The instructions for installing the Texas T distributor states number 1 cylinder at top dead center.And both valves closed.How does one determine if both valves are closed with out removing the head?
Take the plugs out to make the engine easy to crank, and stick your left thumb over the #1 spark plug hole while you slowly turn the engine with the hand crank. When you feel compression building and air leaking past your thumb, the piston is coming up on the #1 compression stroke. Now take a flashlight and watch the piston come up while you SLOWLY continue turning the crank. You will see the piston come up to Top dead center, stop cranking just before the piston starts back down.
The vendors make a special tool for this, but the flashlight and eyeball method worked fine for me
Hey Mark,Are you saying both intake and exhaust valves for the number one cylinder are closed if the piston is at the top of its compression stroke?
Yes, that's why the pressure in the cylinder is building up and leaking out from under your thumb.
Mark,Thanks very much for the info.
Intake - Piston moving down, Intake valve open, Exhaust closed.
Compression - Piston moving up, Intake closed, Exhaust closed.
Power - Piston moving down, Intake closed, Exhaust closed.
Exhaust - Piston moving up, Intake closed, Exhaust open.
As you can see, there's only one stroke when the piston is moving up and both valves are closed--The compression stroke. This is the pressure you feel under your thumb.
Thanks for the excellent and very detailed explanation of how the four cycle engine works.No one could said it better really appreciate it!
Just to add for TDC I do as suggested put my thumb over number one as I or someone SLOWLY cranks.
As SOON as I feel pressure build up, I have a 15 inch straight coat hanger wire I carefully place in the spark plug hole hitting the top of the upcoming number one cylinder.
I then or have someone SLOWLY crank the engine an inch at a time as I feel the coat hanger wire tight between thumb an finger, slowly slide up. You can tell when it stops moving up you are at TDC then check position of the rivet hole in the crank pulley.
Thanks for the message. sound like a good way to check for TDC.I will give IT a shot.I'm all for anything that makes some thing easier and more effective.You have a very nice 23 touring. A beautiful T
I'm sure there are online animations that demonstrate operation of the four cycle engine. Even the Android app store has an app for such an animation (although it's a DOHC) and you can drag and rotate the screen into any viewing angle and watch the engine run. There's also a slider control to increase and decrease the rpm.
I like Ken Kopsky's description. Just remember that on the intake side there will be a suction on your thumb as it/the piston goes down. When it comes up on the compression stroke there will be the firing stroke and I believe the crank pin will be straight acrroos(horizontal). Correct me if I am wrong as both my "T's" have coils instead of distributor.
Thanks to Garnet and Bill Dugger for your posts.
I learn some thing from each message.
Tom: Well I forgot one thing , and I am sure the you know that if you are hand cranking the "T" to never-never -never wrap your thumb ever-ever around the crank handle, as you may look for a new thumb if it tries to run backwards. I was WARNED-WARNED about early on and luckily it never happened, maybe just because I was lucky.
As one of Forum users says "Go out and enjoy the ride". ALWAY'S check the spark lever and make sure it is in the FULLY RETARDED position, and I am sure that hold true on all ignitions
Bill:I think that was one of the first things I was told when I purchased my Model T,but thanks for reminding me in case I'm having a senior moment ha,ha.
Tom, does the instructions include adding a ground wire from the Distributor head to the engine (Ground)?
Make sure you add the ground wire.
Tom, you may not be interested in doing this but it is easy for me to get perfect timing every time....It let's you know when you have top dead center......I have three marks on the flywheel, 1st. top dead, 2nd 3 degrees, 3rd 6 degrees....I always put it on 1st mark when piston is up as everyone stated, thumb on the cylinder and you feel the pressure pushing....Then I put a wire with a clip on the spark plug and the other end on the pos. side of the coil...I loosen up the distributor so I can rotate it.....When the plug sparks I move the distributor back and forth until I am sure I have it perfect....It will spark each time you move it back and forth... and then I tighten it down......This system works great for me....Hope this helps....Chet
Tom, I should have read my post closer, I meant to say when I move the distributer with the switch on and the plug sparks you have it in perfect timing...Chet
Chester, sounds good thank for the tip!
Les, The instructions makes no mention about adding a ground wire. I have the wire and terminal
so, it will be grounded. Thanks for reminding me!
I have one more question.When setting the timing for top dead center,and the number one spark plug to fire,should the points be open or closed?
Tom, lets go about it this way......
1. Be sure you are at TDC (top dead center)
2. Check to be sure you have the right gap setting on your points
3. Place the rotor and distributor cap back on the distributor
4. If not already, loosen the distributor so you can rotate it freely (should be a small clamp at top of the neck of the distributor)
5. Place the number one plug back in the spark plug wire
6. Put a wire from the positive side of the coil to the number one spark plug (around the threads with a clamp) I have a wire made up for this with a clip on each end for this step
7. Be sure the spark plug is not grounded anywhere, I place a shop rag under my plug
8. Turn on the ignition switch
9. Rotate the distributor slowly until the number one spark plug sparks
10. When it does, move the distributor slowly back and forth making sure it sparks each time.
11. When you are sure you have it setting at the right spot, turn off the ignition switch
12. Tighten the distributor down securely (do not over tighten)
13. Remove the wire from the coil and the spark plug
14. Place the spark plug back in number one cylinder and place the plug wire on the spark plug
15. Turn the ignition switch on
16. Pull the choke
17. Push the starter button and pray I didn't forget anything
If I missed something someone please chime in......Good Luck....Chet
Tom, the points should be just opening at the firing point. You can check the firing point with a test light or multimeter while turning the dizzy head. Installation instructions should detail how to find the correct firing point, if I recall correctly.
Strange that your set of installation instructions doesn't mention the ground wire. Mine does. Just installed it a few months ago. Doesn't say it's required, but recommended to avoid any grounding problems (back page).
Dave, I knew I'd forget something.....the easiest way to accomplish the task....Chet
Dave,I just read the back page of the installation instructions,and doesn't say any thing about the ground wire.Obviously your instructions were revised.Thanks again for reminding about the ground wire!Have a great day.
Chet,Thanks for the very detailed instructions for setting the points to fire the number one spark plug really appreciate it.And have a great day!
Chet, didn't look like you forgot anything. I think we were typing at the same time. Your description is much more complete than mine!
Dave, No actually I was thinking the ol' time way as it seems I usually do.....Your way would be an easier and more correct and accurate way... Thanks for bringing it to my attention...I will try it next time...just when I am taught to do something and it works I forget of the other ways to go about it.....That's a bad habit I need to get out of....... Thanks....and Tom, if you still have a problem ask for more advise......These T'ers are some of the most brilliant people that truly amaze me with all their knowledge....I have so much to learn and I try to read these post every evening.... Chet
Thanks Chet I will.And I agree with you there is a lot of brain power on this web site.And also a lot of super nice people.What more could you ask for!