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Forum Category: PT Boats of WWII
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Forum Name: PT Boats - General
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Topic: Needed 4M-2500 blueprints
http://www.ptboatforum.com/cgi-bin/MB2/netboardr.cgi?cid=101&fid=102&tid=2205



Anyone know where they are hiding ?

Specifically, I'd like to know the diametral pitch of all gears used in the construction of the 4M-2500 Packard marine engine.

Thanks for any help!



Posted By: magneto | Posted on: May 26, 2011 - 7:44pm
Total Posts: | Joined: Unregistered



The Operating Manual (TM55-1010) for the 4M2500 is available from PT Boats, Inc as part of a collection on CD. However, while it contains a number of constructional drawings, the only one with any kind of quantitative information related to gearing is this illustration:
[IMaGe]http://i73.photobucket.com/albums/i204/alross2/gear.jpg[/IMaGe]

Al Ross



Posted By: alross2 | Posted on: May 29, 2011 - 12:55pm
Total Posts: 919 | Joined: Oct 30, 2006 - 8:19pm



There is actually a slightly better set of engineering drawings on pages 111-112 figs. 106-108 in restricted operating manual Packard marine engine model 4M 2500 types W7 through W16 or corresponding W7 through W10 plus others.(small manual 5 1/2" x 8 1/4") There is a good photograph of timing gear train in the maintenance manual TM 55-1011 section I page I-1 Perhaps someone at Packard motorcars international has some original prints



Posted By: rcr | Posted on: May 29, 2011 - 7:41pm
Total Posts: | Joined: Unregistered



I think I have seen a drawing of the supercharger drive train somewhere. We had to replace our center engine supercharger drive shaft ~2 years ago when it snapped during a backfire during startup. It was due to a sticking carburetor. Anyway the 1 inch steel drive shaft was twisted and snapped like a twig. I will look around and see if I can find the drawing. I think there are 3 gears involved in the drive of the supercharger fan. Are you even interested in this? Jerry PT658 Portland, OR

Jerry Gilmartin

Posted By: Jerry Gilmartin | Posted on: May 29, 2011 - 8:07pm
Total Posts: 1288 | Joined: Oct 8, 2006 - 11:16pm