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Or maybe "putting a square peg in a round hole"! That's what I've been doing in the shop for a while today. Now, everybody knows that timing marks on the camshaft and crankshaft gears are supposed to line up, right? But what happens when the valves don't open and close where we want them to do when the timing is "correct"? It's possible to make minor adjustments of the cam and/or crankshaft position with an offset Woodruff key, but there's another way. How about cutting a new slot for the key(s) to fit in a slightly different angular relationship to the gear teeth? That's what I'm getting ready to do. There's a machinist's tool known as a "broach" that is used with a hydraulic press to cut keyway slots in pulleys, sprockets, or gears so they can fit over a keyed shaft. In order to work properly, a broach must have a slotted guide that fits the hole in whatever part needs a new keyway. I've been making broaching guides that will allow me to cut an extra slot or two in a stovebolt timing gear so I can tinker with the cam timing on the Franken-Bolt when I start doing exotic things with the roller lifters and rocker arms I'm planning to use. I'll relieve the press fit between the cam and the gear so it's a snug slip fit, and install a center bolt to keep the gear in place, instead of pressing the gear on and off the cam every time I want to make a timing change.
Jerry

Put the what what in the what what?

Jerry wouldn't an offset woodruff key be easier? Those can make up 3 or possibly 4 degrees of adjustment, yes?

Will you be able to get the slots far enough apart to keep from them running together? The width of the woodruff key will likely be more than just a few degrees based on the hole diameter. I don't recall what the hole diameter is, but it's not huge. Say for a 1-1/2" diameter hole, a 3/16" woodruff key would take up about 14 degrees, and you'd need to offset moer than the width of the key to have a distinct slot (not overlapping.) That seems like a lot of shift in cam timing. You may have to cut additional keyways in the cam to get less than 14 degrees, offsetting both the new key slot and the keyway on the cam. That 1-1/2" diameter guess is probably large, and for a smaller diameter, the key would take up more degrees of angle.

The keyways will be about 120 degrees apart on the cam gear- - - - -I'm going to totally ignore the timing marks, and concentrate on where a line drawn from the edge of one side of the keyway intersects a tooth on the perimeter of the gear. In the mid-1970's, Datsun used the same approach on their timing sprockets to adjust for timing chain stretch. They used a dot, a triangle, and a square mark to identify different slot positions. One slot will be a few degrees advanced from the original keyway, and the other will be a few degrees retarded. Then woodruff keys with various offsets will allow me to have a much wider range of adjustment than offset keys and the original key slot would do. The same approach could also be used on the crankshaft gear. I've been setting up racing cams with a degree wheel and a dial indicator for decades, so some train driver's opinion about where a timing mark needs to be is a moot point.
Jerry

Sounds like a plan, Jerry. It wasn't clear from your original post how you were going to deal with it.

That is some advanced hotrod engineering, HRL. Be interesting to hear how it turns out.

Each offset key can be installed backward to make even finer corrections.

When we ran the Furd 2.3L. OHC 4 cylinder engines in the "Mini-Stock" class at a 1/4 mile dirt track, somebody was selling a cam belt sprocket with about 10 keyway slots in it. Some of those little screamers would run 9K RPM or more.

I'm thinking about setting up one of those modified stovebolt engines on a trailer with my water brake dyno hooked up, and making the rounds of a few swap meets and car shows with it.
Jerry

On many sprint cars the water pump is driven off the end of the cam so additional key ways are used. Since these cars are push started they have no flywheel which allows accessories to be mounted to the back of the cam also. For a custom key way a degree wheel and a dial indicator will get it spot on. I still have a drawer full of broaches, both the step and adjustable type. PS-- I always thought you squared a circle by driving a 4x4 up a bulls butt.

Its fairly common to have multiple keyways in the Hi-perf sector as far as v-8s anyhow. It never fails, someone has a cam ground to a specific spec., and the cam grinder either doesnt get the keyway right or for whatever reason the cam doesnt degree correctly. Inline wise, I ve only ran across this on a model a that I was putting together an overhead valve conversion on. I had a custom grind built from a fellers notes when he was playing with them in the 40's, and I just couldnt get into the butter zone without a new keyway. In my case, I broached the crank gear instead of the cam, because the cam had more or less a dowel pin. With custom grinds quickly becoming a thing of the past on ancient engines, and as the hot cams get picked up by smaller and smaller shops (especially if reusing blanks), I can certainly see the need for it. Custom begets more custom.

To a serious engine builder, a "stock" engine is just like an artist's blank canvas- - - - -boring, but just the thing upon which to make a masterpiece. Engine parts don't know, or care which manufacturer's equipment they are supposed to fit. Any real engine builder with a little creativity and access to some machine tools can make those parts do things they were never intended to do, and work in places they were never intended to go. The guys who get obsessive-compulsive about "XXXX" part number being the only thing a particular engine can run probably need to get a life- - - -or maybe a girlfriend!
LOL!
Jerry

I would agree with that. When I build a trail rig, I don t much care what flavor it is.... it will have a transfer case doubler with a np205, it will get a dana 80 or 14 bolt rear with a truetrac (learned my lesson about air lockers), it will get a dana 60 front , if a manual it gets a nv5600, auto wise, a th400 usually. I build the engine for the hp to come in where I want the rpm, dependent upon tire size and gear ratio. I don t build from manufacturers logos, I build for what I know is the strongest parts that I can get ahold of.