G-226 fuel economy stats
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=192758
Printed Date: 05 Nov 2025 at 5:29pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: G-226 fuel economy stats
Posted By: DrAllis
Subject: G-226 fuel economy stats
Date Posted: 05 Jan 2023 at 9:55pm
| It would seem that A-C was trying to better themselves in fuel economy on the G-226 engine from 1957 (the first D-17) to 1967 (the first One-Seventy). Using Nebraska Test data, it has been documented that a D-17 gas made 52.72 belt HP at 1650 RPM and burned 4.535 GPH of fuel in November of 1957 at 62 degrees F air temp. So, ten years later in October with 75 degree F air temp, the new One-Seventy delivered 51.46 PTO HP at 1624 eng RPM's (540 pto speed) while only burning 3.986 GPH fuel. I calculate if the engine was tested at 1650 identical RPM as the D-17 engine, the fuel rate would be 4.049 GPH and HP to be at 52.28. By raising the compression from 7.25 to 1 (M code) to 8.0 to 1 (Z code) the fuel consumption was reduced by 1/2 gallon per hour, (approx 11%) to develop nearly the same HP !! I think this is pretty remarkable considering the One-Seventy had a hydraulic system that was flowing 8 more GPM continuously than the D-17 did !! Also, in recent information seeking, the compression increase wasn't the only thing different. The One-Seventy Zenith carburetor venturi hole was only 11/16" diameter versus the D-17 Zenith venturi of 13/16". All the air and fuel that enters into the engines cylinders has to pass thru this size hole. So, the fuel economy is better with a smaller venturi and the engine still makes equal HP. Fascinating !! |
Replies:
Posted By: Mikez
Date Posted: 05 Jan 2023 at 11:12pm
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Interesting dr thanks for sharing. We have a early D17 that my grandfather sold new to my great uncle. Farm and dealership basically on same property. Before my time uncle joe was brush hogging and something went wrong with governor and over reved and blew up. Gramp got a new engine from allis which is a latter one with oval muffler. But I believe has the original carb on it. My neighbor bought a new 170 from gramp and he always says how our d17 can walk all over his 170. And always talks about how he loved listening to the d17 working the fields next door. Sorry to jump off your gas usage topic. This came to mind reading your post
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Posted By: DrAllis
Date Posted: 06 Jan 2023 at 7:42am
| Back in 1977, I sold a customer a nice low hr'd 7030 with a factory air conditioned cab. He traded me a D-21 series2 platform tractor. Both tractors were actually in the 135 HP range. After the first springs use, I asked him one day how he was getting along with the 7030. He said: " it's a really nice tractor, but just doesn't have the power of my D-21". I knew his tillage practices and asked him what gear he was pulling his 22 ft tandem disc ? He said low 4th high button. And, I said you pulled the same disc with the D-21 in 5th gear, right ?? He said yes. Well, he used to pull the disc at 6.3 MPH with 50% rear rubber and now he was pulling the same disc at 6.8 MPH with 80% rubber in a nice quiet cab. Yeah. In his mind the D-21 will always be king. Nothing would ever change his mind. |
Posted By: captaindana
Date Posted: 06 Jan 2023 at 12:58pm
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About those Nebraska tests Doc, assuming both tests were done at the same elevation above sea level, the only atmospheric variables I can think of would be actual barometric pressures for each test day, the dew point (humidity)and of course the 13* difference in temps. Very interesting! ------------- Blue Skies and Tail Winds Dana |
Posted By: DrAllis
Date Posted: 06 Jan 2023 at 1:24pm
| Barometer reading of 29.025 for the D-17 and 29.140 for the One-Seventy. |
Posted By: Tracy Martin TN
Date Posted: 06 Jan 2023 at 4:26pm
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I have a one seventy and a 170 gasser. Biggest complaint I have with them is the throttle.They are too sensitive can't always find the sweet spot easily. They are not user friendly like the D15 throttle. JMHO Tracy
------------- No greater gift than healthy grandkids! |
Posted By: captaindana
Date Posted: 06 Jan 2023 at 7:20pm
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Gee Doc both low pressure days, do you know the altitude where these tests were in Nebraska or the closest airport? Just curious as I have never considered altitude when reading these h.p results. Thanks ------------- Blue Skies and Tail Winds Dana |
Posted By: DrAllis
Date Posted: 06 Jan 2023 at 7:31pm
| University of Nebraska, Lincoln. |
Posted By: captaindana
Date Posted: 07 Jan 2023 at 5:06am
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Lincoln KLNK sits 1219 feet above sea level. Correcting for the unusually LOW pressure on these two test days brings the actual air density to over 2000 foot elevation. Thinner air equals less hp, but still the fuel burn on the 170 is quite an improvement! Also I would guess for sure the manufacturer’s advertised their hp corrected for a standard day (59* and 29.92) at sea level, as all engines are on planes and jets. ------------- Blue Skies and Tail Winds Dana |
Posted By: DrAllis
Date Posted: 07 Jan 2023 at 8:28am
| Interestingly enough, I just looked at one of my D-17 series 3 advertising literature books. This book was printed in December of 1962. A-C chose not to give the Nebraska Test results of 52.72 HP for gasoline, but their own numbers of 54.43 PTO HP** (HP corrected to 60F temp and 29.92 in HG). Then, when they printed the series 4 literature, they did use the Nebraska Test rating of 52.72 HP. Go figure !!! |
Posted By: Les Kerf
Date Posted: 08 Jan 2023 at 2:41pm
This is good stuff!  Question: Do these engines have the same spec camshaft? The compression ratio improvement is obvious, but the reduced venturi diameter is not. Perhaps the smaller venturi produces improved atomization of the fuel? I'm just guessing. |
DrAllis wrote:Posted By: DrAllis
Date Posted: 08 Jan 2023 at 3:28pm
| Same camshafts. My theory is with the same venturi size, the HP result was more than they wanted. Initially, the D-17 series 5 (replacement for the D-17 series 4) was to be "around 60 HP," according to Swinford's book. I think as they got closer to new model introduction time, instead of HP ratings of 60ish (new model)..... 75-77 (One-Ninety)......and 89 to 94 HP (One-Ninety XT), they settled in on 54....64......75-77.....89-94 HP sizes to better compete with other brands. So, the smaller venturi was a very easy way to get that done and have better efficiency too. EDIT: The 170 engine was documented to be 12.91 HP/Hrs per gallon efficiency. If they kept the fuel burn rate at 4.53 GPH like the D-17 engine, the HP theoretically could have been 58.48 HP @ 1800 RPM. |