The engine lowest RPM possible

verrece

verrece

Senior Member
The CAFA "Club Amigos del Ford A" in Argentina organizes each year a meeting where participates more than 150 Ford A. (see the link below this thread)

In this event, there is a contest consisting in choosing the car with the engine running at the lowest possible RPM.

Do you know if Is there in USA that competition? and wich is the winner = the sustained lowest rpm obtained before the engine stops?

http://www.clubamigosforda.com.ar/menu_principal.html
 
If your engine is timed and running good, you should be able to remove three plug wires away from spark plug for no fire, and the fourth one remove about 3/8" from the plug and the engine should still run at a very very low rpm. it works I know!!! Do this with the engine running at idle while removing wires.
 
Dear all
Thanks for your answers, but nobody told me wich is the lowest RPM that we could run in our Model A engines.
Here in CAFA, the last winner runs at 180rpm with all spark plugs connected and the engine running at idle
 
verrece said:
Dear all
Thanks for your answers, but nobody told me wich is the lowest RPM that we could run in our Model A engines.
Here in CAFA, the last winner runs at 180rpm with all spark plugs connected and the engine running at idle
Click to expand...


I have never been in a contest but I am impressed with your 180 RPM score. My best measured RPM one one of my A's was 300 RPM. Adjusting the timing and fuel setting to idle slower than that would not allow me to drive the car normally.
Rainmaker Ron
 
I know its not a Model A, but my Daimler SP250 with its 2.5 litre hemi head V8 idles at 100rpm according to the rev counter which I've no reason to question.
It should idle at 600rpm but I've adjusted the idle control screw on the SU carburetors incorrectly
 
Timing is not the big issue in striving for the lowest idle RPM. At or close to TDC is good. The critical area is getting enough of the right fuel/air mixture into the cylinders to ignite reliably. First, this means no vacuum leaks! Obviously, the intake and carb gaskets have to be good. But also the throttle shaft has to be tight, not sucking air around the shaft. The intake valve stems and guides must not be worn. The ONLY way for air to get into the cylinders must be by going past the throttle plate, to get the right mixture. The throttle plate must be centered in the carb. bore so it can close completely with the idle speed screw backed all the way out. Needle and seat must be good, no dribbling. Float level must be right (may need to experiment for the best height). Begin by adjusting for the best idle at 500 RPM then back out the speed screw and keep readjusting the idle mixture as the speed comes down until it just won't go any lower.
You also need to check for slop in the timing and distributor gears and shaft so the timing doesn't jump around too much.
If you have a stock cam and flywheel, challenge the light flywheel and touring cam guys to a slow idle contest!!
 
40 Deluxe said:
Timing is not the big issue in striving for the lowest idle RPM. At or close to TDC is good. The critical area is getting enough of the right fuel/air mixture into the cylinders to ignite reliably. First, this means no vacuum leaks! Obviously, the intake and carb gaskets have to be good. But also the throttle shaft has to be tight, not sucking air around the shaft. The intake valve stems and guides must not be worn. The ONLY way for air to get into the cylinders must be by going past the throttle plate, to get the right mixture. The throttle plate must be centered in the carb. bore so it can close completely with the idle speed screw backed all the way out. Needle and seat must be good, no dribbling. Float level must be right (may need to experiment for the best height). Begin by adjusting for the best idle at 500 RPM then back out the speed screw and keep readjusting the idle mixture as the speed comes down until it just won't go any lower.
You also need to check for slop in the timing and distributor gears and shaft so the timing doesn't jump around too much.
If you have a stock cam and flywheel, challenge the light flywheel and touring cam guys to a slow idle contest!!
Click to expand...

If it has stock cam and flywheel, I would put an engine with NO flywheel against it any time. Been there and done it.
 
Tom Wesenberg said:
How could you get a 4 cylinder engine to run, much less idle with NO flywheel?
Click to expand...

Circle track race cars have no flywheel. You can start them either with a portable starter or by pushing.
Go to a track sometime and see them idle in the pits when they come in from the track out of gear. Contrary to popular opinion, a long duration race cam CAN be made to idle very slow in a slow idle contest.
VERY rough but slow.
 
I watched the video on your website. I didn't think Argentina was a right hand drive country. Why are most of the Model A's right hand drive?
 
Found my answer on Wikipedia:

Argentina
When the Pan American Highway from Alaska to Cape Horn was planned in the 1930s, it was decided it should use one side of driving its entire length. A few countries along the route used left-hand traffic, one being Argentina. On 10 October 1944 Decreto Nacional 26965 [50] was issued, introducing right-hand traffic in Argentina eight months later, on 10 June 1945. Strict speed limits kept the number of fatal accidents low after the conversion. 10 June is still observed each year as Día de la Seguridad Vial [51] (Road Safety Day) in Argentina.
Trains built by the British, as well as the Subte or underground railway in Buenos Aires, run on the left.
 
Wow Pete, none of my racing junk would ever run that slow with a light flywheel.

As far as a slow engine contest, a worn-out engine with low compression and a heavy flywheel can idle down very slowly but I'm not sure how to do an accurate determination of the exact RPM.
 
BRENT in 10-uh-C said:
Wow Pete, none of my racing junk would ever run that slow with a light flywheel.

As far as a slow engine contest, a worn-out engine with low compression and a heavy flywheel can idle down very slowly but I'm not sure how to do an accurate determination of the exact RPM.
Click to expand...

The easiest way to check rpm on any rotating part is make a chalk mark on the rotating part and look at it with a strobetach.
These are also handy for looking at valve spring flutter and rocker arm movement. With the proper setup you can see valve float also.
 
Last edited:
Anybody have an 'A' engine running in a test stand where you can pull off the flywheel and hand crank it? That would be an interesting video; to see if it would even start!
Maybe rig up an electric motor to spin the engine with a V-belt on the crank piulley so it will spin fast enough, or borrow one of those remote race car starters. Then see how it will go.
 
40 Deluxe said:
Anybody have an 'A' engine running in a test stand where you can pull off the flywheel and hand crank it? That would be an interesting video; to see if it would even start!
Maybe rig up an electric motor to spin the engine with a V-belt on the crank piulley so it will spin fast enough, or borrow one of those remote race car starters. Then see how it will go.
Click to expand...

A 1 inch drill motor with a socket adapter in the chuck will work fine.
 
Dear colleagues
The contest issue is to find the slowest rpm that a model a ford engine could run without any modification. The only part you can touch is the advance spark rod and the throttle screw. I did not say anything about to drive the car normally, the contest is with the engines in idle. As I said before, the last winner was at 180 RPM .
 
it wasn't a Model A, but a while back there was an event called a "Slow Race"... Several cars involved... The spark and hand throttle were all way up... the car was a 20's Buick, the driver got out of the car and slowly walked beside the car to win...Seen it done by the Buick several times....great event...
 
BrianBurkert said:
I watched the video on your website. I didn't think Argentina was a right hand drive country. Why are most of the Model A's right hand drive?
Click to expand...
Argentina changed from RHD to LHD on the 10 June 1945, along with the appropriate change in the side of the road to drive on. Since the A's were made before the change, they are RHD. Argentina changed so the Pan-America highway was consistent along its entire length. My Tudor came from Argentina and is RHD.
 
You must log in or register to reply here.
Back
Top