A few of you may recall that I bought my '24 touring car about 2 months ago. I've been slowly and carefully learning to drive it on quiet roads. One thing I've noticed is that on almost any hill it will slow down and I usually have to drop to low gear to climb it. It even slows down on the steep ones in low gear. Since this is my first T, I have nothing to compare it to. On level ground it runs along nicely at 30-35mph (as fast as I want to go). I'm not concerned about going any faster, but I am concerned about making it up some long steep hills near my home.
The motor seems to run well and smooth, although its a little hard to start (probably my fault, as I'm still learning the routine). It seems to idle smoothly and at speed I feel no "missing". So overall it seems to run good, it just seems to be lacking in power to get up the hills. The engine was rebuilt about 10 years ago and the car has been on many tours. The motor is basically stock, standard head but it has adjustable lifters I was told.
I want to inspect the ignition system first to see if everything is as it should be. I started out by pulling the plugs (Bosch FR9HP using adapters). They all looked a nice medium gray color, see below. They are arranged front to rear (front plug is to the right). The flash makes them look a little lighter in color than they really are. I think they look pretty good.
Next I removed the anderson timer to see what it looks like inside.
So my question is tow-fold.
1. - does it sound like the hill climbing power I have is normal or is it lacking?
2. The timer needs to be cleaned no doubt. Are the contacts too worn or is this normal.
Ok - another question. Should I check the coils for anything? They were rebuilt also. They seem to be firing ok based on how the plugs look.
I want to check the compression this weekend and see how that looks. What else should I look at?
Thanks guys!
I could only put 2 photos in the original post. Here is the rotor.
The timer is shot from the looks of it. You have got your money's worth from that one. Fortunately new Anco timers are still made, and a phone call or web order will bring one to your house in a couple days.
You need to know the compression of each cylinder and is the throttle butterfly opening all of the way first. Then you can proceed with more diagnosis. Since you are new to driving a T, how do you adjust the timing while driving? How large of a hill is this?
Stock T's are notoriously under-powered but you sound perfect for the hobby.
I live in hilly country also and I find a Ruckstel very handy. T's do not do real well on semi-steep hills (I know... very subjective) I have 3 T's and each varies in power. Ironically, my heaviest T (Tudor) seems to be the strongest of the three! Still, the previous comments will certainly help you.
Retarding the spark a hair when going up a hill will give you a little boost in power.
Its hard to explain the steepness of the hills I'm concerned with. I'm not taking about the streets of San Francisco, but steep enough that even ardent bicyclists walk their bikes up the 1/4 mile hill. I run with the spark fully advanced until I start slowing down, then retard it a bit.
When I bought the car, I also got a pick up load of parts. I recalled seeing another timer, so I went digging. I found 3 more Anderson timers. One has a note written with it saying it needs a shorter rotor. There are some scrape marks inside that timer shell. Another is only slightly used with no marks. The 3rd is new, unused. I read in the archives about varying cam lengths and the occasional need for a shorter rotor. Mine seems to be one of them. I have not yet removed the rotor from the cam, but I assume it is a shorter one. I think I can use that barrel and swap another new flapper onto it.
What do you think of these plugs? I'd rather use original type plugs. Champion X ideally. I did find some used champion A-25s in the parts pile.
I would also like to check the coils, what should I look for? Point gap? I don't have a T coil tester, but do have an old Eisemann magneto coil tester. Not sure if this can be used or not. BTW, the car runs equally well on magneto or battery.
Not sure what the Eisemann is, but unless it is a hand cranked coil tester, then I'd say no, it's not up to the task. Point gap is not extremely important, so don't worry about that part of it. Not much you can check on a working coil without the HCCT or a Strobospark. Generally, it should run a little better on Mag than on 6 volts at higher speeds. If no one in your area has a HCCT, PM me.
It's not a hand cranked tester, so it probably won't work. Here's what it looks like:
I have been reading the MTFCA Electrical System handbook and it has a good basic test procedure for the coils using an ohmeter. I'm sure its not as thorough as a hand crank tester, but I may try it tomorrow.
The adapter with modern plugs could be issue, along with coils, and the Anderson flapper timer is a bit worn too much. With adapters, hard to know what plug depth you are having for good spark. Would switch to Champion X plug that was made for the Ford.
The best bet is to check the magneto output with the light bulb test and analog meter, that will tell the magneto strength.
