| Author | Message | ||
| Mike Merriam (Cricket)
Registered Member Username: Cricket Post Number: 19 Registered: 2-2010 Posted From: 148.244.83.195 Rating: N/A |
I am looking @ a 1966 MCI5 http://ocala.craigslist.org/cto/1613398826.html. She needs a new clutch but the bus is very nice (my opinion). I had a mechanic check it out & he was very impressed with the whole package, EXCEPT... This thing burns oil. 1 qt oil in 1 hour of running in place (Bad clutch cant drive). The mech. thinks it is piston blow by. After it runs for a hour the oil consumption & cloud get better. The new clutch installed is about $2000. The rebuilt motor is $7000. Here is my question. Do these old 2 strokes allways burn oil? She has been sitting for (4) years. will it get better? Is rebuilding a 2 stroke that tough? I'v rebuilt 10+ gas motors. never a diesel. | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 32 Registered: 1-2010 Posted From: 68.151.248.141 Rating: N/A |
Just ask your self if you would pay $14000 for it and you have the answer. Before rebuilding a 8V71 I might look for a good drop in. lots of them are still available or consider up grading to possibly a 6V92. We own a 1966 MC5A. they are a great coach but check it over very carefully for rust before making a decision. Look in the blower area as well as the air beams. Also in the baggage compartments. Look above the door for cracks in the skin as this can indicate corrosion These are the places that we had rust problems on ours. The 2 strokes all seem to use a bit of oil and they all leak If you do decide to go ahead and buy it and need info I have my original parts and service book for the 66 challenger Les | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 195 Registered: 5-2007 Posted From: 174.91.217.214  Rating: N/A |
It's a crap shoot buying a used vehicle....I'm not sure what kind of shoot it is buying a used vehicle that is inoperative to the point that you can't road test it. Worse than crap though  It's all about you though, if you love the bus and can find a decent drop in engine, go for it. I've rebuilt a few vehicles over the years, that being said, I bought a basically running bus, and have found more than enough to do without the added hassle of clutch and engine replacement. beauty is in the eye of the beholder, all I know (and I was told at the time but didn't listen) is with proper research more $ upfront will save you more $ down the line, Basically a cheap bus will cost more to prep than the total cost of better more expensive bus. It is a buyer's market, shop around a bit, there are a lot of people trying to unload. Also the further away it is the more it costs...the amount of time/$ required to go get a bus really adds up. | ||
| JC Alacoque (Jc_alacoque)
Registered Member Username: Jc_alacoque Post Number: 87 Registered: 7-2006 Posted From: 207.34.166.7 Rating: N/A |
You would have to pull the engine to do the clutch. While the engine is out, you might as well overhaul it. It is not rocket surgery, it just takes time and attention to detail. Get the DD service manual. Then you would have one the best buses ever built. JC | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 196 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
A good 8V-71 should burn a gallon about every 2,000 miles. Under 1,000 miles per gallon means overhaul time. Good Luck, TomC | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 849 Registered: 3-2007 Posted From: 71.53.153.91  Rating: N/A |
I has been sitting a while also. Tires also. Gomer | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 459 Registered: 2-2001 Posted From: 184.0.5.73 Rating: N/A |
You have to wonder how many hours that bus has run while sitting there in the yard. When these engines sit unused or idle a lot, they will smoke a lot until you are able to get it out on the road for maybe 30 miles. They often smoke when cold and even if your water temp got to 165 that engine was still cold. They have such a heavy duty cooling system it's nearly impossible to get them properly heated up without driving them. (You ought to see a Detroit 2 stroke powered fishing boat when it idles along trolling for 4 hours, then opens up to come home. They leave an awesome cloud behind for a half mile!) And I am wondering how you determined that the engine had burned a quart in an hour. (Yes, I know you looked at the dipstick, LOL). What I mean is that unless you know exactly where the oil level