Re: alfa-digest V7 #625 - Roll Pin Oil Restriction

[AlfaNeely@domain.elided]

In a message dated 4/8/99 12:48:57 PM Central Daylight Time, 
owner-alfa-digest@domain.elided writes:

<< 
 Date: Thu, 8 Apr 1999 08:11:03 -0400
 From: Hirsch <Catenary@domain.elided>
 Subject: RE: engine roll- or dowel pins

	<snip> 
 I realize oil flow is restricted by using roll pins. This is
 one advantage of using the small rings instead.
 
 Regards,
 Rich Hirsch  >>

	I think there is too much concern about restricting oil flow with 
roll pins.  A friend of mine intentionally cut down the flow of oil to the 
heads.  This is on a race engine and it has run at least two years with the 
modification described below.
	The modification was done at the suggestion of a well known Alfa 
mechanic, who's name has been on this list many times.  The thought is that 
keeping the oil pressure down in the bottom of the engine will help late in a 
race when the oil gets thin.

	My friend drilled and tapped the Alfa head above 5 of the 6 roll 
pins.  He inserted an Allen screw in which he drilled a 1/16 th hole.  
Drilling the Allen screw was the hard part.  The left front hole on the 
driver's side was left open as that is where most pressure is exerted from 
the drive chain.
	My initial reaction to this was to suggest he weld up the outlet to 
the oil pump and put the pressure sender ahead of the weld if he wanted to 
build oil pressure.  However, his engine has been run very hard for several 
races without any problem.
	If you look at the cam bearings, they are just cut into the aluminum 
of the head.  No babbet or other insert is used and there is no groove cut 
for full pressure oiling.  There is no oil feed in the bearing cap.  Cams 
turn half crankshaft speed and the pressure from the valve spring is not all 
the great compared to the stress on the crankshaft bearings.  I conclude the 
cams do not need a great volume or pressure of oil.

	Any body know why Don Ereminas quit making his own head gasket?  I 
used one in an engine I built about 1985 without problems.  I liked the fact 
that his design required no O rings, but when I tried to order another 
several years ago, he said he quit having them made.
Ciao,
Russ Neely
Oklahoma City

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