Broken Down off of I-10 Louisiana

[Scott & Heather]

Ok, so now that I might be settling on an engine, I have a host of other questions that I would be so grateful if some of you with vaster knowledge could help me sort out:

1. Can I convert my 50dn to a pulley drive unit? Or do I need an entirely new one?

2. Can anyone recommend a specific standalone transmission cooler for my Allison 748 so that I don't have to tie into the engine cooling system. It's already overburdened with an 8v92 and I have a ton of room on the drivers side of the engine compartment. Now is the time to fab something if I can. I just need to know what you guys think will work in terms of size/rows/fins etc.

3. Whilst I have the engine and tranny out, anything else I should deal with at that time?

[chessie4905]

Haydn 2305 or 1292. Available several places, including amazon. Add an automotive electric radiator fan with a thermostat . I would add an oil temp gauge to oil pan also.

[luvrbus]

Ok, so now that I might be settling on an engine, I have a host of other questions that I would be so grateful if some of you with vaster knowledge could help me sort out:

1. Can I convert my 50dn to a pulley drive unit? Or do I need an entirely new one?

2. Can anyone recommend a specific standalone transmission cooler for my Allison 748 so that I don't have to tie into the engine cooling system. It's already overburdened with an 8v92 and I have a ton of room on the drivers side of the engine compartment. Now is the time to fab something if I can. I just need to know what you guys think will work in terms of size/rows/fins etc.

3. Whilst I have the engine and tranny out, anything else I should deal with at that time?

Alternators are cheap about $1.00 per amp,air to oil coolers are a challenge on a MCI with the 2 tiny radiators,maybe mount it on the side with a electric fan will work for you the 700 series require a lot of flow through 1 inch hoses (18 GPM)and in your travels you need some way to control the temperature in cold weather Allison's do not like cold oil   

[luvrbus]

It was the sixties, and it forced me to consult the manuals and figure things out, so maybe he was being very clever and saw my potential to operate without guidance (and ease his workload). 

Walter you were in the civilian world this was military by the book.one of my best students was female and she was a remarkable young lady with a great attitude to get it done right the first time

[chessie4905]

Dont turn the fan on too early. Very cold, you could block some of the radiator area or add temp controlled shutters. If you intend to keep using the coolant/oil cooler also, dont even bother.

[buswarrior]

Jack Conrad has an aux cooler in the curb side engine access door for the transmission, pick his brain on that one.

Good idea, transmission contributes a lot of BTU to the coolant, that will free up some capacity.

Happy coaching!
Buswarrior

[Scott & Heather]

Awesome. Jack and I will come up with a plan on the aux cooler.

Now to find a dyno near Arcadia? Anyone have ideas?

[Scott & Heather]

So I've been calling all over southern florida to find a dyno and having zero luck. The only dynos are tite dynos....

[luvrbus]

Florida Detroit Diesel should have one close they did a Allison for me years back I purchased in FL

[Iceni John]

To lessen my HT740's heatload into the coolant I installed a Thermal Dynamics DB-00341DC remote cooler between the transmission and the engine's heat exchanger.   It has a 14" fan and a rudimentary shroud, and the transmission fluid now is usually a few degrees cooler than the coolant so it's slightly helping lower engine temps by a smidgen.   This way the coolant will also help warm the transmission on a cold day.

If you buy one of these, eBay prices are much lower than what I paid to a vendor in FL;  it was still drop-shipped directly from the factory in CA.

John

[chessie4905]

Thats my point. Cooling and then reheating trans fluid loses most of the benefit of aux cooler. Running a trans on the cool side wont cause problems, unless you run straight motor oil. The fluid will still get warm/hot without fan running. Converters make tons of heat.

[luvrbus]

Allison don't generate a lot of heat only when in they are in the converter mode,they are happy at 180 to 195 degrees you need to keep it warm no matter what fluid is used,The military 8v92 engines never used the double water cooler on the engine only air to oil for the transmission, those 740's are nasty when you tear into one too from being cold and they used Dexron ATF    .

[chessie4905]

I guess the only way to settle it is to use an air radiator only and check temperatures. Id like to see any mess created by tran dexron from running cool. Never seen it in car and truck transmissions

[luvrbus]

I guess the only way to settle it is to use an air radiator only and check temperatures. Id like to see any mess created by tran dexron from running cool. Never seen it in car and truck transmissions

No oil cleans cold.you never took a engine apart that was ran cold for years ?,if Allison wanted the transmission to run cold they would not have published a operating range ,they shift terrible when cold, condensation is your worst nightmare on the 740's with cold Dexron always has been ,Synthetics do a better job running cold I was told but I don't waste the money for the synthetics on the older Allisons       

[Scott & Heather]

I just want my coach to run cooler especially with a 500hp tune. I know for a fact the Allison dumps a ton of heat into the coolant because when I was running my retarder the coolant would get really hot. Temps pushing 200° or more.

So another question, how hard is it to add jakes to my new engine? Anyone have a set and the new covers?