63 Corvette Mystery Motor

david montanbeau

Well Known Member
Ok, here is the latest cam info on the mystery motor.

I have 2 of the "0" cams and I have no idea which one to use, both look fine. I called Rusty and discussed with him. He said somewhere in the back of his mind he remembers Crane had made one but could not remember details. He is using one of the original cams. So, I picked up the phone and called Crane. After talking to lots of real nice people, none of which knew anything about what I was talking about, "what's a Mystery Motor" sent me to the "gray haired" guy Allen. I left a message for him.

Very promptly the next day he calls to discuss my story. After sharing all of it, he slightly laughed and said yes they did a cam, but it was so long ago and after all their trials and tribulations, computer system changes, etc, that they would not have retained anything. We talked more, about cams, heat treating, etc. I hung up the phone and began thinking about what to do next.
Next day Allen calls back. He says guess what?, I was walking by our tech guys and mentioned our conversation, he said all of a sudden one of the "gray haired" tech guys said, "oh, I have that file right here, I printed the profile sheet and kept it because I thought it was so cool"...that was 2004!

Seems the project was the Junior Johnson, Holley Farms NASCAR car that was being restored!

Allen also told me he found a blank shaft, a that was made and not ground for that project and they would be glad to make a cam.!!!! WHAAATTT ARE THE ODDS!!!

Below is what I clipped from his email to me yesterday:

"We will build you an mechanical roller camshaft from an 8620 steel billet “round lobe” cam core. (The original flat tappet “cast iron” camshaft core for this engine no longer exist.) We will have to grind the lobes and journals to match your special interim engine between a 409 and a 396 Chevy designs.
Our records show that the GM Mystery cam wasn’t a slouch for its day. Advertised duration was around 284° / 292°, with the duration @ .050” tappet lift at 250° / 253°, the lobe lift were in the .320” range +/- .002”, which would bring the valve lift to around .560” with a 1.75:1 rocker arm ratio. The power range would be estimated to be 3800 to 7000 RPM in its original racing form. We can figure out the details as what profile you will require, this isn’t a problem, it’s all custom made anyway."

Very exciting to fine this cam core.

Now, I told him since I am the camshaft genius that I am :), I would feel better if I sent you the cams, I have to just make sure.
One thing he instructed me to do was ship it securely and insured!

He told me of instances where cams were sent in the cardboard tubes only to arrive broken in half. So, we are making a wooden crate to hold the tubes with the cams.

On the pistons, we have measured each hole and have sent pistons and measurements along with the combustion chamber info to Ross and they are about 6 weeks out, but that's fine.

That's all for now, thanks for listening. Getting closer!!!
We ship cams in double PCP pipe.
 

Blk61409

Well Known Member
Supporting Member 9
Jody, have not made it back to the track. After all the problems with the hydraulic clutch we came back and began working on other projects. We began building a cross shaft, cutting, bending, welding etc. nothing worked. More time goes by....I reached out to the guy I bought the Richmond 5 speed from and discussed the problems. In the conversation he said "the only time we have ever had shifting problems was with dual disc clutches". Whaaaat I asked?? That's exactly what I have.
So, here we go, changed to a single system and about 90% better. Working on the next 10%.

More on this later.

Tom, here are a couple of photos.
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Blk61409

Well Known Member
Supporting Member 9
Pat,what do you think of those Demon carbs?


Demons certainly will dump the fuel!! I have 2 sets, one set on the original Z-11 intake as you see here with electric chokes. This is the setup I attempt to drive on the street:). The others are on the tall high riser Z-11 intake Lamar/Rob makes. I have not attempted those yet other than the effort at Great Bend when we had the clutch problem.
More later, thanks for asking.
Pat



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models916

Well Known Member
Supporting Member 7
I've had the plastic housing versions 2x600 on mine all Summer. Feels fantastic all around. We tested previous year on a chassis dyno and got good increase from out of the box carbs. I went one color softer on the step up springs and haven't touched them since. Mine is an Offy 360 with a 1" open spacer. I recommend on the street.
 
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