Restrictors in the oil passages

[JHertzman@domain.elided]

The modification which Russ Neely mentioned that his friend did at the 
suggestion of a well known Alfa mechanic - restricting the oil flow to the 
cams in order to maintain pressure down below - is a new one on me. 

I will admit that I can't recall having heard of great problems with camshaft 
bearing wear, but I have seen (and heard of) badly worn cam lobes and badly 
scuffed cam cups, and had assumed that they got their lubrication by a fairly 
substantial flow-through from the cam journals.

Using the allen screws, and then drilling them to get the desired 
flow-reduction seems odd. I have seen references to reducing coolant flow by 
plugging water holes with threaded aluminum rods and then drilling; the CRH 
says suitable "allen head set screws can be used if they are aluminum", but a 
friend did this sort of thing on his GTA with heliarc welding.

I have just flipped through the CRH to see if I could find any historic 
observations about the head gaskets, O-rings, cam lubrication and all that. 
Didn't find it, will have to ask some of the Seniors. In the section of notes 
on Sebring follow-up (GTA) I noted that 7500 was the recommended max RPM and 
oil pressure was given as 40 normal, 30 minimum, which I couldn't help 
relating to the "keeping the oil pressure down in the bottom of the engine 
will help late in a race when the oil gets thin" mentioned in the 
passage-plugging explanation.

The CRH is perennially interesting reading. At the bottom of Group 1 Page 1 
there is a lovely section on valve train balancing - the camshafts must be 
balanced, and the cam sprockets must be balanced separately (and dynamically) 
while allowing for sprocket lock bolt weight, and everything else - heady 
stuff.

John H.
Raleigh N.C.

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