1923 roadester eng noise

kwisor

kwisor

Senior Member
hello all
i have a 23 roadster the motor and trans was rebuilt about 8 years ago it runs great but i have a slite knock when i have the timing rod set where it runs best. when on a hill it will stop only when cursing. if i retard the timing just a little the noise will go away any ideas what that may be
kevin
1923 model t roadster
1930 model a tudor
 
Yes you should retard the spark so it doesn't knock. your modern car does this for you. My shop teacher said ignition knock = bearing abuse.
 
You know Kwisor, while a "spark knock" is a possibility I've never heard of any T'er actually complain about it as an incorrect spark lever position. A noise like that is almost uiversally associated with a bearing or wrist pin or something mechanically loose. Now since it only happens under certain conditions while driving, unless you or some one who knows can diagnose what that noise is it'd be difficult to pin down. Especially if it won't occur when your standing still where it's easier to listen for or pin point. My '23 did some thing similar. That is a noise only under certain driving conditions. I'm not good enough to diagnose it but there are people that can. In the mean time I didn't worry about it as I was able, as you can, to make it go away. I didn't have the car long enough for it to develop into any thing worse and perhaps it never would but there you go. If you know some one knowledgable have them listen to it at least you'll find out what's happening.
 
It is good practice to adjust the ignition timing to suit various road conditions,such as climbing hills,descending hill,high speeds,ect.as mentioned above modern ignition does this for you.Phil
 
One other thing: a spark knock has a noise similar to marbles being rattled around in a tin can any other thumping is some thing else.
 
The low compression ratio of a model T does not usually make spark knock or "pinging" likely, but if retarding the spark slightly makes your car happy, by all means do so. Driving a T means the timing is always your job. In a modern car the timing is retarded automatically under heavy load or low RPM by the centrifugal and vacuum advance mechanisms or the computer. It is normal to retard the spark just a little when a T engine is working hard for best performance. Under those conditions you will notice less noise and more power if you back off the spark advance some. This is normal. If the problem is a loose rod bearing or wrist pin it will be noisy under low load conditions. A main bearing problem creates a heavy thump under load. I think you should just retard your spark to suit conditions as you have been.
 
I have a hill here that runs for about a good mile and starts off at a stop sign. I usually find myself cursing at about the 2 block point, but being a timing condition, the Pollinator starts to "buck" and lurch a bit. Ill retard the spark 2/3 of the way up and she'll just chug up the hill. I may only get 8-10 horses out of her max, with no difference on the throttle position. personally, I think you need to have a peek at the rod bearings.
Main bearings will rumble on a flat road at speed (usually faster= more rumble) and a rod will tap at a higher speed lightly loaded, as in topping out in low gear or cruising on the flat with little or no throttle change. If changing the throttle up or down a tad quiets it down, you'll need a bearing adjustment. ws
 
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