was when you started it, and left it off before checking for maybe an hour or so, you will show a lower level because a lot of oil is still up in the engine. IF you marked the exact level before starting it, go back now & check and I'll bet the level is just about where it was. If it put out a pretty good blue/grey cloud when first started, then kind of a lightly smoky exhaust for about 30-40 minutes, then it's doing what mine does which stops in the first few minutes if driven. My 6-71 burns about a quart every 500 miles which works out to a gallon every 2000 miles. If it smokes like a "bleach burnout" for 30-40 minutes, that's WAY too much. And most of these beasts burn less oil if you leave the level about 1 gallon low for some reason. You can top it off but that top gallon goes away quick so lots of guys just run it at that level. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1132 Registered: 11-2005 Posted From: 173.202.43.215  Rating: N/A |
What Jim said plus; you didn't say if it was run at fast idle? At normal slow idle it will spew oil like crazy, never run it more than a couple of minutes at slow idle. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1102 Registered: 7-2006 Posted From: 74.162.78.89  Rating: N/A |
Hey Mike? Re: "Here is my question. Do these old 2 strokes allways burn oil? " There's two things that weren't mentioned yet.... 1. The oil level when full, should reach the seam between the oil pan and crankcase. If it's higher than that, the oil's going to spew out all over, and smoke like all hell. 2. If the oil that's been in the crankcase, and the oil you've been adding isn't the oil that should be in it, it's gonna' leak and smoke like all hell. ------- Detroit Diesel recommends a straight 40 weight oil meeting certain criteria, which is as follows: SAE Viscosity Grade: 40-API Classification: CD-11 Military Spec.: Mil-L-2104D Sulfated Ash: Less than 1.0% under normal temperature conditions. ------- That help a bit? | ||
| George Martinez (Foohorse)
Registered Member Username: Foohorse Post Number: 55 Registered: 1-2010 Posted From: 76.26.23.103  Rating: N/A |
I am a bit confused, if a healthy 8v71 is supposed to burn 1 gallon per 2,000 miles leaving it low 1 gallon to causes it to use less oil seems to me like abuse. it is a 2 stroke it is suppose to self scavenge its own oil to mix with the fuel. I have also heard that overfilling it one gallon helps it run cooler on long hauls in hot weather. I await enlightenment from those wiser then myself. because I may have a trip coming up to Ocala second time (newbie) I drive my 4905 shell of a bus to visit friend Gomer | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 342 Registered: 12-2000 Posted From: 72.187.35.208  Rating: N/A |
George, You are a bit confused. The engine does not consume oil like a two stroke weedeater. Oil consumption is just the oil that gets by the pistons as in any engine that uses oil. These old engines were designed with much looser tolerances than the modern engine, thus a bit of normal oil consumption, just like the cars of the forties. So, the gallon per thousand is not a requirement, just a norm. The engine will run just fine if it burns no oil at all. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1250 Registered: 12-2000 Posted From: 108.112.75.149  Rating: N/A |
Although it is a 2 cycle engine it does not require mixing oil with the fuel. It does not "scavenge" motor oil for lubrication. The lubrication system is very similar to a 4 cycle engine with an oil supply in the pan, an oil pump, and galleys supplying oil to all the neccessary places. The engine has exhaust valves (unlike a "weedeater" 2 cycle). The big difference is that the air is forced into the cylinder by a blower throug intake ports in the cylinder sleeve. As far as running the engine low on oil, A John Deere engineer on an RFD call in show was asked about proper oil level. He replied that anywhere between ADD & FULL is OK. ADD mark is minimum amount and FULL is maximum. To help avoid confusuon, they now mark the area between ADD & FULL with SAFE. | ||
| David Guglielmetti (Daveg)
Registered Member Username: Daveg Post Number: 155 Registered: 2-2009 Posted From: 66.122.182.221  Rating: N/A |
The oil a gallon low is something different than consumption too. | ||
| Dallas Farnworth (Dallas)
Registered Member Username: Dallas Post Number: 33 Registered: 7-2004 Posted From: 72.172.43.196 Rating: N/A |
