Further to my thread here http://www.mtfca.com/discus/messages/257047/317128.html?1350320644
I decided to check the firing point for each cylinder with my original Anderson timer which has done about 23,000km of work.
I measured the piston position in thousandths of an inch below top dead centre at which each spark plug fired, with the timing lever in the fully retarded position. The results were quite revealing and it was no wonder the ignition wasn't up to its normal performance. Apart from considerable timing variation, the timer contact for #3 cylinder suffered from contact bounce; i.e., the contact would make then break before making again. In otherwords, a potential source of double sparking.
A new Anderson timer was considerably better, and despite being retarded for contact #3, has fixed the ignition problem.
The point I'm making is that I'm running the coils on DC, and therefore the contact spacing of the timer is critical. In this regard, the Anderson would be not such a good choice, especially if it wears unevenly as my original had done. On the plus side, and the reason I use this timer is the positive, self cleaning wiping contact, and mechanical reliability.
John, one of the great advantages of an Anderson is that you can adjust the contact point of each contact just bend them till you get the result you want. I would have thought as you are electrical savvy that you would have equipment to do so.
After meeting and staying with Mark Hutchingson who makes the Anderson and going for a ride with him in his 27 Roadster which easily ran at 60 mph plus and having an Anderson which allowed me to run at 45 mph all day for several weeks I have to say its only a matter of fine tuning of the ignition. But you will never get best performance until you switch to magneto ignition and off the battery.
I'm sure Mark would be only too happy to give you some help to get the timer working spot on.
This illustrates the major problem with the Anco timer. Even on magneto sometimes the contacts are so far off that they cause one cylinder to have more or less advance than the others.
The bends in the contacts, location of the mounting holes in the timer case, and wear are critical with the Anco design.
John,
I like your piston position measuring set up.
Just to put more meaning to your piston position measurements I calculated the crank position that corresponds to your new timer measurements.
1 = 3.9° ATDC
2 = 1.6° ATDC
3 = 9.9° ATDC
4 = 2.0° ATDC
Of course these angles would be half on the timer.
I wonder how much effect the plus or minus 4° timing variation actually has on the engine performance?? Running on the mag you can only get a choice of timing on nodes spaced at 22.5°.
The real issue may be that it is important to check your timing on each cylinder to really know where you are in regard to starting safely. For example if you had set the timing using #3 cylinder and 5° ATDC, then #2 would fire 3° BTDC. Not a good condition for starting.
Jim
This was the way I checked mine. I located TDC of No. 1 with a dial indicator then I made a shaft for a degree wheel like this drawing:
It proved to be much faster and just as accurate.
With those differences I would suspect the alignment of the timing gear cover or its concentricity. Just my two cents.
The Tulsa Club has had this and other great files on their website for many years. They have done a lot of great work and are to be commended. Model T owners should be scouring the various Clubs on the internet and benefiting from the great material that is usually freely available.
Piston Position vs. Crankshaft Angle
http://mtfctulsa.com/Tech/pistonposition.htm
Other Tech files:
http://mtfctulsa.com/Tech/index.htm
Regards,
Garnet
Thanks to everyone for the responses. I should make it clear I'm not criticising the Anderson timer, but merely drawing attention to the timing variation that can occur. Until the e-timer drops to an affordable cost, the Anderson will always be my timer of choice.
Peter, I'm aware that I can adjust the contacts for optimum timing, but with having a club run the following day there just wasn't time. No doubt it can only run even better once I do adjust #3.
Nevertheless, I was happily cruising at 70+ km/h on 6V battery on Sunday afternoon. I'm well aware of the top speed limitation running on battery, but it just so happens that 75km/h is the most I'm comfortable with a stock car anyway.
I have ordered a rebuild kit for my old timer so will go through the timing procedure on that as well. Another test I ought to do is see what the variation is when the timing lever is set for driving speed. If there is any variation with camshaft eccentricity, the results will be different. One should in theory adjust the contacts for when the timing lever is in driving position, ensuring of course none are advanced when in starting position.
Garnet,
That is one fantastic idea!
I am going to post a new thread to see if any others can contribute to your idea.
Mike Green
Bending the contacts is not the way to adjust the timing on the anco. The insulators are laminated and the timing can be adjusted by peeling off some of the material and checking for even timing as noted above. A few degrees variance in each cylinder will make for a poorly performing engine.
Willard,
I'm not saying you can't do adjustments the way you are but, I wouldn't do it that way. I would carefully bend the fingers as needed.
As always I am certainly willing to help anyone having a problem with an Anderson Style timer. hutch a.k.a. Tip Top Timers
You might want a second opinion with another type of timer.
If the front plate is not centered around the camshaft, you will have readings similar to those, although those results are not consistent enough to suggest the front plate is off center.
