I'm assembling my mild performance rebuild AMC 360 from an '84 Grand Wag. Timing set is
from PAW, their part number PAW 500. This item is a double roller chain set, made by
Dynagear, their part number 78118, as near as I can tell.
While putting this together, I was studying the oil pathway from the camshaft to the dizzy drive
gear. In the cam timing sprocket mount hole, there's a groove opposite the keyway, to let oil
through the sprocket and into the matching groove in the fuel pump cam, then into a similar
groove in the dizzy drive gear. Once into the dizzy drive gear, the oil fills a cavity in the end of
the gear, formed by the end of the camshaft, the inside walls of the dizzy drive gear, and the
heavy washer used to hold the drive gear onto the end of the camshaft. There are four small
holes in this cavity area, through the drive gear into the toothed area of the outer diameter,
to oil the pair of gears. Going back to the camshaft drive sprocket, there are radial grooves on
the front face of the hub of the sprocket which will allow oil to run out toward the cam chain
for chain oiling.
So here's the question. On the old timing gear, the original AMC piece, the oil groove on the
inside, opposite the keyway, is a full groove all the way through, so as to make lots of room
for oil to run through. On the new gear, the groove is almost all the way through, but there's
a small wall in the middle of the groove which is the same diameter as the cam nose hole, so
only a small amount of oil would ever "leak" through this area. I feel that there needs to be
quite a bit of oil flow here, to supply the timing chain and the dizzy gear drive.
So I filed the oil passage groove in the sprocket out to look more like the original sprocket.
I feel that I just saved my engine from eating dizzy gears, and very rapid timing chain wear.
Do y'all think I did the right thing? Anybody else seen something like this?
Should I let PAW and Dynagear know that I think they have a problem?
Thanks, maybe this will help somebody else, too.
Al
from PAW, their part number PAW 500. This item is a double roller chain set, made by
Dynagear, their part number 78118, as near as I can tell.
While putting this together, I was studying the oil pathway from the camshaft to the dizzy drive
gear. In the cam timing sprocket mount hole, there's a groove opposite the keyway, to let oil
through the sprocket and into the matching groove in the fuel pump cam, then into a similar
groove in the dizzy drive gear. Once into the dizzy drive gear, the oil fills a cavity in the end of
the gear, formed by the end of the camshaft, the inside walls of the dizzy drive gear, and the
heavy washer used to hold the drive gear onto the end of the camshaft. There are four small
holes in this cavity area, through the drive gear into the toothed area of the outer diameter,
to oil the pair of gears. Going back to the camshaft drive sprocket, there are radial grooves on
the front face of the hub of the sprocket which will allow oil to run out toward the cam chain
for chain oiling.
So here's the question. On the old timing gear, the original AMC piece, the oil groove on the
inside, opposite the keyway, is a full groove all the way through, so as to make lots of room
for oil to run through. On the new gear, the groove is almost all the way through, but there's
a small wall in the middle of the groove which is the same diameter as the cam nose hole, so
only a small amount of oil would ever "leak" through this area. I feel that there needs to be
quite a bit of oil flow here, to supply the timing chain and the dizzy gear drive.
So I filed the oil passage groove in the sprocket out to look more like the original sprocket.
I feel that I just saved my engine from eating dizzy gears, and very rapid timing chain wear.
Do y'all think I did the right thing? Anybody else seen something like this?
Should I let PAW and Dynagear know that I think they have a problem?
Thanks, maybe this will help somebody else, too.
Al
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