Danny G Posted November 16, 2019 Share Posted November 16, 2019 Looking for recommendations. I've seen some of these that have a plunger that goes up and down and others where you get a rough estimate then set a screw rotate one direction then the opposite and halfway between us TDC. Any preferences? Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 17, 2019 Share Posted November 17, 2019 I made a simple one by taking the porcelain out of a plug, tapping the hole through the middle, and running a carriage bolt in it along with a lock nut. It isn't fancy but it works. So I'd go with the simple one. Yes, you have to rotate the engine back and forth and find the mid-point for TDC, but it isn't difficult. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 18, 2019 Share Posted November 18, 2019 I made a simple one by taking the porcelain out of a plug, tapping the hole through the middle, and running a carriage bolt in it along with a lock nut. It isn't fancy but it works. So I'd go with the simple one. Yes, you have to rotate the engine back and forth and find the mid-point for TDC, but it isn't difficult. That is how I do it Gary. But dome the end of the bolt so you don't create a burr (hot spot) on the piston crown. Then slip the wheel around until you get the same degrees either side of tdc. I have to remember the alternator pulley trick! 😉 Let me see if I can dig mine out of the bottom of my *homemade and specialty tools* drawer.... Edit:  Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 18, 2019 Share Posted November 18, 2019 That is how I do it Gary. But dome the end of the bolt so you don't create a burr (hot spot) on the piston crown. Then slip the wheel around until you get the same degrees either side of tdc. I have to remember the alternator pulley trick! 😉 Let me see if I can dig mine out of the bottom of my *homemade and specialty tools* drawer.... Edit: Jim - I put the carriage bolt in with the head hitting the piston. But I may have had to turn the head of the carriage bolt down in the lathe to get it through the spark plug hole - I don't remember. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 18, 2019 Share Posted November 18, 2019 Jim - I put the carriage bolt in with the head hitting the piston. But I may have had to turn the head of the carriage bolt down in the lathe to get it through the spark plug hole - I don't remember. I realized this after I replied.... Facing either way, it accomplishes the same thing. Link to comment Share on other sites More sharing options...
Danny G Posted November 18, 2019 Author Share Posted November 18, 2019 I realized this after I replied.... Facing either way, it accomplishes the same thing. I don't have anything to check TDC now but seems like either way is pretty close to the same method, and either are better then a thumb over the hole and feeling pressure to guess. The stop works by stopping it in both directions and marking TDC. The plunger you have to watch rise and fall and then mark TDC. Maybe I'll try both lol. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted November 18, 2019 Share Posted November 18, 2019 I don't have anything to check TDC now but seems like either way is pretty close to the same method, and either are better then a thumb over the hole and feeling pressure to guess. The stop works by stopping it in both directions and marking TDC. The plunger you have to watch rise and fall and then mark TDC. Maybe I'll try both lol. No, there is a big flat spot (arc?) near tdc. It's much more accurate to stop on the upswing either side, sum and divide. Link to comment Share on other sites More sharing options...
Gary Lewis Posted November 18, 2019 Share Posted November 18, 2019 No, there is a big flat spot (arc?) near tdc. It's much more accurate to stop on the upswing either side, sum and divide. Yes! Don't get too close to TDC. Stop in the range of your balancer's marks, but as far out as you can. Link to comment Share on other sites More sharing options...
grumpin Posted November 18, 2019 Share Posted November 18, 2019 I don't have anything to check TDC now but seems like either way is pretty close to the same method, and either are better then a thumb over the hole and feeling pressure to guess. The stop works by stopping it in both directions and marking TDC. The plunger you have to watch rise and fall and then mark TDC. Maybe I'll try both lol. Here’s what I used on aircraft. On a truck I’ve got it on compression stroke then use a pencil and as your moving the piston feel where it stops moving up and starts moving down split the difference and see where you are on the timing mark. The tool for aircraft has a degree wheel to split the difference. https://aircraft-tool.com/shop/detail.aspx?id=E25 Link to comment Share on other sites More sharing options...
Ray Cecil Posted December 2, 2019 Share Posted December 2, 2019 Here’s what I used on aircraft. On a truck I’ve got it on compression stroke then use a pencil and as your moving the piston feel where it stops moving up and starts moving down split the difference and see where you are on the timing mark. The tool for aircraft has a degree wheel to split the difference. https://aircraft-tool.com/shop/detail.aspx?id=E25 Ive never needed more than a pencil, stick or screwdriver to get close enough. I use my finger to feel for compression stroke. Link to comment Share on other sites More sharing options...
Recommended Posts