My Tractor Forum banner

1956 Super 55 questions

952 Views 6 Replies 4 Participants Last post by  Newsman
1956 4 cyl gas.

I have 2 questions; the first It surely has been asked, I've searched but did not find an answer: Oil. What kind of oil can I use. In my searches, people say 15w-40 but not in all seasons, they talk about zinc additives and flat tappet cam needing zinc additives. I'm confused...

What I'll do with the tractor is plowing some snow in the winter, and in summer use, wood splitting and some light duty work in the yard. Can I use one type of oil all year long or is it better one type for the cold season and one type for the hot season. I live in Quebec, temperature can drop to -20F. All I want is to use the good oil to avoid damage of the engine;)

Other question, the engine runs ok but is kind of sputtering at full throttle. The four spark plugs are new (autolite 386 copper). Compression is 150 psi on 3 cylinders and one at 135 psi. Before throwing parts at it, I wanted to know from you that knows those machines what to check first. Carburetor is clean, I'm using super (octane 91 gas) is it ok?

Tractor sat for 2 years outside, I cleaned the distributor, change fuel hose and filter, and it started right up.

Is the site OliverParts a good place to buy stuff without any trouble?

Thanks in advance and here a pic or the tractor:D


1 - 7 of 7 Posts
I the summer time I like to run 30w in my tractor. If it gets below 0*F, I use 5w-30. I use Schaeffer oil, seems to be good stuff.

Does the engine smooth out when put under a load. Do you have a fuel pump or is it gravity flow. What make of carb is it. I know that some of the Oliver tractors were required to be tuned when under a load.
Gravity flow, Bendix carb. And yes it seems to smooth out when riding it on the road a max RPM in 6th gear. It's the only "load" I can put on the engine for now since the accessories are at my neighbor's place, unless trying to push the barn with it :LOL:

For the oil, Synthetic or mineral? And in the case I don't have access to that brand of oil, is Castrol of Mobil 1 (mineral of synthetic) safe for that 64 years old engine?

In all my snowblowers, lawn and garden tractors I just use synthetic 5w-30 Castrol all year long, but they are not as old and are not comparable in terms of engines...

Thanks for your time!


I run synthetic oil in my 1941 McCormick Deering and have had no problems. I always like to run a high quality oil in my equipment. It is better to change to a lighter oil in the winter time because the oil gets thicker when it is cold and takes longer to pump to moving parts. Also, use a thicker oil in the summer time so the oil is not to thin on startups.

Sounds like your carb needs adjusted. Try turning the fuel mixture screw a 1/4 turn outward to make a richer air and fuel mixture. Then test throttle response. If your engine runs smoother at full throttle, but still sputters, you can try to richen the fuel mixture a little more.
  • Like
Reactions: Rivers
I'm a fan of Rotella T5 HDEO diesel oils for these applications. They have higher levels of the ZDDP, which is the additive which is supposedly good for the flat tappet engines. They don't go to 5w30, but have a 5w40, which is what I use in my stuff that sees cold temperatures.

You will probably open up a hornets nest with the synthetic vs mineral question. Opinions are polarized. I've switched and have had no bad experiences. Others will likely chime in and say that you'll spring leaks everywhere and stir up crud in the engine. There is probably no right answer.

Modern day Castrol (or really any oil) is many orders of magnitude better than the oils that engine was built to use. I don't think you need to worry about that.
  • Like
Reactions: Rivers
I everyone, a little update on my problem, I opened the carb and rebuilt it with new gaskets and the problem is solved. The gasket inside the carb was so bad I wonder how it worked anyway!
Glad to see you solved the problem Thanks for the update letting us know what it was.
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.