ONE-EIGHTY 4 cyl gas: The first and the last !!!

I've had a very nice Labor Day holiday !! I was able to see and test drive the one and only surviving A-C One-Eighty 4-cylinder gas tractor, out of about 100 or so ever built. It also just happens to be the prototype model with an interesting chassis serial number of : WP V d17 T2 . The "V" is actually the symbol for Roman numeral 5, which I can't make with my keyboard. I wonder now if the T2 was meant to be 1/2 because the "T" was on its side !! I have 14 or so things that I was able to verify in the design and build of this One-Eighty prototype tractor from the beginning in December of 1965.  #1. The chassis serial number is clearly unique. The engine s/n is 17-104951. Nothing really noteworthy about that.  #2. Carburetor is a Marvel Schebler brand, quite similar to what the 175 gas tractor wound up with. Larger air inlet and probably venturi size as well, compared to the D-17 engine. I know the compression was increased and can only assume the camshaft was also the same grind as a 175 tractor to arrive at the desired 64-65 PTO HP @ 2,000 rated load RPM's with a no-load high idle of 2,200 RPM. This would calculate out correctly, as the 175 tractor had 61 (60.88) HP at 1800 RPM and an extra 200 RPM increase would be 4 more HP to bring it in at 65-ish HP @ 2,000 RPM.   #3. Flywheel and clutch size appear to be 11 inch, same as a D-17. Pressure plate bolts are 3/8" diameter and flywheel looks small inside that 190 bellhousing. So, I think it's safe to say that the gas tractor got an 11 inch clutch and diesels got the 12 inch clutch.   #4. There is a camshaft operated fuel pump under the full-flow engine oil filter, just like a Gleaner "E" combine engine would have had.      #5. Muffler and manifold appear to be regular stock items as the muffler inlet/manifold outlet pipe is the same diameter as a D-17. So, the only change in this area would have been the muffler which would have been the same for the new One-Seventy and One-Eighty gas engines, with the inlet being the same as the D-17 III and IV and the outlet pipe being slightly larger in diameter and taller than the late D-17 series.       #6. Engine rear adapter plate is the same as a D-17 with the same D-17 starter too.     #7. Engine front mount plate also the same as a D-17 with 3/4" spacers added on each end so it fits between the wider side frames of the 180/190 tractor chassis.     #8.  Cooling fan is the 5-blade D-17 design with a very deep metal radiator shroud that comes back about 4 inches to meet the fan properly. This shroud actually extends rearward enough it is exposed on the bottom as you can easily see it standing from the side.      #9.  The triple section hydraulic pump is (I assume) the exact same pump they eventually used on the later 170/175 tractors. It is located under the radiator and air cleaner area. The interesting thing is they used a U-joint at the crankshaft pulley end and possibly one on the pumps drive shaft end too. I'm wondering if the pump maybe does not sit in a perfectly straight line with the crankshaft, like most front pumps do. It would take some disassembly to verify that, but not worth the hassle.  #10.  The hydraulic pump suction tube is routed like the diesel tractor, up and over the bellhousing and then along a centerline inside of the left side frame. Then, they added an extension to go thru the front engine mount plate where the steering shaft would normally be on a D-17.   #11. The front steering support/bolster is clearly unique to this tractor chassis. First, it is not the traditional 190 zipper style front end with dual internal pistons. It is more like an early One-Seventy housing as it has an external steering ram inside of the right side frame, up tight to the engine at the right front corner. But, it is different than a One-Seventy, because they have hogged out the area underneath the radiator for the triple hydraulic pump to mount. This area is clearly a different design than any other A-C tractor of any time frame. Even the steering ram appears to be larger in diameter than a One-Seventy.  #12. The fenders were clearly prototype as all the bends and kinks are much sharper than production. The platform pieces appear to be production like, as do the brake pedals, but the clutch pedal pad is clearly different (thicker) and I was told made of brass not cast steel. All seat suspension parts and brackets appeared to be production.   I didn't have a tape measure, but I swear the battery box was 2 inches shallower than production.  It just looked not nearly as deep.   #13. Three point top link anchor bracket wasn't one piece cast....it was 2-piece mild steel, just like tractors ten years later would have.  #14. Lastly, the gear ratios of the driveline appear to be production. By this I mean the shift progression is 1-2...3-4...5-6...7-8 with 20% spread in Power Director ranges.  When this tractor was originally built in Dec 1965, (according to Norm Swinford book) the gear ratios should have been the same as a One-Ninety 1-2..3-5..4-6..7-8 with 30% spread in Power Director ranges.  The "up-graded" and improved "XT" parts hadn't even been built yet, so I have to assume it was originally built with 30% spread and then it too was updated to the 20% spread parts. I know what's in it. I just don't know what it was built with for certain. Anyway, it has the newer production parts.    OK. I think I'm done. Pictures will be coming. Thank you to the Kelly, Sandra, and Trigbee Lien family from NE Iowa. The tractor came from the A-C test farm south of Milwaukee to Richard and Nancy Sleichter, Sandra's parents. Also thanks to Dean Byerly for his help in making this informational meeting happen. My brother and I were warmly welcomed and they really went out of their way to make our trip worthwhile. Hope you A-C people enjoy this bit of digging into the past.

