| Author |
Message |
Hiro Protagonist (205.183.46.161)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 05, 2001 - 4:05 pm: | |
What is the difference between the 8v71 and the 6v92TA in regards to power and fuel consumption. I am looking at the RTS and I can get it in either the 8 or 6. I understand the 6 is a turbo and the displacements for both engines is nearly the same. What kind of fuel milage would I expect from on to the other? I know gearing and tranny play a role in mpg, but I am just trying to get an idea about power vs. fuel consumption.
Thanks you guys! |
jimnh (172.162.12.194)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 05, 2001 - 6:10 pm: | |
The two engines are functionally equivalent with the 350hp 6v92 obviously having more horsepower. Advantage of the 6v92 is 25% less stuff when it comes time to rebuild. Fuel mileage is really dependent on the bus and your right foot. It takes the same amount of energy to move the bus down the road regardless of engine. Now, if you use the extra hp to get up the hills 20mph faster.... that burns more fuel. Given the opportunity to have either engine in comparable condition and equal money, give me the 6v92.
Jim |
Terrance A.Haag (Mrbus) (205.188.195.49)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, February 06, 2001 - 5:24 pm: | |
Hiro,
At the risk of really starting something, I am going to try to answer your question.
I have been involved with the maint. part of comercial motorcoaches for way too many years, so I have had some exposure to both these engines. The 92 series has not been a great money maker for us, but in a conversion, you would never put enough miles on it to make much difference. We have traditionally had very poor results with overhauling these engines. We even went so far as to have them done at the local Detroit shop, same result, we tried purchasing a rebuilt from one of the major advertisers in all the bus magazines, same result. But like women and cars, everyone will have their personal choice and will praise their attributes.
The 8V71 is deffinitely "old Technology", but it still works, and you can find someone to work on them in almost anyplace on the planet.
As far as horsepower differences, we run the 8Vs right along with the 92s, and they always arrive at the destinations together.
So, after all this, it probably comes down to which engine you can buy the cheapest.Just make sure you get someone with enough experience to evaluate whatever you buy.
I am still running the old 8V71 in my Eagle, and it surely is not as fast as the newer coaches with the big Cummins and 60 Series DD, but I am not trying to win any races. I figure that all those guys passing me are in a hurry to get somewhere, but I am already exactly where I want to be, rolling along in my coach, so I have no need to rush.
Gus Haag |
dougthebonifiedbusnut (24.147.157.103)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, February 06, 2001 - 6:52 pm: | |
i might be mistaken but i dont think anyone has answerd the origanal question where dd are concerned the letter designations mean 6 or 8 or even 4 tells you how many cylenders you have the 71 or 92 tells you how many cubic inches per cyl you have and the v tells you that the engine is in a v configuration no v it is inline so if you have an 8v71 well i guess you can figure it out oh ya the t and the a mean turbo charged and aftercooled. |
Geoff (206.173.201.236)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 07, 2001 - 9:02 am: | |
To answer the original question-- everything being equal mechanically (running condition), the RTS with the Silver 6V92TA is by far the better choice and superior engine. Both are set up stock at around 277 HP, in order to get more horsepower out of the 8V71 you have to take the back of the engine apart and advance the timing, then install bigger injectors to get 318 HP. With the 92, all you have to do is install bigger injectors to get 350 HP (the turbo does not have to be changed on an RTS). The 6V92TA will give you more hill climbing power with the turbo, and you can get 7-8 mpg over the road. |
Peter Broadribb (Madbrit) (216.67.194.194)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 07, 2001 - 11:01 am: | |
Whilst we are discussing HP on these motors, can anyone tell me how I can tell what HP the 8V71 in my 1976 MC-8 has, or would have had when new? I have been told lots of "ifs" and "possiblys", just wondered if there was a concrete method such as year related install dates for 318HP motors or what. Thanks.
Peter. |
Geoff (206.173.202.67)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, February 07, 2001 - 8:21 pm: | |
The "ifs" and "possiblies" are right-- you have not owned the bus since 1976 so you don't know what you have-- dates won't work. But I can make a good guess-- if you take the valve cover off and look at the injectors you can see what size they are. If they are size 60 you probably have a 275-270 hp 8V71--the original horsepower when it was new. If you have size 65 injectors and your bus doesn't smoke black under load, you probably have 318 HP @ 2300 rpm, or 304 HP @ 2100 rpm. |
madbrit (216.67.193.193)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 08, 2001 - 1:52 am: | |
Geoff,
Thanks for the info.
Peter. |
Wulf P. Ward (63.59.218.4)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 29, 2001 - 9:55 am: | |
There is only on little thing I like to add. I converted 2 RTS buses, 1 Model 10 Eagle and a Neoplan Spaceliner. They all cost me about
$ 100,000.00 when completed. If I would have put the money into a bank it would earned me about
$ 4,000.00 per year. Before every time I pull out and that is two time per year I spend some money going over some of the bus. Insurance are about $ 800.00 on a $ 100.000.00 bus per year. Driving 6,000 miles per year I think I pay
$ 1,250.00 for diesel at 6 MPG or $ 937.50 at 6 MPG. It cost me $ 0.21 per mile to drive my bus and not going anywhere at all it cost me $ 0.80 per mile. Now if you are delivering Pizza in your bus then mileage does matter. |
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