Original Posted By: oil can
Subject: Pietenpol-List: Re: The timing gadget--more thoughts from an O.F.>What is the correct timing for the Model A ?? We see Top dead center and>12 Degrees before. Which is correct??I read through my reprints of the Model A ford service bulletins thisevening. No where in the four years of service literature does it give thetiming of a Model A in degrees. The base timing is TDC.A stock Model A has a timing control lever where we now have the turn signal/ headlight dimmer switch is on our steering columns. ( There is a rumourthat it will be returned to the floor as too many drivers are getting theirfeet caught up in the levers.)The travel of the lever is limited by a notch in the distributor cap. I willmeasure the angle of the notch and let you know what it is. The crank timingtravel will be twice the notch as four strokes run 2:1. This would bemaximum advance.The standard approach to timing A's is to set them static at TDC andadvance or retard the spark lever while driving according to speed load andfuel mixture as you drive. Not a great way to do it. I wonder how manydrivers understood the control when A's were new? I would suspect that the best timing for a conversion engine will prove tobe somewhat less that the maximum of a stock A. Under heavy load on 87octane you have to retard an A slightly from the full advance position toprevent pinging. If you use a mag with an impulse coupling it will providethe retarded timing for starting and then advance to the run setting whichin my "swag" is somewhere close to 15 BTDC.Be prepared to experiment and try different settings. I would suggeststarting about 5 degrees and working earlier (advance) until best power isfound. Remember best power timing is usually later than best economy cruisetiming. Newer auto engines used vacuum advance that retards the timing atfull power- high manifold pressure. No body knows for sure as each of ourinstallations is slightly different. This is why these creations of ours arestill are classed as experimental aircraft. Go experiment!John Mc________________________________________________________________________________
Pietenpol-List: Re: The timing gadget--more thoughts from an O.F.
Pietenpol-List: Re: The timing gadget--more thoughts from an O.F.
Original Posted By: Earl Myers
If you really want to be CHEAP (like me), just grab the pack of cigarettes out of your neighbors [you don't smoke, do you?] pocket. Slip the cellophane from around the pack, and take it with you the next time you go to the airport. First thing you gotta' do is remove all the spark plugs. Don't worry about the wires, the switch, or anything else. Remove the darned plugs. All of them. This way, the engine not only turns over easier, IT CAN'T FIRE AND HURT YOU. Next, turn the crank until the number 1 piston is approaching top center on the intake stroke. You can make sure it's the intake stroke by holding your thumb over the spark plug hole. If there is a considerable amount of suction, you're on the correct side of the power curve. The engine is telling you that the exhaust valve is closed, the intake valve is open and approaching the firing spot. Slip a pencil or other non-metallic rod down the spark plug hole, and wiggle for the true top center, as described before. Go around to the front (prop end) of the engine, and make a mark on the edge of hub that is close to a point, any point, on the case/block. The closer these two points are, the more accurate your adjustments will be at later checks. Make a matching mark on the case. Make them permanent.Rotate the crank 180 degrees, checking the top center the same way you did for the intake stroke, and make a not necessarily permanent mark on that edge of the hub matching your case mark. Now take a strip of paper about one quarter of an inch wide and wrap it around the hub, between the two marks. Mark the two spots on the paper and remove it to a nice comfortable table/chair combination for further high-tech shenanigans. Looking at your strip of paper, the distance between the tow marks represent 180 degrees of crank travel. If you halve that, it is 90 degrees, halve again is 45 degrees, etc. You can figure out how much distance the appropriate number of degrees BTC you need, and make a mark on your strip of paper. Take your strip back to the prop hub, and using it as a guide, make another permanent mark on the hub at the appropriate spot on the edge. Just make sure that you mark the BEFORE side of the hub. Now you have a set of reference marks to repeatably adjust your timing.Now for that cellophane tool...The first thing you have to do is make sure you put the number 1 cylinder back on the proper number of degrees BTC of timing. Gain access to the points in the mag. Loosening the mount bolts, rotate the mag slightly BACKWARDS, setting the firing point farther back on the timing. Ever so gently, pry the points open and insert the cellophane between the contacts. Sloooooooly rotate THE MAG in the "towards zero degree timing" direction until you can just slip the cellophane out of the