8.2 L Detroit Diesel

[cadillackid]

depending on your rim width you may be able to go up to 11R22.5 tires which would gain you a few MPH... you'll have to re-cal the speedometer... I didnt read to see what chassis this bus is on? if its IHC I have a fighting chance at getting you the proper dip switches for the speedometer..

-Christopher

[ashandrik]

Sorry to hijack the thread, but where do you guys get new (or used) gears for your bus' differentials (or any other parts in general for that mater)? I'm used to being able to pop down to AutoZone and pick up whatever I need. But now... I have no clue!

[cowlitzcoach]

It may be easier and less expensive to purchase a complete used rear end in order to get the gears you want.

As far as where to go to get them, you need to think truck wrecking yard.

A quick Google search brought up this company: Truck Salvage Company

[rty12345rty]

Originally Posted by cadillackid

depending on your rim width you may be able to go up to 11R22.5 tires which would gain you a few MPH... you'll have to re-cal the speedometer... I didnt read to see what chassis this bus is on? if its IHC I have a fighting chance at getting you the proper dip switches for the speedometer..

-Christopher

thanks Cadillac kid for the information

[Kubla]

first you need to find which rear end your bus has under it

[rty12345rty]

I talk to a guy that sells used school buses and he said the 8.2L is a good engine as long as you do the PM on them at regular basis. He has seen 8.2 GMC Blue Bird buses with 300k on them and still running good. He told me the 586 rear end I have in the trolley will run that buses 55-60 mph at 3000 rpm and that is where the Detroit Diesel is design to run at. He said they are high rpm engine and running the engine at 3000 rpm is good for the engine.

[cadillackid]

always does seem like the Detroits like to run faster than the other variants..

are all detroits 2 cycle?

-Christopher

[opus]

Originally Posted by cadillackid

are all detroits 2 cycle?

-Christopher

No, they are not.

[Tango]

Most of the old 2 stroke DD's were designed to run at what are considered high RPM's compared to most diesels. My old 6v53 "screamer" had to stay at 3000 to 3300 to keep moving. And it would hit 3500 on most inclines (note that did NOT say "hills". That was a whole nuther matter).

[tincaneasybakeoven]

2 stroke detroits have very strong but narrow power band ~~~~~~~~~~~~ my oven setup 22.5's 4.44 ratio 444 engine 2500 rpm 60 mph .... with the calculator 3.55' ratio brings 75mph~~~~3.55 brings 72mph~~~~ radius of 24 vs 22.5 tires would gain some mph but i cant remember how much. tires and rims on craigslist are relatively cheap pick and choose the cheap ones one at a time and build your reserves imo.

[rty12345rty]

The Guy I talk to about the 8.2 Detroit his name was Paul and the name of his business is Paul's Equipment Atwater Ohio 44201, Phone#330-947-1147, Website usedschoolbusses.com. He has parts and used buses to sell. He ships parts all over the world. Go to website and you will see what I mean.

[EastCoastCB]

Originally Posted by rty12345rty

The Guy I talk to about the 8.2 Detroit his name was Paul and the name of his business is Paul's Equipment Atwater Ohio 44201, Phone#330-947-1147, Website usedschoolbusses.com. He has parts and used buses to sell. He ships parts all over the world. Go to website and you will see what I mean.

Maybe he's such a fan of them since he's selling them, man.

[rty12345rty]

Originally Posted by EastCoastCB

Maybe he's such a fan of them since he's selling them, man.

I don't think so, go to the website see all the different models of school buses he has. I called him to see if he rear end for my bus, I told him I had 586 gear ration and I wanted to lower the gear ratio down to the 444, he said that most all GMC Blue BIRD Buses came with that 586 gear ratio with 8.2 Detroit engine. He said the 8.2L sweet spot is at 3000 rpm also you get good fuel mileage at 3000 RPM and with 586 gear ratio. he talk me out of buying another rear end.
This last weekend I made my first trip with the trolley, I travel 55 mph sometimes 60 and the engine ran great, I have to do something to suppress the engine noise inside of bus. Does anybody got any ideas on how I can suppress the engine noise? I know one thing that this 8.2 Detroit can run circles around 6.9L International 60 passenger school bus I bought brand new. I had to put a 6.9 rebuilt engine in the bus at 20,000 miles, then at about 50,000 miles the engine started pumping oil out of the exhaust pipe like it did before with the new engine from factory. This time I went out and bought a 7.3L International with no turbo. The 7.3L engine was little bit better on power than 6.9L engine was. The bus had 145,000 on it when I got rid of it and still had the 7.3L engine I put in.