Hey Mike? Re: "Here is my question. Do these old 2 strokes allways burn oil? " There's two things that weren't mentioned yet.... 1. The oil level when full, should reach the seam between the oil pan and crankcase. If it's higher than that, the oil's going to spew out all over, and smoke like all hell. 2. If the oil that's been in the crankcase, and the oil you've been adding isn't the oil that should be in it, it's gonna' leak and smoke like all hell. Sorry to disabuse you John, but, according to the Detroit Diesel Field Service Manual, the oil level is one inch below the oil pan / crank case seam. | ||
| George Martinez (Foohorse)
Registered Member Username: Foohorse Post Number: 56 Registered: 1-2010 Posted From: 76.26.23.103 Rating: N/A |
Thank you Len ,Jack, David, I feel like here I can get real info instead of wives tales. no offence to any wives out there. and one more thing fellas I prefer to label my 8V71 weedwhacker not weedeater it sounds more menacing. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1103 Registered: 7-2006 Posted From: 74.162.78.89 Rating: N/A |
Dallas ! OOps, and thank you for correcting that. 1" below the seam is the fill limit. After reading that a few years back (4 or more?), I measured my stick against the tube to the seam, and the "low mark" was way the hell too high. It's a good thing to check with a well used bus. An overfull crankcase can drive you nuts with the oil loss and smoke. | ||
| bruce ohlson (0le)
Registered Member Username: 0le Post Number: 2 Registered: 9-2008 Posted From: 71.142.95.194 Rating: N/A |
Hey George, Overfilling it by a gallon is NOT a good idea. ~0le | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 196 Registered: 5-2007 Posted From: 70.51.31.123 Rating: N/A |
Good points about the idling/smocking stuff (though my bus sat for 2 years just being idled regularly, and it didn't smoke much when first started) Everyone's talking about the engine but the clutch doesn't even work...and who knows if it's just the clutch. p.s. Do spicers ever break? I have yet to hear of one. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1120 Registered: 10-2006 Posted From: 66.82.162.16  Rating: N/A |
Underfilling by a gallon is a far worse idea , as a lack of lube oil can cost at least the bearings and perhaps the engine. One concept is WHEN to "read" the oil level. AS far as I can find in Da Book , its 3 min after shutdown. If its a gallon low before start on a drained engine I shudder to think how much oil is missing! There is a huge amount of oil pushed round these engines , and quantity counts!The oil is used for cooling and sometimes running the fan. Underfill,,,, NEVER! Usually fixing the leaks will lower the oil use , it certainly did for my DD. "Do these old 2 strokes always burn oil?" OF course , every engine will leave a film of oil on the cylinder walls so the piston doesn't seize. On a 4 stroke the exhaust stroke scrapes the oil but does not burn it off, the 2 stroke will burn off the oil with each power stroke. A DD that "does not burn some oil" i9s either refilling the oil level with condensation and blowby or with a fuel leak that is even more dangerous. Oil sampling is the norm for DD folks that plan on keeping the same engine. And in the service we RV folks have (few miles over many months) 6000 miles is a good change interval. On a "new to you " coach 500 to 1000 is a good first time number. FF (Message edited by Fast_Fred on March 26, 2010) | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1134 Registered: 11-2005 Posted From: 173.202.22.55 Rating: N/A |
George, What Bruce said plus it is NEVER a good idea to overfill any engine. This results in foaming oil and usually the extra oil gets thrown out of the engine. Light airplane engines are infamous for this and most auto engines will do it. Running a DD one gallon low is no big deal since most hold so much oil, it all depends on your engine and oil pressure. I do it all the time on my 671. The pressure gage tells me when it is time for more oil. I would guess that most DDs leak/throw more oil than they burn. Mine throws it all over the engine compartment but it keeps the rust down!! A DD in real good condition will not burn much as has been shown by a number of posts here. | ||
| George Martinez (Foohorse)
Registered Member Username: Foohorse Post Number: 57 Registered: 1-2010 Posted From: 76.26.47.82 Rating: N/A |