contacts. Congratulations! You have just set the timing on your engine. Tighten the mounts, bump the prop back a few degrees before the correct timing, and reinsert the cellophane. Carefully bump the prop until the cellophane can again be removed, and recheck the timing marks. They should be OK. If not, redo it until they are.Make absolutely positive sure that the cellophane is removed from the mag, close it back up, and install your plugs and wires. I'll wager your engine runs as advertised. By the way, Continental engines have the timing degrees on the crank flange and you line it up with the case split. Lycoming engines are usually on the flywheel and the starter boss.I'll see if I can find that schematic for the 'buzz box' and get it scanned for you.Hope this helps some of you. I'll probably see all kinds of mistakes after I send it, but if I do I'll immediately correct them.Ed ________________________________________________________________________________
If you really want to be CHEAP (like me), just grab the pack of cigarettes out of your neighbors [you don't smoke, do you?] pocket. Slip the cellophane from around the pack, and take it with you the next time you go to the airport. First thing you gotta' do is remove all the spark plugs. Don't worry about the wires, the switch, or anything else. Remove the darned plugs. All of them. This way, the engine not only turns over easier, IT CAN'T FIRE AND HURT YOU. Next, turn the crank until the number 1 piston is approaching top center on the intake stroke. You can make sure it's the intake stroke by holding your thumb over the spark plug hole. If there is a considerable amount of suction, you're on the correct side of the power curve. The engine is telling you that the exhaust valve is closed, the intake valve is open and approaching the firing spot. Slip a pencil or other non-metallic rod down the spark plug hole, and wiggle for the true top center, as described before. Go around to the front (prop end) of the engine, and make a mark on the edge of hub that is close to a point, any point, on the case/block. The closer these two points are, the more accurate your adjustments will be at later checks. Make a matching mark on the case. Make them permanent.Rotate the crank 180 degrees, checking the top center the same way you did for the intake stroke, and make a not necessarily permanent mark on that edge of the hub matching your case mark. Now take a strip of paper about one quarter of an inch wide and wrap it around the hub, between the two marks. Mark the two spots on the paper and remove it to a nice comfortable table/chair combination for further high-tech shenanigans. Looking at your strip of paper, the distance between the tow marks represent 180 degrees of crank travel. If you halve that, it is 90 degrees, halve again is 45 degrees, etc. You can figure out how much distance the appropriate number of degrees BTC you need, and make a mark on your strip of paper. Take your strip back to the prop hub, and using it as a guide, make another permanent mark on the hub at the appropriate spot on the edge. Just make sure that you mark the BEFORE side of the hub. Now you have a set of reference marks to repeatably adjust your timing.Now for that cellophane tool...The first thing you have to do is make sure you put the number 1 cylinder back on the proper number of degrees BTC of timing. Gain access to the points in the mag. Loosening the mount bolts, rotate the mag slightly BACKWARDS, setting the firing point farther back on the timing. Ever so gently, pry the points open and insert the cellophane between the contacts. Sloooooooly rotate THE MAG in the "towards zero degree timing" direction until you can just slip the cellophane out of the contacts. Congratulations! You have just set the timing on your engine. Tighten the mounts, bump the prop back a few degrees before the correct timing, and reinsert the cellophane. Carefully bump the prop until the cellophane can again be removed, and recheck the timing marks. They should be OK. If not, redo it until they are.Make absolutely positive sure that the cellophane is removed from the mag, close it back up, and install your plugs and wires. I'll wager your engine runs as advertised. By the way, Continental engines have the timing degrees on the crank flange and you line it up with the case split. Lycoming engines are usually on the flywheel and the starter boss.I'll see if I can find that schematic for the 'buzz box' and get it scanned for you.Hope this helps some of you. I'll probably see all kinds of mistakes after I send it, but if I do I'll immediately correct them.Ed ________________________________________________________________________________
Pietenpol-List: Re: The timing gadget--more thoughts from an O.F.
Original Posted By:> Ed0248(at)aol.com
What is the correct timing for the Model A ?? We see Top dead center and12 Degrees before. Which is correct??
What is the correct timing for the Model A ?? We see Top dead center and12 Degrees before. Which is correct??
Pietenpol-List: Re: The timing gadget--more thoughts from an O.F.
