Harmonic Damper question

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jos51700

jos51700

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I'm am wondering...does the the keyway slot on the harmonic damper line up with the TDC mark on the damper?

In other words, does the keyway slot on the crank line up with Cylinder #1 crank throw?

I don't have any dampers available at the moment, so if you do and could post a picture, that would kick ***!

Thanks
John
 
I didnt think so either, but the pic above sure implys that it is.........................I just when and looked at mine. It's close to the tdc mark but NO not inline with it.
 
Just looking at the pic, it looks a bit askew from lining up like fever said. It's a 318-340-360 pro-race damper from summit that I used as the basis for a blower drive. Wonderful machining, I'd buy another in a heartbeat
 
My question is, "why do you care?" and I'm tryin' to be smart, either

Even if the key DID line up, you would never want to try and use the key for a reference point, and neither would you want to use the cam timing marks, because you can actually move the crank "some distance" before it would be immediately obvious that you are "off" TDC.

This is why when you FIND TDC, using either a dial indicator or a stop that you do so with the piston "down" in the cylinder. That's because the piston slows way way WAY down as it comes "up and over," and movement is very difficult to see. Not only that, but you have reduced the radius (at the crank) by so large a degree (no pun intended) that it gets that much more difficult.

THAT IS WHY some guys today like to use a "huge" degree wheel, something I never even saw or dreamed of "back when" I screwed with a lot of these in the 70's----I.E. the bigger the degree wheel, the more accurate the setting, assuming the wheel is accurately built.

The wheel I used to have was hardly larger than a typical dampener

THIS is what I call a degree wheel:

2


mdmp_1011_01_o+how_to_degree_a_camshaft+moroso_pro_wheel.jpg
 
It's not a timing-based inquiry. It's a reference point inquiry, on multiple points. #1 can the keyway be used to check for damper slippage, and if so, #2, can the keyway be used to reference true, accurate, dial-indicator TDC.

IF the damper hasn't slipped (and will looking at this tell me), where is the slot in relationship to TDC?

That's what I'm after.
 
I just looked at a spare damper I have, and it looks a lot like close to 10 btdc, but that was just eyeballin' it. PM me if you want a much less eyeball measurement :)
...edit...
Ok I got bored and wanted to know myself, with a straightedge and still eyeballin I got 2 btdc. But without having perfect center located, it's still a guess.
 
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