Crankshaft end-play

W

warrene

Member
I'm 88, had a Model A's since 1948, driven them well over a hundred grand, I know ever nut, screw & bolt on these cars, also the engines ... been there done it.
The 'book' calls for crankshaft endplay ... I've seen different numbers but can tell you that all are wrong, there is NO reason whatever for any endplay, this is only asking for trouble, any endplay in the shaft and main rear bearing is only going to cause the ends to crack and break, I've seen this over and over.
I overhauled my latest, a '29 Town Car, as usual the rear main ends were cracked, I ground them out, used radio solder to fix them, then added solder to the rear ends of the halves, hand fitted the shaft to fit, with no more than .001 endplay, this has worked great, you do not want that shaft and heavy flywheel slamming and slopping, those bearing simply cannot stand this.
Oil pressure to the center main is good also, learn how to do this.
I fit all engines at .001, all bearings, I use 5-20 synthetic oil, change about every 2K since there is no filter. Mine uses no oil, does not loose water, no leaks, the new O-ring ****** shafts end the rear leaks, I highly recommend them.
Warrene
 
Good for you! I'm only 84, and have owned A's since '58. I modify and race A and B engines, successfully. You use the words "any clearance", I say a little clearance is needed, for oil to lube the thrust bearing. Racers use more clearance on all moving parts, to allow oil to flow and keep everything cool. Keep on truckin!
 
Radio solder? What variety of solder do you recommend? The regular 60/40 lead/tin or tin/silver eutectic or the lead free solder you buy for plumbing? Or what? Also what flux do you use? I assume you have shinny babbett to solder to but what about the steel? How do you you handle that? Plus, what soldering iron do you use?
 
Thanks, young man for posting !
I look forward to reading more of your A ownership and knowledge you share !
What was your first A owned.

Ive owned many old As…. started with junk yard rescues / revivals. My favorites in memory ,
Truly a car that I fixed… on the run between work and home !
 
warrene said:
The 'book' calls for crankshaft endplay ... I've seen different numbers but can tell you that all are wrong, there is NO reason whatever for any endplay, this is only asking for trouble, any endplay in the shaft and main rear bearing is only going to cause the ends to crack and break, I've seen this over and over.

I overhauled my latest, a '29 Town Car, as usual the rear main ends were cracked, I ground them out, used radio solder to fix them, then added solder to the rear ends of the halves, hand fitted the shaft to fit, with no more than .001 endplay, this has worked great, you do not want that shaft and heavy flywheel slamming and slopping, those bearing simply cannot stand this.

Oil pressure to the center main is good also, learn how to do this.
I fit all engines at .001, all bearings, I use 5-20 synthetic oil, change about every 2K since there is no filter. Mine uses no oil, does not loose water, no leaks, the new O-ring ****** shafts end the rear leaks, I highly recommend them.
Warrene
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Not sure which book(s) you are referring to, but I have found the most accurate place to get my information is from the A-6005 factory Engineering Print which gives us the same specification the factory workers used when machining. You should take a moment to look at the specifications given on the A-6303 Crankshaft print too. So much to learn from that, -and it is not second-hand information or hearsay that can often be erroneous.

As a Model-A engine rebuilder, I can share my experiences that setting up your thrust clearance. If you set-up your end clearance that tight, it will not stay that tight for very long. Because you do not have any positive oil flow into that area, as soon as the clutch is depressed, -or as soon as thermal expansion happens between the dissimilar metals, it will squeeze the oil out and friction will clearance it to 0.004"+ after a few miles. Once opened up where the main bearing oil spills over, it will protect that clearance. Also, generally speaking, cracking is not caused by the crank flange slamming, but is usually caused by not clamping the thrust surfaces during the peening process.
 
In '55 I was back from Europe and the army, a friend and I built an A dragster, later used a B, had an OHV head, ran on alcohol & nirto, our best time was 126 mph in the quarter, Twin City Speedway, Minneapolis. My first A ended up souped also, had the 'works' on that one, cops got me at 92 on night, that tudor pushed a lot of air, a coupe would have been better but ....
I'd say the Model A was one of the best cars ever produced, simple, sturdy, most anyone could and can fix them.
 
