My new mechanic friend is a delightful person, full of enthusiasm for cars and brimming over with experience and interesting stories. Of course, they are only interesting if you also like cars. He clearly has a good heart, a helpful and gentle spirit, and has followed his calling as a mechanic. One of those rare individuals who clearly knows his place in the world, and is immensely satisfied to do what he is doing. Peaceful. Serene. Fun to be around.
Anyway, Mr. Mechanic says the camshaft in my engine is new, but completely unmarked. He can't make sense of what it is. This is a problem because the camshaft sets the valve timing for the motor... in a way it is the heart of the motor, just like the motor is the heart of the car. It's one of those key things that, when selected properly, pulls everything else together... and when not selected properly, will make everything miserable.
Do you ever experience things like that?
The camshaft controls the intake and exhaust valve timing. This determines how the intake, exhaust, heads/valvetrain, and carburetor will work together. Each of these things can be optimized on their own, but only the camshaft grind will pull them into an integrated whole. All of my goals and intentions for the performance of this engine center on the camshaft. But which camshaft to pick?
Here is a simple primer on valve timing. The key parameters are the lift, duration and overlap (lobe center - smaller number means more overlap). There is a LOT of info available online about different cam grinds for the y-block, and I'm taking my own crash course in valve timing. A "big" (racing) cam can give my little bird a lot of power (with big carbs and headers), but it won't idle well and the engine needs to rev way up before it makes that power. A "recreational vehicle" cam will give lots of torque on the "bottom" (right off idle), and probably be more pleasant for most people to drive, but won't make big power on top. Mr. Mechanic says that hot-rodders tend to err on the side of using too "big" of a cam, enticed by the promise of big horsepower, but giving up torque and driveability where it counts (on the bottom end). This in fact makes the car slower overall, as well as less fun to drive.
Mr. Mechanic recommends that I buy a new camshaft from a y-block expert (like John Mummert), along with a set of new lifters. I need the lifters no matter what, and I doubt that it's worth the effort for him to analyze the cam... they aren't all that expensive. The engine will remain in pieces until I decide what cam I want. But, as you can tell from the above discussion, that cam decision will directly impact every other decision I need to make about this motor... what exhaust, what intake, what I do to the heads, etc.. It also determines how much peak power I can expect out of the motor, how "mean" it will sound, how "lumpy" it will idle, and how much low end torque it will have... which is important for driving around town.
I intend to use the 113 "big valve" heads, milled to provide a 9:1 compression ratio. I also intend to use a '57 intake manifold, with an easy-to-tune modern Holley 7150 style carburetor. This indicates a more aggressive intake duration and lift than the stock cam. I also need to decide now if I ever want headers, because the exhaust scavenging they provide really requires a cam with a narrower lobe center (more overlap). Headers look cool and add a few more horsepower to the upper midrange, but they tend to complicate maintenance, burn plug wires and blow exhaust gaskets. I will probably avoid them.
So, you can see that the decisions that I need to make are highly interrelated. My intentions for this car need to be clear, and as the restoration proceeds, I need to be faithful to that intention. I mean for this car to be shared with my friends and family. It can have a "hot rod" sound, but it needs to be "easy to drive", and especially easy to maintain. My time is valuable, after all. It will never be an impressively fast car... rather, it should evoke positive feelings in those who experience it. It can be assertive, but never obnoxious. Much like my Grandma.
That intention statement provides me with a lot of clarity! Here's what I want for the motor...
An engine that makes the car pleasant to drive, using the stock Ford-o-matic transmission, with adequate torque for snappy passing on the freeway. I'd like it to be a little more responsive than a stock motor, especially in the midrange (around 2000-3500 rpm), where the motor will spend most of it's time. It doesn't have to rev much higher than 5000 rpm, but it doesn't have to idle perfectly smoothly either. I will build the engine consistent with that intention, and select a camshaft accordingly.
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I know that God has a plan for my life. I think that, just like the car, he is asking me to think through and articulate an intention for my life. He is also asking me to make decisions consistent with that intention. I'm feeling the weight of those decisions, because they are all highly interrelated. I easily get confused, emphasizing one decision over another, and getting out of balance... "making things miserable, instead of pulling everything together". When I am in this state, I definitely don't "evoke positive feelings in those who experience me". I'm not like Grandma.
I feel the need to meditate on this question: What is my intention for my life, and how will I rely on it to direct my decisions? The answer will determine my own sense of integrity.
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