What parts to get for complete t444e rebuild?

[TheHubbardBus]

Backstory: we're building this bus to last. I fully intend to drive it till the wheels come off, replace the wheels, and drive it some more. I want it to last our lifetimes, or until the DMV takes our licenses away, whichever comes first. So while the engine is healthy now, I want to plan ahead so we have the ability to overhaul / replace it completely when the time comes.

Since this is not only my first bus, but my first diesel as well, I'm not up to speed on the state of parts availability, who manufacturers quality parts, or what parts I'd want to stock now in anticipation of a rebuild later. With the war on diesels, the t444e no longer being used, and it being almost a 20-yo school bus, I'm not sure what I need to act on today (or what maybe I should have purchased yesterday).

If you were planning ahead for a future rebuild (or a complete replacement with a new/remanufactured block), some time in the indeterminable future, what would you buy, and when would you feel it necessary to buy it? Are there any 'rebuild kits' as good or better than OEM quality parts? Any accessory parts (injectors, fuel pumps, etc) that would also be wise to source now? Any 7.3L powerstroke parts (or even complete blocks) that would be as good or better? Any complete engines built as good or better than OEM as an option?

Note: I'm not looking to cheap out. I'd rather pay more for high quality than pay less for inferior bits.

[cadillackid]

if it were me.. and I had the space, id buy a couple engines to keep around.. most generally when you talk mechanicals on a 444E, what ive seen fail most are Lifters and HPOPs.. I almost consider injectors and glowplugs as "long term wear items" to be replaced every 150-200k. a single bad injector can ruin the whole engine if not caught early.. (blackstone labs and vigilant observations are your friend).









Turbos are always a "wear" item that often need attention by 250k.


some people dont like the PMR rods of the generall 00.5 and up engines.. but I dont hear of breakage unless the engines are REALLY hopped up.



there are all kinds of ready-to-fly remans of these out there.. and unless the machine shop is a total dunce, these engines are pretty fool-proof as diesel engines go to rebuild. BUT it still takes good machine tools and good machine tool operators..



you have options when rebuilding, you can opt for an oversize piston kit and bore to .020 over to get rid of most ridging or minor scoring that occurs (if you say dropped a valve).. you can also opt for standard size pistons and have service sleeves pressed into the block.


I trust Agkits and Mahle for kits and parts.. lots of people running these..



the **BIGGEST** failures of engine rebuilds are in the labor.. a few thousands skew on a cylinder bore will end up in premature ring failure. screwing up bearing clearances and result in lube issues if clearances are loose.. or seizures if clearances are tight.. improper block decking and head resurfacing results in blown gaskets.. things not being perfectly clean and you have fine metals go through your new engine.



you will spend more $$ to go buy a kit and have a local shop reman your engine (than buying a already reman unitt) but in doing so you will likely get an engine thats as good if not better than factory..



spare parts? the 7.3 will fall through the cracks for all but the most stringent states regulations.. pretty much every vehicle with a 7.3 will be "vintage" by the time they get around to pushing these laws through the bulk of states.. the first ones are already considered vintage in ohio.. as anything 25 years + can be a vintage vehicle.. some states its 30 years.. but we will see a back and forth of federal administrations that will delay and reset a bunch of these regulations.. ther asftermarket is still alive and well with 7.3 parts and engines.. and there are still quite a few good cores in school busses still in service... on my travels I often still see 'T-444E' on the side of trucks and yellow busses still doing work..



in my case ill probably get tired of the bus or wear out its body before i need to worry i cant get engine parts for it... that said, I have thought about building a second engine for it since ive been playing the performance arena with it a bit.. the likiliehood of blowing it up is a lot higher when im pushing 325+ HP out of it vs the paltry 190 it came from the factory.. cores are still cheap so now is a good time to buy / build spares..


-Christopher

[TheHubbardBus]

Thanks so much, Christopher. That's a wealth of information that helps me tremendously.

You say "Can go with an oversize kit", where in the gas world I come from, overboring (so long as you have the wall thickness available) during a rebuild is pretty much a given.

