Cam wear on BMC and some other cars is nothing new. Just a bad hardening
process and/or crappy material together with a total lack of quality
control, nothing to do in general with ZDDP. Regrinding without some
form of hardening does not help either. Loose tappets worsens the
problem even more. It happened as well long before ZDDP was even the
beginning of an issue.
A notorious engine for cam wear is the Rover/Buick V8. It can happen
within 40.000mls.
Replace with a new camshaft (e.g. Kent) and do not forget to check the
bearings and do fit all new cam followers. If the old ones are used the
cam shaft will be scrap in no time. Fit with plenty of graphite grease
or similar to give it initial lubrication.
Kees Oudesluijs
NL
Michael schreef op 19-7-2014 16:51:
> What you are describing Bob is exactly what I encountered with AHX12.
> I believe that it was attributable to the dreaded ZDDP problem.
> I would suggest that you drain the oil and check for metal content.
> In 12 the flakes of cam lobe and lifter were all through the engine. The first
> indication of trouble was very low oil pressure caused by the relief valve
> being jammed by the metal flakes.
> I rebuilt the engine completely and thereafter used Valvoline VR1 non
> synthetic oil, just put 10 bottles in #174, and the problem never reoccurred.
> Michael S
> BN1 #174
>
> -----Original Message-----
> From: "Bob Spidell" <bspidell@comcast.net>
> Sent: b7/b19/b2014 9:44 AM
> To: "healeylist" <healeys@autox.team.net>
> Subject: [Healeys] Removing cam in situ
>
> Thanks to all who responded to my inquiry. As I suspected, it's a major
> task.
>
> I asked because when I was recently adjusting the valves I noticed a couple of
> the pushrods didn't appear to be lifting
> as much as the others, probably indicating flattened cam lobes. I don't know
> what could have caused this, because I
> have always fed good, clean 20W-50 oil to this engine (it has about 100K since
> rebuild). It's possible it's been this
> way since rebuild, as I always had lower compression on a couple cylinders
> (why a reputable cam grinder would screw up a
> re-grind is unknowable, but possible I suppose).
>
> I just had the front pulley and timing cover off to replace the cover seal,
> and had the radiator in and out 3 times due
> to water pump issues, so when I get to the cam I'm likely to pull the engine
> and do an overhaul. The big nut on the
> crank is the issue; I bought a 3/4" impact wrench and socket to get it off,
> but there's insufficient room to get the
> wrench on the nut due to the front X brace. I ended up ruining the nut and a
> new one was $40 from Moss. The new nut was
> good quality, but the original had a conical section machined away to clear
> the Woodruff key, and the new one did not
> but seems to be OK.
>
> Bob
>
> --
> *******************************************************************
> Bob Spidell San Jose, CA bspidell@comcast.net
>
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