Hi Eric, What’s the measurement from the threads to the top of the piston stop. As I don’t have one, I’d like to know the distance introduced into the cylinder. Thank you.
OK lets try this: I used to (before I got the piston plug and the timing indicator) take a pencil and put it in the #1 spark plug hole, let the piston push it up (compression stroke) and that would be TDC, I noticed that if I went backwards I would get a different reading (small difference but different nun the less). The directions that came with the piston plug says to do it the way I do it in the video, as I thought about it, it would depend how far you had the piston plug screwed into the spark plug hole as to what reading you would get. So turning it both ways will give you travel in both directions, when you divide by 2 you get exact TDC. As long as you turn it both ways (and record the readings on the indicator) it would not matter how far you had the piston plug in the hole (as long as it contacted the piston. Hope this helps, Eric
As I recall; Both Lycoming and Continental have TDC notches on the propeller flange. Just line it up with the crank split, then back off to the ignition timing mark provided.
With the piston plug used, you first turn the propeller in the direction of travel find the end of the piston travel on that stroke, you then turn the propeller in the opposite to find the end of the piston travel on that stroke. Divide the number of degrees on the indicator by 2 and you have TDC. You then find the compression stroke on #1 cylinder (by placing your thumb over the spark plug hole and turn the propeller in the direction of travel until you get compression under your thumb) turn the propeller (in the direction of travel) until you get to "0" on the indicator, that's TDC. Hope this helps, Eric
Yes, when the piston is at the end of its travel thats TDC, the trick is to bring the piston to the end of its travel in both directions to determine TDC. If you can envision the piston reaching the top of its travel the connecting rod may not be at the end of its travel, by doing it in both directions and then "Splitting" the difference between the readings you ensure that you have reached true TDC. Hope this helps, thanks for the question. Eric MyAnnual.net
Ok I understand you now, in 4:00 you said that , that's TDC cause the piston touch the pin ok that's a common sense and I accept that . but I wanted to know the reason why you spin the prop to the opposite direction of rotation and splitting by 2 since you already found your TDC in 4:00 and you re saying to ensure that you have reached true TDC or to make sure that the connecting rod is at the end of it's travel , Am I right ?
Correct it is not. Just a stop. Prop must be rotated back around other direction to the stop. When you get both end point numbers the same 0 will be TDC
Thanks Eric for the very good explanation of finding TDC. I like this way because it is the most accurate indication of TDC and takes into consideration gear lash.
Hi Eric. Thank you for yor very nice and prof. videos. For me that`s the best instruction videos what ever I have see. Good Quality in the pictures an clearly comments.
Piston stop is a tool usually screws into sparkplug threads. A probe extends into the cylinder. In this case a few inches. Piston comes up hits the stop or probe. That it. To find TDC a dial indicator must be used. Tool can be homemade as long as it stops the piston.
He never did find tdc. If you are thinking the piston stop is TDC it is not. Just a random stop This is why engine is backed all the way around to the other side.When both numbers are the same you have TDC. A little to simple, Give it a little thought I believe you get it !
WHY are you going through all that Rigamarole, with a timing disc? All you need to do is to find the compression stroke on Number 1, then look at the propeller mount flange,, or starter gear; TDC will be right there. Back off the prop to 25 Deg. mark. Time your mag to that. It's a lot more accurate, than using the timing disc, because it's exact. The only time that I have ever needed a timing disc, is on a radial engine. (Pratt?)
Thanks it’s been a while. Thought I remembered how to do this but needed confirmation.
Hi Eric, thanks for the great videos! I think I met you a few years ago, my parents are Walt and Mary Berry....keep up the good work, Steve
Excellent video. You’ve explained this well. Thank you.
Great info Eric, thanks.
Hi Eric, What’s the measurement from the threads to the top of the piston stop. As I don’t have one, I’d like to know the distance introduced into the cylinder. Thank you.
