As the 1450's Fiat 615 model was a 'big brother' to the 1250's Fiat 415, the styling of the 1450 was much the same as the 1250, including the 1250's fancy--and distinctively European style--Siem headlight units, outboard of the grille. 1450 models were available in 2 or 4 wheel drive versions, the latter with the same 'side drive' front wheel assist axle as the 1250. A single stick (with an outboard high/low lever) 7 speed forward, 2 speed reverse transmission, featuring disc brakes and an independent PTO, was a welcome feature for utility work, as was the standard power steering. Three point hitch lift capacity was an impressive 4400 pounds, or over two thirds of the tractor's overall 6000 pound weight--nearly double that of the 1250. The 1450 also optionally incorporated a 2 speed planetary power shift, known as "Ampli-Couple", which apparently didn't work out very well, as no Fiat-built Cockshutt tractors appeared after the 1450 with a power shift of any sort. Head gasket problems plagued the 1450 as well, with copious coolant leakage often being readily apparent along the left side of the cylinder block. The blackest cloud on the 1450's horizon was not the leaking of the head gasket itself, but rather the repair of it, as it's specially-tapered head studs tended to twist off during removal, and then had to be drilled out. A drill bit wandering off of the top of a hardened stud could--and often did--penetrate the 1450's thin water jacket, thus destroying the block. Many, if not most, of 1450's met their Waterloo this way.
The Oliver 1450 was built from 1967 to 1969.
Major redesign: New for 1969, the Fiat 415/Oliver 1250's replacement was the Fiat 450/Oliver 1250-A. Being that the '50 Series was still being built (and larger models being tacked on the top end all the time), the suffix had to be "50", but, being that this new tractor wasn't physically larger than the 1250--and that there was a Cockshutt (no Oliver) 1350 built, the number "1350" was out. So, obviously, was "1450"... The new tractor wasn't smaller than the 1250, so "1150" was out, too. so... what? The answer: 1250-A.
Fiat wisely included a CAV fuel filtration and Diesel injection system on the 450, elevating it onto a more mainstream plateau. Serviceability improved greatly by this single, simple, but prudent move. The disastrous leather diaphragm in the pneumatic governor of the 1250 was relegated to the 'lessons learned' margin of the engineer's notebook by the neat, tidy, and eloquent CAV Diesel injection pump used in the new Fiat 450/Oliver 1250-A.
A gear driven oil pump, much like the type used in the 1250 Gas, but heavier duty, with a built-in relief valve handled lubrication duty, and a sturdy, much more vibration-resistant cast aluminum oil pickup and screen than either the 1250 Gas or Diesel engines had, pre-filtered the oil before delivery to the pump. Again being more similar to the 1250 Gas than the 1250 Diesel was the spin-on, disposable engine oil filter used on the 3 cylinder 1250-A. Merely called a 'vent' in the Oliver parts books, but actually an auxiliary engine cooling unit, it not only vented the bypass gasses from the cylinders and valve stems, but allowed cooler outside air to enter the crankcase, aiding the radiator in maintaining engine temperature.
Compression ratio in the new Fiat 8035 engine of the 1250-A was reduced to a more modest 17:1, down 4½ points from the 1250's 21.5:1. A heavy, solid, well-ported cylinder head securely bolted down on the new 8035 engine maintained compression exceedingly well. With a heavier duty, shorter crankshaft, and a lower compression ratio, up went engine lifetime expectancy--into the stratosphere compared to the 1250. With proper maintenance, these engines could run up to an incredible 10 000 hours before needing their first rebuild.
A hefty, all-business, high volume water pump on the 1250-A took the place of the automobile-inspired unit of the 1250. A larger radiator than the 1250's unit was also made standard equipment in the 1250-A. Coolant capacity was up from 9.1 quarts in the 1250 Diesel to 13½ quarts in the 1250-A, even though, cubic inch-wise, the 1250-A only boasted a 4.5 cubic inch displacement increase over the 1250 Diesel. Larger blades were provided on the 1250-A's fan than the 1250's stubby-bladed unit. Fiat obviously wasn't taking any chances with overheating problems shortening the lifespan of their new tractor engine.