Then get the coils tested and set on a HCCT or Strobospark unit, that will assure the coils are like factory new.
Then replace the Anderson timer with the new Anderson you have, add some high strength lube, a bit placed on the flapper, that will allow the timer to function with longer life.
Test drive your hills, I bet you will find a difference!
Anderson after 3500 miles without lube, a bit of wear evident, but still was running smooth.
Section showing the plug length needed for good spark, with Champion X plugs made for the Ford.
Though you say their darker the plugs look like their running lean. Carb needle setting off? Get the correct plugs for it. The timer, as stated, is toast. You found a problem that would show up later. As you stated it ran OK/no missing so it was probably still working. Coils: If your's aren't re-built (new capacitors) and HCCT set-up that needs to be done. You won't believe the over all running/power improvement it brings. Don't do what I did. For years! Put in new caps, adjust and get a spark and their OK. Bunk. Bob J. set up 4 for me on his HCC and the car started on mag. Cold.
In my humble opinion a Model T is an old fashion hill detector.
I didn't realize my neighborhood had so many hills before I got my T.
If your coils are working, they will probably pass the ohm meter tests. Leaking condensers and poorly adjusted points are what makes the difference between coils that work and coils that work PROPERLY. Ohm meter tests are useful for identifying coils that can be successfully rebuilt, but cannot detect whether the points are adjusted properly.
Here's one guys opinions, others will disagree strongly:
- why screw with adapters? Get some 1/2" pipe thread plugs. If you don't have the Champions, both Motorcraft and AC's have worked fine for me.
- Flapper type timers always seem to have some sort of problem. Get a "New Day" and be done with it. (and check the timer against piston position),
- Coils are important. Unless you KNOW they have been rebuilt recently by someone reliable, have them checked.
- Make sure that carb is clean and the float set properly (and that the butterfly opens 100%). Try one of those hills with a full tank of fuel.
- Check for fuel flow at the carb.
- back off on the spark advance on a steep hill...experiment.
- remember you only have 22HP max if stock and in good shape. Don't expect V8 performance.
Good luck
schuh
Thanks for all the replys. I'll install a new Anderson timer and check the timing to #1 cylinder. The plugs were gapped at 030", that seems ok. I will order a set of Champion X plugs. I'll also check to make sure the carburetor butterfly is opening fully.
I think .030 is too wide, especially for platinums, Steve. I would try them at .020 . Hard starting when cold is a sign of too much gap. Wide gap is bad for coils.
I would not waste the money on X plugs if the ones in the engine are doing the job, as yours appear to be. But then, I don't run buzz coils nor mag.
.020" ? I was think of trying .025". Are these Bosch FR9HP plugs resistor plugs? I've learned from working on antique motorcycles that resistor plugs do not play well with old electrical systems. Thanks
Steve:
Since a T uses an updraft carburetion system it must be choked fully to start it. Since your car is a '24 it has that double bell crank affair for operation of the choke. When you pull on the dash knob for choking, make sure that your travel is NOT being limited by that bell crank hitting the firewall before the choke has fully closed and bottomed in the carb bore. This is an easy mistake caused by the bellcrank to carb linkage wire being too long. Take a mirror and look into the carb entry way and make absolutely certain that the choke is fully closing when you pull the dash knob. Hard starting is common if the choke is not fully closing. Most T's will start instantly when you choke the thing but the "FIRE" happens when you drop the choke knob while cranking so pull the choke knob all the way up, hit the starter button and after a few seconds, DROP the knob while still standing on the starter button.
Your plugs look good and is the same as what I have been using for a long time on many tours with good results set close to .025" gap with a Z head. Royce is right, That Timer has seen better days a long time ago. Any new timer will make your car run 100% better. You might out the E Timers and you will never have to think about maintenance there again. First learn how to operate you original T system spark advance.
Ralph is right about too wide of a spark is hard on the coils. You can't adjust the coils without the right equipment. Send them off to an expert or fellow club member with experience.
Good Luck and enjoy
One thing to remember is when folks in this era drive a Model T espically if you havent driven one all that much its not like driving todays cars. 22 HP isnt much compared to at the very least 140 HP++. There really is a difference in a car thats close to 90 years old.
