19 replies to this topic

[Ed Sommers]

The majority of, what are called, Busnuts, have the 8V-71 Detroit Diesel Engine. They are old two strokes that were in almost everything that ran on an engine of that size (318) during WW2. Trucks, landing craft, generators, etc, were the 8V71.

They are almost bullet proof, will run when broke, and have a reputation for oil leaks. An 8V-71, that is running strong, and not burning oil, will almost certainly last for an RVers lifetime. Parts, and whole engines are still available. The thing thats needed, and hardest to find is (for many) the correct oil. They must have straight 40 weight formatted with less (IIRR) than 1 percent ash content. I, and most others, use Dello 100, 40 Wt. with Rotella T 40 St close behind.


Ed

[Kellie Roberts]

Although we have an 8V92 in our Bluebird - I second that on the oil. We use the Rotella T40, and the best place we have found, both for convenience & price, is NAPA. You can call it in one day generally pick it up the next.

We're big fans of this beast of an engine

[Technomadia]

That's what we have in our 4106...

Have been told:

"If it's not dripping oil.. then you're empty'.

We felt confident going this route as many said that it should run a long time if kept maintained. But if it doesn't, might be cheaper to just scrap the bus.

If you have specific questions... please ask.

We're total mechanical-noobs but readily learning, but have so far found that most problems we've encountered could be solved with WD-40 and a hammer. The bus nut community is *awesome* about supporting each other, and we feel so incredibly blessed to have some true 2-stroke experts on speed dial as a result. And we're favoring garages that let us in the pit with them and are willing to teach us.

- Cherie

[Liberty]

We have an 8V71 non tubro in Liberty. We enjoy the motor. Ours does not leak so it may only last another 500,000 miles. DD jokes go along the lines of I took a picture of our new motor and hung it on the wall. the darned thing leaked on the carpet. To be fair these motors will run for 1,000,000 miles when properly abused. Run them hard do not run them slow and try to pull hills in a high gear, just wind them up and go.I would love to find a waste gate tubbo system for ours. This would give us horsepower left over at the top of big hills.

What are you looking at one in?

When you get one learn who Clifford is.

[Ann N Gene]

ah.....Double Breasted Yamaha. Built like a tank or a brick s.h. They will take most any abuse you can dish out and keep running. Besides, nothing sounds sweeter!! All just my opinion.

[dreamscape]

We have just finished installing a pretty low hour 8V71 to replace the same. Also attached an Allison HT 740 behind it.

I like the simplicity of the engine. No electronics to control it. If something does happen much easier to troubleshoot.

Here is a link to a short video our first fire up of the new engine.

http://www.youtube.c...h?v=7BcDaM2y1G8

[OHVRanger]

Maybe this thread should just be called 2-strokers? We have the 892 and love it. I run 30wt low ash available at some Walmarts. I ran Rotella in all our farm equipment many years ago, but they were 4 strokers. 6 years with no oil problems so I'll continue with the cheaper Walmart oil. 2000 miles after a change and the oil is still on the full mark and clear. Did I say how much I love our Detroit? I would run 40wt if we were down in the SW, but are usually up north where it is cooler. I like the fact that it's pre-dedec- no electronic problems short of a bad idle buffer switch that controls the Jake brakes. The high idle still works, so I just control the jakes manually. Will

[Missouri Mule]

8V71 DD engines come in several horsepower ratings determined by injector size and engine RPM. All mechincal contols no ECM or other issues to worry about. Not to fuel efficient. Good long live engines if you ran them hard, lug the engine and it did not last as well. Most were set at 318 HP turning 2100 RPMs. Possible to install HV70 injector and reset RPMs to 2400 with a Horsepower rating of 350. Getting a mechanic that knows these engines will be a problem if you have an issue.
Just my $.02

[OTT]

When I worked for hand shaker(Mason Dixon) one of the drivers with an 8v loved the truck so much he put a picture on his wall at home. His wife made him take it down becuase it leaked oil on the carpet.

[oRV]

The majority of, what are called, Busnuts, have the 8V-71 Detroit Diesel Engine. They are old two strokes that were in almost everything that ran on an engine of that size (318) during WW2. Trucks, landing craft, generators, etc, were the 8V71.

They are almost bullet proof, will run when broke, and have a reputation for oil leaks. An 8V-71, that is running strong, and not burning oil, will almost certainly last for an RVers lifetime. Parts, and whole engines are still available. The thing thats needed, and hardest to find is (for many) the correct oil. They must have straight 40 weight formatted with less (IIRR) than 1 percent ash content. I, and most others, use Dello 100, 40 Wt. with Rotella T 40 St close behind.


Ed

ED: You may correct me if I'm wrong, but I don't believe that there were any 8V-71s in WW11. I believe that the 71 series replaced the 51 series in the early fifties. I spent many years driving a bus for the old Continental Trailways (American Buslines Division) with those wonderful old DD8V71 engines. They could really take the abuse. . . except, as noted, lugging. Our old Eagles would be started up in Los Angeles and driven to New York and back without shutting them down. As always, oRV

[Jarlaxle]

Some Sherman tanks were powered by a pair of inline 6-71's...the 8V71 came around in, IIRC, the late 50's.

[OHVRanger]

Some Sherman tanks were powered by a pair of inline 6-71's...the 8V71 came around in, IIRC, the late 50's.

Even by today's standards, can you imagine a straight 12 cylinder powering around in a tank? Oh what fun

[Jarlaxle]

I recall they were side by side, actually.

[earnhart3]

I recall they were side by side, actually.

All previous posters still loving their 8-VS WITH 5 DOLLAR a gal fuel. We had an 8v92TA in a prevo and the ONLY time we could get over 5mpg is when we kept it down to 60mph and had very little gen time


good thing about ours was its in a prevo conversion everything else is a compramize

[Liberty]

We run 6 MPG with the generator on and 6.6 WO/ the genset. 2000 rpm @ 70MPH 34,000# Allison 740 trans 3.73 gears

[Liberty]

We avg. 6 MPG with the generator and 6.6 wo the genset. 2000 rpm about 70 MPH Allispon 740 w/ 3.73 gears. loves everything but long grades

[OHVRanger]

When planning a long trip I calculate at 5 MPG's. That way I always feel like I skinned the cat when we fuel up and discover we got closer to 8. Of course, we rarely run the genny as I have a separate alternator for each battery bank. With the house battery setup we can run almost 5 days through the inverter without needing a charge and the DW has the TV on almost 24/7. It's a 32" flat screen connected to a dome satellite which also uses a small amount of juice. The fridge and water heater kick over to gas and if it gets chilly, the catalytic heaters don't need anything but propane. Last trip of any distance was just over 400 miles and at 60MPH on the highway with a 4600# toad we got 7.8 MPG. The bus with all of our belongings weighs in at approx 40,000# That's better than a lot of gassers out there.. Did I mention how much we appreciate our 2 stroker?
Will

[Paul Stough]

Even by today's standards, can you imagine a straight 12 cylinder powering around in a tank? Oh what fun

Not sure what engine these have, but it still might be fun! http://www.driveatank.com/

Paul

[OHVRanger]

I recall they were side by side, actually.

Because the 2 stroke can turn in either direction, in boats they used to face them together and run one backwards-that was a true inline 12. I guess a tank wouldn't be long enough to do that