In my search for a flatty for my 53 Merc, I came across several engines (including the 53 Merc truck engine that I bought) that had different heads on one side than the other. Lots of stuff happens in 73 years but it seems really common to have replaced one head only even though the combustion chambers were different and with a different volume. I have seen one 8RT with and EAB, and my engine has one 8CM and one EAC… how well did these engines run? Was it even noticeable?
Probably not that noticeable. Low compression, low power engines where the head design does not make much of a difference, especially during daily driving. As long as it started, and got you from point A to B, most folks just don't care.
People did what they could. I've been in bike engines where one cylinder was bored different than the other.
Guessing it had been rebuilt at some point, whether a one man shop or large facility. Most likely a head that appeared corroded, or warped, was simply swapped for another.
I don't remember exactly but I read somewhere that the deck height on at least flatheads were not the same. Maybe this was a cheap way to attempt to correct that. I doubt it but guys did crazy things.
The Jalopy Journal