I have had a good day working on the car. I installed the new Anderson timer and checked the timing to piston #1 per instructions. Then I turned to the plugs. Turns out the Bosch plugs are resistor plugs. I set all 4 on the head and cranked slowly buy hand, watching for spark from each coil (on battery). Only 2 sparked. I dug through my parts and found 3 Champion 25s and 1 Motorcraft F-11 in a box. An odd combination but I decided to clean them up and try them. After cleaning and gapping to .030" I put them in my old Champion plug tester (that uses a model T coil).
They all tested good. I hooked them up, set them on the head and again hand cranked. Each sparked nicely when its coil buzzed. Out came the 14mm adapters (and boy were they tight) and in went the new (old) plugs. After double checking everything, I gave her 3 notches of advance, about 5 notches of throttle, pulled the choke, set it to battery and hit the starter. She fired right up! Better than ever before. I switched to mag, enrichened the mixture slightly and she was purring like a kitten.
Out for a test drive, it run very smooth and seemed to have a little more power, nothing earthshaking, but a noticeable improvement. For an additional test I had my 275 lb son get in the back seat and out we went. She was a little slower on the hills, but did ok. I dropped him off and went back out, determined to attack that worrysome hill. I went a few miles into town and ran into 10,000 people at the Octoberfest with part of downtown blocked off. Lots of waves, hoots and hollers. Now to head home, via the dreaded hill. Of course there is a stoplight at the bottle of the hill, so I couldn't get much of a running start. But I made it about 1/3 of the way up in high, then dropped down to low and made it to the top with no problem. I tried to get a shot of the hill as I climbed it. Its hard to tell how steep it is, but you get the idea.
Yeah, it was slow, but the old girl took it in stride. I was very pleased. The coils seem to be working fine, but I would like to have them checked out and adjusted, just to make sure they are giving their best. I will also get a new set of 4 plugs, either Champion 25s or X. But these will do for now.
Thanks to everyone for your advice and suggestions. I made good progress today and learned a lot about the car. You guys are a great help - many thanks!
I checked compression today, front to rear it was: 54,52,52,57. This was using a "hold it in place with my hands" type gauge. Not sure why the rear cylinder was a bit higher than the others. Maybe more oil in the cylinder. Overall, I think this is pretty good. Took it out for another 12 mile drive today and it ran like a watch. Big smiles!
One should never use platinum plugs in ANY engine hat is not fuel injected. Never.
That's excellent compression. Good tight motor. Get those coils done and watch it take the hills.
Aaron, can you explain the platinum in fuel injected only?
Based on many platinum spark plug manufacturers they can be used in any conventional engine. They are just supposed to last longer then conventional plugs.
http://www.acdelco.com/parts/spark-plugs/rapidfire-platinum/
Jim
Oh boy! Here we go; etimers, oil, tire flaps, I know I'm missing one, and now platinum spark plugs.
The problem with using any of those exotic metal plugs in an old car is that they do not operate properly on low power ignition systems. The platinum / iridium / unobtanium tipped plugs need high voltage and high current, otherwise they foul easily. They are made of these exotic metals to withstand the welding - level current and voltage found in modern cars and trucks. This is yet another case of more expensive does not equal better for your T.
You will find that the cheapest plug you can buy that has the proper heat range will last nearly indefinitely if it extends far enough into the T cylinder to fire.
I like Champion X plugs, and buy them any time I see them under $5 apiece. They last forever, rarely foul and can be cleaned without any special equipment.
All I know is that my car was hard to start with those Bosch plugs. With the old Champion A25s and Motorcraft F-11, it starts starts much easier. I suppose the new timer helps also. I have about 6 rusty old Champion X plugs that I thought about trying to resurrect, but they're pretty rough looking. I wish the new ones weren't so pricey.
Steve
"If wishes were horses, then beggars would ride"
(Sorry - one of my grandmothers favorite expressions & I don't get to use it often ;o) )
schuh
"If wishes were horses, then beggars would ride"
I'll have to remember that one!
Steve
Royce gave very good advice. Find your "X" plugs at flea markets. My '19 is running "FORD" X plugs that are original and none too pretty. They run marvelously well.
My only experience with Bosch plugs were in my '13 which could not be started at all with them. Putting in some old "X" plugs made starting (by hand) a breeze. Bosch plugs were in it when I purchased the car from a friend's estate auction and the car had to be pushed to get it running...it ran with little pep on the bosch plugs. This engine is pretty tired, though runs well and that probably accounts for the fact that your car will run with them and mine will not.
