Best Speed/RPM for long engine life ?

G

Greg out west

Senior Member


Hi Guy's


What would be a good Speed/RPM for long engine life..I wouldn't drive my modern car full throttle,,,But you can with the A...It's a long stroke engine & a lot of Mass going up & down


1800 RPM ???


Greg out West
 
A long stroke engine lives better at lower RPM's. I try to stay 2000 or less and 2200 is my upper limit. If the Model A was a stationary engine running a generator or compressor, I'd like about 1200 RPM.
 
No good answer.

Seriously.

The primary factors limiting the A engine is how well it was built and how well you can set the timing for the driving conditions.

So how well built was your car?
What are the specs for your crank?
How well centered are the mains and how well is the flywheel located?
How good are you at setting the proper advance for the driving conditions?

A well balanced engine with properly poured babbitt you can run hard and put it away wet. It will be happy to do the next run.
So long as you do not have the timing set to far advanced for the driving conditions.

It all comes down to a well balanced system just spinning happy all day long vs imbalanced system beating itself to death.
 
If you will calculate based on miles per RPM you're better off running the engine at a high RPM, lugging any engine is harder on it than high speed.
 
Hey Greg,
Two things govern , IMO. First, do not 'lug' engine either when driving around town (short trips). Second, do not lug engine when on the long run, i.e.- find/use the right gear to ensure not lugging at speed (say uphill, etc) and keep rpm at, say 55 to around 2200. Now second thing is done with gearing thru overdrive (better/more expensive)and rear end and tire combinations. Good luck :)
 
Tom Wesenberg said:
To make the engine last longer you should add counterweights to the crankshaft, or buy the new Burlington crank.
Click to expand...

I have a Burlington coat...will that help:) Having said that I just completed the install of a 39 ******(go ahead guys hammer away I have my new flame suit on) and its is a dream compared the the original transmission. I find now I will shift to 2nd instead of plodding along when I know I should not. Slipping it into second is a breeze and you don't have to deal with the howling of the old ****** and you can actually hear the engine turning now:)

It has changed the drive ability of this car so much it is unreal(at least for me it is)


dusty
 
Tom Wesenberg said:
To make the engine last longer you should add counterweights to the crankshaft, or buy the new Burlington crank.
Click to expand...

Hey Tom,
Yeah, Burlington, if you can get one ! Now long ago , here on this site, the Burlington maker explained that he would no longer make a crank for us...due to lack of sufficient demand(do file search) ? What that means, is obvious, but does not compute..IMO. As there are still guys here who will want such.

Now, there is good/bad to this situation. Bad is....that Burlington only made Model A size crank, but NO Model B size...bummer,eh! I and IMO a lot of others would buy B size Burlington cranks ! Why they did not make a B size was not known,
Good is...that SCAT still makes us an A size and a B size crank....Bad is that scat cuts the rod journals down to A size (1.500), but keeps mains at 2.00. I just spoke to scat rep and ask...'why would I buy a B crank (bigger/stronger) and use A rods with small (weaker) rod journals :confused:
Well, he said that that's the way it is !! But, hey you can get it drilled or no. With cut down rod journals...I said no, as needed drilled crank , but not weakened drilled crank.
I settled on a henry C crank that is drilled AND beefy :) !

BTW..cost of a new Scat $1550 +/-
 
My A is completely stock and nice and tight, I usually run about 50mph as it runs nice and smooth at that speed. Different cars vary. Pay attention to how it feels/sounds.
 
Advice in Reply #10 sounds like very good judgment ........ attention to "feels/sounds" ........ different cars do vary.

Test Question: If one has a radio in one's Model A, (fixed, or portable battery operated), with all windows rolled up, while driving on a paved highway with little or no traffic, at what incremental RPM's and/or at what incremental speed(s) does one have to re-set & increase the radio volume to hear the hourly news? LOL
 
Jeez Dusty! Don't you crackers know anything? A 39 Trans in an A? Well, no surprise, I guess, with green fenders. I bet you'd put a Buick auto in it if you could. Criminy!

