[DeTomaso] July POCA newsletter and distributor installation

[JDeRyke at aol.com]

In a message dated 7/7/11 6:01:43 PM, Thomas.Tornblom at hax.se writes:

> The article mentions that the gear should have a 0.010" clearance to the 
> block boss and should never touch the block. This is just plain wrong and 
> will potentially destroy your distributor. The boss acts as a thrust 
> bearing, and it is what takes up the axial loads of the distributor shaft from the 
> load of the oil pump through the spiral gears.
> 

Thomas, I don't know what to tell you. Looking at the distributor boss on 
my OEM '72 block, the junk block in my photos and a third block I have in 
stock. none show any trace of contact between the boss and the distributor 
gear. I also have a 351-Windsor block that shows no trace of gear contact. So 
apparently 0.010" static clearance is very close to what's needed. Whether the 
gear then pulls down to kiss the block in operation, or whether there's 
still an oil film between, I don't know- but there's definitely been no metal 
to metal contact on these 4 examples. All used standard oil pumps during 
their operation, so maybe the loads imparted were not high enough to pull the 
assembly into full metal-to-metal contact.
 Bud Hower has brazed a bronze washer to the base of his gear on the 
example block that showed actual metal to metal contact, so after he gets some 
miles on the rebuilt motor, we can see how this works as an actual thrust 
bushing.   Cheers- J Deryke