What's a safe rpm for a good touring eng.?
 

I have an inserted engine and an overdrive. What is a safe rpm to run for extended periods when not in overdrive?

Re: What's a safe rpm for a good touring eng.?
 

For the life of the engine and for better fuel economy, I like to keep the engine speed under 2200 RPM. I'd rather have an overdrive and keep it about 1800 RPM, like my newer car.

As far as red line to keep from blowing the engine, I'll leave that open to someone else.

Re: What's a safe rpm for a good touring eng.?
 

What does your engine builder say?

Re: What's a safe rpm for a good touring eng.?
 

Usually listening to your engine will give you the best idea where the sweet spot is and when you are exceeding it.

Re: What's a safe rpm for a good touring eng.?
 

I find mine run better in the 2,00-2200 range. Less than that feels like it is lugging, more seems just too much for extended use. Same RPM would apply either in or out of overdrive, just the MPH would differ.

Re: What's a safe rpm for a good touring eng.?
 

OK,thanks guys.I wasn't looking for redline,just a comfortable uphill rpm for longer uphill runs out of overdrive and a good rpm for extended overdrive use.You have all given me about what I was expecting to hear and 1800-1900 od is close to what I'm using with 2000 and no od for hills. As Eagle says,"sweet spot". Appreciate the input. Bill

Re: What's a safe rpm for a good touring eng.?
 

I don't have a tach in my car. At 2000 RPM, how fast are you going when not in OD? I assume you have a standard axil ratio?
Thanks,

Re: What's a safe rpm for a good touring eng.?
 

If you have a 30-31 with 19 in wheels and 3.78 , at 2000 RPM you are going 45 MPH..

RPM /44 = MPH. 2200 is 50 MPH.

Re: What's a safe rpm for a good touring eng.?
 

Maybe this has already been answered above but on a 1929 stock engine with std rear end, what is a reasonable MPH for RPM not hurting engine. Is 45-50 MPH the proper top speed to give your engine a reasonable life?

Re: What's a safe rpm for a good touring eng.?
 

If all the rotating parts are properly balanced and centered then do not worry about the RPM's.

The car was designed to run 60 and extended runs at that speed will not kill it if the engine is built properly. Running 50 to 55 all day long is a no brainer for a well rebuilt engine and a stock driveline.

Your bigger concern is to understand how you should set the spark advance to have the engine run right. The wrong setting here could damage the engine.

The wrong spark settings for the driving conditions can beat the engine up.

Re: What's a safe rpm for a good touring eng.?
 

Nobody seems to have answered your specific question although you say you are not looking for the redline?
From what I've read, the big end dippers are the limiting factor as to what revs a Model A can be safely revved to as above something like 4000rpm (assuming your motor can rev that high) the dippers leave a channel in the oil limiting the amount of oil they can pick up?
I recall reading that someone at Bonneville with a Model A engine car was revving to that or more without oiling problems.
I add this as my motor, yet to be tested on the road, has the potential to rev higher than normal ,probably limited by valve bounce more than anything as I have retained standard valve springs
Keith

Re: What's a safe rpm for a good touring eng.?
 

I am only chiming in because the experts have not addresses the red line question. Some here are sure to know the red line designed per Ford. But I know that 2200 is advertised as 40 HP. that will give you 50 MPH. I have heard two numbers for red line. I think 2700 is the design limit. Some will say 2500 RPM. 2500 is 57MPH. 2700 is 61 MPH.

Re: What's a safe rpm for a good touring eng.?
 

Let the engine "speak" to you. After awhile you will know what is "correct".

Be well -

SHEC :cool:

Re: What's a safe rpm for a good touring eng.?
 

Speaking of tachs. What do you hook the leads up to on a Model A? I haven't used this since the 60's. Still in my tool box. Made in USA by AMC.

Re: What's a safe rpm for a good touring eng.?
 

Normally the red clip will go to the points with a negative ground system, and black would go to ground, but you may have to reverse the leads for the Model A with a positive ground system.

Does the meter say good for 6 and 12 volt systems? If not, then it may read low when used on 6 volts.