stock MC cam differences?

[Eric]

For some reason I can't get my posts to go to the list.  Very strange.

Anyway when I first got my KH motor I discovered it had a badly warped head.  So I went to my local junk yard and ordered a replacment.  The trouble was the person who sold me the KH told me it was from an 86 (I know better now) and so I ordered an 86 head.  Well what I got was an MC head with a relieved cam.  Sadly the head will not bolt up to a KH block so I managed to give it back to them for a small "restocking" fee.

Now I am assuming that it was infact off an 86, but junk yards will often use equivalent years so it could have been slightly newer.

I did mic the two cams and the MC cam had slightly higher lift.  My theory on the reliefs is for slight parasitic loss reduction, but that is just a guess.

-Eric


-------Original Message-------
From: auditude at cox.net
Sent: 07/07/03 05:34 PM
To: Eric <eric-audi.ql at mindspring.com>
Subject: Re: Re: stock MC cam differences?

>
> Hi Eric,

Okay, that probably does help.  If this is an early MC-1/'86 5kt, then
maybe it has the same cam or style cam as the KH.

You could be asserting that an '86 MC has the relieved lobes (or you could
be basing that on what I expected to see), but since I don't think you
are, I'll take it only as information regarding how a KH turbo cam looks.

Unless the lobe relief is a non-turbo cam thing.  Could the non-relieved
lobe be used to transfer more heat out of the lifter/valve?  Just out of
curiousity, I doubt it matters much.

Thanks!

Ken

Eric <eric-audi.ql at mindspring.com> wrote:
>
> I can't answer most of your questions but I do know that my 85 KH turbo
> motor does not have the relieved lobes like an 86 MC does.
>
> -Eric
>
> 4kq (started pulling the motor Sunday to insert quantity 1 KH motor)
>
> auditude at cox.net wrote:
>
> >Hello again list,
> >
> >Another lister has sent me his old MC cam, from an '86 5kcstq, so that
I can use it instead of the funky cam I have that seems to have a lobe too
close to the cam cap and had machined into the side of it.
> >
> >I got the cam, but it is different from the funky one currently in the
head.  One, the back of the lobes are not "relieved" (to reduce friction
and/or rotate the lifters in the bores).  Second, the eccentric lobe that
would run a vacuum pump on a normally aspirated car has wear on it that would
indicate it was driving such a pump.
> >
> >The lister said as far as he knows it is the right cam for the car it
came out of.
> >
> >Does this seem like the right cam?  Is there a way to check part
numbers or something to verify?
> >
> >There is an oil squirter that looks like it would squirt directly at
the middle of the eccentric lobe, so it is possible that the detergents in
the oil would make a clean area that would look similar to that lobe driving
a vacuum pump.
> >
> >I'll probably end up using the cam regardless, but I would like to
confirm that it is the correct one for a turbo, at least.
> >
> >Is the relieved cam lobe thing only for turbo motors, or maybe it is
only for later models?  Is there anything besides a vacuum pump that would
wear the eccentric lobe?
> >
> >Thanks,
> >
> >Ken

>