| Author |
Message |
tom cariello (216.179.4.59)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 08, 2004 - 3:29 pm: | |
Ihave a 6v92 in an 80 eagle bus.The bus does'nt have the power to climb a hill. I had it put on an engine dyno and they said it put out 155 wheel horsepower at 55 mph at 14 psi boost. I never got more than 5lbs boost and that was at 1600 rpm. Does anybody know what these readings should be? I was told the engine is tired and needs to be rebuilt. I was also told that the 6v92 isn't powerful enough and that I should consider putting in a 8v92. Any comments? Thankyou, Tom |
Geoff (Geoff) (66.238.121.35)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 08, 2004 - 10:12 pm: | |
Yes, I have comments. What size injectors do you have? 155HP at the wheels is very low, I think you should have over 275. I can't remember the loss between horsepower at the flywheel and horsepower at the ground, but I thought it was around a 20% loss. If your engine is running smooth and doesn't use or lose a lot of oil it is probably okay. Also, the problem may be as simple as a bad rack adjustment not giving you full power.
--Geoff
'82 RTS CA |
James Maxwell (Jmaxwell) (66.81.43.169)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 12:38 am: | |
Maybe an 8v92 would be better, maybe not. Lot of them out there w/ 6v92, which properly equipped and set up will put out 350hp, more than enough. Geoff's suggestion on the rack adjustment is a wise starting point. Many DD have been condemned when they needed little more than a properly set rack. |
Peter Broadribb (Madbrit) (67.136.216.54)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 6:25 am: | |
Always everyone discusses horse power, it is the torque that gets you moving and hauls you up the hills.
That is why the Series 60 goes so well. Often more than double the torque of the 8v71. The 60 in my Freightliner is the baby at 11.1 liters with a potential max of 365hp and 1450 ft/lbs of torque depending upon computer program installed.
I was told that the 8v71 in a bus was only rated at around 275hp anyway. This would make the rear wheel performance readings at 220hp with a 20% drivetrain loss. Still along way from 155hp.
Peter. |
Geoff (Geoff) (66.238.120.39)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 9:12 am: | |
My book only shows the 11.1 Series 60 having 1250 ft lbs of torque at 350 HP, whereas an 8V92TA set up at 350 HP has 1175 ft lbs of torque. A 6V92TA set up at 350 HP has 1020 ft lbs of torque. |
Peter Broadribb (Madbrit) (67.136.216.54)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 9:26 am: | |
Geoff,
Different book then, mine shows the 365hp option and standard 1350 torque and apparently there is a way to get another 100 torque when it is reprogrammed.
Peter. |
Don Fairchild (209.234.134.61)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 4:20 pm: | |
Tom; I have to ask the same queston and others, what injectors do you have, what turbo do you have, are you getting full throttle, do you have a throttle de-lay, does it smoke, does it use oil,are the air filter and fuel filters clean, how does the engine run over-all. Give us more info and we will help you.
Don |
Ian Giffin (Admin) (64.228.43.91)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 4:43 pm: | |
This thread had originally appeared in WoBN's The Flea Market, posted by Tom. Today, he re-asked the question here on THE BOARD, so to be helpful, I have moved the Flea Market thread over here.
Hope this serves everyone better.
Ian
www.busnut.com |
BrianMCI96A3 (69.34.170.181)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 9:46 pm: | |
Personally, if I had a 6V92, I'd stick with it. First thing I'd do is have the rack run by someone competent, Geoff is right a bad rack adjustment can severely limit engine output at full throttle.
If that made significant improvement in performance, I might leave it at that OR I might look into what it takes to set a 6V92 up to put out 350Hp...
Although, as Peter mentions, torque is the oomph that gets you over that hill, often when you increase the horsepower for a given powerplant you also increase the torque output as well.
It is my feeling that the headache of an engine swap is not balanced by increases in torque of an 8V92, especially when it also comes with a decrease in fuel economy.
Brian |
jim mci-9 (209.240.205.60)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 10:15 pm: | |
removing the huge oil-cooled delco and the coach air will add 10-15 hp.... that is, if you dont need all 250 amps.... i put a belt-driven 27si delco on my mci-9....i gained something..... |
James Maxwell (Jmaxwell) (66.81.49.148)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 09, 2004 - 10:16 pm: | |
Brian: Not always true abt. the mileage. My 350hp 6v92 averages 6.7 mpg. The 500hp 8v92 averages 7.3. Both run 'fairly clean' but will puff some black if I stand on them from a start. Perhaps I should get that rack run in the 6v92? Is there a mileage recommendation for checking the rack adjustments? |
BrianMCI96A3 (69.34.170.181)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 1:30 am: | |
Jmax, for those that aren't aware... and even for those that are... the 92 in 6V92 and 8V92 stands for the cubic inches of displacement of a single cylinder. With All things being equal... engine mileage, engine tune, standard size 90 injectors an equivalant load @ equal RPM, given all that, an 8V92 MUST use more fuel than a 6V92 for a given period of time.
That your 6V92 uses MORE fuel than your 8V92 may be due to a larger injectors in the 6V92, or poor injector pattern possibly, and yes perhaps your rack is out of adjustment... even if it seems to be running fine.
Brian |
Geoff (Geoff) (66.238.120.40)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 7:51 am: | |
Jim-- From what I've seen 8V92's usually get around 2 miles per gallon less fuel mileage than a 6V92. Getting 6.7 from your fully converted bus sounds normal, to get better you have to drop your rpms while driving. Getting 7.3 out of an 8V92 with an automatic is phenomenal!
--Geoff |
tom cariello (216.179.3.73)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 2:46 pm: | |
Thanks for all the help. I don't what size injectors I have,I had the rack adjusted and that helped. The bus uses about 3 qt.oil for 400 miles. I had a new turbo boost installed still only get 5lbs. of boost Would the engine overhaul help the boost too? The guys who adjusted the rack are the ones who told me I need an engine overhaul Thanks again Tom. |
James Maxwell (Jmaxwell) (66.81.43.43)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 10, 2004 - 7:00 pm: | |
Geoff, Brian: I should say that the jury is probably still out on the 8v (It is a DDEC II), but that was the consistent mileage on the trip home when I bought it (2600 miles). And with my 2 lead-foot helper drivers, it ran most of the way at 75mph; abt. 65 when I drove; their claim was "they were road testing it" to which I responded "doesn't matter, I already bought it" or they were breaking it in properly, where I would remind them that it already had approx 45k mi. on it. The over-all weight gain of my conversion will probably be in the 1500# range, + liquid loads and the towed (I removed approx 4400# when I stripped it). As for the 6v, yes it has 9F90s, and generally I run 60-65. I don't care to talk about the mileage when I run it 65-70 for extended time. |