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Timing Gear positioning on 1275

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TulsaFred

TulsaFred

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My timing gear "dots" appear to line up on TDC of the exhaust stroke rather than the compression stroke.

Did I get it out 180 degrees when assembling or is the way it is supposed to be?

The shop manual isn't clear on this.


Fred
 
Wow a stumper!

I looked it over today. Since the woodruff keys only allow the gears to go on one way this has to be the way it was designed. It's weird that they would not have the dots line up on the compression stroke.

Any engine builders care to confirm before I proceed?

Thanks!

Fred
 
Fred, #1 and #4 are TDC at the same time, which put the crank keyway at 12 o'clock. The cam should be keyed at roughly 2 o'clock, never assume fatory or aftermarket non adjustable gears are right, as far as keyed positins, thye can be off a few degrees.
 
Your instinct is to expect the dot-to-dot alignment to put #1 at TDC on its firing stroke. It's not. From memory, the alignment occurs when #4 is at TDC on firing stroke as Hap said.
 
thanks Doug and Hap,

So I guess I have it right, the alignment of the dots occurs with #1 at TDC of the exhaust stroke/#4 at TDC of compression stroke.

I still think it's odd, but at least I didn't screw it up.

Fred
 
you can not screw it up if the dots align.
 
Well, I'm sure there is a way to screw it up if the dots align, but it's probably nearly impossible.

I find, in this context, I am good at doing the nearly impossible. It is one of my few superlatives :0

Fred
 
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