Author Topic: 672 cubic inch Cummins  (Read 5137 times)

theakerstwo

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Re: 672 cubic inch Cummins
« Reply #15 on: April 29, 2012, 07:20:09 PM »
The H engine that was a 672 was a 4 7/8 bore. The block was same as a 743. The liner was thicker on the 672 and could have the 5 1/8 liner installed making it a 743. And the N in a NH stands for 4 valve.The H was two valve.glenn

NHRS

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Re: 672 cubic inch Cummins
« Reply #16 on: August 10, 2012, 11:08:32 AM »
As I remember things from the early '60's, turbos were just catching on, and most new trucks were still naturally aspirated.

Cummins sold horsepower, and charged for it. That meant an NH-195 (672 cubes) was exactly the same as an NH-220 (743 cubes), except for the thicker/thinner liners, AND the price.

The guys that taught me to drive, bought new Diamond-T's with NH-195's, and during their very 1st overhaul, they became NH-220's.

Kind of interesting, maybe only a coincidence, but the Mack Thermodyne back then was 672 cubes.
If you don't ask, they can't say no.

busman7

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Re: 672 cubic inch Cummins
« Reply #17 on: August 11, 2012, 09:23:56 AM »
[/quote Doug McKenzie]

A JT Cummins is an in-line 6 cylinder.
Back in the late 50's my Dad was going to purchase an RD-200 International with a JT engine - tried it out for a trip but returned it and never bought a Cummins again.
Quote

Smart man. 8)
« Last Edit: August 12, 2012, 10:05:31 AM by Rob Archer »

doug mckenzie

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Re: 672 cubic inch Cummins
« Reply #18 on: August 12, 2012, 08:16:23 AM »


A JT Cummins is an in-line 6 cylinder.
Back in the late 50's my Dad was going to purchase an RD-200 International with a JT engine - tried it out for a trip but returned it and never bought a Cummins again.
[/quote]

Smart man. 8)
[/quote]

That's been there, done that in my family too.
Even to the point of the International RD.
Right-wing Old School.

NHRS

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Re: 672 cubic inch Cummins
« Reply #19 on: August 12, 2012, 12:08:29 PM »
Guys- just so we get on the same page, Cummins J engines were a completely different motor series than the H, NH 672/743 family. Can't remember the displacement, but they were lots smaller.

Even had a cute little iron-lung supercharger for them, too.

As in JS, and RJS. Which means, a J motor with supercharger. In those days with Cummins, R meant pushing in more fuel, so higher rated horsepower, often with a  wilder cam and lower compression pistons. Timing usually retarded, since a mixture with boost burns faster.


When you see H engines this old at truck shows, the 150, 165 motors only turned up to 1800, so they didn't have a vibration damper on the nose of the crank. I think 180 hp turned 1900, so they got a damper.
If you don't ask, they can't say no.

wig wag

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Re: 672 cubic inch Cummins
« Reply #20 on: January 15, 2013, 09:34:53 PM »
I wanna testify!
Ok. The paint was called old gold. They stopped using it where I worked ( Cummins Ontario)
about 72 73 that's when they changed to cummins beige.  Except some Big Cam II's came
came from the factory painted Marine White. My 82 KW came that way. 903's where Charcoal
Grey. The small "V's" 165 V6, 185' 210, 555 came beige, Emegency Fire engines such as the
NTA 420hp engines where red. The newer style 8V 265 that Doug mentions Looked just like
a 903 but had plane square profile rocker covers that where 2 piece like the 903, where
still painted Old Gold. The high torque NTC 270 was painted lime green. They where usually
hooked up to a 9 speed Eaton Road Ranger.
Engines in Internationals where red, Fords where blue.
As for the engines that had an "H" they where 2 valve heads. "R" signified that the intake
manifold was on the right side of the engine when looking from the Flywheel end.
If the had 2 "H" s then it was a horizontal "pancake" engine.
"N" as was mentioned before signified that it was a 4 valve head.  " NTC" s had full flow cooling,
identifiable by the water pump that has the adjustable idler pulley.  NTA's where a 855 c.i.d.
Engine that had a big abighelian water pump mounted off to the right front of the front cover.
They also had lots of extra cooling pipes.
The engine in the truck that you are looking at is the early version of the V 265. There where
a few in ford Super Duty 900's and such. Doug would remember Gilbert Steel on Brittania.
They had at least one.
These engines where of the same era as the monster 375 - 450 hp V8 beast that was 950 c.i.d.
Not meany of those went into highway trucks. I was told back in the day, that most went into
a tank that was popular with the Isreali Army.
There is, or was one on display in the lobby of Cummins Western? In Langley B.C.
The "c" and the "J" models looked very similar, the "J" being the newer of the two, it was
sometimes turbo'd as in "JT". They are a smaller engine close in size to the one that you
would find in a Dodge P/U. They had a single cylinder head. As did the L-10, and the M-11.
There where the small "B" models in construction equipment. And back in the 50's two monster
engines, the "L" and the "K" not to be confused with the "KT" these brutes also had individual
cylinder heads for each cylinder, except they where the size of a case of whiskey.
These engines where used to power generators on the "Dew Line", tugs, and refrigeration plants.
They where air injection start.
Hope this helps clear up some questions regarding older Cummins Engines.

