Timing a Model A

J

jiffy

Member
I timed my Model A by the book and I did not get that great Model A exaust sound, So I retarded the timing about 5% and it sounds great. But can that hurt the babbit firing 5% early from TDC. Thanks for the info. John
 
Consider asking another person to drive the car while you stand next to the road as they drive by. You might find that the car has the sound you desire, even when timed properly. They sound differently from the outside.
 
If you retarded the timing you aren't firing earlier you are firing later (less advance). So that is less stress on the Babbit...... So, the answer is no.
 
Duffy1 said:
What can happen if you run it retarded like this ?
Click to expand...
I believe two things will happen: 1. You'll have less power. 2. The engine will get hotter.

Here's a guess at why retarded engines run hotter. (Experts, feel free to correct!) When retarded, more cylinder wall is exposed to the flame because the piston has traveled farther down when the ignition finally occurs. Heat is then transfered to the coolant. If ignition extends beyond the compression chamber where it is designed to remain, everything else gets hotter -- valves, rings, piston, head.
 
Last edited:
The big question is do you want to drive the car, or listen to it idle? If you want to drive it, time it correctly, and enjoy the drive. If you just want to listen, set the timing where the sound pleases you best.
 
I knew a man with an AACA national show Model A who liked to let his engine idle VERY slow at the shows. He had the timing so retarded that you could count each cylinder firing. Everybody loved the sound. He never drove the Model A except off and on the trailer. That was one of the nicest and one of the most useless Model A's I have ever seen. No way it could have been driven on a tour with his "show" tuneup.
 
It's my understanding that if you run your engine in the retarded mode, it may put unacceptable stress on your crankshaft. I knew this to be true in Model Ts. Perhaps someone else can shed some light on this.
Rog
 
If you dont have the correct muffler or have a higher comp head and/or reground cam,it will affect the sound. retarded timing will put less stress on the crankshaft but will make the engine run hotter & have less power.Set the timing exactly the way its supposed to be and you will have the best performance.Do you want to use the car or listen to the retarded timing?
 
Thanks for all the comments. I really do want the best running engine. I also want it to soung like a Model A should/ And most do sound the same. Mine was quieter and there was some concern that it was not running correctly. Sounds good now. I will keep a watch on it. Thanks, John
 
The "model A sound" that many of us are accustomed to is false. It is loud and tinny, caused by the cheap, incorrectly and poorly made repro mufflers we have been using for 30 or 40 years. A model A fitted with an Aries muffler will sound like a model A did when new, but will not sound like the "model A sound" most are accustomed to. It is quiet, and runs cool. It is all a matter of what you want. If sound is most important, the cheap midas muffler is the one to have. I have thrown away several in the past few years.
 
Duffy1 said:
Will running retarded cause carbon to build up ?
Thanks
Click to expand...

Probably not. I have noticed that since the lead was no longer added to fuel the plugs and pistons don't have all the deposits they used to have.

Retarded timing will cause loss of power, poor fuel economy and overheating.
 
Tuning for sound????? The ACID test to know if timing is correct: Adjust carb idle speed nice & slow, adjust idle mixture screw for best & smoothest idle with spark retarded THEN, on retarded idle, it should run rythmical, like tada, tada, tada, tada! On 1/2 advance, idle will be faster & smooth. On full advance, idle will be faster still, but a slightly rolling idle. If you have these sounds, DON'T MESS WITH IT! ITS AS PERFECT AS YOU WILL GET IT!!
Timing only changes if your point gap closes up, then reset the point gap correctly, and timing will be correct again.
Don't listen to too many timing "tales" as there are many that don't know "doodley" about what works properly! Bill W.
 
You must log in or register to reply here.
Back
Top