My T is hard to start because I am using a Z head and the 6V battery at 6.40V isn't enough but starts right off using a 400 amp booster such as a Schumacher booster. what are the down sides of using such a booster other than it is unhandy?
these boosters are available for about $100 at parts stores.
Ed: if you are using a Z head why not mount another 6 volt battery of the same CCA rating in parallel (positive to positive and negative to negative) this will double the amperage of the batteries giving you much more power at the same voltage without damaging anything?
The Z head gives no trouble hand cranking and shouldn't strain a good starter, so no need for extra batteries or boosters if wiring and parts are OK.
The battery should be load tested - maybe it's shot? Another problem may be bad contacts for the wiring - check for hot spots after cranking with the starter for a while. Often the earth connection or the start contact needs some attention.
I can start a Hemi on my '53 Chrysler with a six volt battery so something else must be causing the problem. Bad ground, bad starter or possibly a weak battery but there is no reason it won't start well with a six volt system.
I agree with G.R., Roger and Val. The problem is not your Z head. Check all connections from the battery to the starter, especially ground connection at the battery and at the starter. Think about the problems that could interfere with a ground at the starter. There is a gasket between the starter and the hogshead insulating the starter from ground especially if a heavy coating of gasket sealer was used and the mounting bolts got coated with sealer as they were turned in and tightened. Many people have added another ground strap from the engine block to the frame because paint on the frame rails between engine mounting points can insulate from ground. If all connections are good and heavy enough wire is being used have the starter checked.
I can start my engine via hand cranking and I have a Z head, I use a stock 6 volt system with wooden coils, and I use a Holley vaporizer. I could not hand crank the engine when I had the Kingston vaporizer on because it was not sucking up fuel very well - I would have to use the electric starter for that - even then, it would not fire right up. I don't think it has anything to do with the Z head or the 6 volt system. I would go with the ideas that Val suggests and even go as far as seeing if your carburetor is working properly.
Ed,....The starting problem with your 1915 touring is because your cowl and tail lamps don't have a brass top of the chimneys !..;o) ...All seriousness aside, I agree with the dead battery cell suggestion. Low cranking amps. The starter motor should be grounded to the block with the 4 machine screws.
Anybody have E&J brass tops (3) for a '15 they'd sell ??
A wore out starter can draw so many amps with drag.I would suggest using a gauge that slips over the wire and call Ron Patterson with your readings.Bud.
There seems to be a common theme so far. The gist of it is that the desire to "spin faster" is based on the mistaken assumption that a Model T engine needs to turn over rapidly to start. The gist is correct, and the assumption is wrong. With the correct mixture of fuel, compression, and spark, it will start with a slow pull of the hand crank. No "spin" needed. Hard starting is not caused by slow turning.
Ed, DO NOT measure that battery voltage when it is just sitting there, measure it when the starter is engaged and placing a normal load on it.
Then measure the voltage between the starter terminal and a good engine ground.
You could be losing half you voltage in the starter switch or cables, if they are not 00 or 2/0 Gauge cables, although 0 or 1/0 Gauge were original, these are 10 % better.
Otherwise your battery is getting old and low.
A friend has a 1921 with a Z head that turns over faster than my 1926 with a stock head.
Yes, should start easily with 6 volts. Don't make the mistake so many others do and blame the hard starting on the 6 volt system. Find what is broke or worn out and repair it.
Running on with Tim's notion!
I have a very slight grounding issue with the starter on my 18 with a 23 engine. I've seen a small spark where it almost touches the frame. :-)
With that said, I was absolutely AMAZED at how fast the engine turned over when I pushed the switch down! 6 volt!
Yeah, it's my first starter. :-) New valves, pistons, rings and a stiff engine!
Like folks around THOSE tables, I'm Duane, this is my first starter. :-)
I also used to think that the 6 volt system was antiquated/not up to par after starting a late 40's IH truck that cranked over soooo slowly.
My buddies IH is a temperamental beast. My 18 T with a 23 engine is not. :-) Starts so nice. :-)
Ed, when you find the problem, let us know. :-)
I would agree a T should not need to spin fast at all to start.I have heard and i think experenced starters drawing so much power there was none left to fire the points.Could this affect a model T? Bud.
As shown in other post about starters, the post is only riveted to the buss bar and often over the years has come loose making for a bad connection. You might check yours and if loose silver solder in in place.
I have read all of the above posts and find myself wondering:
For how long have you been using the Z head and more importantly: how did the engine start BEFORE you installed the Z head?
Did it start "kinda OK, but not great" and now it is much harder to start? Could there be some fundamental hard starting issues present before the head change and they have now been exacerbated? In other words the high compression head is now emphasizing other problems. Good luck with your project, Bill.
For what it's worth I have had the starter drain so much juice there wasn't enough to fire a coil on many cars. Normally a bad connection or sickly battery.
There is no mention of what system is in use for the sparks.
The TrueFire is basically a 12 volt system and needs all the voltage that is not always there to operate with the built in 6 volt doubler circuit.
It gets a lot of bad publicity from bad cables and batteries.
I did 4 valve jobs and replaced the engine in my first Model T, as it was very difficult to start and had very little power when running. It came with a rebuilt engine installed and should not have needed any of my attention. The valves always looked good too.
Then I realized that two items had never been changed out and I had not paid much attention to their condition. They were the coils and the carburetor and all were bad.
Then I learned that coils normally need more than new points.
I had a totally easily starting and different running engine with those repairs made.
I had one of those foreign made starter swithes on my '22 roadster and it would hardly crank. Rewiring didn't help much. When I finally replaced the switch with another repro it cranked like it should. This new switch was advertised as better quality. Looking at both repro switches, they look exactly alike. When I replaced the old battery with an Optima 6 volt one it cranked even better.
Some of the more electrically talented guys here on the forum might want to chime in here, but as I understand it, a 6 volt battery measuring only 6.4 volts is basically a "dead" battery in terms of what the starter needs. A good 6 volt battery with a full charge and no load on it should measure around 7.2 volts, and believe me - the starter will notice it! I've proved it to myself with my own cars on several occasions.
As it has been so eloquently stated by others above, you gotta make sure about cable size, tight connections, a good starter with a soundly soldered cable lug, good clean ground, good switch, ad nauseum.
Hi, thanks everybody -except George House-George-thanks for the brass cowl light lens rings- that's halfway or something else halfway..
as to "the problem" everything is good leading to the starter-new battery, 6.40 V, 125cc, proper cable size, clean terminals, new switch and engine to starter ground cable. The voltage from starter to ground with starter running is 4.95/5.00V digital. The compression is 65/70 psi cold. When the crankshaft approaches TDC it appears to stop-then after a time commences to turn and then after a few of these cycles the engine starts. It appears the starter is not providing the torque it should with the available power but is lively with a "booster". the plan now is to pull the starter. I did run and complete the Texas T party Tour in October and only used a booster once and never hand cranked.
Your battery is dead and you probably have a voltage drop on the ground side.
Ed, I'm trying to get someone to send you brass chimney tops for your '15 cowl and tail lamps. Take your 6.4 v battery to someone who can load test it. (O'Reilleys or AutoZone) I still believe it's a dead cell. You can still have satisfactory voltage with a dead cell.
The digital meter is the problem with the reading.
You need an analog meter with a dial and pointer for an accurate measurement.
how is a digital voltmeter inferior to analogue when measuring battery voltage?