Scott - I'll pull out the crusty X's I have and see what I can do with them. Nothing lost by trying. I'm not going back the platinum Bosch plugs. I've got a bunch of extras of those too, but have no use for them. They'll be going in trash.
Steve
You should not be using resistor spark plugs or resistive plug wires in a Model T.
Ron the Coilman
Thanks Ron. From much previous experience on old motorcycles, I agree.
I dug through my box of old crusty plugs and found these candidates for resurrection.
The 3 in the bottom row to the left are Ford script. A couple seem to have slightly different size bodies. They all seem to have crusty, but usable electrodes. Do they look salvageable?
Should I attempt to take them apart or is that just asking for trouble? I know better than to sand/bead blast them, but I was thinking of trying electrolysis. I have used electrolysis before on rust iron with very good results. Other wise its a wire brush and carb cleaner. Any other suggestions?
Steve,
When we had a tudor, I added a Z head and the increased power (and better cooling) were amazing. Just a thought for the future. Also, I'd recommend practicing retarding the spark (as mentioned early on in the thread) to help "pull" up hills. that might allow you to stay in high.
A way to practice using the spark for more low speed power is to gently shift into high at low speeds. At the same time you shift into high (at low speed), throttle down and retard the spark. You'll find the "sweet" spot where the motor is able to pull better. Then as the car begins to increase speed increase the spark advance too.
When I drive our cars, I almost always operate the spark and throttle levers either accelerating or slowing.
Enjoy,
Rob
Noone has answered the question about why you can't / should not use a platinum resistor plug.
I switched the same Bosch plugs that Steve is using several years ago because of a test done of various spark plugs by Reid Welsh.
They have a nice screw top and a long reach. I have always had good performance with them with no fouling and pretty much look like the ones Steve took out with a nice grey.
The price is good and you can get them at any parts store while on tour.
I do have a set of new X's that I thought I might try because many have said how much better their car runs but I really find that hard to believe. Earlier this spring I had a new top speed with top and windshield up of 68 so was more than happy with the performance.
Gene at 65 in a light fog:
Barreling past Humble Howard.
Rob - I have been seriously considering the Z head. I've read about the improved hill climbing ability with it. I'm not interested in going any faster, I just want to be able to get up the hills at a reasonable speed, especially if I have a couple passengers. The Z head seems to be an economical way to do that. But before that, I want to make sure everything else is in good shape and working at its best. Thus my work on the ignition system first.
I don't fault anyone else for using the Bosch plugs. But for MY car, changing back to the old style plugs made it start easier and it runs just as good.
BTW - I'm glad the forum is back up. It appears my previous post was the last one before it went down - I thought I broke it!
I was submitting this last night when the forum went down.....
I haven't run into one that wouldn't come apart........yet.......
Take them apart and be careful not to lose the copper gasket UNDER the porcelain.
Don't blast the porcelain. Once apart you can clean it.
You can use harsher methods to clean the body of the plug.
Steve wrote, "After double checking everything, I gave her 3 notches of advance, about 5 notches of throttle, pulled the choke, set it to battery and hit the starter". Nobody said anything!
I too am new at this but I have been told to "fully retard the spark" before attempting to start the motor, especially when hand cranking. Also I realize the spark control rod setting would make a difference. Is Steve okay with his procedure or is he taking a chance of backfire and possible engine damage? Should he recheck his adjustment to be sure the timing is set properly so the motor would start at the fully retarded position. I am asking this on behalf of Steve but also for my own information.
Steve,
Those X plugs of yours look better than mine did. See all the pits in mine?
Take those apart and clean the porcelains with some scotchbrite and a bit of gas. Then wire wheel the metal parts and shoot them with flat black to keep them from rusting right away, except the part that needs to make contact with the head.. Every 8 - 10 years you have to do it again to keep them from looking rusty.
James,
The spark rod setting will vary on different cars. Some can retard more than others. To be safe, all the way up is best (on battery). Starting on mag for me always requires several notches down on the lever. Also, if the car is cold or starts hard, a little "extra" advance will help the car start better, because the advance makes the spark occur at a better point in the combustion cycle, HOWEVER, WE KNOW WHAT HAPPENS WHEN IT IS ADVANCED A SMIDGEN TOO FAR!
Rob
One other source of poor power that can be missed is an intake leak. It is easy to undo the manifolds, clean the mating surfaces, place some quality gaskets, and be sure. It can make a big difference in performance.
