Belt question or re-verifying

[Ace]

Our H3 has 3 belts. One wide belt to run the fan pulley and 2 twin belts that run the a/c compressor. I think it would be ok to do this with no harm but hey, that's what this board is for so here goes. Our over the road original bus air does not work. I thought at one time about getting it fixed but thought about taking that money and starting the conversion instead. I know that running the bus air takes more hp which means lower fuel mileage. Since the a/c doesn't work, is it ok to remove the belts from the compressor or does it only matter if the compressor is under a load such as when the a/c is working and on? I look back there when the motor is running and I see these belts doing absolutely nothing but turning a compressor that isn't doing anything! Removing these twin belts would mean that there would only be ONE single wide belt for the fan! This is an DD 8v92 if that matters and I have already begun the task of removing the bus air.

Thanks...

By the way, our trip to T-ville resulted in the use of 1 gallon of oil total for the whole round trip which was about 1000 miles. Is that good or bad?

Oh anyone need a bus air or parts from a H3 Prevost? 

Ace

[RJ]

Ace -

Since you're removing the over-the-road AC, there should be no problem removing the compressor drive belts.

The difference in fuel economy between operating AC and non-operating AC is negligble - you might get 6.6 vs 6.5, as an example.

Oil consumption is about normal for a two-stroke.  New rebuilds may go 2K on a gallon, "broken-in" somewhere in between.  500 miles/gallon is rebuild time.

Call the maintenance dept at your local charter bus companies and ask if they've got any H3s in their fleet.  If so, you might have just found a source for your take-out parts.  (One busnut on the MCI Yahell group actually had a company pull the components they wanted from his coach for him!)  The compressor alone should interest someone - just make sure the lines are plugged so no debris gets inside.

Good Luck, and HTH. . .

[belfert]

The A/C compresser has a clutch on it so you aren't actually turning the compresser when the A/C is not turned on.

Brian Elfert

[TomC]

Ace- if the belts are just turning the compressor pulley and not the center part of the compressor, take them off-as a matter of fact, if you're not using the over the road A/C at all, then take them off!  As to the oil consumption, you're getting close to the magical 800 miles a gallon when an overhaul is suggested.  With the better piston kits now, the 8V-92TA should be getting more like 2,200miles per gallon of oil.  We went to Arizona for 2,300 miles, then down and back to San Diego (250 miles) then drove to Bakersfield (125 miles) for a total of 2,675 miles and the oil was just below add-and that's on an 8V-71N.  Many times, you could just get by with a piston ring replacement.  But with the 92 series, the problem with that is, you don't know what shape the cylinder liners are in.  When the 92 is overhauled, even if the cylinder liners are not worn, you should pull them out to inspect the wet area where the coolant touches it for pitting.  If pitted at all, replace.  If not, then you can reuse and by all means install new O rings to prevent future leaks.  The one big advantage to replacing the complete cylinder kit (cylinder liner, pistons, rings, connecting rod) you will have a completely matched set since Detroit is constantly changing the designs on the interors of the engines.  The design between the original engine when the bus was new and the designs now will be very different.  For instance, on the Series 60, about the only thing in common with the first series and the new ones now are the block and head castings.  Everything else has been redesigned.  Ace- don't wait to long-it is always better to rebuild before the engine takes a dump.  When that happens, it becomes expensive-sometimes adding twice to the cost.  Good Luck, TomC

[Busted Knuckle]

The A/C compresser has a clutch on it so you aren't actually turning the compresser when the A/C is not turned on.

Brian Elfert

Yes but if the clutch should lock up  & I've seen it happen things get ugly fast!  Ace if yer removing the air anyway do yerself a favor and go ahead and lose the belts! Might as well go ahead and lose the compresser too. It'll free up space & weight too! FWIW BK 

[Ace]

Tom, this motor has only about 35ish thousand miles since being rebuilt. I don't think it needs a rebuild yet!

It maybe leaking a little oil someplace and that could be the most usage from this past trip. Nothing looks wet on the top but down on one side I see some wet area that I will have to investigate. Doesn't look like much but any leak is oil loss! It doesn't smoke much either!

As for the belts? Thanks... consider them gone!

Ace

[Burgermeister]

Ah!,  but who did the rebuild?  Did the owner tie the hands of the mechanic, etc.?

There's more than simple oil consumption (leaking is loss, not consumption) to evaluate whether an engine needs attention.

Here's hoping that it's loss and not consumption and you have a leak from a loose screw or something.  If it isn't, take a vacation in the direction of Luke or someone else whom you respect!

Onward and Upward

Good Luck!

[Hartley]

Detroits tend to leak a little around the sharp edges. At your mileage and low oil loss I wouldn't worry about it for
another 100,000 miles or if something big happens. If you get to 5 gallons per 1000 miles I would look for a leak
if it isn't burning the oil and making smoke. The extra lubrication on the back of the bus helps make it easier
for air to flow around there. Keeps the airstream lubricated and tail gaters back a little farther.

On the issue of a/c belts.. I just used a razor knife and zapped them off, that way I didn't have to remove the blower
belt.

[DrivingMissLazy]

Wow!  I never heard of anyone using 5 gallons per 1000 miles. That would be, in my opinion, a very serious oil problem, whether it is leaking or burning it.

Based on my experience and talking to many others, I would speculate that you are at the upper limit of usage.

I would suggest one thing you do. Run it one gallon low for several hundred miles and see if it keeps going down. Many have indicated that in-accurate dip stick marking or other factors cause this symptom and usage significantly decreases after you get to this lower level.
Richard

Detroits tend to leak a little around the sharp edges. At your mileage and low oil loss I wouldn't worry about it for
another 100,000 miles or if something big happens. If you get to 5 gallons per 1000 miles I would look for a leak
if it isn't burning the oil and making smoke. The extra lubrication on the back of the bus helps make it easier
for air to flow around there. Keeps the airstream lubricated and tail gaters back a little farther.

On the issue of a/c belts.. I just used a razor knife and zapped them off, that way I didn't have to remove the blower
belt.

[RJ]

Normal "full" position on the dip stick is one inch (1") below the engine block/oil pan interface.

Check to see if yours is accurate - mine wasn't!   

HTH. . .

[DrivingMissLazy]

Also make sure you are using the correct oil. My consumption dropped about 50% when I switched from 15/40 to the correct 40 weight. BTW, that was before the days of the internet and busnut boards. LOL
Richard
Richard

Normal "full" position on the dip stick is one inch (1") below the engine block/oil pan interface.

Check to see if yours is accurate - mine wasn't!   

HTH. . .