BCIII Cummins Rebuild.

[cfherrman]

That would be cool, need more old iron in the world

 

[Welder Dave]

I'd bet your rebuild is a lot more precise than what the salvage yard would do. The salvage yard was probably impressed with your engine stand. Could be a good thing for you if they give you some leeway and not ridiculous deadlines to be finished.

 

[Truck Shop]

Too funny, I spotted this 129594 Cummins flywheel for sale on ebay. Real nice except who
ever machined it doesn't know much about 15" flywheel's & clutches. When the friction
surface is cut the outer centering lip has to cut the same amount or the possibility of the
clutch not bolting flat to flywheel mating can cause clutch slippage plus break the mounting
bolts. Area in Blue.
*

 

[petepilot]

That reminds me that I need a flywheel for a 6 bt

 

[Truck Shop]

Decided to use up a bunch of parts I had left, made a complete out of it.
*
Machined block {decked counter bored for lower press fit liners with shims just like a N14}
6 rebuilt rods, 3 completely rebuilt heads with all new valves and injector sleaves. Std crank,
reused perfect cam & followers. NOS 3529040 Holset single entry turbo, jakes gone through.
Rebuilt compressor, rebuilt accessory drive. New crank damper, new oil pump, new water pump,
new Delco 8200308 high torque starter. Reman injector pump, reman Cummins injectors. Turned
15" flywheel, cleaned & pt'd aftercooler, cleaned & resealed oil cooler, new camshaft bushings.
Test fired, ran 49 psi cold at idle which is on the high side {spec is 40 to 46}. Timed at nominal
70. I'm listing it here, so people-if any interested can ask without a PM.--Price is still $16,250.
I know where to buy parts and get machine work done without the cost of arm and leg. You
can't build one for this. Jakes were energized while running to check operation.
*

 

[DMiller]

Very very nice

 

[Truck Shop]

Very very nice

Ah--thankyou.

 

[Acoals]

I want that engine . . . I just don't have anything to put it in . . .

 

[DMiller]

Last BCIII I was into was in 1990

 

[colson04]

Decided to use up a bunch of parts I had left, made a complete out of it.
*
Machined block {decked counter bored for lower press fit liners with shims just like a N14}
6 rebuilt rods, 3 completely rebuilt heads with all new valves and injector sleaves. Std crank,
reused perfect cam & followers. NOS 3529040 Holset single entry turbo, jakes gone through.
Rebuilt compressor, rebuilt accessory drive. New crank damper, new oil pump, new water pump,
new Delco 8200308 high torque starter. Reman injector pump, reman Cummins injectors. Turned
15" flywheel, cleaned & pt'd aftercooler, cleaned & resealed oil cooler, new camshaft bushings.
Test fired, ran 49 psi cold at idle which is on the high side {spec is 40 to 46}. Timed at nominal
70. I'm listing it here, so people-if any interested can ask without a PM.--Price is still $16,250.
I know where to buy parts and get machine work done without the cost of arm and leg. You
can't build one for this. Jakes were energized while running to check operation.
*
View attachment 309325View attachment 309326View attachment 309327View attachment 309328

Sharp looking engine, probably nicer than when it out of the factory.

@Truck Shop , when you build up your Big Cam engines, do you always build them to the same specs? I've tried to follow all of your discussions on engines, and I was just wondering if there is one CPL, or personal combination you found that really makes a nice Big Cam, or if you build them to a variety of specs? Sorry if you've answered that question before.

 

[Truck Shop]

Sharp looking engine, probably nicer than when it out of the factory.

@Truck Shop , when you build up your Big Cam engines, do you always build them to the same specs? I've tried to follow all of your discussions on engines, and I was just wondering if there is one CPL, or personal combination you found that really makes a nice Big Cam, or if you build them to a variety of specs? Sorry if you've answered that question before.

If it was going to be a BC II, I build to CPL 449, BC III either CPL 531 or 625, BC I CPL 393.
449, 531, & 625 all use the same piston liner kits-same compression ratio of 14:1 and timed
at 70 nominal 69 is fast 71 is slow--injector timing. Some like to retard to as much as 75 but
these engines smoke cold, when timed 72 to 75 they really smoke, but pull allot harder.
the faster the timing less smoke cold. It does give a quicker throttle response but don't pull
quite as well. The BC I 400 was a little different it used a higher compression ratio of 14:5
and was timed at 65, then Cummins did a reset on timing for the 393 to 68. But most have
been redone with later 14:1 ratio and timed at 70. Still the 393 in original form ran pretty good.
The major difference in these CPL's-BC I used a lower flow aftercooler {not by much}, single
oil filter. 449 shared the same aftercooler as the 531, 625, 449 still had single oil filter.
BC III had the the full flow and bypass oil filters. All used the same camshaft although there
is about 9 different part numbers for the same cam. The total difference was in pump & injector
settings & injector flow rates. The 449 had a slightly lower rail pressure with a higher flow
injector, was a dirty engine but ran well. The one big difference in 393 CPL was the fact it
was in the last of the BC I's, from then on BC's used longer head bolts, the early BC I engines
used the shorter head bolts of a small cam, 393 had long bolts.
*
Best I can tell you.

