Is there a noticeable power difference between the old/ne

[rick 48 cub]

Hi all,

How much difference in real power is there between a 1948 and 1978 cub? Is it dramatic or barely noticeable ?

I am thinking of adding to my fleet of Cubs ( I presently own a 1948 cub) with a 1978 model. I mostly use my old cub for mowing with a 60 belly mower.

Thanks!

[Eugene]

Answer is, no real draw bar horse power difference, providing both engines are in the same, like new condition.

[Boss Hog]

Answer is, no real draw bar horse power difference, providing both engines are in the same, like new condition.

There is quit a bit of difference in my opinion. I have owned 12 of the late model cubs as well as many many of the older ones some of which I overhauled the engine. There is a big difference.
Boss

[tst]

I agree with Boss, I have both, I can climb big hills no problem in 2nd gear with a C3 mower with a late cub, the early cubs even running good it is a struggle to do so
Tim

[Bus Driver]

Nebraska tested Cubs in 1947 and 1956. Significant (my opinion) engine changes were made about 1953 ( I hope to eventually locate my records of the specifics of that). Other changes could also affect performance. Test 386 in 1947 showed 9.23 maximum belt horsepower, low gear maximum pull of 1596 pounds at 1.96 mph and slippage of 10.98% Test 575 of 1956 showed 10.39 maximum belt horsepower, low gear maximum pull of 1605 pounds at 2.25 mph with slippage of 6.73%. Tractor ballasting could have been different as full details are not provided at my (not online) information source. But clearly the 1956 had the better performance with slightly great pull at higher speed in first gear. Looks like 13% to 15% improved performance. Greater ballast generally yields greater pull but lower speed as the tractor must move extra weight.

[rexxon]

I have also have had a few of each, and I'm with Boss (again) on this one-- quite a bit more power with the last Cubs

[Tezell]

Very noticeable difference.

I have a 53 that is by far my strongest round nose but, it is no where near my 75 or my 77. All my square nose tractors seem quite a bit more powerful than the round nose ones.

I love them all but there is a power difference.

[64/67lo-boy]

I think there was a change in main jet size 47 to 56 was .030 part # 354192R91 and 57 to 74 was .035. part # 364610R91. Could have added a little more power. This was the IH 3/4 updraft carburator.

[Bus Driver]

Often our sources of information do not agree and often they are incomplete. Parts catalog TC-37F is one of my most-trusted sources. And it is incomplete in some respects. For the IH Cub carburetor, it shows jet 354192R91 for Cubs serial 501 to 172438. That is 1947 to sometime in 1953. From other sources, that jet size is 0.034. Jet 359551R91 is for serial 172439 to 196899. That is during 1953 to early 1956. I have not found a size for that jet. Jet 364610R91 does not specify a serial number range but the carburetor number itself suggests that it is the later model tractors. Other sources show that jet to be 0.032. Then there is jet 404945R1 for carburetor 63349C91-- I have no further information on that one.
And Page 12 of Group 12 in the TC-37F shows two different various discharge nozzles and the carburetor for which they are intended. Those parts are different. 352717R11 can be identified with a #52 drill and 355717R11 can be identified with a #39 drill. Do not remove any metal when using the drill as a gauge.
I have not been able to find other verification for any of this dimensional information.
The TC-37F is not clear (not to me at least) about which jet goes with which discharge nozzle.
The I &T manual IH-50 shows the Cub jet as 0.034 with no further explanation. I & T IH-8 does not list a jet size. For those who do not already know, the I & T manuals are (my opinion) slightly better than nothing.

[Alan Gee]

Not to highjack this post about Horse Power but we had a tree go down on the South end of our property. I got out the Sears lawn tractor to push it off into the woods. The Sears tractor is the biggest one they make , its the so called
proffesional grade tractor with 28 HP and rear wheel chains and a what they call the " dozer blade " up front. I tried to push the tree and the thing just sat there like a spoiled brat and never moved the tree an inch. I went back and got out the Cub with its booming 9 or so HP and it pushed the tree with zero problems.

[Barnyard]

I went back and got out the Cub with its booming 9 or so HP and it pushed the tree with zero problems.

That was the torque moving the tree not the HP.

[64/67lo-boy]

Yup BarnYards right a lot of folks get HP and Torque mixed up. For pulling or pushing you need torque. And maybe thats why they had a cam change on the later C60 which gives a little more torque. These are small tractors and torque moves things not HP.

[Bus Driver]

The greater weight of the Cub is a factor. Nebraska tests show that the horizontal pull in pounds is never greater than than the weight of the tractor doing the pulling. Traction is one of the crucial factors.

Tires with larger outer diameter have more area touching the supporting surface which helps with traction. The larger the circle, the nearer the periphery is to a straight line.

[64/67lo-boy]

Thats very true. Makes perfect sence. Traction, cub weight, gearing torque. you dont get the true picture if you just look at HP. HP can increase and torque can be decrease. There are alot of factors that determin maximum pulling power. It doesnt mater how much the cub weighs if you dont have the torque to turn the wheels.

[brichter]

Quite a bit of difference in pulling discs and plows, cutting grass, and other jobs when using the late 75 as opposed to the round nose cubs.