Is An Off Color Question Grounds For Impeachment?

The HD-21 my cousin had was a turbocharged 844, but it may have been a later one than your pic...the early ones may have been different. That was a pretty good old dozer, it had a cable blade & a diesel torque converter. The 844 was a nice-running engine, smooth & started really easy. I did an in-frame on it, or I put it back together after he & his brother tore it down. By the time they got parts & the heads done it was December & -10 when I assembled the engine...right out in the open, in about a foot of snow...he had a space heater blowing under the tractor from the back, & an old salamander in front. Good times! NOT...I wouldn't do that for any kind of money now. 😄
The Allis-Chalmers forum guys probably know all about the differences. I know the HD-20 had a 6-110 Detroit, those were a beast...

Upon further search...
That is a Roots blower if I ever saw one.

And the turbo version like Cuz's...

You would think that A-C would have made a huge point of the engine being super-charged.

I wonder how long after Caterpillar introduced the D-9, before A-C turbocharged their engine, and when did A-C change their construction equipment color from Persian Orange to the pale yellow?

Art,

I ran a brand new HD 11 in 1968 which had the pale yellow but my uncle owned an orange one that he bought around 1962-3. So my guess is they changed color about '65-66. Also the HD 21s we had in the Seabees and were about "66 or '67 era machines all had turbos. I liked them a lot- way better than the IHC TD 20s that we had.

Jan

The early hd 16's and 21's used a Buda 844 with a turbo on the 21's to get the extra hp needed. I'm not sure if any were supercharged, but it is possible. They were a Lonova design with the energy cells in the opposite side of the head from the injectors. After AC bought Buda in the early '50's they started calling the engines the 16000 and 21000 engines with few changes except for AC cast on the manifolds instead of Buda. I had a Buda model 6DCS 844 on my sawmill for several years, until it decided to retire. It was a smooth running engine and used about 4 gal/hr on the mill. I replaced it with a 2 valve 671 which burned 2.5 gal/hr and seemed to do a better job. Could be the Woodward governor was just more responsive than the governor on the Buda's Bosch inline pump.

Rick

Cousin's 21 was the pale yellow, & I don't think it had ever been repainted. I don't know the year, but would guess middle to late 60's, as Jan said.
I do believe it was a 21000 designation, as I remember. We had hell finding main bearings, finally had to send the old shells to a guy in Washington State that rebuilt them.
It also was direct injected, the injectors were inside the valve cover...I remember that clearly, as there was a leaky banjo washer on the return line that immediately started making oil after the overhaul...first oil change came pretty soon. 😛

From my book, 'AC Construction & Industrial Equipment" by Norm Swineford,

The 844 Buda type engine was offered NA, supercharged and turboed. This engine is a prechamber type. It appears that the original HD21, 1954-56 used a supercharged 844 engine rated at 235 hp. 56-58 used a turbocharged version of this engine rated at 256 hp. The NA 844 engine was also used in the HD-16 rated at 163/170 hp.

The later 21000 & 16000 series engines are the same 844 CID, but are a complete redesign of the engine to a direct injection cross flow type. the 21000 was used in HD-21 series and was turboed; 16000 & 17000 were used in the HD-16 series and were NA.

Looks like paint colors were a customer option at least in 1960-65.

From my book, 'AC Construction & Industrial Equipment" by Norm Swineford,

The 844 Buda type engine was offered NA, supercharged and turboed. This engine is a prechamber type. It appears that the original HD21, 1954-56 used a supercharged 844 engine rated at 235 hp. 56-58 used a turbocharged version of this engine rated at 256 hp. The NA 844 engine was also used in the HD-16 rated at 163/170 hp.

The later 21000 & 16000 series engines are the same 844 CID, but are a complete redesign of the engine to a direct injection cross flow type. the 21000 was used in HD-21 series and was turboed; 16000 & 17000 were used in the HD-16 series and were NA.

Looks like paint colors were a customer option at least in 1960-65.

[quote="jaluhn"]From my book, 'AC Construction & Industrial Equipment" by Norm Swineford,

The 844 Buda type engine was offered NA, supercharged and turboed. This engine is a prechamber type. It appears that the original HD21, 1954-56 used a supercharged 844 engine rated at 235 hp. 56-58 used a turbocharged version of this engine rated at 256 hp. The NA 844 engine was also used in the HD-16 rated at 163/170 hp.

The later 21000 & 16000 series engines are the same 844 CID, but are a complete redesign of the engine to a direct injection cross flow type. the 21000 was used in HD-21 series and was turboed; 16000 & 17000 were used in the HD-16 series and were NA.

Looks like paint colors were a customer option at least in 1960-65.[/quote]

Thanks. I think my AC-nut neighbor has that book, but I've never got to read it.