We've just returned from a 1300 mile trip in our '29, from east central MN to Medora ND, we drove 45 going out there, were in a car show, won first place in the unrestored original class, I put the pedal down coming home, 55 and 60, oil is still on the line, did not odd any water, this overhaul has done fine, the new rings are far better than times past.
5-20 synthetic, those 'ball bearings' all the same size, far easier on babbitt at close tolerance. I had to fix the engine, was burning oil bad, really bad, the rest is original.
 
My first was in '48, 25 bucks from gramps', a '30 tudor. By 1951 it was beating everybody at the stoplights, it was fast. Cops finally got me at 92, I took that body off, put on a sport coupe body and went back to town, this fooled them for a time.
 
nkaminar said:
Radio solder? What variety of solder do you recommend? The regular 60/40 lead/tin or tin/silver eutectic or the lead free solder you buy for plumbing? Or what? Also what flux do you use? I assume you have shinny babbett to solder to but what about the steel? How do you you handle that? Plus, what soldering iron do you use?
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I buy radio solder online, (I'm not in the shop now) it flows much better, has it's own flux. Babbitt has to be CLEAN, I use a lot of ether for cleaning. I have two larger electric irons, you have to clamp those broken ends down tight both ways, solder will not stick to the block but doesn't have to, no different than modern shell bearings.
The trick is to fit things really close, use light synthetic oil, the 'ball bearings' in synthetic oil are all the same size and won't push babbitt away, your engine will stay snug for a long long time. We just ours at 55 mph plus, a solid 550 miles from western ND to east central MN, used no oil or water. Some of the rules for modern bearings do not apply with babbitt, keep that in mind.
 
First off I can tell you that you are by far not the oldest one on this forum. There are several that were born in the 20's.
The next thing is, I do not doubt that you are setting your bearing clearances at the numbers you quoted. It is just that your measuring techniques are at fault.
You are NOT exempt from the laws of physics.

By the way, solder/babbit WILL stick to cast iron. It has to to get a good babbit job.

As far as 126 in the quarter in 1955 with a 4 banger. Fantasy.
You are an engineer so it should be very easy for you to calculate how much horsepower it takes to do that. Not going to happen with a model B engine, especially back then.
 
I'll agree that the end-play number should be relatively small.
However. My particular engine was rebuilt last in 1961, has 45# compression. It runs good, leaks or burns nothing. So I continue to run it. Oh, the end play ? You could pull a cat thru it.
 
warrene said:
We've just returned from a 1300 mile trip in our '29, from east central MN to Medora ND, we drove 45 going out there, were in a car show, won first place in the unrestored original class, I put the pedal down coming home, 55 and 60, oil is still on the line, did not odd any water, this overhaul has done fine, the new rings are far better than times past.
5-20 synthetic, those 'ball bearings' all the same size, far easier on babbitt at close tolerance. I had to fix the engine, was burning oil bad, really bad, the rest is original.
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Warren, I am not following you. Which ball bearings are you speaking of that are easier on babbitt? :confused:
 
126 in the quarter is great! I ran a Cook, mostly on gasoline, and was consistent at 116 MPH. My friend Vic Smaldino ran his Fargo on 100% nitro, consistently beating all other bangers, flathead V8's and many late V8 dragsters. His fastest time was 136, backed up at 2 different strips. Believed to be the fastest banger ever. His car is now in the Speedway Motors museum. I've run my Cook at Bonneville, in lakester class. Fastest time for me was 167, turbocharged on strait alcohol.
 
Jim Brierley said:
126 in the quarter is great! I ran a Cook, mostly on gasoline, and was consistent at 116 MPH. My friend Vic Smaldino ran his Fargo on 100% nitro, consistently beating all other bangers, flathead V8's and many late V8 dragsters. His fastest time was 136, backed up at 2 different strips. Believed to be the fastest banger ever. His car is now in the Speedway Motors museum. I've run my Cook at Bonneville, in lakester class. Fastest time for me was 167, turbocharged on strait alcohol.
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As I remember, back then MPH in the quarter was timed in the "traps", which was from 60 ft. before the finish line to 60 ft. after the line. Some years back this was changed to 60 ft. before the line to at the line, so speeds went down a little.
 
You guys sound like the ones to ask this.... So what do you think about adding a harmonic balancer? My new engine warranty will be up in November. I'd like to never have to do the engine again as long as I live, and I'm 60. There sure were no shortcuts taken on this engine... A for real shop, and it has cost me a bundle.
 
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