Richard A. Day, Jr., Restoration, Maintenance, and Operating
‘Notes for Palmer ZR Series Marine Engines. Published by the
author, 6 Windward Dr., Severna Park, MD 21146, $5.00, plus $.70
postage. Maryland residents add 5% sales tax.
This book is the fourth in Dick Day’s series on Palmer
engines. The previous three were reviewed in the February 1986
issue of GEM. It is in 8? X 11 format and has 90 pages. Twenty-four
of these are of his authorship and the remaining are reprints of
Palmer, Bosch, and Zenith data.
The Palmer ZR engine was considered the Cadillac of work boat
engines. It was built in one, two, three, and four cylinder
versions; however, the best-known is the single-cylinder engine
used without a reverse gear. It is a big, rugged, slow speed
four-cycle engine with lots of polished brass. Unique features are-
a ‘T’ head design requiring two cam shafts, dual spark
plugs (one for battery ignition and one for an optional magneto),
and a lever to shift the exhaust cam endwise during starting. This
last device allows an extra bump on the cam to reopen the exhaust
valve during the first half of the compression stroke. Dick Day
writes of the ZR series because there were other similar models-the
NL and PNR.
The book contains a great many pieces of information useful to
the collector. To mention a few-design variations over the years,
how to date an engine, the proper paint color, how to time the
camshafts, how to remove the flywheel, tappet clearances and
bearing fits. This is information not available elsewhere. In
addition, Dick Day’s book is fun to read.
With these good things said, I must mention some faults and
omissions. Early in the book there should be a table describing the
ZR and the other similar models-bore, stroke, weight, HP, rated
speed, overall height, and years of production. Secondly, he states
that the model D Schebler air valve carburetor was used on all but
the last engines built. The only carburetor information included is
the Zenith that was on the late engines. Similarly, he tells that
the Bosch ZR magneto was used on most engines, yet the data
included is for the MJB used on late engines.
Despite the flaws, the book is essential for anyone owning or
hoping to own one of these engines. It is a good addition to any
engine collector’s library.
This book review was written by Max F. Homfield, R.R.1, Box 697,
St. Michaels, Maryland 21663. Mr. Horn field is a mechanical
engineer retired from General Motors where he worked on engine
design and development. He now does volunteer work for the
Chesapeake Bay Maritime Museum where he is directing the
restoration of their antique marine engines.