 

[Welder Dave]

Decided to use up a bunch of parts I had left, made a complete out of it.
*
Machined block {decked counter bored for lower press fit liners with shims just like a N14}
6 rebuilt rods, 3 completely rebuilt heads with all new valves and injector sleaves. Std crank,
reused perfect cam & followers. NOS 3529040 Holset single entry turbo, jakes gone through.
Rebuilt compressor, rebuilt accessory drive. New crank damper, new oil pump, new water pump,
new Delco 8200308 high torque starter. Reman injector pump, reman Cummins injectors. Turned
15" flywheel, cleaned & pt'd aftercooler, cleaned & resealed oil cooler, new camshaft bushings.
Test fired, ran 49 psi cold at idle which is on the high side {spec is 40 to 46}. Timed at nominal
70. I'm listing it here, so people-if any interested can ask without a PM.--Price is still $16,250.
I know where to buy parts and get machine work done without the cost of arm and leg. You
can't build one for this. Jakes were energized while running to check operation.
*
View attachment 309325View attachment 309326View attachment 309327View attachment 309328

That's a great price. I spent almost half of that getting a 3204 rebuilt not including the injection pump almost 20 years ago.

What determines the HP and is there a certain HP for each model that's most desirable for longest engine life? I've always heard of owners turning the pump up but don't know if that reduces reliability or lifespan?

 

[cfherrman]

Ts do you know what HP ranges a cpl of 840 is?

 

[Truck Shop]

Ts do you know what HP ranges a cpl of 840 is?

840--Is a NT88 BC IV also listed as a NTC350. It has 3/4" main bolts instead of the earlier 1".
It is also the first with lower press fit liners originally. Low flow cooling system, with the small
stamped steel oil cooler, with a slightly different water pump. CPL's 839 & 840 were in some
cases not some of the better, except for the LPF liners. Some BC III's came with the NT88
block, most all were Cummins recons. The issue with the 3/4" bolts was the mains only torqued
to 255 lb ft, the early blocks with 1" bolts were 305 ft lb at the top of scale. Any NT88 this day
and age would be headed for a line bore, 88's had a issue with fretting at block and cap
mating area.

 

[Truck Shop]

What determines the HP and is there a certain HP for each model that's most desirable for longest engine life? I've always heard of owners turning the pump up but don't know if that reduces reliability or lifespan?

Compression ratio, cam/injector timing & injector and pump calibrations. There is a bad way to set
up rail pressure--by removing the ball at end of throttle shaft and turning screw inside. That will
only give so much and is not the correct method. Correct is changing the button and torque spring,
but depending on factory settings 10% works out to two buttons larger. The engine above stock
button is a #27, it now has a #22 which is 10% over fuel, stock rail IIRC is 168 it is now 190 or
so. To combat high rail PSI injectors need to be flowed if anything over 10%. See a 449 cpl has
a factory rail of 158, so knowing what each cpl rail psi is important. But these engines don't have
iron top pistons like late engines only a double ni rating so they will crack and cams will go to
hell with too much fuel-and not having a shop to correctly calibrate the fuel system. These engines
will run along time at 10% without issues--it wasn't designed to be a rocket.

 

[chidog]

Nice work, someone will be getting a great deal there.

 

[DMiller]

Steady work long life engines by CPLs. Do not self destruct and pull just fine. First BC1 I set cam timing on was a 400, boss had me set it exceptionally Slow and it smoked like a Driptroit. It is still running today some forty years later but has had head gasket issues since day one. Previous boss did not have blocks decked, instead insisted on Copper Coat spray to compensate for eroded wear. Not once ever worked. Last I heard was overhauled twice since mine. At 12 and 22 years. Old COE 9670 ih.

 

[cfherrman]

Thanks for the info ts, a friend bought a old truck with it and it's a good truck.

 

[Truck Shop]

Thanks for the info ts, a friend bought a old truck with it and it's a good truck.

Nt88's were either decent or not so decent, no in between.

 

[cfherrman]

Yeah this one is pretty good, I drove it back in 2016 and I don't think it's had work done to it. The price he paid for the whole truck (water truck) was very good.