F54/P79 Swap Project

[240260280]

1 hour ago, Captain Obvious said:

I disagree completely. I do not believe it depends on the perspective of the viewer. I say that the tension on the chain is independent on which cam index hole 1-3 is used.

Would you believe me if I took some pics? I'll put the gear in position 1 and take a pic of the tensioner. Then I'll move the gear to position 3 and take another pic of the tensioner. My belief is that the tensioner will look identical in both those pics. I say the plunger will be the same distance out regardless of what hole the cam gear is in..

If I show you, would you believe it then? What say ye?  Haha!!   @240260280   I challenge thee to a geek-off.    

Just think if you could stretch the chain so that only 10 links were between the cam sprocket and the crank sprocket rather than the ~42?  You would have 32 extra links now on the slop side and it would be quite obvious.

I am talking about tension to put sprocket back on when advancing the cam ON THE CAR.  I have done it about 10 times and it "seems" like there is more tension. This is what @siteunseen described.  It is relative and not real. I have also put sprockets on 4 times when rebuilding engines and it is no problem as the tensioner and guides are not in place.

Of course the tension on the chain varies as the engine runs when the valve springs compress and unload but we never discussed this. Our discussion is on advancing the cam timing. When you hand crank at the snout with a 27mm socket, you can feel the variations due to the valve springs.

Edited September 16, 2019 by 240260280

[jonbill]

Just think if you could stretch the chain so that only 10 links were between the cam sprocket and the crank sprocket rather than the ~42?  You would have 32 extra links now on the slop side and it would be quite obvious.
I am talking about tension to put sprocket back on when advancing the cam ON THE CAR.  I have done it about 10 times and it "seems" like there is more tension. This is what@siteunseen described.  It is relative and not real. I have also put sprockets on 4 times when rebuilding engines and it is no problem as the tensioner and guides are not in place.
Of course the tension on the chain varies as the engine runs when the valve springs compress and unload but we never discussed this. Our discussion is on advancing the cam timing. When you hand crank at the snout with a 27mm socket, you can feel the variations due to the valve springs.

Moving to hole 2 or 3 without moving the crank advances the cam and sprocket 4 or 8 degrees, in essence without moving the chain so that the cam becomes advanced relative to the cam.
But since a chain link is not 4 degrees you'll nearly always end up moving a bit of slack chain to the tight side when you refit the sprocket (also making the Slack side a tad tighter) so then you turn the engine 720 degrees to tdc again to check the cam alignment marks line up as the should.
The tight side will be as tight as it ever was.
The Slack side will be as Slack.

[240260280]

Nope. The fact the chain is not constrained nor the cam constrained nor the crank constrained along with many teeth pulling as a team seems to be confusing you all.

[jonbill]

No one seems to think they're confused, yet everyone seems to say different things [emoji51]

Do you think the cam timing/sprocket position number affects the tensioning of the chain? It absolutely does not.

[Captain Obvious]

I'm not confused at all, and the proof is in the pics.

System with cam gear in position 1:

I rigged up a little wire pointer to indicate TDC. Doesn't have to be exactly dead nuts on TDC as long as it's the same spot each time:

Here's the timing marks in position 1:

Then I used my chain wedge tool (just like if I were doing this in the car). Tool wedged down into place:

Take the cam gear off:

Move the gear to position 3 and take out the wedge tool:

Here's the system in position 3:

Here's the timing marks in position 3. The valve timing has become advanced compared to position 1. Exactly as one would expect:

Now... For the chain tension. I used a feeler gauge to measure how far out the adjuster is. This is position 1:

Measuring the feeler gauge, the tensioner is out about .115 with cam gear in position 1:

Repeating the measurements for position 3:

End result? The adjuster protrudes the same amount regardless of the cam gear position:

[Captain Obvious]

And no zip ties were harmed during this procedure.    

[Mark Maras]

I'm probably over simplifying (or complicating) this but unless the physical distance between the cam gear and the crank gear changes, the slack in the chain remains the same. The slack will change temporarily while adjusting the cam timing unless the cam is rotated a bit.

[siteunseen]

1 hour ago, Captain Obvious said:

I'm not confused at all, and the proof is in the pics.

System with cam gear in position 1:
Lo

I rigged up a little wire pointer to indicate TDC. Doesn't have to be exactly dead nuts on TDC as long as it's the same spot each time:

Here's the timing marks in position 1:

Then I used my chain wedge tool (just like if I were doing this in the car). Tool wedged down into place:

Take the cam gear off:

Move the gear to position 3 and take out the wedge tool:

Here's the system in position 3:

Here's the timing marks in position 3. The valve timing has become advanced compared to position 1. Exactly as one would expect:

Now... For the chain tension. I used a feeler gauge to measure how far out the adjuster is. This is position 1:

Measuring the feeler gauge, the tensioner is out about .115 with cam gear in position 1:

Repeating the measurements for position 3:

End result? The adjuster protrudes the same amount regardless of the cam gear position:

I knew it!  You read the National Enquirer when you were young standing in the checkout line.

"Enquiring minds want to know"

Geek Off 2019 was a success.

@240260280 explained it in realative terms as being in the car vs on an engine stand.

@Captain Obvious proved it.

 

Edited September 16, 2019 by siteunseen

[Av8ferg]

Well this is settled then! Take a seat in the back row and let professor Obvious move on to the next lesson. Where are we on the shaved head solution now that this is behind us. How are we going to remove the extra slack?
Nice job CO. I was the kid that needed to put my hand on the hot stove. Thanks!


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[Patcon]

5 hours ago, Av8ferg said:

Well this is settled then! Take a seat in the back row and let professor Obvious move on to the next lesson. Where are we on the shaved head solution now that this is behind us. How are we going to remove the extra slack?
Nice job CO. I was the kid that needed to put my hand on the hot stove. Thanks!


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I did it with the cigarette lighter in my dad's Mercury at age 3. I remember it vividly!!! Put a nice big round blister in the palm of my hand

[240260280]

Nope. I disagree. ?

[grannyknot]

A sardine can key in the wall socket, my hand was black but I lived they tell me.