Free Start
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
-
Topic author - Posts: 4072
- Joined: Tue Jan 08, 2019 1:39 pm
- First Name: Norman
- Last Name: Kling
- Location: Alpine California
Free Start
Richard G says free starts are hard on cranks. Why? and How? I can't see how it would be any harder on it than starting with a crank or starter?
Norm
Norm
-
- Posts: 6796
- Joined: Fri Jan 04, 2019 10:51 am
- First Name: Richard
- Last Name: Eagle
- * REQUIRED* Type and Year of Model Ts owned: 1909 TR 1914 TR 1915 Rd 1920 Spdstr 1922 Coupe 1925 Tudor
- Location: Idaho Falls, ID
- MTFCA Number: 1219
- Contact:
Re: Free Start
I don't see either. It isn't firing under load. Going up a hill would seem to be harder on it but I'm no Fizasist. <;Oo
Rich
Rich
When did I do that?
-
- Posts: 2786
- Joined: Sun Jan 06, 2019 12:26 pm
- First Name: Dallas
- Last Name: Landers
- * REQUIRED* Type and Year of Model Ts owned: 26 Rpu, 23 TT, 24 coupe,
- Location: N.E. Indiana
- MTFCA Number: 49995
Re: Free Start
I think it has something to do with the "shock" to the crank when it fires without revelution started. I think it was discussed last year in a thread. I could be all wet to.
-
- Posts: 1922
- Joined: Sun Jan 06, 2019 11:23 am
- First Name: Rich
- Last Name: Bingham
- * REQUIRED* Type and Year of Model Ts owned: 1913 runabout
- Location: Blackfoot, Idaho
Re: Free Start
Dallas, that's the explanation that was given on that thread as I recall it. Like Rich, I find it hard to believe either that the stock T crank is not robust enough to absorb the impulse of a free start, or that it amounts to a great deal more sudden torque than hand cranking or engaging an electric starter. For one thing, ignition of a cylinder charge of fuel mixture doesn't result in an "explosion" but a radial "burn". When it comes to broken crankshafts, I'd think running for extended periods mis-timed, with intermittent "missing" as might be the case with a bad coil, high compression heads and loose rods may in part contribute to hastening the failure of century-old forgings. JMHO
"Get a horse !"
-
- Posts: 311
- Joined: Sun Jan 06, 2019 1:36 pm
- First Name: Colin
- Last Name: Mavins
- Location: Winnipeg Canada
Re: Free Start
Our 1912 free starts all the time,and has been doing it since 1960, now I did break the crank after 103 years. I think after 103 years it just got brittle, even cold if I pull it over once and then turn it on it starts. So I can't see free starts breaking a crank. Just my opinion Cheers From Winnipeg
-
- Posts: 18
- Joined: Sun Jan 06, 2019 1:26 pm
- First Name: kenneth
- Last Name: bechtel
- * REQUIRED* Type and Year of Model Ts owned: 1924 tudor
- Location: PA.
Re: Free Start
The electric starter probably gives a harder jolt than a free start . just thinking again .
-
- Posts: 2345
- Joined: Sun Jan 06, 2019 11:25 am
- First Name: Dave
- Last Name: Hanlon
- * REQUIRED* Type and Year of Model Ts owned: 24 Touring car
- Location: NE Ohio
- MTFCA Number: 50191
- Board Member Since: 2018
Re: Free Start
I can think of a dozen malfunctions and/or operator errors that I would say are harder on a crank than a free start.
My old man, once in a while, in a parade at too slow a speed, would let the clutch out into high and throttle it up and make the car buck like a rodeo steer !!
I don't think the crank has been changed in 50 some years...
My old man, once in a while, in a parade at too slow a speed, would let the clutch out into high and throttle it up and make the car buck like a rodeo steer !!
I don't think the crank has been changed in 50 some years...
-
- Posts: 463
- Joined: Mon Jan 07, 2019 12:32 am
- First Name: Erik
- Last Name: Barrett
- * REQUIRED* Type and Year of Model Ts owned: 1913 speedster 1924 touring 1925 dump truck
- Location: Auburn, Ca.
Re: Free Start
Can anyone here say they have broken a crank or seen it happen during a free start event?