Original Posted By: bwm
for an O.F., you are on the top of todays list of neat people !! thanks a heapfor the really simple way of timing the mags...even I can follow thoseinstructions...it's people like you and many others on this list that offer usnovice builders, knowledge such as this to help us bring our projects to thatlong awaited completion date...THANKS !!!JoeCZion, IllinoisEd0248(at)aol.com wrote:> If you really want to be CHEAP (like me), just grab the pack of cigarettes> out of your neighbors [you don't smoke, do you?] pocket. Slip the cellophane> from around the pack, and take it with you the next time you go to the> airport.>> First thing you gotta' do is remove all the spark plugs. Don't worry about> the wires, the switch, or anything else. Remove the darned plugs. All of> them. This way, the engine not only turns over easier, IT CAN'T FIRE AND> HURT YOU.>> Next, turn the crank until the number 1 piston is approaching top center on> the intake stroke. You can make sure it's the intake stroke by holding your> thumb over the spark plug hole. If there is a considerable amount of> suction, you're on the correct side of the power curve. The engine is> telling you that the exhaust valve is closed, the intake valve is open and> approaching the firing spot. Slip a pencil or other non-metallic rod down> the spark plug hole, and wiggle for the true top center, as described before.> Go around to the front (prop end) of the engine, and make a mark on the edge> of hub that is close to a point, any point, on the case/block. The closer> these two points are, the more accurate your adjustments will be at later> checks. Make a matching mark on the case. Make them permanent.>> Rotate the crank 180 degrees, checking the top center the same way you did> for the intake stroke, and make a not necessarily permanent mark on that edge> of the hub matching your case mark. Now take a strip of paper about one> quarter of an inch wide and wrap it around the hub, between the two marks.> Mark the two spots on the paper and remove it to a nice comfortable> table/chair combination for further high-tech shenanigans. Looking at your> strip of paper, the distance between the tow marks represent 180 degrees of> crank travel. If you halve that, it is 90 degrees, halve again is 45> degrees, etc. You can figure out how much distance the appropriate number of> degrees BTC you need, and make a mark on your strip of paper.>> Take your strip back to the prop hub, and using it as a guide, make another> permanent mark on the hub at the appropriate spot on the edge. Just make> sure that you mark the BEFORE side of the hub. Now you have a set of> reference marks to repeatably adjust your timing.>> Now for that cellophane tool...The first thing you have to do is make sure> you put the number 1 cylinder back on the proper number of degrees BTC of> timing. Gain access to the points in the mag. Loosening the mount bolts,> rotate the mag slightly BACKWARDS, setting the firing point farther back on> the timing. Ever so gently, pry the points open and insert the cellophane> between the contacts. Sloooooooly rotate THE MAG in the "towards zero degree> timing" direction until you can just slip the cellophane out of the contacts.> Congratulations! You have just set the timing on your engine. Tighten the> mounts, bump the prop back a few degrees before the correct timing, and> reinsert the cellophane. Carefully bump the prop until the cellophane can> again be removed, and recheck the timing marks. They should be OK. If not,> redo it until they are.>> Make absolutely positive sure that the cellophane is removed from the mag,> close it back up, and install your plugs and wires. I'll wager your engine> runs as advertised.>> By the way, Continental engines have the timing degrees on the crank flange> and you line it up with the case split. Lycoming engines are usually on the> flywheel and the starter boss.>> I'll see if I can find that schematic for the 'buzz box' and get it scanned> for you.>> Hope this helps some of you. I'll probably see all kinds of mistakes after I> send it, but if I do I'll immediately correct them.>> Ed________________________________________________________________________________
for an O.F., you are on the top of todays list of neat people !! thanks a heapfor the really simple way of timing the mags...even I can follow thoseinstructions...it's people like you and many others on this list that offer usnovice builders, knowledge such as this to help us bring our projects to thatlong awaited completion date...THANKS !!!JoeCZion, IllinoisEd0248(at)aol.com wrote:> If you really want to be CHEAP (like me), just grab the pack of cigarettes> out of your neighbors [you don't smoke, do you?] pocket. Slip the cellophane> from around the pack, and take it with you the next time you go to the> airport.>> First thing you gotta' do is remove all the spark plugs. Don't worry about> the wires, the switch, or anything else. Remove the darned plugs. All of> them. This way, the engine not only turns over easier, IT CAN'T FIRE AND> HURT YOU.>> Next, turn the crank until the number 1 piston is approaching top center on> the intake stroke. You can make sure it's the intake stroke by holding your> thumb over the spark plug hole. If there is a considerable amount of> suction, you're on the correct side of the power curve. The engine is> telling you that the exhaust valve is closed, the intake valve is open and> approaching the firing spot. Slip a pencil or other non-metallic rod down> the spark plug hole, and wiggle for the true top center, as described before.