I add another vote for the champ X plugs, and yours look like great candidates.
This perhaps has not been spoken to: Assuming you are running on all 4 and the timing is set right, the compression is good and the carburetor is properly set. The T should be able to pull a 6% grade about 22 MPH in high gear. It will settle in to that speed no matter how fast you approach the hill and keep right on chugging along. But, if you stop and try to start out again, you might need to use low gear. Anything steeper, will usually require a lower gear. If you need to pull a lot of hills in low, you should consider a Ruckstell or other reduction transmission.
There is one hill in Alpine, where I live which I can climb in either of my 26 T's with both Ruckstell and low pedal together. I haven't even tried in the 22. The cars with the gas tank under the seat, must be full or nearly full to climb some steep hills or they will die of fuel starvation. Some have resorted to using fuel pumps in such cases.
Good luck.
Norm
James R. - Your point about starting with a little advance is well taken. When I bought my car 2 months ago the seller showed me how to start it, including giving it a little advance. I raised the same question you just did. he told me that each car is different and that is what this car liked. So I've been following his advice. But that was with the Bosch plugs and worn out timer. I will try starting with it fully retarded and see how it goes now.
Royce - thanks, that's what I was hoping to hear. I think I read a previous post by you where you recommended using two sockets rather than holding a plug in a vice. Makes sense to use six point sockets so both hexes are gripped on all six flats.
Erich - good point also. I thought about that, but by the even color or the Bosch plugs and no other indicators of a manifold leak, I think it is ok. But I'll keep it in mind.
To touch on Gene's question about why platinum resistor plugs should not be used, I can only comment on the resistor part of the question. My previous experience was with motorcycles from the teens through the 1940s. Many old bikes have magnetos. Many of us found that the extra resistance built into resistor plugs (about 5K ohms, if I recall correctly) makes it more difficult for a spark to jump the plug gap. When using magneto or relatively low power 6 volt coils, this is just another factor that contributes to hard starting. Same goes for resistor wires. Another thing to remember is the old test of laying a spark plug against the head, kicking it over to watch for a spark, was not a reliable indicator. Air (in the gap) has resistance. Air resistance increases as pressure increases. So a plug that sparks ok laying against the outside of a head, may not spark well under compression where are pressure is raised significantly. My old Champion spark plug tester has a chamber that can be pressurized to simulate engine compression. It uses a model T coil to fire the plug and has a window and mirror so you can watch the spark. I've used it many times. It is interesting to watch the spark start out strong and bright at ambient pressure, but diminish as air pressure is increased. It is a very useful tool.
I'm new to model Ts and am learning a lot from you guys. I'm sure others can comment more on resistor and platinum plugs and wires.
I'm going to start on these old Xs tonight.
Steve
Preference is to use the vise to fix the top thread cap. Then turn off the large body from the plug. Saves damage to the porcelain, when two wrenches are used, the one that slips will be the one that cracks the porcelain.
Use good penetrating oil on rusty old Champion X's
Well the first X came apart easily and I started cleaning it up, but noticed a crack in the insulator, bummer. I set that insulator aside and continued to clean up the other parts. Hopefully I can salvage a good one from another plug.
The second one came apart easily also. I cleaned it up and everything looked in good shape. I blued the steel barrel and lock ring, polished the brass, put it back together and gapped it at .030". It looked pretty good. Here it is next to a couple of its dirty cousins.
The big test was to put it into the old Champion plug tester. I set it up with 55 PSI of air and fired it up. It sparked beautifully.
Of course the real test will be in the car, but I'm pleased with getting one ready. I have another one soaking in Kroil, as it did not want to budge and another one apart now and its insulator looks good. Enough for tonight, I'll continue tomorrow.
I was thinking about this last night and on my way into work this morning. Of the 3 plugs I took apart last night, each had a different combination of copper seals. Did Champion change what they used over the years or is this just the result of 70 + years of being taken apart and put back together wrong? Sorry I didn't take a photo of what I found, but there seems to be 1 or 2 thin copper cup washers and 1 small copper O-ring (not all had this). So what is the correct combination of parts and in what order do they go? I see in Dan's photo above there is a copper cup washer on the bottom (electrode) side of the insulator rib, should there be one above it also? Which side of the rib does the copper O-ring go? In the scanned text Dan provided it mentions "copper asbestos gaskets". The ones I've found so far appear to be just copper. Did these change over the years also? Thanks!
