Cummins 250 hp upgrade

[bcowanwheels]

Guys i run small and big cam cummins engines for 22 yrs over the road. The best turbo for these if you want brute pulling power is 1 of these 2 turbos
cummins part numbers

3801919

or

3801918

and for you small can guys the best cpl for them is

industrial 420 hp

or magnum 400 hp

the magnum is slightly better puller

 

[wreckerman893]

You can't gold plate a turd. Well you can but then you just have an expensive turd.

 

[R Racing]

Now now Richard! ! Just because you don't like them doesn't make them bad. It's like possum casserole , just because it bites you back doesn't mean it doesn't taste good.

 

[patracy]

3801918 is a HT3B. I'm running one on my 250 in the SEMTT. The 3801919 is a HT4B, which IMO, is too much.

Remember, these NHC 250's don't have oil squriters, you're not going to get 400hp out of them safely. You'll need to install a boost and EGT gauge. I've change buttons and turned the pump up to around 200psi. I see about 12-14psi of boost max. Realistically you should aim for 300hp at most.

 

[bcowanwheels]

Is there provisions in the side of the block on the passenger side for piston oil coolers ? If there is its easy to install them, you dont even have to pull the pan. 300 BC3 SPEC,S WOULD BE NICE IN ONE OF THESE 5 TONS.

 

[patracy]

No. It's a labor intensive process to install them.

 

[bcowanwheels]

IF there isnt provisions for oilers rather machineing the block it would be alot better to just get a block or a whole engine and swap it out. also i,ve found going with lower press fit liners is a huge plus and it totally eliminates head gasket seepage. is there anyway someone can post a picture of the side of the block ? i thought when cummins went away fromm the 220hp engine all of them had provisions for piston oil coolers.

 

[patracy]

Easier to swap engines than adding squirters. Plus you'd have more power/potential from a big cam.

The NHC 250 series doesn't have squirters since its a NA engine.

What are you needing a pic of exactly? The squiters are inside the block next to the crank at the bottom side of the liners.

 

[bcowanwheels]

nope, there in the side of the block on passenger side. same with all big and small cam 855 cu.in. cummins engines.

 

[patracy]

Ok......

 

[bcowanwheels]

did some research on this version of the 855 engine. its definatly vehicle specific. it has a really small oil cooler, all from accessories are specific to this application, DEFINATLY NO PISTON OIL COOLERS and no provision for them. I,d be real leary in doing very much hop up to this engine and if you wanted to install a civy engine gosh it would be a mix of the mil & civy components then the radiator wouldnt be big enough to cool it under a load. even my old petes had a hard time keeping my 400,s cool on long hard pulls. think i,am gonna pass on these trucks.

 

[doghead]

So, should this thread be deleted?

I'm confused what the op is saying.

 

[Carlo]

I've always been told you can't run a turbo on a motor that did not have oil sprayers on the bottom of the pistons and expect the motor to survive on normal use. I've seen a 250 bare block I did not seen oil sprayers for the bottom of the pistons.

 

[swbradley1]

So, should this thread be deleted?

I'm confused what the op is saying.

I would have deleted it already.

 

[doghead]

Why don't you put the icing on the cake then, Cupcake?

 

[WillWagner]

They, the cooling nozzles, are inserted into the block from the exhaust side at the main oil rifle, from the outside. Internal nozzles didn't happen until the L10 series came into being.

The NHC IS an 855. there were also other 855's produced that were turboed and had no piston cooling nozzles, they were 220 and 230 hp, 2100 rated engines mainly used in trash trucks. The USPS had a fleet of them too.

 

[bcowanwheels]

YES for getting engine life you need piston oil coolers with a turbo however if your just gonna drive the truck around and not work it it will probably be ok. it takes a load on the engine to build boost. i,am also concernned about the really small oil cooler. its the smallest cooler i,ve ever seen on a 855 engine.

 

[patracy]

YES for getting engine life you need piston oil coolers with a turbo however if your just gonna drive the truck around and not work it it will probably be ok. it takes a load on the engine to build boost. i,am also concernned about the really small oil cooler. its the smallest cooler i,ve ever seen on a 855 engine.

I'm still confused with your posts. You asked for the best turbo. Then asked how to install squiters, then explain what has been stated, then revert and make an exception.

Here's the highpoints:

HT3B is the turbo to use
NHC 250s do not have oil squirters
Squirters are not easily added
Squirters are inside the block
A small cam nhc 250 cannot safely put out extra power above the 290hp mark without driving by gauges
A big cam will provide more power safely
Any diesel fueled beyond factory spec can fail or have a shortened lifespan by careless operating.
A NA diesel can be turbocharged, IF, an understanding of the limit is observed at all times.

Do you have anything else your wondering about or need help on?

FWIW, I speak from experience, owning the combination you're asking about. As well as other NA turbocharged engines lacking the Squirters. It's all about defining limitations from the start and adhering to them. And driving with a brain and not a lead foot.

 

[doghead]

I thought he told us the 2 best turbos.

I did not see any questions asked in his first post.

Ii thought he was making a statement(like teaching us something).

 

[bcowanwheels]

going with a ht3b turbo is putting alot of boost in a 250. i ran ht4b on my small can built to industrial 420 spec,s for 25 yrs. untill i switched to a kt fuel pump i had 0 problems but with the kt pump i did burn it down several times. piston oilers arnt inside the engine they install from the passenger side of the engine block.a 5 ton 250 isnt machined to except them. the bosses are there but you,d have to send bare block to a machine shop to have it bored to except oilers and in that case you,d be better off to buy a bare block that is machined to already except them. i think going all bc3 set at 300hp would be sweet personally. sure wish there was a 5 ton close by so i could go look at the engine arrangement. does the 5 ton axles have lockers in them ?