The engine shown is a O&R.60. It is not a conversion .the conversion kits for the .60's came with a ball bearing thrust washer that looked like it came from the front wheel of a bicycle & the plug for the intake was a cork . Nothing was said in the instructions about cutting the old intake off just plugging it .
The 1948 staked on aluminum head .60 sideport (last side port model made ) came with a 1/4" X 32 plug ( no adapter) & all O&R.60's after that .The last model made was the "Purple Head" (RARE !)'
The .29's came first with a aluminum colored head & the last models had a "Blue Head".These were de-tuned mostly by the soft aluminum cylinder to case gasket (one or two). The.33 only came as the "Red Head" .
The first problem with the .29's on up were the connecting rods breaking ,hence the steel rod that didn't break but brought on the next problem of blowing off the cylinders,hence the aluminum washers that lowered compression.Ended up with low power.
The O&R boys were in trouble by then & just never caught up with all the problems !
I still love them though . Max H.