James:
"another type of timer"... I don't think there is another type of timer... which works consistantly for long periods and distances.
"If the front plate is not centered"... bending and setting the contacts on an Anderson style or ANCO timer will correct for this error. This is the only timer in common use which has this property.
Respectfully, TH
So, how does one bend the contacts? I haven't yet investigated, but I would guess the contacts would be hardened steel. I could imagine bending them in situ crushing the insulators. And just bending with pliers etc. might cause a twist causing uneven flapper wear.
Just for the record, the proper timer cover centering tool was used when the engine was reassembled in early 2010. Prior to this, it was as it left the factory.
John
I sent you a PM hutch
John,
After a bit of use the Anderson timer contacts wear. It is likely that they will not wear evenly. I adjusted mine by grabbing them with a plier and bending. It wasn't a problem and I didn't distort the timer case. Of course if you have taken a Gorilla Muscle Builder Course your experience may vary. Doing this requires a little finesse as a little bending goes a long way. It's been a while since I did it but I seem to remember that .004" gave something like 5°.
I used a very sensitive gauge... a sheet of paper taped onto the radiator. I pulled the crank handle until the coil buzzed and marked the center of the handle onto the paper. You get #1 & #4 on one mark and #2 & #3 on the other.
The first time you mark it you will probably get four distinct marks. What you want to do is bend the contacts until the coils JUST START to buzz with the marks exactly 180° apart and with both coils starting exactly the same spot on the paper.
I found that getting the coils firing at exactly 180° (or the same spot 360° later depending on which coils we are talking about), not early or late, makes a huge difference on the way your car runs.
IMHO, TH
Any of you who are in Britain should visit Neil Tuckett's shop. He has a Model T front timing cover set up with a camshaft stub (perfectly centered) and timing gears connected to a large degree wheel.
You can compare an Anderson timer to a Ford roller timer for example. The amount of cylinder to cylinder variance with an original Ford roller timer is zero.
Royce, All the roller timers I have used (admittedly reproductions of possible dubious quality) suffer wear to the insulator between contact segments. This causes the roller to bounce making the car run very poorly. When the roller bounces all that built in precision is lost.
I have found the same problem with wiper contact timers like the "New Day". Again the insulator (in the case of the New Day it is the actual timer case material) wears away faster than the contacts causing wear and damage to the wiper and a form of bounce in the wiper spring.
With the Anderson you don't get bounce, but over the years you will get wear to the flapper and the contacts. This is completely compensated for by resetting the contacts by bending.
One advantage the Anderson has is that you can do this at any time, even at the side of the road. Other timers need to be taken in to a shop to be repaired.
Another advantage is that you can go thousands of miles before having to fuss with the Anderson timers. All of the wiper and roller style timers I have used have failed within 50 to 100 miles with normal use.
TH
I use Ford roller timers or older Tiger or Bulldog timers. At Chickasha this year I bought four good ones for $4.They do not wear at all if kept lubricated. I us Mobil red grease and typically clean it annually which is about a thousdand miled in the 15, maybe 500 miles each for the other two Ts.
If a roller timer failed within 50 to 100 miles it must have been a piece of junk or not taken care of. If they are taken care of they run great for many miles.
Stephen
What timer did Constantine use, anyone know ? Regards, Bede
Constantine had an Anco timer on his car for the trip. He ran the whole way on MAG. Battery fell out in the middle of Africa on a rock strewn dirt road, didn't slow hime down.
Royce, I'm curious what kind of clutch was in constantine's 13? Also, what parts of the car are not stock?
Thanks,
Stephen
Terry:
"if the front plate is not centered" and you bend the contacts to compensate - that is only going to work at one setting of the timer since when you rotate the timer your compensation is actually going to make matters worse since off center timer case will move the now off center contacts to a new location and both are now off center more than if one is perfect and the other off center. Think about it. Some timers by design are less sensitive to timer centering than others but I don't think you can compensate for off center mounting by then making the contacts off center to match.
Stephen,
I don't know the answers to those questions. Hopefully Constantine will tell us more at some future date. I believe the cylinder head was the one that was on the car when I sold it, an aluminum one made by Ralph Reeder.
The previous owner of "Anderson" timer business use to also rebuild the original Anco timers and set them up properly and state not to remove or loosen the contact/binding posts as they were adjusted for proper dwell or what ever..All new posts,contacts adjustment and return shipping was like 30 bucks several years back...I guess the new Anderson guy doesn't do this?
David
Tip-Top timers, the new Anderson mfg, will do-over any original ANCO timer you send to them.
I like using the original timer cases, and with new guts and flapper from Tip-Top.
I am happy to rebuild these old timers. The cost has gone up a little, $50.00 plus shipping. Feel free to contact me if you have specific questions 509-220-0892. hutch, Tip Top Timers