[alfa] Spider Head Differences

[AlfaNeely@xxxxxxx]

In a message dated 12/9/2004 9:07:28 AM Central Standard Time, 
owner-alfa-digest@domain.elided writes:
Date: Wed, 8 Dec 2004 21:37:47 -0600
From: "Roger Hambro" <rhambro@domain.elided>
Subject: [alfa] Spider Head Differences

In comparing a remanufactured head I just purchased to my original '78
Spider head I noticed that my original '78 head has large approx, 1" x 1/4"
oval oil drain passages cast into the oil pool area between each pair of cam
followers whereas the reman. head does not.

It would appear that the passage would allow oil to drain back into the
engine after the oil in the cam follower oil pool area rises to the level of
the cam cover gasket.  The reman. head does not have these passages, so oil
returns to the engine by traveling a longer path around the front and rear
camshaft caps.

Anyone know why these differences exist?  Which came first?  Does it really
matter?

Roger Hambro
'78 Spider
Algonquin, IL

    It sounds like you have an 87 or later head, which should also have 
different intake ports.  The roof of the intake ports on the L Jetronic heads have 
a semi circle cut out for the Bosch injector to spray into.  The late head 
should work fine, but you may need to match your intake gasket to make sure it is 
sealing properly.
    Why Alfa did away with the drain back holes between the camshafts and the 
spark plugs in about 1987, I have no idea.  On the later Motronic heads they 
apparently even did away with the drain back holes at the back of the cylinder 
heads.  The problem with that is that the head gasket manufacturers may have 
also done away with the sealant on the gasket that keeps coolant from reaching 
the oil drain holes on the back of the early blocks.
    You may also want to compare your head gasket to the later head to make 
sure everything matches up correctly.  Do not be afraid to use some silly cone 
to help with sealing, just do not get it anywhere close to the six O rings.  I 
have probably broached the silly cone arguement, but I like the stuff.


Ciao,
Russ Neely
Oklahoma City
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided