I posted this in the skymaster FB group as well:
With much help from Kim Geyer, who maintains a fleet of T337Hs....
Looks like it might be possible, via field approval, to get rid of the Janitrol heater from a T337B-E, and replace with an exhaust heat exchange system similar the one used on the T337H.
It appears the parts cost might run around 4k, so not far from cost of overhauling your janitrol. But in this case, you get rid of the extra fire under your cowling and future janitrol maint expenses.
Lmk if you have an interest in doing a similar project on your plane, and we can see if there's any savings if more than one of us is doing it.
Drop me an email at
networkgunslinger@gmail.com