Is there any compelling reason I would not want to buy a .020 overbore kit, if I went that route, in anticipation for a future rebuild?

[cadillackid]

Originally Posted by TheHubbardBus

Thanks so much, Christopher. That's a wealth of information that helps me tremendously.

You say "Can go with an oversize kit", where in the gas world I come from, overboring (so long as you have the wall thickness available) during a rebuild is pretty much a given.

Is there any compelling reason I would not want to buy a .020 overbore kit, if I went that route, in anticipation for a future rebuild?

in any engine strength and Mass are always sacrificed when you overbore.. strength is obvious if building a high HP project.. mass shows up in cooling.. again these things really only matter if you are going to build a performance engine..



me coming from a world of hot-rodding thinks about those things alot.. LOL I knew that even a school bus couldnt take the hot-rodder out of me... as i sit there with my 444E has bigger injectors, a pretty aggressive tuner, high perf HPOP, a Built tranny and a bigger turbo ordered (if i ever get it).. ha!!



overboring comes down to the machine shop.. I lost a good 4 bolt SBC 350 because a crappy machine shop bored the cylinders a few 1000s oval!. mightve been fine if i was building a grocery getter but since I was building a 650 HP stroker things didnt work out so well...



-Christopher

[TheHubbardBus]

Yeah, I've read through a number of your threads regarding your engine / tranny / performance mods and I'm as much impressed as I am jelly If I had another bus I might be tempted in the same vain. However, I don't, and it will take a lot of learning before I know enough about what I'm doing.


I'm still not clear on the issue of overboring. Is it common to be able to slap the same size pistons in a 250K+ diesel and get good ring seal w/o excessive piston-wall clearance? I don't care about overboring to increase the displacement, but do want tight cylinders. I'd prefer to leave the stock bore, for all the reasons you mentioned... I just didn't think it would be a probably option.

[cadillackid]

In the 7.3 service sleeves are an option for damaged cylinders or a way of bringing bore size back down. I don’t think .020 is an issue in a 7.3, I just bring it up as thoughts.

Nothing is ever really set in stone with bus building or such. We are all here sharing a dead and experiences and that’s just awesome!

[Diverdude0075]

These engines are so well built and known to last a long time (with proper maintenance). If it were me I would look for some low mileage runners to throw into storage. In fact, I may do some searching soon since I have plenty of room to store them.

My '99 with the 7.3 is pushing 230 HP (190 stock) from just tuning from Power Hungry Performance (PHP). I also did a transmission upgrade to the A2000 from a AT545. My bus will scoot at 75 MPH unloaded. I did tow a few months ago my ('78 F100) 1500 miles fully loaded with my stuff with no issues.

I think I averaged around 9.8 MPG too. I had to keep my foot out of it uphill to keep engine temps down, and generally she seemed happy at around 65 MPH with all the weight and towing. She is so much fun to drive!

[cadillackid]

my cooling upgrades solved my 444E high temp issues..



I switched from the ole green coolant to AMSOIL poly-organic ELC coolant..
swapped out from the crappy metal fan to the 9 blade plastic 24 inch fan (fits in stock shroud).
Upgraded from the Viscous Fan clutch to a Horton E450 electric Fan clutch.. i use a Dakota digital Fan controller so I can turn it on earlier.. (or manually with a switch).


Swapped the 190 Degree thermostat for a 180 Thernostat.



I could do more like an aux trans cooler to keep 100% of the heat away from the radiator.. my allison doesnt make a lot of heat though.. even on the hottest summer days the allison sits in that 190-195 degree range.



ive got a pretty aggressive trans program where at lighter throttles it goes into higher gears but get into the throttle much and its going to downshift pretty agressively as to keep the revs (and fan speed) up on hills..



once I re-gear down to a Lower rear.. 3.54 to a 4.10 or 4.30 ill be better off in the engine load factor as well... thats a goal of mine for this spring (aint no re-gearing going on in ohio winter!!)