Erson Cam question.

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Old May 28, 2018 | 04:23 PM
  #1  
OldsMotion's Avatar
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OldsMotion
 
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From: Liberty, NC
Erson Cam question.

I have an Erson Viking 100H cam that was previously installed in this 455 I'm building. I've never heard it run, but it was very low mileage running motor (rebuilt) before it got swapped out for an undisclosed brand of engine. It seems as though the cam events do not coincide with the timing chain marks being at 6/12 like the Factory OE Chassis manual suggests. Ive installed two timing chains to be sure, one Cloyes 3 keyway roller, and then a Cloyes 9 keyway, and TDC on compression occurs when the timing marks are 12/12 for both.

Can someone verify (Cutlassefi perhaps) that this particular cam has to be degreed starting with the timing marks at 12/12?

Going a little nuts here.





John
Old May 28, 2018 | 05:48 PM
  #2  
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Spin the crank one more turn and it’ll be at 6/12. Cam runs half of what the crank does. Put a degree wheel on it to remove any doubt.
Old May 29, 2018 | 11:32 AM
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OldsMotion
 
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From: Liberty, NC
Originally Posted by cutlassefi
Spin the crank one more turn and it’ll be at 6/12. Cam runs half of what the crank does. Put a degree wheel on it to remove any doubt.
I guess I'll try it again. Two chains, twice each both positions. We shall see.
Old May 29, 2018 | 04:37 PM
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I think John's point is that with the marks at 12-12, he expects the no. 1 cylinder to be at TDC on the EXHAUST stroke, and at 6-12 to be TDC on the COMPRESSION stroke. Instead he's getting the opposite with this cam. Obviously it doesn't matter from the standpoint of engine function, but it's interesting if they have the cam dowel pin 180 deg out from "normal".
Old Jun 15, 2018 | 08:01 PM
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OldsMotion
 
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Originally Posted by joe_padavano
I think John's point is that with the marks at 12-12, he expects the no. 1 cylinder to be at TDC on the EXHAUST stroke, and at 6-12 to be TDC on the COMPRESSION stroke. Instead he's getting the opposite with this cam. Obviously it doesn't matter from the standpoint of engine function, but it's interesting if they have the cam dowel pin 180 deg out from "normal".
Thank you Joe, that is exactly what the deal was with it. I can't explain why, but after I sorted that out it was also off 15 deg when I degreed it. Used a 9 keyway chain instead of the three and got it to 10.5, and they wanted installed at 9 according to the cam card. It was a PITA.

Will be running it this weekend. I figure Im going to have to pull and drop the distributor at least once. LOL.
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