but Gus forgive me for asking but when the gauge is beginning to warn you isn't that because the oil pump is beginning to cavitate from an ingress of air and consequently it reads a pressure drop? and even before that happens at what point is the level low enough where the crankshaft is not splashing the bottom of the pistons? in an automotive engine going by the gauge would amount to abuse. all Rolls Royce and Bentley cars have a switch that momentarily converts the fuel gauge to an oil level gauge, this is a big convenience especially on any English automobile. Is the DD 8V71 designed to be immune from this. thank you all for helping me along in understanding. for what it's worth I thought the 1 gallon over seemed iffy. | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 460 Registered: 2-2001 Posted From: 184.0.5.73 Rating: N/A |
Fred, I think what Da Book means is not to check it BEFORE at least 3 minutes after shut down. And I would think that is too soon. Now when we're talkin about the Allison trans, you do want to check it right after shut down, before it drains. If the dipstick shows 1 gal low on an engine that has drained down, then the engine is 1 gallon low. And, I wouldn't rely on the dipstick 'till I had measured it compared to the block/oil pan seam to be sure it is marked right. | ||
| Mike Merriam (Cricket)
Registered Member Username: Cricket Post Number: 20 Registered: 2-2010 Posted From: 148.244.83.195 Rating: N/A |
Let me start by saying, I'm stuck working in saltio Mexico & there are old buses everywhere. This must be where they go to die because there are hundreds. But as far as this MCI5 , I think I can summerize this oil issue by saying a heathley DD 2-stroke should not burn excessive oil or smoke up the neighborhood regardless of how long it's been sitting. I Have to believe my hired diesel mechanic checked proper levels during his 5 hour inspection. he even pulled the "y" pipe to find unburned oil coating the inside. The air boxes were oil filled also. The bad part is, this mechanic gave the bus a very high rating. everything looked very well maintained & very high quality. Even the Michilin tires were blocked up & covered to minimize dry rot. The clutch does not scare me, we've all burned them up. the motor sounds all used up also. I'll keep looking. | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 648 Registered: 10-2006 Posted From: 71.254.35.22  Rating: N/A |
This might come to a shock to some on the bus boards, but I thought that it looked liked a reasonably good deal, possibly even a very good deal. If the engine is bad, get a good used take out (like from NIMCO) and for little money, you have a decent usable coach. It might just have a stuck ring or two. Running it under load might help it. It was a professional conversion right? That would be a huge plus for me. There should have been some wiggle room on the price. Did you make an offer? Lowball it and see what happens. Then offer to meet them halfway and you will probably walk away with it. The only thing I didn't like about it was the manual transmission. But, if the price was right you might could apply the clutch money to an auto. I am biased towards the 35' low coaches because I often go where the 40' cannot. Being that it is an MCI, do they still support it? Not a big deal if they don't because I do just fine with my non-supported GM. If I didn't have a bus, that one would be on my radar. | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 649 Registered: 10-2006 Posted From: 71.254.35.22 Rating: N/A |
Another thought, could the blower seals be bad? Wouldn't that cause excessive oil use? I am throwing that out there because this is not my strong point, but I would like to know. | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 1104 Registered: 7-2006 Posted From: 74.162.78.89 Rating: N/A |
Hey Mike... Re: "I Have to believe my hired diesel mechanic checked proper levels during his 5 hour inspection." Two things he probably didn't check: 1: The proper length of the dipstick (measured against the dipstick tube, to the seam of the oil pan; 1" below is the add point) You'll find the wrong stick, and/or the wrong tube on many old buses. 2. The proper viscosity and grade of oil. If the wrong oil's been used, it's gonna' leak and spew and burn. My old MC9 looked like it needed an engine overhaul, the way it was coated with oil; The smoke was dense as well. The operator I bought it from was using 10w30 el'cheapo Walmart residue. He gave me three gallons with the bus and it probably used that on the 12 mile home. If the bus started on the first click and ran smooth, it's a decent sign of a decent engine. The oil spew is the least of the problems you'll see out of an old bus. How's the front end? The radial arm bushings? The rear end? How much metal fell out of the transmission oil pan? You ain't seen nuttin' yet, my friend. | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 347 Registered: 12-2000 Posted From: 72.187.35.208 Rating: N/A |
