broken engine ear

Fri May 30, 2014 8:02 pm

I know I have not seen as many cubs as a lot of members have, but in the years I have dealt with them i have seen 3 with the right front ear broken off, 2 of which were leaking oil at the ear. All 3 of them were 47 through first quarter 48 models, and 2 were casting number 251341R1, I do not know the casting number of the 3rd one. I was curious if anyone else has kept track of the years and casting numbers.

Also, as I noted in a posting last summer, the 251341R1 castings I came across apparently used an oddball valve spring (not a roto cap spring). A standard valve spring is too tall to install the keepers, intake and exhaust both, and as I mentioned they do not have roto caps.

Re: broken engine ear

Fri May 30, 2014 8:25 pm

they made the castings thicker in that area around 50 ? or so, they knew it was problem
Tim

Re: broken engine ear

Fri May 30, 2014 10:14 pm

I have seen hundreds of cubs over the years and have worked on many. I have had atleast 20 or so that the right ear was either cracked or broken off. I have has atleast two that the ears were broken off both sides. A few had loaders on them at one time and some were justs abused. I had one come here to be repaired. It had cultivators attached. The owner was cultivating in second gear as fast as it would go. HIt a rock that stopped it dead in its tracks.It was a late 50's model. I was able to repair many of these broken ears. I learned how many years ago by talking to the local owner of a welding supply store. I purchased the welding rod and followed his instructions. I welded a old junk block with a broken ear for practice. He told me that if done properly the weld would be stronger than the original. I welded it as directed. let cool. then propmtly took a big sledge to try to brake the weld. The weld did not brake.

Re: broken engine ear

Sat May 31, 2014 7:58 am

At one point when I was looking at a lot of cubs in a years time. It was not uncommon to find the broken ( and repaired ) ear on a 47 and 48, but seldom on anything newer. As Tim (TST) said the ear was made thicker on the later years. Most of the repair welds did what they were intended to do and a few cracked in or next to the weld. I would not say that a welded ear is as god as new , but repaired by a quality weld they do seem to hold together.

Re: broken engine ear

Sat May 31, 2014 8:15 am

My 53 has a welded ear and has been worked pretty hard with no problems.

Re: broken engine ear

Sat May 31, 2014 8:17 am

I have two that have the broken ear. One of them is a 1950, and the other is a 1968 lowboy. Both of them were broken when they come to me, so I can't speak to the cause.

Re: broken engine ear

Sat May 31, 2014 11:59 am

My 49 has the broken ear, not sure of casting number.

Berlin

Re: broken engine ear

Sat May 31, 2014 6:21 pm

I purchased a 48 a couple of years ago to sell and it had a broken ear also.

That is the only one I have ever see in person.

Re: broken engine ear

Sat May 31, 2014 7:43 pm

I have scrapped 30 or more with a cracked, broken or welded ear. most all pre 1960.

Re: broken engine ear

Sun Jun 01, 2014 6:00 am

Isn't this why Bezirk made up those engine braces? I've got a set on my '55 Cub. As someone said: Cheap insurance.

Re: broken engine ear

Sun Jun 01, 2014 7:23 am

Yes that is the reason I had a friend design the braces , I discovered that My 49 had a broken ear. The braces provide protection from breaking and if already broken they help distribute the load between the bolster and the the flywheel casing .

Berlin

Re: broken engine ear

Sun Jun 01, 2014 7:23 am

Yes that is the reason I had a friend design the braces , I discovered that My 49 had a broken ear. The braces provide protection from breaking and if already broken they help distribute the load between the bolster and the the flywheel casing .

Berlin

Re: broken engine ear

Sun Jun 01, 2014 8:45 am

John,
My '48, serial # 24264 Has a repaired right engine ear.
Nick

Re: broken engine ear

Sun Jun 01, 2014 9:07 am

A thought on the occurence of broken ears; (thanks to gitractorman's Cub spreadsheet)
120,949 Cubs were made in the years 1947-50.
132,202 Cubs were made in the years 1951-79. (157,695 if including Lo Boys)

Roughly speaking an equal number produced in a four year span as in the following 28 years. If broken ears happened at specific rate, say 1 in 500, you would find more per year in the first four years simply because there were more ears made those years. Using my theoretical 1 in 500 number: 1948 production of 46,482 would give us 92 broken ears. Picking another year, 1963 production was 3,556 (including Lo Boys) would give us 7 broken ears.

Add to the fact that you are numerically more likely to see a broken ear on one of the first four years that those are also the ones with the weaker ear and are easier to break. That theoretical 1 in 500 could go to 1 in 250, and that 92 number becomes 185, versus the 7 for 1963.

Re: broken engine ear

Fri Jun 06, 2014 5:13 pm

My 1948 Cub had a broken lower right ear on the engine block. Completely broken off the block.
Repaired it using stainless steel filler rod and my Hobart stick welder (Super Missile Rod, 1/8" rod, DC+, 90 amps). It took a while because I had to use the short bead, backstep method and allow the parts to cool to 100F or so before welding the next bead.
I fabricated the standard ear braces that have been described numerous times in this forum and installed them for added strengthening in this weak part of the Cub block.