[opus]

[rty12345rty]

Real Funny Asshole!!!!!

[JA Savage]

Wow that was a pretty extreme reaction. School buses are noisy. If you have a lot of money you can do some things to dampen the sound. If you are poor, like me, the foam earplugs work fine.

[Tango]

There are lots of sound dampening products out there and they typically work one of two ways, They utilize very fine fibers (fuzzy stuff) to trap, absorb and convert the sound (vibrations) into heat...or they employ mass to do the same thing. The fuzzy stuff is fine if you have room for a foot or so of it, but it really comes down to mass. The only way to reduce noise is to convert the vibrations into something else...heat. And mass can do just that quite well but if you don't have room for lot of the fuzzy stuff, go with lots of mass in a thinner layer.The best product out there is sheet lead, but the toxicity issue has made it unpopular lately. Next best thing I know of these days is barium loaded (AKA; mass loaded) vinyl. It can be found in various sound deadening products and the more mass it contains, the better it works. You can get an idea of what is in them by their weight per square foot. The good stuff will weigh in at around 2 to 2.2 lbs per sf. You can find it in self adhesive rolls and there is even a plywood product that has a barium loaded core. Amazing stuff. Often used in high end yachts and is popular for constructing sound stages. That's where I first saw it in action. A girl in high heels walked across a stage about five feet off the ground that was nothing but this plywood supported by 2 x 4's and her footfalls never made a sound. Just what the soundman wanted. Where most sheet wood acts like an amplifier, this stuff sucks sound. Very cool. The vinyl sheet material does the same. I used a double foil faced foam with the barium center to help silence my old DD 6v53. I only did the doghouse but it did drop the Db's a bunch. Applying it to more of the (vibrating) sheet metal would have been better but I was in a hurry way back then.

[cadillackid]

in the past ive always used dynamat on the floor of hotrods (that werent race cars)... it as tango says weighs in quite heavy (and pricey).. however it works... I found it to reduce both Noise and heat transfer...

ive noticed that at least on my conventional there is pretty much ZERO insulation except for a small amount on the doghouse and what looks like some thin coating on the firewall under the hood.. otherwise inside its bare hot metal...

there are other brands of product than just dynamat.. ive just used that one because i know it has always worked for what i was doing..

-Christopher

[goinbroke2]

Well, since i'v logged on an do have extensive 8.2 experience i'll add my 2 cents. 8.2na will run all day,week,month at high idle (wide open 3500rpm) they don't make a lot of power but are excellent on fuel for the hp level. I'm running a 8.2turbo with a 5spd manual and 5.29 gears. When on back roads I cruise around 2000 an on th highway keep it at 2500. I get 13mpg consistently. I've run it as high as 2700 getting a run on for a hill. Bottom line, mechanical inj which will run on ANYTHING, I dump veg oil, furnace oil, veg based hy oil. That said, it' only 225hp (the only fault I have with it). If the engine is screaming, it'll be hard on fuel an there is no reason to scream it unless it's a company truck. Get a tach and keep it at 2500. If you're going too slow, regear it. At 2500 i'm doing 100kmph (62.5mph)

[Jolly Roger]

Originally Posted by goinbroke2

Well, since i'v logged on an do have extensive 8.2 experience i'll add my 2 cents. 8.2na will run all day,week,month at high idle (wide open 3500rpm) they don't make a lot of power but are excellent on fuel for the hp level. I'm running a 8.2turbo with a 5spd manual and 5.29 gears. When on back roads I cruise around 2000 an on th highway keep it at 2500. I get 13mpg consistently. I've run it as high as 2700 getting a run on for a hill. Bottom line, mechanical inj which will run on ANYTHING, I dump veg oil, furnace oil, veg based hy oil. That said, it' only 225hp (the only fault I have with it). If the engine is screaming, it'll be hard on fuel an there is no reason to scream it unless it's a company truck. Get a tach and keep it at 2500. If you're going too slow, regear it. At 2500 i'm doing 100kmph (62.5mph)

Ok mr. Detroit. I do want to do a re-gear on my rear end but first I want to add a tach. To see what my RPM's are? I am computer challenged to a point but have a lot of old school mechanical knowledge.
My question is what tach should I be looking for?
I have seen some that you attach to the outside of the alternator and have to have calibrated after the fact and I see some that connect to the alternator if it has the spade for it and a way to open the alternator and stick a lug out for it and it's supposed to be spot on?
So what is the best way, the shade tree mechanic way without a timing light?
I know the old dial style but I need real data not to just look cool?
Thanks for any and all advice.