How bad is the clutch? Are you sure you can't adjust it enough to get it moving? If you can get it to move under it's own power and the price is right (it should be VERY right if it cannot be driven), buy it. Change the oil to the proper 40wt and drive the crap out of it. My bet is that it will cure itself after 100 miles or so. If your mechanic is not a Detroit two stroke guy (probably over 60 years old!), then I would not have all that much confidence in his opinion. | ||
| Mike Merriam (Cricket)
Registered Member Username: Cricket Post Number: 21 Registered: 2-2010 Posted From: 148.244.83.195 Rating: N/A |
The clutch has been adjusted to get her to move, but no confidence in taking her out for a drive. The pro. conversion was done in "81". The diesel gentrator runs fine. the basment air blows 59 degs. The mechanic has over 140 2 stroke rebuilds under his belt (Marine shrimp boats). The owner is an Amsoil rep so he has been putting Hi detergent 50wt in it to unstick the rings. Th mechanic thinks it will make it to Detroit with no problem (extra oil & fuel filters). He might take $4000 but has not confirmed & I havent pushed it because I wont make a real offer untill I'm ready to back it up. The original owner's wife died Than he died. Now his Best Friend is helping with the estate. She does have a signed title. The mobile mechanic will do the clutch where it sits. He will also do any other service I request for the trip Home. I planed on a fun first trip with my wife to drive this bus home but the mechanic warned me of the oil issue. (that's what I paid him for). I think the labor on a motor swap would cost mor than me doing a in frame overhall ($2000 parts). This would give me the understanding I NEED to own a old bus. I am a jack of all trades (except diesel). | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 650 Registered: 10-2006 Posted From: 71.254.35.22 Rating: N/A |
Pardon the oil consumption pun, but the more I hear about this, the more it sounds like a smokin' deal! 99.5% of the time I am slamming what I feel are bloated prices in bad economic times. Then I get flamed from those who think I am betraying the conversion market by saying so. I look at bus ads all of the time (Some may remember I posted this MCI awhile back) so it takes something out of the norm to get me excited. Cricket, At $4k and you don't want it, put me on the #2 spot for an opportunity to check it out. I don't need another bus, but I don't mind an upgrade from what I have. Has anyone priced a diesel genset lately? Close to 2x the asking price of this bus. Working basement air, a clean roof-line, and after 5hrs even the mechanic likes it. I'm going crazy, someone slap me, please! Have I lost my mind and gone over-the-top? I would have thought there would be a pile on for this. But the responses have been lackluster at best. Are there lurkers out there who are are trying to work a deal and keep this off the radar? I have recently seen some thumbs up for some real junk. This is not junk. I must be missing something. (Message edited by barn_owl on March 28, 2010) | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 651 Registered: 10-2006 Posted From: 71.254.35.22 Rating: N/A |
Playing matchmaker now. There is MCI 5 posting on the other board that is being parted out. Take a look: http://www.busconversions.com/bbs/index.php?topic=14790.0 | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 199 Registered: 5-2007 Posted From: 174.91.225.235 Rating: N/A |
Didn't realize it had a diesel gen as well,. If the gen is in good shape you could sell it, sell the bus for scrap and make a profit ;) | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1141 Registered: 11-2005 Posted From: 173.202.9.56 Rating: N/A |
George, I misled you. I don't wait until the oil press needle starts to vacillate! The cavitation point is never reached. The decreased press just tells me it is time to check the gage. As long as it never goes below the LOW mark I won't worry. |