Ford's Quadricycle Engine

[Rdean33422]

I made up the exhaust valves and some head gaskets today.


I always make extra gaskets it's so easy to damage them.



Here they are installed on the engine.



Thanks for looking
Ray

 

[Rdean33422]

Not much shop time lately with the cold weather but I did get the rocker arm cut out of 0.200 aluminum plate.


I started on the other pieces for the valve train but didn't get very far.

Thanks for looking
Ray

 

[Rdean33422]

These are the pieces for the rocker arm.
Yep that was a 1/2" bolt with two nuts reduced in width for the center stand.


Arm installed and the valve timing set.


I started with the push/pull timing gear connector attached to the large timing gear at a radius of 0.375. I had no idea just where it should be so I errored on the side of it being too much. It really was too much so I moved the pivot to 0.180. That was better but still too much. I ended up with a radius of 0.100 and that is just right.
Getting all the pieces adjusted so that each side of the rocker arm has the same lift was an adventure. I wanted a valve lift of about 0.070 but adjusting the push rod would effect both sides and if I had to move the center pivot distance that would change the push rod adjustment too. So it was a back and forth of adjust, adjust, and adjust again. When done I really tightened the center pivot bolt and I hope I don't have to ever move it again.

Thanks for looking
Ray

 

[Steamchick]

I guess H. Ford had the same experience?
A lot of empirical "tuning" - just to get to a condition you think will be correct - just to find that things are not as expected and iot doesn't work, so then lots of trial and error to get to a working condition.
I would have guessed that a drawing or a few calculations should have given you a closer "starting point" (Radius of 0.100" instead of 0.375" ?)? - But you got there anyway.
Well done Sir!
I am learning a lot about this engine. - Fascinating!
K2

 

[Rdean33422]

K2 the really interesting part is yet to come.
The ignition system is next.

Ray

 

[Steamchick]

Looking forward to it. I thought the valve gear was a bit unique!
H. Ford did have a way of taking a simpler route than many to achieve the same ends. My first experience of Fords was with 1960s cars, which compared to others had a lot of little clever simple alternative ways to do various things.
Henry Ford loved "simple, effective and cheap". A great friend and companion to Eddison, who wanted "a thousand patents so I can find the one to make me a millionaire" - or something?
They lived and built their Engineering empires on innovation, study, trial and error.
K2

 

[Rdean33422]

The ignition system will be next on the list.
The circled part below had me stumped. Just what is it and how does it work. It has no wires connected to it and in looking at several different engine builds it is completely disconnected and sometimes with out the springs.


I found this article in Popular Science from June of 1963 by George De Angelis where he was given access by the Ford Museum to the original Quadricycle and the engine was partially dissembled.
Here are his words from the article.



My engine won't have these but instead will have a CDI module with a hall sensor and a magnet attached to the flywheel.





This is only half the story and Ford came up with a elegant solution.
One ignition coil can not have two spark plugs connected to it in series or parallel. It can not reliably direct the spark to the correct plug and since one of the plugs would be on the intake stroke that plug would have an easier path to ground and would spark there not the one on compression where it is needed.
The wood block attached to engine has a center pivot post. The output from the ignition coil is attached to this post. It has a metal arm that pivots on it and it is not insulated from the post so in effect the coil is directly attached to that arm. The arm is moved via an insulated strap that is attached to it and the rocker arm so it moves with the rocker arm. There are two metal straps attached to the board with one plug wire attached to each one. When one of the pistons is close to TDC the arm has moved so that it presses against the end of the metal strip for that cylinder. It acts as a closed switch. When the ignition module fires there is now a complete path for the spark to travel to that plug. The opposite end of this arm is not touching the other metal strip so it acts like an open switch.
When the other piston comes up on compression the same thing happen but now the switches have been reversed.

That's the next part to build.

Thanks for looking
Ray

 

[Steamchick]

I had guessed that the rocker arm was used somehow as a High tension disributor... or maybe something attached to the push-rod, but maybe the push-rod and rocker are near mid-stroke when the spark fires?
There are a number of twin motorcycles that use "redundant spark" - with coils that have 2 HT cables from a single coil. The cylinder at "atmospheric" pressure (towards the end of the exhaust stroke) easily passes the spark at a couple of kV, so the large majority of the 25kV or so generated by the coil can still fire the Compression stroke spark plug. But those 2 plugs are in Series on the HT circuit. You are right that a parallel-HT-cable & spark-plug arrangement on the HT circuit would ONLY fire the un-compressed plug, as the resistance in the cylinder approaching max compression has a far greater resistance to spark voltage.
K2

 

[Jasonb]

The parts with the springs on are part of the Ignitor. It is grounded so no earth wire needed. Most hit and miss engines have the ignitor as one and actuated by the exhaust push rod.

On the Ford the fixed anvil (insulated) is the one where the the braided cable goes to. And the horizontal bush is what the hammer pivots in and is held open by the spring. The braided wire does not go to a spark plug

The ignitor contacts were held shut by the spring. As the rocker moved it completed the circuit as the piston was coming upto TD and the Low Tension coil was energised. This is like the exhaust push rod closing teh anvils on a traditional ignitor.

There was a post on the piston crown which actuated the rocker within the cylinder space and opened the circuit just before TDC which caused the spark to jump and fire that cylinder.

The rocker arrangement would ensure that only the correct cylinder got the circuit made so no wasted spark

 

[Rdean33422]

Excellent that explains it and it makes sense now.
Thanks Jason

Ray

 

[a41capt]

Things are looking great Ray. I love the use of ignition system technology to ensure a running model. I can’t imagine building Henry’s make and break system in model scale!!!

John W