine starts much easier and sounds much better starting in the cold. Since the most wear on an engine is when it is first started, getting the oil circulating and lubing is better with the lighter oils than the cold thick 40wt.
Quote from: bobofthenorth on December 26, 2010, 04:32:04 AM
Quote from: NJT5047 on December 25, 2010, 07:27:45 PM
You probably know this, but don't be tempted to change the 40wt to "winter" or multi-viscosity oil. 40wt is correct for your use. Even in the winter.
Actually the book says to put 30W in for colder temperatures (can't remember exactly how they define "colder"). I don't like doing that and its not necessary if you can properly warm the block up prior to starting but as somebody has already pointed out, with temps in the 20s (F), 40 weight oil is like molasses.
According to DD, 32 degree's ambient without starting aids (e.g. block heaters, ether, ...) or below 0 with them.
Quote from: Detroit Diesel Lubricating Oil, Fuel and Filters Engine Requirements, section 2-4At ambient temperatures below freezing (32 F or 0 C), sufficient starter cranking speed
may not be achieved to start the engine with SAE 40 grade oils. Where starting aids are
not available or at very cold temperatures (0 F to -25 F or -18 C to -32 C) even if
starting aids are available, the use of multigrade SAE 15W-40 or monograde lubricant
SAE 30 will improve startability. These lubricants must possess a High Temperature
– High Shear Rate Viscosity (measured by ASTM D 4741 or equivalent) of 3.70 cP
minimum. These oils must be replaced with monograde SAE 40 lubricants as soon as
ambient conditions permit.
I went to my local parts store and they looked up a block heater for a truck with the 8V71. I had the choice of 2 wattage sizes and took the larger one. I think the cost was around $50. Looking at the motor on my MC with the rear doors open the heater mounts in the block on the right hand side facing the rear of the bus just below where the head and block mate. It is a 1" NPT threaded fitting with an immersion tube that goes into the water jacket. If I am correct it was rated at 1500 watts and generally plugging it in for 2 hours makes the ole girl fire like it is summer. I have an Allison and that block heater is independent of any lines associated with the tranny cooler. Hope that helps....
You only need to drain the coolant to below the location you are installing it.
So, in an MCI, with the rads higher than the engine, it's a lot of coolant, in a side mount radiator like a GM and an Eagle, you will drain a lot less to get the level down below your opening.
Where on the continent does the temp not drop to freezing and below on some irregular basis?
An easy afternoon install in the warm weather....
happy coaching!
buswarrior
QuoteThe electric block heater for the 8V-71 goes on the right rear of the block at the square plate with 4 bolts holding it. Problem is-this is also where the coolant line for the transmission is taken from.
Problem I had but found the solution that Chopper Scott used:
QuoteIt is a 1" NPT threaded fitting with an immersion tube that goes into the water jacket.
Word of caution! Do not start your bus with the block heater on! The shock of diesel ignition will break the element. Just like an incandescent light bulb filament is very fragile and easier to break while it is on. I found out the hard way, and got educated by the manufacture's tech support.
Lastly, it is a myth that using ether will make your engine dependent. Engines get hard to start for various reasons, and instead of finding out why they don't start like they used to, it is easier just to spray it and keep spraying it. And from that time on blame the ether instead of fixing the problem. There is a reason I call my conversion "Wheezy bus", it is absolutely worn out. If ether destroyed engines then the engine in Wheezy would be in pieces by now. I find ether easier than re-powering it (I have a donated rebuilt 8v71 to put into it but what I have still works and I don't want to take the time to swap it while the children are still at home. But my dream re-power is a 6v92 turbo if I could find one). Those old engines were made to use ether as a starting aid. My bus and many others still has the ball cup on the blower for it. The only way I know to get into trouble with the stuff is to use too much at one time. A nice shot into the air intake on mine always gets a quick fire. A tiny squirt into the old ball cup also works well.
Quote from: Geoff on December 26, 2010, 05:05:13 AM
You guys are diehards. Using straight Rotella, etc., 30w or 15w-40 is much better in freezing temps than straight 40wt. Your engine starts much easier and sounds much better starting in the cold. Since the most wear on an engine is when it is first started, getting the oil circulating and lubing is better with the lighter oils than the cold thick 40wt.
Noooo....don't do that. Multi viscosity isn't at all recommended for 2 stroke detroits. Detroit recommended going to 30 wt only if there was no other option. Detroit recommends 40 wt for highway use in all highway use above 0*. Even dem Canadians run 40 wt.
Everyone needs a block heater of some sort.
BTW, draining coolant from an MC9 will require a container of about 12 gallons...with the heater gates closed.
Gitrdone! JR
I replaced my block heater without draining. Just have the new one all ready with permatex unscrew the old it only leaks about two glugs (about a pint) and swap it out.
Rick 74 MC-8
Quote from: Rick 74 MC-8 on December 27, 2010, 09:34:10 AM
I replaced my block heater without draining. Just have the new one all ready with permatex unscrew the old it only leaks about two glugs (about a pint) and swap it out.
Rick 74 MC-8
That's how I did it also. I lost a bit more than 2 glugs however!! Not quite as swift I guess but still probably lost less than a 1/2 gallon. I probably would have lost that much draining the system and spilling it anyways!
Little trick here guys I can install one where the factory installed on the block without losing any coolant not even a gurgle.
I have plug that fits the surge tank with a 1/4 inch hose I pull a vacuum with the truck or shop vac bingo your done now you know lol only takes 3 or 4 lbs of vacuum no coolant lose,just be sure it is above water level
good luck