> Go around to the front (prop end) of the engine, and make a mark on the edge> of hub that is close to a point, any point, on the case/block. The closer> these two points are, the more accurate your adjustments will be at later> checks. Make a matching mark on the case. Make them permanent.>> Rotate the crank 180 degrees, checking the top center the same way you did> for the intake stroke, and make a not necessarily permanent mark on that edge> of the hub matching your case mark. Now take a strip of paper about one> quarter of an inch wide and wrap it around the hub, between the two marks.> Mark the two spots on the paper and remove it to a nice comfortable> table/chair combination for further high-tech shenanigans. Looking at your> strip of paper, the distance between the tow marks represent 180 degrees of> crank travel. If you halve that, it is 90 degrees, halve again is 45> degrees, etc. You can figure out how much distance the appropriate number of> degrees BTC you need, and make a mark on your strip of paper.>> Take your strip back to the prop hub, and using it as a guide, make another> permanent mark on the hub at the appropriate spot on the edge. Just make> sure that you mark the BEFORE side of the hub. Now you have a set of> reference marks to repeatably adjust your timing.>> Now for that cellophane tool...The first thing you have to do is make sure> you put the number 1 cylinder back on the proper number of degrees BTC of> timing. Gain access to the points in the mag. Loosening the mount bolts,> rotate the mag slightly BACKWARDS, setting the firing point farther back on> the timing. Ever so gently, pry the points open and insert the cellophane> between the contacts. Sloooooooly rotate THE MAG in the "towards zero degree> timing" direction until you can just slip the cellophane out of the contacts.> Congratulations! You have just set the timing on your engine. Tighten the> mounts, bump the prop back a few degrees before the correct timing, and> reinsert the cellophane. Carefully bump the prop until the cellophane can> again be removed, and recheck the timing marks. They should be OK. If not,> redo it until they are.>> Make absolutely positive sure that the cellophane is removed from the mag,> close it back up, and install your plugs and wires. I'll wager your engine> runs as advertised.>> By the way, Continental engines have the timing degrees on the crank flange> and you line it up with the case split. Lycoming engines are usually on the> flywheel and the starter boss.>> I'll see if I can find that schematic for the 'buzz box' and get it scanned> for you.>> Hope this helps some of you. I'll probably see all kinds of mistakes after I> send it, but if I do I'll immediately correct them.>> Ed________________________________________________________________________________
> Re: The timing gadget--more thoughts from an O.F.
Original Posted By: Creative Ice
> > If you really want to be CHEAP (like me), just grab the pack ofcigarettes > out of your neighbors [you don't smoke, do you?] pocket. Slip thecellophane > from around the pack, and take it with you the next time you go to the > airport. > > First thing you gotta' do is remove all the spark plugs. Don't worryabout > the wires, the switch, or anything else. Remove the darned plugs. Allof > them. This way, the engine not only turns over easier, IT CAN'T FIRE AND> HURT YOU. > > Next, turn the crank until the number 1 piston is approaching top centeron > the intake stroke. You can make sure it's the intake stroke by holdingyour > thumb over the spark plug hole. If there is a considerable amount of > suction, you're on the correct side of the power curve. The engine is > telling you that the exhaust valve is closed, the intake valve is openand > approaching the firing spot. Slip a pencil or other non-metallic roddown > the spark plug hole, and wiggle for the true top center, as describedbefore. > Go around to the front (prop end) of the engine, and make a mark on theedge > of hub that is close to a point, any point, on the case/block. Thecloser > these two points are, the more accurate your adjustments will be at later> checks. Make a matching mark on the case. Make them permanent.> > Rotate the crank 180 degrees, checking the top center the same way youdid > for the intake stroke, and make a not necessarily permanent mark on thatedge > of the hub matching your case mark. Now take a strip of paper about one > quarter of an inch wide and wrap it around the hub, between the twomarks. > Mark the two spots on the paper and remove it to a nice comfortable > table/chair combination for further high-tech shenanigans. Looking atyour > strip of paper, the distance between the tow marks represent 180 degreesof > crank travel. If you halve that, it is 90 degrees, halve again is 45 > degrees, etc. You can figure out how much distance the appropriatenumber of > degrees BTC you need, and make a mark on your strip of paper. > > Take your strip back to the prop hub, and using it as a guide, makeanother > permanent mark on the hub at the appropriate spot on the edge. Just make> sure that you mark the BEFORE side of the hub. Now you have a set of > reference marks to repeatably adjust your timing.