Engine Question!

[Utahclaimjumper]

It would be enteresting to see a "turbo Motor", seeing as a "motor" is an electrical device, most turbos I ve seen are on "engines" as in internal cumbustion.>>>Dan

[turbobrat930]

It would be enteresting to see a "turbo Motor", seeing as a "motor" is an electrical device, most turbos I ve seen are on "engines" as in internal cumbustion.>>>Dan

HAHAHA...very funny!!  Yes, you are indeed correct... motors are electric, engines are internal combustion... 

[blue_goose]

There is a problem with your engine if you don't get more MPG with the series 60 than you did with the 8v92.  Any 4 cycle engine that is set up like it should be will get better milage that a 2 cycle when running at the same power and speed. 

Jack

[kyle4501]

Maybe not if the gear ratio puts the engine operating at the 'wrong' rpm.

[buswarrior]

An S60 tied to an HT740 and the old 3.7 gearing won't give you much different fuel mileage, cuz she's still having to spin up at 2000 rpm, where she gets LOUSY fuel mileage.

Some fleets made that engine/gearing choice early on.... oops.

happy coaching!
buswarrior

[makemineatwostroke]

Jack; I am set on 550 hp I have been up to 625 hp any honest trucking outfit will tell you they are getting around 5 from the 60S it was different several years back before the EGR engines (mine is non EGR).Kyle you are right on about the gearing mine are too high (3.73) for the 8 speed Cat CX 35 transmission it needs to be in the 4.56 range.Jack I have read to many print outs from 60 series and know they get around 5 to 6 average for the 14L what do you average on your 50S with a 740 and the Eagle gearing I would venture to say 7 to 7.5 the Greyhounds with that setup got about 6 to 7 mpg according to readout  and a 500 hp 8v92 DDEC will do the same at 1400 to 1800 rpms all day and all year long      have a great day

[Zeroclearance]

makemineatwostroke> What are the mileage numbers that you have seen for 500HP 12.7ltr S60?   And BTW, sorry for asking what is your first name?   I owe you a Thanks on a previous thread!   

I am getting 6.8 to 7.2 mpg, depending on how hard I push it.

[Songman]

There is a problem with your engine if you don't get more MPG with the series 60 than you did with the 8v92.  Any 4 cycle engine that is set up like it should be will get better milage that a 2 cycle when running at the same power and speed. 

Jack

Another common belief that is not true. People in this thread have already shown that their own experience disproves this belief. And like Uncle Ned says, I have Don nearby and all of my experience comes from what I have seen from engines he has built or tuned. I have not seen anyone on this board with a 4 stroke getting the mileage he gets out of his 8V92, and this while towing his 1 ton dually. 4 strokes are great for bragging rights, but a good 2 stroke done right can be just as dependable and even more economical... Not to mention a heckuva lot less expensive!

[uncle ned]

Songman

   Any one that knows anything about flow through a engine should look a dons pistons and liners compared to detroits.


Just wish i had meet him sooner before i replaced the ones in my 6v92

uncle ned

[blue_goose]

Answer to fuel MPG for my Eagle.

I have driven my Eagle 186,000 miles in the past 23 years.  When I bought the bus I rebuilt the 8v71 to a 318.  In 106,000with the 8v71 and a 3.76 rear I got about 6.5 MPG.  68,000 miles with the 8V92 and a 3.36 rear about 5 MPG.  Now with the series 50 for the 12,000 miles that I have put on the coach I am getting a true 7.7 MPG.  Allison 740 for all 3 engines and the coach weight is about 39,000 lbs.
Jack

[belfert]

I have a Series 60 engine and a B500 tranny in my bus.  Gear ratio is 4.10.  My Series 60 is factory installed.

I got an honest 7.72 MPG on a 4,000 mile trip crossing the Rockies this fall.  The MPG included some 40 hours of generator time too.  The bus was filled at the same pump at the beginning and end of the trip.  The fuel tank design is such that it is easy to fill the same every time.

The bus was loaded pretty heavy with the bays jammed full and nine people inside with a small 500 pound trailer attached.  Weight is 37,500 lbs without passengers or cargo.

[blue_goose]

If your Dina is like the ones that I have driven it is only set up for 5 speed.  With the 4.10 rear you could reprogram the B500 to a six speed and get even better than you are now.  I put a series 50 in my son's bus and it has the world 6 speed with a 4.10 rear and dose great.

