How fast should I drive?

Maclab58

Maclab58

Well-known member
I just put a new touring engine from Antique Engine Rebuilding in my 28. I Have about 300 miles on it now and it runs great but Im a little concerned as to what the top speed that is safe to drive it. I have hit 60 a couple of times on a short burst but the engine seems to have more room to go. Is there a point where I shouldnt push it past? Im new to A's so any suggestions? BTW, stock trans and rearend, the engine has a balanced crank, insert bearing and Chevy pistons and a lightened flywheel.
 
I would push a new engine to 60 miles per hour with original gearing. Give it time to break in. Also can you stop at 60?
 
Going that fast on a new engine doesn't sound like a good thing to me. They need to be broke in and have the rings seated before pushing them that hard.
I would check with your engine builder and get their recommendations on driving speed and duration of the break-in.
That being said, a stock Model A is said to have a TOP speed of 60mph. You might get a little more RPM with the counterbalanced crank, but without a grearing change or an overdrive, your not going to get much more speed. It is not a good idea to run the car at top speed for very long. Mine is all stock and it likes to run @ 45mph.
Also make sure you have the brakes to stop if you plan on going this fast!!!
 
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My "A" (stock counterbalanced B engine, 3.54 rear end) seems to like 55. Much faster than that there is a problem with the fenders acting like airplane wings. This combined with a large side area make passing 18 wheelers and canyons that cross the highway dangerous.

Charlie Stephens
 
Maclab58 said:
I just put a new touring engine from Antique Engine Rebuilding in my 28. I Have about 300 miles on it now and it runs great but Im a little concerned as to what the top speed that is safe to drive it. I have hit 60 a couple of times on a short burst but the engine seems to have more room to go. Is there a point where I shouldnt push it past? Im new to A's so any suggestions? BTW, stock trans and rearend, the engine has a balanced crank, insert bearing and Chevy pistons and a lightened flywheel.
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Your running it to fast, to soon. No faster than 40-45 for the first 1000-1500 miles. After that you can gradually increase your speed. After 1500 you can run it 60 if you want. People will tell you thats way to fast and all that stuff. But if you have the brakes to stop you, you will be fine. We have the antique engine rebuildings stock rebuild with stock rear end and trans in a fordoor sedan and I once ran it 70mph for 86 miles. It will do it, but give it time to break in properly, let the rings seat and bearings break in then you can run it hard.
 
Maclab58 said:
I just put a new touring engine from Antique Engine Rebuilding in my 28. I Have about 300 miles on it now and it runs great but Im a little concerned as to what the top speed that is safe to drive it. I have hit 60 a couple of times on a short burst but the engine seems to have more room to go. Is there a point where I shouldnt push it past? Im new to A's so any suggestions? BTW, stock trans and rearend, the engine has a balanced crank, insert bearing and Chevy pistons and a lightened flywheel.
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"60"! Hmm, ever ride in a car where you had the feeling that the driver was going too fast and mabe the speed was excessive:eek:? And, at that time, did you think of what condition the major components of that car might be in? And, can you imagine a car that has the aerodynamics of a (large)barndoor barreling down a highway....and along comes ole MURPHY:eek::eek:! Oh, you don't know him? Well, let me introduce him!!
 
Will heed the advice will keep it to 40-45 for 1500 miles. It is just so fun to drive. Some of my non model A buddies make fun of it calling it a POS. I think they just wish they had one.
 
Maclab58 said:
... Is there a point where I shouldnt push it past? Im new to A's so any suggestions? BTW, stock trans and rearend, the engine has a balanced crank, insert bearing and Chevy pistons and a lightened flywheel.
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Have you asked the engine rebuilder what his recommendations are?
 
Have you pain up your life insurance? Like suggested above these old cars may have other possible problems other than the engine that could cause your wife to collect on your life insurance.
 
Well, it's already too late. By driving 60 :eek: during the break-in period you have voided the warranty! :D LOL

I think it would be good to stay under 35 for the first 200 or 300 miles, then 40 for another 300 miles, then 45 until at least 1,000 miles are reached. I really don't like driving faster than 45 any time, but you should be OK to 55 once 1,000 miles are reached, especially since you have a counterweighted crank.
 
With todays roads and drivers..I have a hard time driving the lower speeds..thats why I went with a counter balance crank and all the other goodies...wish I lived in town with lower speed limits...(second thought)...NO I DON'T...d32
 
Years ago, Perfect Circle piston rings recommended running the motor up to some high speed (don't recall) and immediately back down to slow; repeat ten times; drive.

I drove my new Rich Falluca motor with counter balanced crank and 5.9 head and OD with ~200 miles on it from Kalamazoo to the Williamsburg meet and back (~2500 miles), a lot of time at 50-60 mph. Did some pounding through mountains of WV. No problems so far.

Steve
 
Your safe top speed is more dependant on your chassis condition, i have run my stock engine all day at 65 before(700 miles after new babbitt), the car runs comfortable at that speed on good roads ---when it has working shocks, I drove it some when the paint on the shocks was drying(no shocks), it was scary at 45.
 
One of my cars runs original babbitt, standard bore bone stock motor, 3.78 rear. I have no problem running 55-60 for as long as I want to run it at that speed.

Another has a 3.54 ring & pinion, Brumfield 5.9 head, Winfield regrind cam, single Stromberg 81 on a Zephyr intake. It can ride at 65 easily & I have buried the speedo on a few occasions.

One thing to remember is how comfortable are you with the car? The car is only as safe as you make it. I drive mine rather hard compared to most who putt around under 45 and only take them out on sunny days.
 
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