251 into B-3 PW

[firemechjeff]

My first post. I hope that I can get some ideas on the installation of a 251 into a '51 FFPW. I bought this truck as a basket case parts truck with the idea of saving it. I am up to my eyeballs in the restoration after 2 years. The truck was not together when I got it. There was a 251 engine on the flatbed. So I decided to go with it. Matt, I emailed you with the same question. After looking at my friend's 1947 FFPW that I am also working on, I think the 251 install is going to give me all sorts of problems with the radiator location. I can fab mounts, etc, I have experience with that but the radiator cowl is what I am seeing as a big problem because of the cap location. I hope for some ideas.
Thanks,
Jeff

[Torvald]

Hello Jeff, Sorry for the tardy reply, I've been over my head busy for the past half year. I have put a 265 in my '51 PW, so I know that it is possible. I also know that it is a LOT of work and hugely time consuming. You are correct that the radiator and it's mounting are the greatest problems, essentially everything else drops in. I used the original radiator and the original water pump, but in order to do that I had to do major modifications to the radiator, and built a mounting plate for the water pump that set it ahead and down from it's original position. If at all possible I would suggest getting a pump, radiator, radiator channel mount, radiator to pump elbow, and probably a few other things that I have forgotten form a EEPW with the 251. Then you won't have to fab such a terrific amount of stuff.
I documented the work documented in my facebook album https://www.facebook.com/media/set/?...9282310&type=3 I believe that you can see the documentation even if you don't have facebook, you just can't post anything.

Alterations that I made to make it all fit were:

• Turn radiator top and bottom tanks around, kept original radiator support but extended radiator mounts ahead about 3 ½”.
  • This will allow room for the fan, but it now has to be moved down with respect to the engine in order to clear the top tank.
  • While the radiator is being altered be sure to have the tubes cleaned.
  • Radiator alterations/rebuild starts at https://www.facebook.com/photo/?fbid...09305249282310
  • A good picture of the installed radiator is: https://www.facebook.com/photo/?fbid...09305249282310
• Fabricate a waterpump mount.
  • Allows the waterpump to be moved down so fan can clear the top tank
  • Another option would be to find a waterpump from a 251 PW (something I couldn’t do)
  • Here’s a view of the mount: https://www.facebook.com/photo/?fbid...09305249282310
• Reposition crankshaft pulley to align with re-positioned water pump pulley.
  • https://www.facebook.com/photo/?fbid...09305249282310
• Change the engine coolant outlet elbow to match the new position of the radiator
  • See https://www.facebook.com/photo/?fbid...09305249282310 and https://www.facebook.com/photo/?fbid...09305249282310
• Revise the fan shroud to accommodate the new position of the fan with respect to the radiator.
  • I revised the shroud from an M-37
  • Picture of it installed is here: https://www.facebook.com/photo/?fbid...09305249282310
• Use front engine rubber insulator and mounting plate from 251 (this is probably already on your engine)
  • Can also use a 230 mounting plate, insulator and support plate by adding extensions to the support plate so that it matches up to the frame mounting holes.
• Used the 251 grill extensions from VPW to move grill forward 1 ½”