What an interesting story! Thanks for sharing the info. 

Very nice and interesting! Thanks,, 

I've got several thoughts on this vibration problem. Remember, I have a One-Seventy gasser that I have configured to have a 180 platform ( a really nice tractor to operate by the way). I too had some vibration issues at high idle or near high idle. My problems were dancing clutch and brake pedals. I fixed those with rubber stops for each pedal. Then, the battery box cover (left platform) was shaking. I took some rubber edging and placed it around the top of the battery box lips, so the lid/platform was then suspended by rubber. All problems were solved. Sooooo, I have no bonafied engineering degree, but it wasn't too hard to solve my vibration issues. Why did they bail out ?? All four cylinder engines, to a degree, have an inherent problem with this. A spinning balancer in the crankcase area is one (expensive) way to solve it. Well, instead of the D-17 flywheel, why didn't they make a special heavy/larger diameter flywheel that would accept a 12 inch clutch, similar to the diesel engine ?? I guarantee if it was perfectly balanced, it would certainly have helped dampen the problem they had, but no, I doubt they even tried that. They didn't come up with any rubber pedal stops or batt box cover rubber isolation either. I think it could have been dealt with. But, that's my opinion. I do feel the fenders on this one tractor may have played a role in why this tractor was smoother than the others. The fenders on any 180-185 are bolted to the right platform and left battery box. Engine vibrations travel thru sheet metal. Those fabbed up non-standard fenders are quite a bit lighter and are shaped differently than a production fender. I think that could be one reason things were different. The other possibility would be the spinning balance of the crankshaft and flywheel. All of these engine parts have a tolerance spec to fall into. Plus or minus something. I'm sure this hand built engine may have had some "special" attention given to the specs and was held to a tighter standard. Combine this with the lighter weight and slightly different shaped fenders and that could have been thee difference in this case. Again, just opinion and from my own One-Seventy vibration experience.

Edited by DrAllis - 04 Sep 2023 at 7:39pm

Interesting story, were you allowed to take any pictures?

A few pics coming. Yes, we went into the display area.

Inline four-cylinder engines have an inherent vibration problem due to having two pistons stopping/starting in the down position while two pistons are stopping/starting in the up position; this results in a 'rocking couple' that twists and bends the crankshaft to and fro, and when this rocking couple coincides with the wrong harmonic frequency it can become quite noticeable.

Big inline fours are worse. Big, heavy flywheels help, big heavy crankshafts help, counterweighted crankshafts help, reverse rotating counterbalance shafts help but the inherent dynamics are always there.

I've come to accept the fact that the West Allis Engineers never went more than a 4.500" stroke just because of that. They were able to keep those vibrations in check up to 2,000 RPM without issue the way they were doing it. They kept raising compression ratios and using different carburetors and in the end a higher lift camshaft to attain the HP levels they desired. A 5 inch stroke would have just added to these vibrations and maybe even forced the RPM's downward to keep them at an acceptable level.  Also, if you read between the lines in Swinford's book, the original plan was to replace the D-17 IV with a new looking "60" HP tractor.  I imagine when some of the larger dealerships and Blockmen heard about that, that's when the D-17 IV was to be replaced with a same size 53-54 HP new styling tractor (170) and the 60 HP future tractor became 64-65 HP. So, in the beginning the G-226 was only going to be 60 HP (like the 175 gas eventually was) but was then forced into becoming something it maybe shouldn't have been (64-65 HP). I know the overhaul hours would have been shortened at 2,200 RPM/64-65 HP. Probably down to 2500-3000 hrs instead of 3500-4000 hrs of the series 4 engine.

Neat piece of history and thanks so much for the pictures. Curious how many hours are on it?

Edited by AC720Man - 05 Sep 2023 at 6:07pm

It's always neat when a prototype tractor survives, especially since there don't seem to be as many AC prototypes out there.

Great post! Thanks for sharing 👍

Old post but the spinning balancer was interesting to me.The 4 cylinder Fiat motors in my Oliver 1365 tractors have a balancer on the crank as they call it.They have zero vibration and run smooth but at low idle have sort of a 'lope' that can't be felt but able to hear it.Supposedly the there is a firing gap between some cylinders different from others.The balancer is inside the block BTW

Excellent post Dr. Allis - bookworthy certainly!  At this point, am wondering why AC didn't pursue some sort of balancer for the gas motor similar to that equipped by Perkins in the 4-236 which was the option of the 170 diesel tractor.  AC was taking delivery of the venerable Perkins 4-236 engine at the time and one could assume AC had the Perkins engine apart at some point to have  a look at the internals and evaluate it operational characteristics within the design RPM range.

orangeman wrote: At this point, am wondering why AC didn't pursue some sort of balancer for the gas motor similar to that equipped by Perkins in the 4-236 which was the option of the 170 diesel tractor.

Edited by DanielW - Yesterday at 10:17am