8v92 475hp exhaust issue

[tr206]

When I bought my bus it had a 4" straight pipe (really restrictive for 475 8v92 right or wrong? ) she would get warm pulling the mountain passes but managable with a radiator mister so I thought I would put a 5" exhaust system on it took 3 elbows for room to get it down and out the back with a short straight throw muffler I also wrapped the pipes to keep the heat down in the engine compartment hoping to solve the problem all together to my total surprise it wouldn't even pull the hills of north dakota on a hot day without having to pullover and let it cool down so thinking stuck thermostats I put new ones in no difference pulled the muffler off seemed to help I can get through the dakota's now but I'm not sure I can pull a pass on a hot day kind of scared to try. What the hell did I do wrong? Clifford any thoughts.

[Bill Gerrie]

Have you used an infra red gun on the rad? Might be plugged.

[buswarrior]

What bus?

Some of them are really not capable of cooling 475 hp without religious attention to the cooling system, and still have to be driven like carrying a live grenade.

Might be nothing "wrong" with the existing bits, just overwhelmed?

Happy coaching!
Buswarrior

[tr206]

Bill it's got a new oversized radiator bigger then the screen door not sure how they got it in there and 5 core thick no I haven't used a ir gun on it because it new. Thing is I drove it home from Nevada after I bought it in the heat over passes with the 4" exhaust pulling a toad with no big issues all I did was increased the size of the exhaust to 5" I don't get it should have helped not gone backwards. I have heard the water pump impeller can spin on the shaft if the nut comes loose could be coindinence I guess haven't checked that yet. buswarrior I realize what your saying It was managable when it had the 4" pipe but not the 5" pipe.

[luvrbus]

Bill it's got a new oversized radiator bigger then the screen door not sure how they got it in there and 5 core thick no I haven't used a ir gun on it because it new. Thing is I drove it home from Nevada after I bought it in the heat over passes with the 4" exhaust pulling a toad with no big issues all I did was increased the size of the exhaust to 5" I don't get it should have helped not gone backwards. I have heard the water pump impeller can spin on the shaft if the nut comes loose could be coindinence I guess haven't checked that yet. buswarrior I realize what your saying It was managable when it had the 4" pipe but not the 5" pipe.

A 475 hp 8V92 the min is 5 inches with no bends, the air cleaner should be at least 1500 CFM on the 92 @ 475 hp

[tr206]

Clifford I here you, I can run the exhaust straight out the side of the bus it would be about 2 1/2' long straight pipe but I worry about the noise but it's the only way for no bends. Air intake is acceptable I think 7" tubing with a 2000 cfm filter again can't go with bigger tubing no room. With that said it still ran cooler with the 4" straight pipe with two bends any explanation for that would be appreciated?

[chessie4905]

outside air temps the same both trips?

[luvrbus]

You have something else going on the 5 in exhaust is not the problem, time to chase it down with a IR gun ,the water path in case you don't know it goes from the water pump through the oil cooler first,could be if a auto transmission it is causing the heating by not locking up or wrong fluid levels .The 8v92 has to reject a lot of btu's to cool and everything needs to be just right, those water pumps are 65 to 95 GPM  ,  ? what model of bus is it.

After working on Van's 8v92 in his H-40 lol I look for shop towels left in the cooling system that rears its ugly head after a period of time
   

[edvanland]

To finally get our 8V92 to cool after doing everything else, I installed a very large cab over diesel radiator with 6 electric fans with the radiator grill on the back can't tell where I'm coming or coming or going. I still have to be careful but it worked for me. Bus is a MCI 7 and they came with smaller radiators.

[Iceni John]

To finally get our 8V92 to cool after doing everything else, I installed a very large cab over diesel radiator with 6 electric fans with the radiator grill on the back can't tell where I'm coming or coming or going.

What direction is the airflow through it?

John

[tr206]

ok. Outside air temp's probably close to the same and I wasn't pulling a car when I had the heating issue either. Radiator like I said is big and new fan belts are tight. Clifford the tranny was rebuilt at Global idustial automatics in Tucson AZ your neck of the woods 7/24/2017 trans oil bulk at ever that means but 99% sure it's plain atf smells like it and it's red. How do you tell if it's locking up or not shifts the same as when I bought it? Model bus is Eagle 05 Lewis use to own it. I will post pictures of the old and new exhaust lot of bends I know but it was the only way I have seen more curve on trucks but they didn't have detroit's in them. Also what are the chances of the water pump impeller slipping on the shaft? Icenti John air flow the fan sucks outside air in. Air intake has been replaced to 7" tubes and disposable 2000 cfm air cleaner after the fact that's not in the pictures I guess I'm as sure that will help as I was about the larger exhaust.

[Utahclaimjumper]

If it ain't broke,, don't fix it..>>>Dan

[tr206]

I here yeah. Vee band on the exhaust side of the turbo was broke so glad found that anyway. If it ain't one thing it's six.

[Bill Gerrie]

Years ago I redid the exhaust system. I used the muffler that was specified for the 8V71 only to overheat in 50 miles. Turned out the muffler was chocking the exhaust causing the overheating issue. I now run a 5" in and out resonater style muffler with no issues.

[chessie4905]

tap a pressure gauge after the turbo and see what it is at full throttle in 3rd. May need to run tube and gauge to rear side side window and duct tape fast and have someone watch and report.