Yes indeed all the parts vary greatly over the last 90 years that Champion X plugs have been made. The newest ones only use a single copper seal. X plugs made pre - Kennedy administration have two copper seals, and those were made in a half dozen varieties. Some had asbestos string in there, some have asbestos under the copper ring. Be careful not to ingest any of the dust that might come from within the plugs.
Pay attention to which seals go with each porcelain. Some are not compatible with others.
Steve,
I lust after your plug tester. It's awesome.
I am relatively a newbie myself. I have owned a running T for only two years. The two smartest purchases I have made regarding my Model T fetish has been a crusty old set of Champion X plugs and a Strobospark coil tester from Fun Projects. Both purchases produced a noticeable increase in power and reliability. These two things really did give "the best bang for the buck". (pun intended)
Thanks Royce, that explains the variety I see.
Michael - I found the plug tester at a swap meet 20+ years ago for $20. Watch Ebay, they come up occasionally. A fellow forum member contacted me the other day. He has a strobospark and has offered to test my coils. He lives about 25 miles away so I'll be visiting him on Saturday.
I wonder if you would be better off with a gap of .025 instead? Just as good performance, longer coil/point life?
There is a Champion Spark Plug Tester on eBay now. Closes in 2 1/2 hrs.
http://www.ebay.com/itm/vintage-Dependable-Champion-Spark-Plug-Tester-old-texaco -station-/110957229410?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DRE C.CURRENT%26ao%3D1%26asc%3D27%26meid%3D2481725943169718886%26pid%3D100033%26prg% 3D1011%26rk%3D2%26sd%3D190731766082%26
Jim
Having a real spark plug tester would be nice, but for now, just a check on the HCCT works too. At least a nice fat spark in normal atmosphere, should be ok for the engine
Steve, what did you use to blue that plug with?
Tnx, Ken
erich - maybe, I'll play around with it after a get a working set of 4.
Ken - its Birchwood Casey's Perma Blue.
http://sport.birchwoodcasey.com/Finishing/FinishingDetails.aspx?ProductID=f046a1 2c-2249-4eb3-98a6-81a867399319
Available at most gun shops or sporting goods stores, maybe even Walmart. Degrease the metal, wipe on the solution with q-tip or rag, let it sit 30 seconds and wipe it off. Then rub down with light oil.
I use gun "cold blueing" on many T parts (spark plugs, intake, carburetor bowl,....). Looks good, stops rust for quite a while, easy to do. Available at most "real" sporting goods stores.
I wish to address the case against resistor plugs. It is not a simple "not recommended" item. Using resistor plugs or resistance spark plug wires can absolutely destroy your T coils! This is not an exaggeration. The coil is protected from internal arcing by the spark plug. When the plug fires it thus limits the spark voltage that the internal workings of the T coil is exposed to. If you are only concerned about the coils ability to spark a plug then just remember that the "effective gap" that the coil sees at the plug is the plug gap multiplied by the compression ratio in the cylinder. Since a T motor is about 4 to 1 compression a plug gapped at 1/32" looks to the coil as though the external gap is 1/8" (4 x 1/32 = 1/8). When a resistor is in series with the gap then the coil voltage must rise much higher to overcome the voltage loss of the resistance. Thus the gap that the coil sees is the summation of the plug gap multiplied by the compression ratio PLUS the voltage drop in the plug resistor PLUS the voltage drop in the resistor type spark plug wire if also used. The original author of this thread was very lucky not to have destroyed one or more of his coils by the use of the resistor plugs. I had a customer destroy all 4 of his new coils when someone told him modern resistance wire was the "hotter setup" for his ignition.
Resistance plugs and resistance spark plug wire are mainly used to reduce the radio frequency interference caused by the "jump spark" system used in auto ignition. AM radio and also FM radio to a lessor extent are interfered with by the spark system acting as an old fashioned "spark gap" transmitter as in the days of the Titanic. The spark plug wires will act like antenna without the series resistance to limit the radiated RF energy of the High Voltage ignition. There is absolutely no reason to use resistance wire or resistor plugs in your T unless you also have a high end stereo system in your T in which case you are on the wrong forum ha ha.
John - thanks for taking the time to explain this. Your explanation is clear and concise, far better than my feeble attempt. I hope my coils are ok, I'll find out this weekend when I meet up with a fellow model T'er who has a strobospark machine.