[luvrbus]

Guys, compair apples to apples hp has to have fuel I get 7-to 7.5 on my 8v92 set at 435 hp up it to 475hp drops downs 5.5 to 6 mpg with 3.36 gears my bus weighs in at 41,000 lbs I could do better when I have time and go see Don and get the air and fuel ratio right.

Not a thing wrong with the 2 stroke I had a new C15 Cat to install in my bus but passed because of the expense and after research found out the mileage was going to be less.I don't know what the hp on Jack's series 50 is most are 320 hp you see a few at 350 hp and Belferts Dina all I have seen are 11.1L and around 365 hp. remember a Clydesdale eats more than a Shetland. I know a guy that has a series 50 in his 01 Eagle and he struggles here in the West in the mountains                     good luck

[Songman]

Don gets close to 9 out of his 8V92 pulling his dually. So I will say again that I have not seen anyone with a 4 stroke on this board getting close to what Don gets out of his 8V92. He does have a 6-speed so obviously that helps some but the fact is that his engine is set up right. We've got his engine out of the bus right now doing more things to it so his mileage will probably go up even more!

I am not trying to sell anyone on one engine over another. Just responding to the myths about 2 strokes vs. 4 strokes. Detroit 71 and 92s can be clean engines. They can be strong engines. And they can be efficient engines. And in almost every case where that is what your bus came with, it is the least expensive engine. (ie - If your bus came with a S60 obviously putting in a 2 stroke would not be the least expensive answer.)

If you think the answer to Don's mileage is the transmission, I submit that in that case it would still be cheaper to just upgrade your trans that it would be to totally redo your bus to install the 4 stroke. Not saying that the trans is what gives him the mileage, just that some might think that is the difference.

Like I said originally, I am pulling my 6V92 in favor of an 8V71T. The 6V just doesn't have the power or torque that I want in my Eagle. Going to the 8V will allow me to not have to run wide open all the time and it will be better for my engine plus give me better economy. If I can find a 6-speed I can afford I will put that in at the same time. If not I'll keep the 748.

I think some have mentioned above, the best engine for your bus is the one that is working! Fuel economy, cost of upgrades, bragging rights... those are all extras that can come down the road. With the economy on shaky ground, I would feel much better just rebuilding my current engine, no matter what it is, than I would trying to lay out the huge expenditures of changing to something different. From what I have seen, any small gains that someone might think they see by changing from a 2 stroke to a 4 stroke will never recoup the money put into the swap.

[TomC]

With my original engine (8V-71N set at 318hp) with the V730 and 4.56 rear end, I got 4.5-5.5 mpg (summertime driving with the gen running).  Now with the 8V-71TATAAC (Turbocharged Air To Air Aftercooled), this last August went on a 1200 mile loop in California from L.A. to Mammoth, Carson City and Virginia City Nv, Lake Tahoe, Sacramento, San Francisco and home and averaged 6.2 mpg with the gen running alot of the time since in 12 days only was in an RV park only 2 nights.  While the fuel mileage is not a big jump, what is the big jump up is the performance.  Especially on this trip with some passes near the 9,000ft mark, and didn't have any smoking or slow downs in the hills. 
Rebuilding your 8V-71 into a turbocharged engine and changing the transmission to a World 5 or 6 spd (can be programmed a 4 spd [gears of which are almost identical to the HT740] a 5 spd [.74 overdrive] or a 6spd [.64 overdirve]), you'll get close to the 4 stroke economy and exactly to the 4 stroke in power.
When I had my Kenworth with the 8V-92TA in it, I regularly out pulled Cummins and Caterpillar 400's-much to the amazement of their owners.
Personally-my only real concern with the 2 strokers, is finding qualified mechanics on the road that still know how to work on them.  If I could take Don Fairchild with me, I wouldn't have the worries.  This is one of the big reasons I am converting my truck into a motorhome.  The Caterpillar 3406B mechanical engine is still being made by Caterpillar under the model name of 3406C, and most any mechanic knows how to work on them.
The biggest factor to fuel mileage is how you drive your bus within the gearing it has.  If you go down the road at 2300rpm at the 76mph with a 3.73 ratio and direct top gear transmission, you're not going to get the fuel mileage that you would at a leisurely 55 mph.  In fact the difference could be over 2 mpg between 55 and 75 mph.  Sean with his giant Neoplan only cruises at 55mph, 50mph on secondary roads.  Besides, aren't we out here to see the sites?  I cruise at 58mph which is right at 1850 rpm, that is an easy speed to keep all day long.  Good Luck, TomC