> > Now for that cellophane tool...The first thing you have to do is makesure > you put the number 1 cylinder back on the proper number of degrees BTC of> timing. Gain access to the points in the mag. Loosening the mountbolts, > rotate the mag slightly BACKWARDS, setting the firing point farther backon > the timing. Ever so gently, pry the points open and insert thecellophane > between the contacts. Sloooooooly rotate THE MAG in the "towards zerodegree > timing" direction until you can just slip the cellophane out of thecontacts. > Congratulations! You have just set the timing on your engine. Tightenthe > mounts, bump the prop back a few degrees before the correct timing, and > reinsert the cellophane. Carefully bump the prop until the cellophanecan > again be removed, and recheck the timing marks. They should be OK. Ifnot, > redo it until they are.> > Make absolutely positive sure that the cellophane is removed from themag, > close it back up, and install your plugs and wires. I'll wager yourengine > runs as advertised. > > By the way, Continental engines have the timing degrees on the crankflange > and you line it up with the case split. Lycoming engines are usually onthe > flywheel and the starter boss.> > I'll see if I can find that schematic for the 'buzz box' and get itscanned > for you.> > Hope this helps some of you. I'll probably see all kinds of mistakesafter I > send it, but if I do I'll immediately correct them.> > Ed > ________________________________________________________________________________
> > If you really want to be CHEAP (like me), just grab the pack ofcigarettes > out of your neighbors [you don't smoke, do you?] pocket. Slip thecellophane > from around the pack, and take it with you the next time you go to the > airport. > > First thing you gotta' do is remove all the spark plugs. Don't worryabout > the wires, the switch, or anything else. Remove the darned plugs. Allof > them. This way, the engine not only turns over easier, IT CAN'T FIRE AND> HURT YOU. > > Next, turn the crank until the number 1 piston is approaching top centeron > the intake stroke. You can make sure it's the intake stroke by holdingyour > thumb over the spark plug hole. If there is a considerable amount of > suction, you're on the correct side of the power curve. The engine is > telling you that the exhaust valve is closed, the intake valve is openand > approaching the firing spot. Slip a pencil or other non-metallic roddown > the spark plug hole, and wiggle for the true top center, as describedbefore. > Go around to the front (prop end) of the engine, and make a mark on theedge > of hub that is close to a point, any point, on the case/block. Thecloser > these two points are, the more accurate your adjustments will be at later> checks. Make a matching mark on the case. Make them permanent.> > Rotate the crank 180 degrees, checking the top center the same way youdid > for the intake stroke, and make a not necessarily permanent mark on thatedge > of the hub matching your case mark. Now take a strip of paper about one > quarter of an inch wide and wrap it around the hub, between the twomarks. > Mark the two spots on the paper and remove it to a nice comfortable > table/chair combination for further high-tech shenanigans. Looking atyour > strip of paper, the distance between the tow marks represent 180 degreesof > crank travel. If you halve that, it is 90 degrees, halve again is 45 > degrees, etc. You can figure out how much distance the appropriatenumber of > degrees BTC you need, and make a mark on your strip of paper. > > Take your strip back to the prop hub, and using it as a guide, makeanother > permanent mark on the hub at the appropriate spot on the edge. Just make> sure that you mark the BEFORE side of the hub. Now you have a set of > reference marks to repeatably adjust your timing.> > Now for that cellophane tool...The first thing you have to do is makesure > you put the number 1 cylinder back on the proper number of degrees BTC of> timing. Gain access to the points in the mag. Loosening the mountbolts, > rotate the mag slightly BACKWARDS, setting the firing point farther backon > the timing. Ever so gently, pry the points open and insert thecellophane > between the contacts. Sloooooooly rotate THE MAG in the "towards zerodegree > timing" direction until you can just slip the cellophane out of thecontacts. > Congratulations! You have just set the timing on your engine. Tightenthe > mounts, bump the prop back a few degrees before the correct timing, and > reinsert the cellophane. Carefully bump the prop until the cellophanecan > again be removed, and recheck the timing marks. They should be OK. Ifnot, > redo it until they are.> > Make absolutely positive sure that the cellophane is removed from themag, > close it back up, and install your plugs and wires. I'll wager yourengine > runs as advertised. > > By the way, Continental engines have the timing degrees on the crankflange > and you line it up with the case split. Lycoming engines are usually onthe > flywheel and the starter boss.> > I'll see if I can find that schematic for the 'buzz box' and get itscanned > for you.> > Hope this helps some of you. I'll probably see all kinds of mistakesafter I > send it, but if I do I'll immediately correct them.> > Ed > ________________________________________________________________________________