2 cycle alternative

[JohnEd]

   I haven't heard any good comment about the 2 cycle except amoung us bus nuts.  I have heard a lot say that it should be avoided at all costs and I thought that must be a rich guy talk'in.  An ex-cement truck driver got a misty whentalking about the 8V92 he used to drive that was all "hopped up" and could "throw that truck down the road".  He had no idea how long it lasted.

So here's my question.  What can be swapped into the engine bay and connected to the AT that isn't a 2C?  Preferably a Cummins.  Are there other swaps that make more sense from a difficulty point of view?  My hunch is that using the stock 2c would be the easiest and cheapest repair of a trashed engine but I am dirt stupid here.  Feel free to talk down to me. 

Thanks  John

WOW!  Great responses, no kidding.  Thank you all very much.

John

[DuaneMC7]

Hi John,

You will hear most people tell you to stick with an 8v.. because a swap to a four stroke is to much money.

If you are going to pay some one to do it for you than thay may be right BUT, if you can do the work your

self than it is not the huge amout of money people say it is. I bought a 96 cabover with an M11 and a 10sd

drove it home for $4000. I could not find just the engine for $4000 and having the whole truck I have most

all the parts I will need for the swap.


Good luck, Duane

[oldmansax]

John

I may be in the minority here but I don't understand why the 2 cycle DDs get such a bad rap. I drove several of them hundreds of thousands of miles all over the US and parts of Canada & Mexico when I was in the trucking business. At the time, the weight limit was 70,000# which gave us an effective limit of 73,280#. (Our buses run 30,000# to 40,000#) I had no more problems with them then you would expect with any other engine. They leak a little and don't have as much power as some of the newer engines but they are long-lived and dependable with a little regular maintenance. Assuming your bus came with a DD, I would consider keeping it.

Have Fun!   TOM

[gus]

There are millions of these engines in use all over the world. Every small boat in the Navy used to use them. Power plants, oil fields and many, many trucks have used them over the years.

They are perfect for long distance highway cruising or steady use such as a generator. My only complaint is poor low end torque but they sure sound nice when wound up and they sure are smooth. Big 4-strokes will shake your teeth out! They are especially good with ATs.

[Brian Diehl]

I'm currently investigating the possibility of using a Cummins ISL.  The ISL can be had in configurations up to 400 hp and 1250 ft/lbs of torque.  It is 8.9L and weighs about 500lbs less than a 6v92.  My research to this point indicates it is about 2 inches longer than a 6v92.  I still have lots of questions to get answered, but I have strong suspisions an ISL can be put in the rear of any MC9 or 96A3.

[JohnEd]

Old and Gus,

I am with you to a point.  The main reason I have heard was more MPG and then they are supposed to get half the miles to a overhaul of a four stroke.  Dirty is a complaint I can live with.  A mech I spoke with said he loved the 8.9 Cum because it was simple and lasted and was efficient.  I have no experience.  I also heard the MII was the best.  Lots of people like the 2cycle for power.

I think the MII in the truck was the best.  If I ever get the room I think I will do that when I need an engine.

Great hearing from you all.

Thank you

John

[TomC]

I can tell you from experience, that both the 8V-92TA and the 6V-92TA are 500,000 mile engines-had both in trucks.  Granted there are some maintenance items you have to do in between-like bearings at 200,000 miles; blower, turbo and injectors at 300,000 miles; then bearings again at 400,000 miles; then overhaul at 500,000 miles.  I doubt most of us will ever see 200,000 miles of use from our conversions.  The 2 strokers are very reliable, granted they don't get the fuel mileage or low end grunt of the 4 strokers, but for about $10,000, you can overhaul your engine completely and be set for the rest of the life of the conversion.  As much as I like the Series 50 and 60, I chose to overhaul my 8V-71 and now am putting the final touches on the air cleaner enlarging for my turboing project.  You shouldn't be so concerned with the bus that gets 6 mpg or goes up the hill at 35 mph. Exchanging for a Cummins ISL or ISM will cost at least $20,000 and then you'll have to work at numerous bugs.  Just work with what you got-it's ultimately the cheapest.  Good Luck, TomC

[lostagain]

I read once that the 71 series DD was considered by the writer (I can't remenber who, but it was in a diesel magazine not too long ago) to be the best diesel engine ever built, because of reliability, longevity, simplicity, etc. Sure, a modern 4 stroke would be nice, but how much $$ can you reasonably sink into the old bus?

[RJ]

JohnEd -

You left out one tiny bit of information in your original question:  What make & model bus do you have?

Reason I say that is if it's a V-drive coach, your repower choices are far narrower than if you have a T-drive.

Another question you have to ask yourself is: "How many miles per year am I going to be driving my bus"

If you're a typical busnut, it will be less than 5K.

How many years would it take you to payback the $$$$$ from hassling a repower to something different than what came in the coach originally?

Suggest you pick up a copy of Larry Plachno's "Beginner's Guide to Converted Coaches" for some valuable insight.  Some comments in this book are a little dated nowdays, but the concepts are "right on".

Also,  IBME that those who bad-mouth a two-stroke often don't have a lot of experience with them.

No other diesel engine ever designed can be configured as many ways as a Detroit can.  TTBOMK, there isn't a single four-stroke out there that can run either LH or RH rotation, for example.

FWIW & HTH. . .

[TomC]

Russ- you are correct in that there isn't another engine made as versatile as the 2 stroke Detroits.  Just in the 71 series, you could have an engine that produced 28hp- 1-71 @ 1800rpm-made only for farm type generators-very rare, all the way up to the 24V-71TTA marine engine that was rated at 1800hp at 2300rpm.  Or to put it another way, from 28hp all the way to 640hp in the non turbo engines, so you could use the same injectors, pistons, liners, etc.  In the inline engines, you could run the engine block with the blower on the right or left, with the exhaust ports on the right or left, and with right hand or left hand rotation.  Seen even a 12V-71 standing up on end for a oil rig generator to conserve space.  They had a water cooled thrust bearing at the bottom to support the rotating mass.

I found out Friday that Detroit is still making 2 strokers, just for military use. I believe that includes the 6V-53TA, 8V-71TA, 12V71TA, 6V-92TA and 8V92TA.  Unfortunately, they have no plans to reopen the production to the public.  Good Luck, TomC

[David Anderson]

That's interesting info, Tom, that DD is still making these engines for the military (gov't).  The EPA won't let us have them, but it's ok for Uncle Sam.  Typical government speak.  Do as I say, not as I do.

David

[Paso One]

That Maybe a good thing. Most of us busnuts are Milatant   So they should sell us parts

[lostagain]

I heard that DD is making new 2 strokes for the military as welll. The military does not care about emmissions.

[Lee Bradley]

You think swapping engines is hard in a bus; try it in armored equipment. Armored equipment is built around the drive train. APCs run 6v53s and 155 mm howitzers SP run 8v71s and I'm sure there are others.