-
- Posts: 726
- Joined: Sun Jan 06, 2019 5:42 pm
- First Name: Matt
- Last Name: G
- * REQUIRED* Type and Year of Model Ts owned: 1926 Touring, 1926 Fordor Project, TT C-cab flatbed farm field find, TT dump truck project
- Location: California
- MTFCA Number: 30697
Re: Free Start
Erik we have a logical problem here. If the engine breaks it is not free;)Erik Barrett wrote: ↑Fri Feb 08, 2019 2:37 amCan anyone here say they have broken a crank or seen it happen during a free start event?
-
- Posts: 83
- Joined: Mon Jan 07, 2019 9:22 pm
- First Name: David
- Last Name: Houston
- * REQUIRED* Type and Year of Model Ts owned: 13,14,19,21,&etc
- Location: WNC
- MTFCA Number: 32227
- MTFCI Number: 23901
Re: Free Start
Mine broke going up a hill, going from low pedal to high pedal when I pulled the throttle down.(broke the crankshaft,bent the rod and the rod hit the camshaft and bent it)
Pops
Pops
-
- Posts: 71
- Joined: Sun Jan 06, 2019 1:21 pm
- First Name: Bill
- Last Name: Coyle
- * REQUIRED* Type and Year of Model Ts owned: 26 Roadster
- Location: Port Clinton, OH
- MTFCI Number: 24067
Re: Free Start
My thought is "what was happening at the time it broke" was only the final straw which broke the proverbial camel's back. When I Magnafluxed the crankshaft from my '26 roadster's worn out sawmill engine which had been sitting for many years, I found 4 cracks. The other interesting fact was the crank measured .030" runout (TIR) on the center main with the 2 end mains on V blocks. It had probably taken a set over the last 50 years resting in bearings that were likely adjusted for clearance but ended up .015" out of alignment. In this case, I'm guessing rotary fatigue caused by misalignment played a big part in propagating the cracks. Well, needless to say, I did not use that crankshaft.
The Model T crank encounters a lot of stress over it's life, and cracks, if they start, continue growing until that final straw is added. Bill
The Model T crank encounters a lot of stress over it's life, and cracks, if they start, continue growing until that final straw is added. Bill
-
- Posts: 463
- Joined: Mon Jan 07, 2019 12:32 am
- First Name: Erik
- Last Name: Barrett
- * REQUIRED* Type and Year of Model Ts owned: 1913 speedster 1924 touring 1925 dump truck
- Location: Auburn, Ca.
Re: Free Start
Nothing free about a broken crank.
-
- Posts: 1431
- Joined: Fri Jan 04, 2019 1:53 pm
- First Name: Rob
- Last Name: Heyen
- * REQUIRED* Type and Year of Model Ts owned: Models B, F, K, N, Ford racer and 3 Model T
- Location: Eastern Nebraska
Re: Free Start
This was Ford's position on free starts, in 1907.
Also good advice when meeting a horse:
Also good advice when meeting a horse:
-
- Posts: 1922
- Joined: Sun Jan 06, 2019 11:23 am
- First Name: Rich
- Last Name: Bingham
- * REQUIRED* Type and Year of Model Ts owned: 1913 runabout
- Location: Blackfoot, Idaho
Re: Free Start
Rob, thank you much for posting that from the Model K manual.
So, according to Ford, a "start on the spark" (aka a "free start") can break a crankshaft, but then it's stated that "Ford shafts are extra heavy to meet this condition . . ." So they ain't worried ? and so it's up to you ? Was this before vanadium steel ? Does that matter ?
(Still good advice regarding horses ! )
So, according to Ford, a "start on the spark" (aka a "free start") can break a crankshaft, but then it's stated that "Ford shafts are extra heavy to meet this condition . . ." So they ain't worried ? and so it's up to you ? Was this before vanadium steel ? Does that matter ?
(Still good advice regarding horses ! )
"Get a horse !"
-
- Posts: 146
- Joined: Sun Jan 06, 2019 2:46 pm
- First Name: Neil
- Last Name: Kaminar
- * REQUIRED* Type and Year of Model Ts owned: 1915 Touring
- Location: Mebane, North Carolina
- MTFCI Number: 22425
Re: Free Start
All the broken cranks that I have seen on the forum were cracked before they broke and all had the signs of fatigue failure. None showed a sudden break because of a heavy load or torque. A fatigue failure is caused by repeated back and forth bending, just like breaking a paper clip by bending it back and forth for a while. The free start is a one time load on the crankshaft and not a back and forth bending. Whether the load from the free start is enough to stress the crank or not, it is not a source of fatigue failure.
