I am looking for any original imformation on the D9900 diesel, how many were produced, are they very rare, does anyone have a photo? Thank's, Regards Mark

Hi Mark,
here is a scan from a Wm. Adams Parts & Service News Letter Jan. 1974.
Also some scans from my General Instruction Book for Early Products--megga $$$--.

max. HP = 99
bore = 6 1/8"
stroke = 9 1/4"
RPM = 900

Do not know production numbers but what I have been able scrounge over the years of the 70's and 80's is as follows :-
Power Unit for Diesel 65--(65-70 hp), 1931-32
Power Unit for Diesel 70--(70-76 hp), 1933

Serial Numbers----D9900----4C3001-4C3150
Diesel 65--1C1-1C157
Diesel 70--3E1-3E51
From the above it would seem reasonable to "ass-u-me" that around 358 of these were built.
I stand to be corrected on this data as when I have enquired with my Cat contacts they couldn't get responses from Yellow Father.
"Old Betsy" last I heard was on display at the Smithsonian Institute.

Hope this helps, as it is all I have, apart fom the OMI, that I have scaned from for the unit as noted above.
Cheers,
Eddie B.

They were a very diff engine it had small fuelpump and filter outside with just few inches of fueline the rest of fuel system was internal, injector pumps under side covers,injectors under valve covers and injector lines inside very clean looking engine you need 1 of these to look at

Here is a D9900 that was installed in the Cat Sixty known as "Old Tusko".
Pic from one of the many Caterpillar books.

Thank you all for your help, Regards Mark