W. Lineman

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Re: 672 cubic inch Cummins
« Reply #21 on: October 27, 2013, 12:04:02 PM »
Just read this one, I never knew that Cummins ever had a 672 like the Mack, but there it is. The literature says the exact same 4 7/8" x 6" bore and stroke that I forever associated with Mack's old Thermodynes and Maxidynes for so many years.

Compared to most engines it IS a very small Bore / Stroke ratio.

NHRS

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Re: 672 cubic inch Cummins
« Reply #22 on: October 27, 2013, 12:27:08 PM »
Always wondered if that was merely a coincidence, or if Cummilong was making a competition point.

Back in those times, Cummins was selling horsepower, with BIG price jumps between their product offerings as you went up the ladder. Which meant, the price gap between an NH-195 (672 motor) & the NH-220 (743 motor) was worth a year-at-the most suffering with a little less power, before correcting that at 1st in-frame.

As I remember, the liner inside-bore was the only difference, other than turn the wick up just a little on the PT pump. So, at least at Hastings Motor Truck Diamond-T in Nebraska, Everybody that bought new, bought a 195, & at first in-frame overhaul (around 100,000 in those days of oil bath air cleaners & oil that could hardly tolerate itself, let alone any trace of antifreeze), installed the 220 liners & pistons.

And in that era, I'd always heard the Mack Thermodyne would get 7 mpg easy, while Cummins struggled to average 6 (remember, this was on 4-axles, 60,000 lbs.)
If you don't ask, they can't say no.

W. Lineman

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Re: 672 cubic inch Cummins
« Reply #23 on: December 31, 2013, 12:08:50 PM »
Trying not to hijack this thread away from the 672 Cummins, but just another point about Mack names, and since you mentioned it, fuel economy:
The old Mack END672 (LJ era) had an indirect fuel injection system (called the Lanova system). When the B-61 came out with the END673, it still had the same 4 7/8 x 6 bore & stroke, but a direct injection system. The direct injection system gave 15% improvement in fuel economy - huge.
Not sure when or how Cummins caught up, but they did catch up.

NHRS

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Re: 672 cubic inch Cummins
« Reply #24 on: December 31, 2013, 01:56:46 PM »
Forgot most of the old-time rare-stuff, but was the "Lanova" system the one where, the injector (usually merely a nozzle on a plunger-body system like Mack & Cat used) shot the fuel across the top of the cylinder to a pre-chamber across on the other side, where the combustion-expansion started?

The only Mack fuel economy I'd ever heard about was, an easy 7 mph, when Cummilong was struggling to claim between 5 & 6.

An old friend (God rest his soul) had 3 trucks on Little Audrey. He replaced a 743 in 262 with the new red-hot at-the-time 855 in 335 in the early 60's, & only a few of their traditional fuel stops were reachable, that the 262 had made easy.
If you don't ask, they can't say no.

65K121

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Re: 672 cubic inch Cummins
« Reply #25 on: January 09, 2014, 10:03:23 AM »
I have a 65 KW K 100 with the V8E-265 and a set of sticks doesthe engine your looking at
have removeable plates on the side of the block and cummins cast into the valve covers? If so then its a 265
the 903 does not have thoes.they use the same pistons and liners berrings and so on as the small bore 250

Dan Burkhart

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Re: 672 cubic inch Cummins
« Reply #26 on: January 09, 2014, 07:55:36 PM »
I have a 65 KW K 100 with the V8E-265 and a set of sticks doesthe engine your looking at
have removeable plates on the side of the block and cummins cast into the valve covers? If so then its a 265
the 903 does not have thoes.they use the same pistons and liners berrings and so on as the small bore 250
Drifting off the topic a bit here, but I drove a 65 K100 40 some odd years ago. thought it was funny that the auxiliary shift handle doubled as the cab jack handle.
 Got a big laugh when I took a new driver out one day to show him how to shift the thing. I lifted the stick off it's post and handed it to him. I said here, you can shift this one.
Good judgement comes from experience. Experience comes from bad judgement.