OK lets try this: I used to (before I got the piston plug and the timing indicator) take a pencil and put it in the #1 spark plug hole, let the piston push it up (compression stroke) and that would be TDC, I noticed that if I went backwards I would get a different reading (small difference but different nun the less). The directions that came with the piston plug says to do it the way I do it in the video, as I thought about it, it would depend how far you had the piston plug screwed into the spark plug hole as to what reading you would get. So turning it both ways will give you travel in both directions, when you divide by 2 you get exact TDC.
As long as you turn it both ways (and record the readings on the indicator) it would not matter how far you had the piston plug in the hole (as long as it contacted the piston.
Hope this helps,
Eric
You got it right. There is no backlash on a crank. He did nothing
As I recall; Both Lycoming and Continental have TDC notches on the propeller flange.
Just line it up with the crank split, then back off to the ignition timing mark provided.
With the piston plug used, you first turn the propeller in the direction of travel find the end of the piston travel on that stroke, you then turn the propeller in the opposite to find the end of the piston travel on that stroke. Divide the number of degrees on the indicator by 2 and you have TDC. You then find the compression stroke on #1 cylinder (by placing your thumb over the spark plug hole and turn the propeller in the direction of travel until you get compression under your thumb) turn the propeller (in the direction of travel) until you get to "0" on the indicator, that's TDC. Hope this helps, Eric
So 4:00 End of the piston travel is not the TDC ?
Yes, when the piston is at the end of its travel thats TDC, the trick is to bring the piston to the end of its travel in both directions to determine TDC. If you can envision the piston reaching the top of its travel the connecting rod may not be at the end of its travel, by doing it in both directions and then "Splitting" the difference between the readings you ensure that you have reached true TDC. Hope this helps, thanks for the question. Eric MyAnnual.net
Ok I understand you now, in 4:00 you said that , that's TDC cause the piston touch the pin ok that's a common sense and I accept that . but I wanted to know the reason why you spin the prop to the opposite direction of rotation and splitting by 2 since you already found your TDC in 4:00 and you re saying to ensure that you have reached true TDC or to make sure that the connecting rod is at the end of it's travel , Am I right ?
Correct it is not. Just a stop. Prop must be rotated back around other direction to the stop. When you get both end point numbers the same 0 will be TDC
I thought there was a top dead center mark on the flywheel that you li ne up with where the case splits open?
Thanks Eric for the very good explanation of finding TDC. I like this way because it is the most accurate indication of TDC and takes into consideration gear lash.
There is no gear lash. Dial is on the crank. If connecting rod has any slop, Stop remove the cylinder or close the shop & go home !
its a lycoming so couldnt you just find tdc from the timing marks given on the flexplate from the crankshaft ?
very helpful better than my instructor
Hi Eric. Thank you for yor very nice and prof. videos. For me that`s the best instruction videos what ever I have see. Good Quality in the pictures an clearly comments.
Excellent video
Piston stop? What is piston stop? Any different for continental and lycoming engine piston stop tool, length? Tq sir.
What the other tool we can use as piston stop.
Piston stop is a tool usually screws into sparkplug threads. A probe extends into the cylinder. In this case a few inches. Piston comes up hits the stop or probe. That it. To find TDC a dial indicator must be used. Tool can be homemade as long as it stops the piston.
in 4:10 Why did you turn the propeller in to opposite direction of rotation since you already found TDC ? ? I didnt understand that :(
He never did find tdc. If you are thinking the piston stop is TDC it is not. Just a random stop This is why engine is backed all the way around to the other side.When both numbers are the same you have TDC. A little to simple, Give it a little thought I believe you get it !
Eric Barnhill has one!
WHY are you going through all that Rigamarole, with a timing disc?
All you need to do is to find the compression stroke on Number 1, then look at the propeller mount flange,, or starter gear; TDC will be right there. Back off the prop to 25 Deg. mark. Time your mag to that. It's a lot more accurate, than using the timing disc, because it's exact.
The only time that I have ever needed a timing disc, is on a radial engine. (Pratt?)
thank it's very useful teaching a student.
instructions werent clear i got my third thumb stuck in a cylinder
I guess not This post should be taken down.
@@pauleyplay Geeze Billy Barton chill out
Pilot kill