Oliver XO-121 Tribute

Not your ordinary restoration

Original XO-121 in the Floyd County Museum

Tribute XO-121 with 1 or 3 original engines

In 1954, Oliver Tractor Corporation’s unveiled their experimental high compression (12-1) engine. It utilized a Hercules DOOB diesel block and experimental high compression gasoline head. 100 octane fuel was developed for this test produced by the Eythl Corporation. Tested against Oliver 70 & 77, the XO-121 had 44% more horsepower output per cubic-inch than the 77 and 92% more than the 70. Fuel economy was greatly increased, also. When measured on the drawbar, there was an 43% increase in power over the 77 and an 85% increase over the 70.(Oliver Heritage magazine, 10/22) Pictured on the left is the original XO-121 as it resides in the Floyd County Museum—Charles City, IA

People restore tractors for many reasons. All of my restoration or build projects have to have a story that resonates with me. My family has roots in the Charles City area and deeply connected to the Oliver brand and the Oliver factory.

I like rare or unusual projects. One of the rarest Oliver's is the XO-121. My Uncle, an Oliver Purist warned me that there can only be one XO-121. I have kept these words close to me as I ventured into this project. I couldn't just copy the XO-121 but celebrate it. Many Oliver supporters didn't even know this iconic tractor existed having been locked up in the Floyd County Museum for many years. I wanted something that could be taken out and inform people of this tractor.

The project really came to light after coming up empty trying to find a Hercules DOOB engine to start with. To date, I have never found a DOOB block in the wild or online, nor have I found anyone who could tell me a model/make of a product with a DOOB in it. I was made aware that there were actually 3 original engines that Oliver produced and that one may be available through the museum which I was able to purchase. As you can see in the photos, this was not much more than a rusty block and a few parts but it was the spark needed to start a very long 14 year journey (2010).

The crazy idea of recreating this iconic tractor came in 2010. The research began and I searched for a Hercules DOOB block as a foundation for the recreation. The search for a wide front Oliver 88 Row Crop was not easy at the time as well. Of course, after I purchased a donor at auction, they became more readily available. The 'restored' tractor that I purchased has several mechanical issues that were unknown at the time. More details in the slideshow on the home page.

Donor Tractor purchased in 2013.

tear down #1

Inner fender skins were fabricated

grill 1.0 taking shape

grill 1.0 looking good

bad gears removed

front axle welded and smooth

early mock-up seemed to go fast

way too optimistic setting the doob engine in

grill 1.0 isn't stamped thus weak

plenty of metal pieces and carnage in the gear box

salvage gears installed

After many engine builders looked at the pile of parts I had and rejected touching it, I found the amazing genius who was ready to take on a challenge. Jeremy Coker of the Compound - Marionville, MO understood that we had one shot to breathe life back into this piece of history and that there was no room for error or a redo. He dedication to see this project through to the end can never be repaid.

its pretty rough

hand fabricated rod sent to Carrillo.

rods are artwork

not much clearance

testing and retesting oil flow

3D scan of the head

custom governor gear had to be manufactured

custom water pump installed & ready

It runs on its stand!

motor getting wedged in!

exhaust is a tight fit

epic day to see it move under it's own power

I enjoyed putting about 10 hours of run time on the motor!

Donor DOOD engine purchased from California for a crank shaft

beautiful pistons

crank was ground

almost looks real

combination of paper template and 3D scanning to get head gasket

spin on oil filter adapter is fabricated

Hercules stamped and etched 'sample' into the timing cover on the 3 experimental blocks

roller rocker valve train

valve cover fabricated

external oil line make sure camshaft is oiling properly

not much room for clutch and exhaust

grill 4.0 is built at the Compound

A new shop and direction was needed. Covid hit and worked stalled for a few years. I drove to Michigan to purchase a new wide front end during this time to replace the worn out front end. I was introduced to Chris Rude out of Springfield, MO who also wanted to bring life to this tribute tractor. His team worked for a year grinding, prepping, sanding, perfecting and painting the tractor.