A few years a friend called me to come out and take a look at his Allis Chalmers C tractor......it wouldn't start.
It had magneto ignition so the first thing I checked for was spark, which was hot as hot gets.
Then I looked at the spark plugs which were resistor plugs. Even outside the cylinder the best the mag could produce was a dull orange spark at the plug.
I told him to ditch those plugs and everything would be fine.......and it was.
Those nasty old Champion X plugs clean up pretty nicely. Get the rust off and apply some bluing from the local gun shop and you're good to go. I agree with Royce on shopping for these. Keep your eyes open for them at auctions and swap meets and you can get all you need without spending a fortune.
G'day,
I will also back the loose manifold for loss of performance. I had recently had a day out with the wife in the "T". The car ran well but lacked her usual get up and go on the hills, had a spanner handy to tighten up a loose bolt I found and then checked the manifold nuts. I was suprised at how loose they were at first, then remembered that I have not checked them since installing new gaskets and glands. The car now runs like her old self again.
Peter
Nice plugs Steve, I'm making progress on mine. I notice on yours the threaded collar on the 2nd plug from the right is set a little deeper. Is that due to a different type or combination of copper seals? So far looking at mine, I've found 3 variations of the seals.
Peter - good point, I'll check my manifold bolts.
I had the opportunity tonight to test my coils on a strobospark. 3 out of 4 tested good with nice spark at 3 points on the strobo's display and no double spark. However, one coil was firing erratically at the 3 points. We tried adjusting it with no improvement. Fortunately I have 2 spare coils which both tested good. So I have a good set of 4 to put back in tomorrow. I also have 4 Champion Xs refurbished and hope to get one or two more. Making good steady progress!
"When a resistor is in series with the gap then the coil voltage must rise much higher to overcome the voltage loss of the resistance. Thus the gap that the coil sees is the summation of the plug gap multiplied by the compression ratio PLUS the voltage drop in the plug resistor PLUS the voltage drop in the resistor type spark plug wire if also used."
John, please help me understand something: Just before the plug fires there is no current flow through the wire or the plug. Therefore, the voltage out of the coil and at the plug should be same with resistance or without resistance. Once spark occurs, and the air in the gap is ionized the external resistance will come into play and reduce the current flow, of course. How could reduced current flow damage the coil?
Aftermarket series resistors were sold before Ts had radios. Go figure.
Been rainy here the last few days, so I haven't had a chance to get the car out. But I put 4 good coils back in and fired it up last night. Seemed to run well. I'll try to get it out this week and see how it does. I still have the Champion 25s/Motorcraft F-11 plugs installed. I want to try one thing at a time. After the test drive with 4 good coils, I'll put the Champion X plugs in and see if there is a difference.
Rick - the reduced current is not the issue - the issue is that the high voltage level at the coil have to be maybe double with resistor than without and with a little moist in the wood in the coil and you have internal arcing inside the coil. Once you have a carbon trace inside the coil - it's toast.
It might actually be that problem with the one coil that Steve found faulty that it is internally arcing because of the previous use of resistor plugs.
And that fauly coil may not be so faulty that it does not fire - it just doesn't fire at the right time or with the right powerful spark so that the petrol/airmix in that cylinder does not realy add to the power. You do not feel the misfire as it do fire, but it really does not work. That may just be the 4 horses so to speak you miss out of the potential 20 when you go uphill and be the difference from going up in high.
You are correct, Michael, the reduced current is not the issue. It's a simple series circuit. Since there is no current flow until the sparkplug arcs over, the voltage at the sparkplug is the same up to that point, with resistor, or without. There is voltage drop across the resistor only after the arc over, and the mixture in the gap is ionized. Then the arc path is relatively low resistance.
A series resistor should reduce the current draw from the coil. What is hard on a coil is wide gap that requires higher voltage to jump, then higher current due to that increased voltage, with still relatively low resistance in the gap, due to ionization.
rdr
Just passing this on. I saw a Champion spark plug tester (like the one discussed in this thread) on ebay for a good price if anyone is interested.
http://www.ebay.com/itm/FORD-MODEL-T-A-FLATHEAD-V8-1927-28-29-30-31-32-33-CHAMPI ON-SPARK-PLUG-TESTER-C2-/140868770526?pt=Vintage_Car_Truck_Parts_Accessories&has h=item20cc6edade&vxp=mtr