Question's For Tom C.?????

[wvanative]

Tekebird- I beg to differ in your opinion of the Series 50.  Except for the fact that it is a tall engine like the Series 60, and gives off some vibration at idle (not too much if you have the right engine mounts), I think the Series 50 is the perfect bus conversion engine.  You can get 350hp and 1150lb/ft torque from it, it weighs about as much as the 6V-92, will get close to 10 mpg, is a proven 1 million mile engine, has a good Jake brake, and is quieter than the 6V-92.

As to changing out the 8V-71-at this point, turboing the 8V-71 to get more power, that is a good choice-I did it and am extremely pleased with the results.  I went from 300hp and 800lb/ft torque to 375hp and 1125lb/ft torque with 9G75 injectors.  You can go with 90 injectors for 450hp and 1350lb/ft torque-that takes you into the 8V-92 realm of horsepower. It is MUCH easier to use the 8V-71 again, rebuilt up into a turbo and air to air intercooled engine rather than replacing with a 6V-92.

If you still want to replace the 8V-71, I would NOT use another 2 stroke in its place.  Rather a Detroit Series 50 or 60, Cummins M11/ISM, Caterpillar C12, C13 of the 4 stroke variety will be more prudent since the 2 stroke mechanics are getting fewer and fewer in between and the straight 40 weight Delo 100 type oil is getting harder to find.  Using a 4 stroke engine, especially one that is electronically controlled will get you an engine that will get 8-10 mpg, compared to the 5-7mpg that most of us are getting with the 2 strokers.  Good Luck, TomC

This post on another thread got me to thinking, I have been leaning toward a 50 series and a Eaton 9 speed auto. Would this combo work in say and MCI-9 what would be pro's and con's? What kind of fuel mileage would you think it might get? I am looking for a shell with no engine or trans, so I can put the power plant I want into it, and have the engine gone through before hand. I found one this spring close but it was only 96" wide and I want a 102" but it sure was a good price at $1630.00 LOL

WVaNative

[Busted Knuckle]

WVaN,
As I told you a long time ago on the phone ya gotta good plan! But I do wanna know where ya gonna find a 102" wide 9? Shoulda snapped up that 96A! IMOHO FWIW   BK 

[RJ]

WVaNative -

MC-9s only came 96" wide, you won't find a 102" width in that model.  Start looking for a 102A3, 102B3 (rare), or a 102C3 model.  "C" models have 3" additional headroom, perfect for RV use w/o a roof raise.

Highly recommend that you just purchase a coach with the powertrain you want in it, even if you have to stretch your budget slightly to do so.  Vast majority (over 95%) of 102" coaches all have automatics in them, which, for RV use, is much more desirable than a stick shift.

Oh, there's no significant difference between an OEM automatic and an OEM stick shift when it comes to fuel economy in the vintage 40-foot coaches most commonly found in the conversion hobby.  BTDT.

FWIW & HTH. . .

[TomC]

Greyhound did many conversions taking the 6V-92TA out and installing the Series 50.  Even though on paper they put out about the same power, the Series 50 pulled much better.  Also, because of the higher efficiency of the Series 50, they took out one of the radiators and replaced it with the air to air intercooler.  With the Allison automatic, they were getting 8-10 mpg with the Series 50.

In order to get a 102" (which I would highly suggest-I have one and that extra 6 inches is really noticeable [that's what she told me too]) you have to go with either the monster MCI6 or with the 102A3, or my choice the 102C3 since it has 6'10" head room.  Mike has one in the classified on this site for $28,000 with Series 50 and Allison.  This would be my choice for the next bus conversion (actually my next conversion will most likely be based on a Freightliner truck). 