There has been lots of speculation on the forum about the source of the back and forth bending that leads to the fatigue failure. Mis-alignment of the 4 main bearings has been brought up over and over. Another possible source of the back and forth bending is the periodic power pulse, especially when lugging the engine. My personal thought is that there is a natural frequency twisting in the assembly of the crankshaft, rods, and pistons. Right around WW II dampeners were added to the front of crankshafts on 6 cylinder engines to keep the torsional vibration in check to prevent the crankshafts from breaking.
If your crankshaft has 40,000 miles on it, the crank has been twisted back and forth about 200 million times.
There has been lots of speculation on the forum about the source of the back and forth bending that leads to the fatigue failure. Mis-alignment of the 4 main bearings has been brought up over and over. Another possible source of the back and forth bending is the periodic power pulse, especially when lugging the engine. My personal thought is that there is a natural frequency twisting in the assembly of the crankshaft, rods, and pistons. Right around WW II dampeners were added to the front of crankshafts on 6 cylinder engines to keep the torsional vibration in check to prevent the crankshafts from breaking.
If your crankshaft has 40,000 miles on it, the crank has been twisted back and forth about 200 million times.
-
- Posts: 6431
- Joined: Sun Jan 06, 2019 11:18 am
- First Name: Scott
- Last Name: Conger
- * REQUIRED* Type and Year of Model Ts owned: '13, '15, '19, '23
- Location: Clark, WY
- Board Member Since: 2005
Re: Free Start
I would suspect that misaligned 4th mains and worn out 4th mains, period, are one of the biggest contributors to crankshaft stress and ultimate failure.
Scott Conger
Tyranny under the guise of law is still Tyranny
NH Full Flow Float Valves
Obsolete carburetor parts manufactured
Tyranny under the guise of law is still Tyranny
NH Full Flow Float Valves
Obsolete carburetor parts manufactured
-
- Posts: 353
- Joined: Sun Jan 06, 2019 10:29 pm
- First Name: Richard
- Last Name: Grzegorowicz
- * REQUIRED* Type and Year of Model Ts owned: 1921 T pickup
- Location: Hartland VT
Re: Free Start
THANK YOU ROB! you guys can inject all your this and that's on this subject why then is the t the only one born with this problem. I just read ROS post, that says it all, don't it .i'm going to bed with a big SMILE.
-
- Posts: 178
- Joined: Mon Jan 07, 2019 1:12 am
- First Name: Raoul
- Last Name: Vaughn
- * REQUIRED* Type and Year of Model Ts owned: 1925 truck
- Location: Egypt, Wa.
-
- Posts: 21
- Joined: Sat Jan 12, 2019 5:47 am
- First Name: samuel
- Last Name: pine
- Location: dighton mass.
- Board Member Since: 2004
Re: Free Start
Things or anything could break or snap caused by shock more so when cold. With its low compression a free
start won't hurt anything. High gear lugging not good for any engine. I have been doing this since I was a kid,
take a ride engine running at its sweet spot. Stop it.> don't retard it put to idle & shut down, turn key to batt then
retard spark then instant start 9 out of 10 times. Even after after days turned key retard it instant start.
The modern new junk snaps cranks too don't ya know. Remembering back in the 70s we had about 60 Gmc
school buses with 350 gas and with their massive crank pulleys they would snap right behind the timing gear,
these were new buses so, gov't motors paid for that.. Told my uncle he should have bought Fords with the
HD 391 FTs....... just rambling again............sam
start won't hurt anything. High gear lugging not good for any engine. I have been doing this since I was a kid,
take a ride engine running at its sweet spot. Stop it.> don't retard it put to idle & shut down, turn key to batt then
retard spark then instant start 9 out of 10 times. Even after after days turned key retard it instant start.
The modern new junk snaps cranks too don't ya know. Remembering back in the 70s we had about 60 Gmc
school buses with 350 gas and with their massive crank pulleys they would snap right behind the timing gear,
these were new buses so, gov't motors paid for that.. Told my uncle he should have bought Fords with the
HD 391 FTs....... just rambling again............sam