Build Thread 1978 Mercury Cyclone. The pig is in the pen.

madmike1157 said:

Today was a "Mike has to see his machinist buddy to get things done" day.

The list of things I need the "special talents" of my machinist for are as follows:
1. Machine the nose of the cam, turning it down from the worthless stock 250 cam gear size, down to SBF size, and then drill the face of the front journal to acommodate the dowel pin.
(Lets discuss this for a minute shall we)
Anybody that knows anything about billet roller cams knows that one of the processes they all go through is a final heat treating to harden all the lobes and journal surfaces. That heat treat makes the camshaft extremely durable, hard as a diamond, and basically is one of the things in an engine that doesn't wear out because of that.

It also makes it impossible to machine.

Had I known at the time of building the cam that there wasn't a decent gear set available, and I was gonna have to make a SBF gear fit,..I just woulda had the cam grinder modify the cam before the heat treating in the beginning. Unfortunately, I just assumed that you could get a decent gear set for just about any engine.

I chose,.................poorly.

Fortunately for me however, The Australian cam grinder I used used a different heat treating process called induction hardening,...that only hardens the lobe and journal surfaces to bearing race hardness,....all the rest of the cam is pretty much just north of standard hardness.


That nose turned down like butter.

Now the dowel pin,..........that was a different story.

Because the 250 journal diameter is much smaller than a SBF, drilling that 5/16" dowel pin got real close (w/i .250) to the journal surface of the first journal. The further away from center, the harder that damn cam got. the initial 1/8 pilot hole drilled easily enough, but the 3/16" bit was starting to complain, the 1/4" bit would actually snap and chatter,..and the 5/16" bit actually walked in the hole,..preferring to drill the softer metal towards the center, as opposed to the kryptonite at the outer edge.

The hole ended up being unusable.

So plan B was to keep the hole smaller, and closer to the center,...so we drilled two 1/4" holes at 90* perpendicular to the now mangulated hole.

That worked. but the cam took the better part of an afternoon, and shot the day.

Moving on,...back to the list:

2. Cut the crank keyway deeper to the front of the crank journal.
3. Mill the mating surface of my exhaust manifold ( Medusa) as it had crowned slightly from welding.
4. Open the center of my 36-1 crank trigger wheel to pilot over the hub on my SBF harmonic balancer.
5. Make three aluminum plugs to replace three of the five freeze plugs so that I can re-direct the water from the pump into the side of the engine, as opposed to the front. I'll drill and tap these three plugs 3/4 NPT, and block the front WP hole. I'll build a manifold to distribute the water after I figure out how I'm gonna get it there.
6. Build 4 spacers to properly space my rear calipers off of my $200.00 Cobra caliper brackets.

After all of that is done,....I'll be able to mock up the crank, and the cam,...and see if the custom roller chain I had to find ( That comes as a replacement for no Ford product) will fit my Ford product.

THAT, will be the next hurdle to jump.

**And.......I do like the new forum look. I got at 2014 black moon skin w/ Gluttony for a color option.
Thanks @Noobz347 .

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