Eaton did make a 9 spd autoshift- it was called the CEEMAT (can't remember what all it stood for [I think Converter Electronic Engine Mechanical Automatic Transmission]) but it had a torque converter instead of a clutch, and was problematic-too bad since the torque converter is far superior over the clutch.  Now Eaton makes two versions- the Autoshift that uses a clutch pedal to stop and start in 10 and 18 spd versions (both of these can be used with mechanical engines-which are called the Autoselect-where you have to do the releasing and reapplying of the gas pedal your self during shifting, whereas the Autoshift is totally automatic-no gas pedal changes during shifting), and the no clutch pedal automatic clutch version that is the Ultra Shift in 10 and 13 spd versions.  Any of these automated transmissions will give you the maximum possibility at best fuel mileage, but with the negative of slow acceleration from a signal when compared to an Allison.  If maximum fuel mileage is most important, then the Auto/Ultra shift will be the transmission.  If maximum performance, especially around town under 40mph is more important, the Allison is the way to go.  Personally- the Allisons world transmission with 6 spds with the top two being overdrives are the way to go.  They have adaptable computers to your driving techniques and loading, and they are just plainly fun to drive.  With careful acceleration and driving techniques, the Allison can get almost the same mileage as the automated Eatons.  Just remember on the Eatons, all the maintenance items on the transmission is on the top-making servicing a bit on the challenging side in a bus-whereas the Allison has all maintenance items on the bottom.  Good Luck, TomC

[Don Fairchild]

Tekebird;

I had two customers I used to build engine for one in AZ and one in texas change out to the 50S engines in there MCI. The one in AZ made one trip with his and traded them off, He did not like that they would not pull the hills, the miliage was worst than the 6V92 and they vibrated so bad the customers complained. on the other hand the people in Texas love theres. I guess it depends on who is doing the change over and what you expect to gain out of the up grade. The other problem I see is they don't make the 50 anymore.

Don

[tekebird]

the first series 50 retrofits were done b Stewart Stevens for CA Govt Subsidised operators.  CARB Mandated

no good feedback from those several hundered buses.

[wvanative]

WVaN,
As I told you a long time ago on the phone ya gotta good plan! But I do wanna know where ya gonna find a 102" wide 9? Shoulda snapped up that 96A! IMOHO FWIW   BK 

[/color]

Yeah BK, I remember now LOL, its that "old timers disease" you know what I mean Vern.
I think I remember you said to only put a "big butt Cat"  I think butt is a nicer word so I can listen to my kitty purrrrrr. Is that about right??? LOL. I know I been picking on you a bit lately, but only because your my buddy, and I figured you'd be one of the first to give me a finger pop on the noggin and say "think man" Cat,Cat, Cat. Well I already have three cats and they eat more than I do LOL.

Tom thanks for your reply but in comparison how would the Eaton out perform the Allison 500 or vice versa say city, flat land, and mountains???

Yeah Russ I have to admit you got me there on the 96 wide & the 102 wide, but that is what this site is all about, asking questions and learning. but to my credit I did know that the 96" was not as wide as the 102" LOL, and that I didn't want it. The reason I want to do my conversion this way is I have a friend who will go through the engine first, and will install the engine & trans for me at no charge.

Tekebird, the 50 series is not set in gold but my understanding is it has more power, and pulls hills better with the right trans. I could use the 8v71 and do what Tom did with his because there are plenty of both of these out there to be had at a good price, and all I have to do is buy parts for them if needed when we go through the engine. I will help him with it and he said by the time we are done I'll have a much better  over all understanding of the the engine & trans and my bus.

Thanks guys for all your help, I learn something new everyday from you guys

WVaNative

[TomC]

Performance wise, the Allison will always out accelerate the Autoshift in any circumstance.  The main difference is in the initial price between the two and that the Autoshift will get better mileage since it isn't spinning rotating clutches and planetary gears.  The Allison just naturally has about 20hp of drag built into it.  Considering our driving habits, the relatively low yearly mileage we put on, and that you want the bus driver friendly, I'll always suggest the Allison over the Autoshift.  But- the autoshift is always better than the manual transmission-especially the lame excuse for a transmission-the 4 or 5 speed manual.  You should at least have a 7spd with a 13 spd being the perfect manual transmission with a gear for all circumstances.  The 18spd is a way over kill for buses-perfect for trucks though.  Good Luck, TomC