Cummins ntc 335

I wonder if this one has a compression release valve for cold start ups ?

 

I never saw one that didn't.

My uncle bought a White Freightliner brand new in 1970, and it had a 335. It had a leaky fuel pump, and my father, who drove it could smell it. They replaced the pump, and when they ran it on the dyno, it was putting out 280 to the wheels. The mechanics at Cummins told them they should cut it back to factory, but my dad and uncle convinced them to leave it turned up.

To the guy who said it was a 290 with a 350 pump, wth? The 335 preceded the 350 by close to a decade. A 350 was a 335 with an aftercooler.

 

There were 2 versions of 335, the NH335 which was 743 cubic inches, and the NTC 335 which was an 855 cubic inch engine, with the 743 ci being the earlier. If your truck has the original engine, it could possibly be either one. I have never, to my knowledge, seen an original 743 version so I can't speak to any external differences on the engines.

 

The NH 335-743 had external fuel lines going to the individual injectors with the first early style PTG pump. No turbo and it was a rare horse at the time because the supercharged NHRS 325-743 was already out and more popular. The NTC335-855 was internal fuel lines with a second generation PTG pump. Newly designed compressor mount and governor and the modern style idle plunger buttons. Turbocharged with a spin on oil filter on the turbo supply line. No aftercooler. The NTC 335 was the last 855 to use the tapered snout crank and two piece rubber isolated damper. The NTC350-855 was the first to use the flat snout crank and Vibratech (new owners) fluid viscous damper.
335’s were good engines and big power for the day, but Cummins had gotten all the power they could out of the tapered snout crank. 335’s were very prone to break when fueled high or lugged below 1700 rpm. They loved 2400 in stock tune tho. That is why it’s replacement was the NTC350-855. Same engine, just new crank. The first 350’s did not have aftercoolers. The cpl160 around 1970-71 timeframe was first aftercooled.

 

I could be wrong, but the 743 335 was a hot rod engine. It was a 300, but they pulled the blower off and put a turbo on. Essentially gaining 35 horsepower by not having the parasitic losses of the driven blower. I road in one when I was 4-7 years old. Richard George sold bought and sold trucks. He sold a 1957 High mount to some place back east, and my uncle drove it to the rail yard to put it on the train. All I remember was the turbo screamed almost like a 1693. Would have been 1969-1972. To think that truck was so much more obsolete than my 1994!

 

Here is a NHRS 275-743 aka “Two and Six bits”. The first of the supercharged series. The 300 and 325 soon followed. These had the legendary “bark” that came in at 1800 rpm and flame out the stack under hard pulls.

 

That flame from the exhaust tip brought back memories driving up thru Wheeler ridge(grapevine) pulling the hill, wasn’t unusual for its time.

 

The supercharger didn’t really use much hp’s to turn because they were gear driven and not belt driven. At idle they put out 7 psi of Manifold pressure. They main reason for removing them and making more power normal aspirated was the noise and flame. No mufflers existed for trucks back then. Donaldson was a Cummins engineer that worked with Clessie to design a muffler for diesels back then. The flames would burn them up. The super charged engines had to run ceramic coated stacks and many trucking companies had big spark arrestors installed on their stacks too not catch overhead trees on fire.

 

My grandfather told me stories about when he would ride with my great grandfather in the 50’s in his ‘51 Diamond-T that had NHB-600-672ci 185hp. At first overhaul around 250,000 miles he sleeved it to a 743-220 and removed the original single disk pump and put on an early PTG pump. They would run breeder bulls he pimped out from Sikeston Mo. to Townsend Montana and back. He always said slow climbing them rockies was flame at night and the smoke would always pass you during the day. Just standard operating procedures back then.

 

You are thinking of the NRTO-6-B-335. That was the 335 hp turbocharged NH743. It came out in the 1954/55 time frame.