Posted by Andrew in MI [172.68.206.37] on Monday, February 17, 2020 at 17:28:16 :
In Reply to: Re: oil pumps and bypass filter systems.. posted by Dozerman51 [172.68.142.80] on Saturday, February 15, 2020 at 18:40:59 :
I have two 251 engines here. One of them has full flow oiling capability the other is bypass only. Some of them could get sodium valves. You could order either style engine block. I imagine full flow was more expensive option especially if ordered with sodium valves in the block.
Easy way to tell the difference, the full flow blocks have a diamond flat with four holes (pictured). Two holes are threaded NPT for oil passage the other two are threaded for bolts that mount an aluminum housing whereby a spin on type oil filter could be installed.
The 251 engine in the picture was from a Clark Airport Tug.