OK, just kidding. But I thought I should take advantage of your "flame suit," and, while I wouldn't do it, your fenders actually look pretty cool.;)
 
Like has been said ; a number of factors come into play when judging the 'correct' speed of your Model A. Things like how the engine was built, the rear end gear ratio, the body weight of the car (i.e. - '29 Roadster vs. '32 Town Sedan), over-drive unit, tire size, etc. etc.

However, that being said - with all things being equal, with a basic Ford Factory built car, my experience has been that each individual cars has it's own 'sweet spot'. Of the ten or so Ford Model A's that I have driven over thousands and thousands of miles during the last 50 years, my cars seemed to have a 'sweet spot' of between 50 to 55 miles and hour. My light weight '28 Phaeton was 'comfortable' between 55 & 60 miles an hour. However, I was NOT comfortable in driving it at 60 miles an hour (brakes, modern traffic, etc.). My '31 Dlx Coupe has a 'Touring' engine, Mitchel Over-Drive, over-sized Firestone tires, etc. - it too likes to run about 55 to 60 miles an hour. Because the Coupe has better crash protection, I don't mind driving at 60 miles an hour in it.

All of these cars were perfectly capable of doing faster speeds, But I always liked to go the speed that my car felt 'comfortable' with - the 'sweet spot'.
 
If you technically want the "best speed/rpm" for a Model A engine; it would be zero rpm and only coast down hill with the engine off for speed.

Sorry, I just had to say that.
 
V4F said:
40 mph @ 1800 rpm for a stock motor .
Click to expand...

I think this answers the question best. Bearing life depends a lot on speed and load. If you are just driving with normal acceleration and also not pulling or otherwise hauling heavy loads, then keeping the RPM at around 1800 max will give you longest engine life. Other things not withstanding like routine oil changes and decent warm up.
 
700rpm said:
Jeez Dusty! Don't you crackers know anything? A 39 Trans in an A? Well, no surprise, I guess, with green fenders. I bet you'd put a Buick auto in it if you could. Criminy!

OK, just kidding. But I thought I should take advantage of your "flame suit," and, while I wouldn't do it, your fenders actually look pretty cool.;)
Click to expand...


Thanks, I need a good slap back to reality:) The only problem is now you got me thinking about that damn Buick Auto transmission:rolleyes:

Now as to engine RPM, I give up:confused: After reading here for many years I have come to the conclusion that I need to get rid of the "A" before for she blows:eek: Don't lug, don't go past a certain RPM, keep it under 50, "I run 55 all day", to be safe put it in 2nd gear around town so that is no chance of stressing the engine at low RPM, make sure the advance is set right for this or this,or that Than after all this you still hear a lot of stories about the engine crapping its self one way or the other as did mine last Summer so I guess its because of not following all the do's and don'ts:( or maybe I made the mistake of just starting it:rolleyes:

After reading all the don't do's over the year it seems to me this engine is very, very fragile:confused: I think for you to be able to enjoy just driving this car you need to install an on board computer from one of the abandon Shuttle space crafts just monitor things so you won't blow it up...no wait a minute forget that, shuttles blow up to:eek:

Saving money in WV for a new engine...its sure to blow up any day now.

dusty
 
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Dusty. You hit the nail on the head! These are tough old critters and if you use some common sense will serve you faithfully. All of the must do and must not do get to be comical after a while.
 
I agree.I've still got my first one that I got in 1960. It still has the original babbitt and has run with non detergent oil for most of its life. I changed to detergent 20w50 in all of mine a few years ago. I run the hell out of it when I was a teenager. I've wound it up until it screamed many times with no i'll effects. I've overhauled the engine twice in the past 54 years and the original babbit is still good. when the shims were all removed I filed the caps. It has an easy life now and I expect it to run for the rest of my life and beyond.
 
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