Not so much to handle the power of the new engine, but to handle it's torque, a 10 inch LUK dual clutch bolted up to the flywheel of the 1250-A. Nearly double the heft of the 1250's light duty 9 inch unit, this new clutch was certainly up to the task. One of the (many) complaints issued about the 1250 was slippage in it's 9 inch, automotive-style clutch. Trying to put a dramatic increase in torque through the 1250's already troublesome 9 inch clutch would have spelled certain disaster, hence, a MUCH heavier 10 inch clutch in the 1250-A, with no less than seven thick coiled springs in the pressure plate, clamping down tenaciously on the captive discs; clutch slippage now a thing of the past.
Running the vastly improved engine, (with it, it's modern, reliable CAV injection system, increased cooling, and lower compression) through the same basic transmission and rear end and final drives as the 1250, made for a REALLY nice little tractor. Small changes were made in the rear end of the 1250-A, such as a slightly improved gear shifter, a revamped PTO engagement linkage, and larger diameter brakes (although the same width as the 411R/415/1250 units) improved the overall package even further.
Apparently preferring to avoid the stigmatism of the readily recognizable cute little 'face'--albeit with the evil that lurked behind it--of the 415/1250, Fiat gave the new 450 a total facelift, making not one single sheet metal piece anywhere interchangeable between the 1250 and the 1250-A. Not one; not even the tool box remained the same! Shying away from the 'cute, innocent' look of the 1250, the 1250-A was given a more aggressive, bolder appearance through a more squared-off bodywork than the earlier model. Even though what mechanically was between the fenders did remain for the most part in it's original design, all effort was made to disguise any resemblance, mechanical or aesthetic, to break away from the 'lemon' label the 1250 generated early on for itself. The entire grille of the 1250-A was removable without tools for even easier access to the air cleaner and batteries than the 1250.
The front axle used under the 1250-A was a very slightly re-worked version of the one used on the 1250 Diesel. The 1250-A upped the row spacing choices to eight, from the 1250's six. Tread adjustment was 50 3/8 inches up to 77½ inches, in four axle positions and two front wheel mounting choices: dished in or dished out. Steering arms, spindles, bushings, wheel bearings, etc.., were the same on the 1250 Diesel and 1250-A.
Lighting on the 1250-A wasn't considered to be as paramount as it was on the 1250; the Siem headlight units were left behind 'across the pond', and regular 'tractor lights' substituted for them in Charles City, Iowa. In Oliver trim, the headlights were also relocated to the fenders, along with fender-mounted, high-visibility, amber lensed safety flashers, mounted high on purpose-made standards Oliver provided. A pair of red rear clearance lights also made highway travel safe. A rear work lamp was also included in the lighting package, as were back-lit gages in the instrument panel. Oddly, given all the thought process put into the new 1250-A, no longer was an oil pressure gage part of the instrumentation package, but was replaced with a red warning light ("idiot light", to it's detractors). The "generator" light remained part of the package, but now it was a modern alternator, at a vastly more standardized 12 volt rating. A temperature gage remained in the system, but shared half of it's round face with a newly-added electric fuel level gage. A tachometer/hourmeter also remained, but the 'tractormeter' part was eliminated, the needle now sweeping 270 degrees of the face, rather than the 180 degree sweep that the 1250's Speed-o-Tac had to, by virtue of it's full diameter needle indicating on two different scales, top and bottom.
The rest of the 12 volt negative ground electrical system in the 1250-A consisted of a 2.5KW starter, the aforementioned alternator (which was externally controlled by a voltage regulator remotely mounted on the firewall), a neat and handy little fuse box, a relay for controlling the alternator light on the dash, and an automotive-style flasher unit, all firewall-mounted. A heavy duty, lever-actuated, starter and thermostarter switch, the thermostarter unit itself, a combination "ignition" and light switch, a gearbox neutral safety start switch, and sending units for oil pressure, water temperature, and fuel level gages made up the rest of the electrical system of the 1250-A, all connected together by a tidy, wrapped wiring harness.
All the many, many improvements of the replacement 1250-A over the 1250 made the new model a welcome addition to the Oliver line by Oliver dealers and Olivers buyers alike. Oliver dealers especially must have breathed a collective sigh of relief being told that the 1250-A would be far, far more trouble free than it's predecessor.
The 1250-A quickly became the 1255, to fit in with the new '55 Series Oliver tractors in 1969. No changes were made--or needed--in the 1255, and it served in superb reliability until it, too, was replaced by the new 1265 in 1971.
Parts for Fiat-Built Oliver Tractors