rebuilding the 871 or repower with cummings

[Don Fairchild]

it is your money but if it were me I would find an 8V71TA from transit or a 6V92TA also from a transit. The 8V will run circles around the 6V but you probabley don't care. You want millage so any turbo two stroke will be better than a naturaly asperated engine. I would seriously look at you friends set up. I have several friends the have S&S motor homes with the 8.3 and they don't get any where near the kind of milage. They also can't keep up in the hills, I have to pull over and wate for them quite often. I run an 8V92TA and get 8.4 mpg pulling my chevy 3500 crew cab 4X4.

Don

[la chiva]

guys don't get me wrong l love that old detroit the one in my 4107 is still running strong but it's pissing oil like crazy and could probably use some ajustment and i also have a 4905 with a spare engine it was park for 7 to 8 years i brought it home put some fuel and batteries she did about 3,4 turn and she went runs pretty good to but have no idee the can of shape it is.it's just that here in quebec the good two stroke mechanic are hard to find unless you go directly to detroit and then is $$$$$ the few shop i have tried if they touch it they all want to rebuild it.and i am planning full time in the bus so just trying to prevent breakdown on the road as much as i can

hey Don you talk about a 871ta or 692ta from a transit why? because they are LH turn

[Busted Knuckle]

hey Don you talk about a 871ta or 692ta from a transit why? because they are LH turn

yup

[bevans6]

Where in Quebec are you?

Brian

[la chiva]

hey Brian
i'm in Rigaud about 5 minutes from the ontario border

[bevans6]

I was thinking that if you were at the other end, near Gaspe or Rivier du Loup you might be able to find 2 stroke technicians at a commercial marina.  Did you talk to these guys?  http://www.wajaxpower.com/contact/dorval/  My local shop (Hamilton, Ontario) was a Harper Power, Detroit Diesel dealer, taken over by Wajax a year or two ago.  They have guys who know two strokes, but they are a commercial shop and priced to suit commercial operators - high!  That's why I do my work myself.  Learned a long time ago that I couldn't afford to do anything if I had to pay other people to do my work.

There is a bus yard on AR-30 south-west of the AR-15 interchange, there is a nice old Prevost in the yard that would have a 2 stroke in it.  Maybe they could help you.  

Brian

[la chiva]

thanks brian

i did talk to the guys in dorval  very expensive this is why i'm trying to find a independant
i do most everything myself to take out a engine tranny put another back in i have ne problem with that as a matter of fact i just pull the engine and tranny out of my 4905 today it's now sitting on a pallet.but before i do anything with my 4107 that i'm using i would like to have it check out by a pro. when it comes to tuning ang adjusthing this is out of my league maybe that
all it needs i just ad the bus for 1 years and i been travelling like this i dont really know the history of that engine i'm sure its not the original engine this one is red

[bevans6]

Check out the bus charter guys, call them up, ask for the service manager, ask him if he has any 2 stroke guys would like to run the rack on your bus for you on their day off...

Brian

[la chiva]

brian heyp that was my nexy plan there is one in ontario not far from me  LEDUC coach
my body drives for them he told me in the old days this company use to run buffalo
i'll go see them

[gus]

The 8V71 with V730 is the perfect engine setup for a 4107. I wouldn't trade mine even for a 4-stroke of any kind.

Nothing sounds as sweet in a bus as a 2-stroke DD!!

To do all you talk about it would be cheaper and much faster to just find another newer bus with what you want, probably a lot cheaper!

[RJ]

La Chiva -

Lots of good comments here, let me add my loonie's worth:

Your 4107 doesn't have a frame, in the traditional sense.  The outer skin, bulkheads and floor make up the chassis.  The engine literally hangs off the roof and the rear bulkhead, as you found out when you pulled the powertrain out of the 4905.  Thus, fabricating T-drive frame rails would be a major undertaking which would literally mean taking apart the entire rear of the coach. 

I saw a 4104 in SoCA quite a few years ago that the fellow had put a 6V92TA/HT740 in a 4104 as a T-drive.  Whole rear of the coach was lengthened 24 - 30 inches, increasing the rear overhang by the same amount.  Also made the coach "look funny" - the proportions were slightly "off."

The reverser V730 is quite rare, as are the few 4-stroke V-drives mentioned by BW.  Just not that many ordered. . . especially since GMC got out of the bus building business.

Why not do some PM on the current engine to see where the oil's coming from?  It may as minor as loose bolts/fittings, etc. - wouldn't be the first time!  (There was just a post recently where a bolt had worked itself loose under the alternator, leaking oil everywhere!)  If the engine runs pretty strong, sometimes if it ain't broke, don't fix it!

These engines will often stop "using oil" once it's discovered that somebody put multi-weight into the crankcase, instead of straight 40wt, and it gets changed to the proper type.

And, as Gus posted, if you really want a 4-stroke, buy a newer, already converted coach - the market's in the toilet nowadays, so great deals can be found with a little searching.

FWIW & HTH. . .

[la chiva]

well guys
thanks to all of you for your advice and comments i finally found a 2 storke mechanic
not to far from me i'm having both my engine check next week just went to pickup my 4107
yesterday from storage didn't even need to charge the batteries first turn she went and purs like a cat

[TomC]

Don Fairchild turbocharged my 8V-71.  We put in 7G75 injectors for 375hp and 1125lb/ft torque (compared to 300hp and 800lb/ft torque with 65 injectors and no turbo).  Turbocharging an 8V-71 REALLY wakes them up.  Yes there is more heat, and I have to slow down on hills in summer, but you have enough power at highway speeds to pass someone!  Keep with what you have.

Yes you can change your engine to a 4 stroke.  The engines that have been used with the V730 using a reverser gear are Detroit Series 40, 50, Cummins ISC, ISL, ISM.  As with any change over, it takes alot of engineering.  Even my turbocharging was an engineering feat since I added an air to air intercooler.  I ultimately had to upgrade (change) my muffler, air cleaner, radiator, and add an auxiliary transmission cooler with fan. I now have 15,000 miles on the turbocharging and the only thing I've had done is new injectors.  I didn't rebuild it to a turbo spec, hence my fuel mileage isn't as good as it could be (the turbocharging cylinder liners have shorter ports allowing a longer power stroke before the exhaust valves open up).  Rebuild your engine to a turbo spec and you'll be tickled pink.  My mileage is the same as when the bus was not turbo'd, but the performance is drastically different.  Good Luck, TomC

[Busgeek]

That's a big chunk to bite off, even if you do all the work yourself assuming you can find all the parts you need.   Also what I know about late model Cummings engines,  personally I won't consider that conversion at all!!!   Hope this helps.   Busgeek.

[la chiva]

well guys

finally found a 2 stroke mecanic work for detroit and does work on the side
he went over the engine needed a rocker job worn out pretty bad so the timing was off
fix a few leaks cost about $2200 and said my engine will probably outlive me definetelly
much better then rebuilt or repower for the difference in price i can put fuel for a while