RE: alfa-digest V9 #370 - cams & followers

["Jeff Greenfield" <alfaguy@xxxxxxxxxx>]

George - 

I'm rebuilding a 2.5 V6 right now with about 105,000 miles on it. This car
has been driven enthusiastically its whole life, not abused and has had
regular servicing.

I've seen several of the V6s that needed cams and/or followers. Amazingly
both in this car show no signs of wear. (these are the stock/original 2.5
cams)

Now for the 10,000 dollar question ... I am putting some new (not reground)
hotter cams in this engine and you've got me wondering if I should replace
all the followers?

I'm open to opinions ... in the meantime I'll go take a really good look at
all of the old cam followers ...

Thanks,

Jeff

-----Original Message-----
From: owner-alfa@domain.elided [mailto:owner-alfa@domain.elided] On Behalf Of
George Graves
Sent: Thursday, March 27, 2003 1:51 AM
To: alfa@domain.elided
Cc: diogenio@domain.elided
Subject: Re: alfa-digest V9 #370

Good luck. I just went through a similar ordeal and ended up buying a 
new pair. Here's what I found:

It looks as if either Alfa 12-valve camshafts are not very hard or the 
cam follower buckets aren't very hard (or both). Every used pair I have 
looked at was seriously worn. Even the ones that came out of a very low 
milage Milano engine (less than 50K) were worn. In turn, this wears the 
followers (or perhaps, vice-versa. Who knows?). I also looked at a 
couple of pairs of 're-grinds' which have been re-profiled to 'S' 
characteristics, then re-hardened. All of these had so much material 
removed from the 'heel' of the cam lobe*, that it requires one to have 
custom tappet spacers made-up to get the valves to adjust as Alfa 
doesn't make any which are thick enough for re-ground cams and you 
can't stack them. A new pair will cost you about US$800, and you also 
need to replace ALL of the cam follower buckets, both for the 6 inlet 
valves and the six exhaust valves because they are bound to be worn as 
well. To check, run your finger over the follower face. If you feel 
ANYTHING at all, that bucket needs replacing. Some of them exhibit a 
ridge where the cam strikes it, and others show pitting right in the 
center. If you do not replace them, these worn buckets will abrade your 
fresh cams like sandpaper.

Not good news, I know.


*When a worn cam is re-profiled, it is required that the worn part of 
the existing lobe must be ground completely away. This means that ALL 
the lobes must then be ground to match the worst one. This results in a 
lot of material being removed. Since Alfa V-6 cams tend to wear fast, 
most cams you see will have one or two lobes that very badly worn. This 
is likely the reason why all of the re-grinds I've looked at had 
insufficient 'meat' on the heel. Also, I have heard that many re-grinds 
are even softer than the factory cams. Sperry's, for instance, seem to 
have garnered a reputation for being extremely prone to wear.

George Graves
'86 GTV-6
now with 3.0 liter 'S' engine
and Power Steering


On Wednesday, March 26, 2003, at 10:41 PM, alfa-digest wrote:

>
> Date: Wed, 26 Mar 2003 21:37:05 -0800
> From: "Dennis Lusis/CPI LABS" <diogenio@domain.elided>
> Subject: Wanted: Pair of good 164 "S" cams.
>
> Looking for good used "S" cams to drop in my 87 Milano 2.5 L. Thanks.
>
> Dennis
> San Diego, CA
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