8BA Flathead Ford Crankshaft Pulley Install

[Working Class Zero]

I’m wondering if anyone can put my mind at ease (or into turmoil)… I removed my crankshaft pulley, painted and reinstalled. My concern is if I did anything damaging. I removed the retaining bolt easily with an electric impact. Then a little rubber hammer tap and elbow grease and the pulley came off easily. I cleaned it, painted it, then reinstalled by tapping into place with rubber hammer on the keyway (slid on nicely) then used impact to reinstall. Is this ok? Or have a made an error in using the impact. Van pelt site stated that ford did not specify a torque so I assumed nice n tight. Impact was my thought as otherwise motor turns over while tightening. I thought nothing of it and was pleased that it went smoothly. But as an over thinker I’m not worried that it’s ok to do it this way. Anyways any input is appreciated as always!

[Working Class Zero]

It’s a 1950 Ford 8BA Flattie by the way

[Working Class Zero]

Stock 3/8 Pulley

[cas3]

Should be no harm done, that is a large fine thread bolt that will easily accept a high torque #

[3twinridges]

As long as you didn’t strip it I wouldn’t worry. That is a big bolt and should be able to hold 50 or 70 lbs fine.

JB

[Working Class Zero]

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Originally Posted by cas3

Should be no harm done, that is a large fine thread bolt that will easily accept a high torque #

That was my thought but I have no idea how much torque I may have put on it. 1/2 battery powered impact and gave it a few good raps

[Working Class Zero]

Originally Posted by 3twinridges

As long as you didn’t strip it I wouldn’t worry. That is a big bolt and should be able to hold 50 or 70 lbs fine.

JB

No didn’t strip it (I assume I would know if I did) haha
Was concerned it might do damage to crankshaft or something rappin on it. But it’s a simple setup I guess not a harmonic balancer or has a bushing or anything I could damage… but as an after thought and as an over thinker I was like shit I hope did that right!

[cas3]

I've not looked at a torque chart, but my guess is that 5/8 fine bolt will take 150 foot pounds in steel, perhaps less in the cast iron crank, but again, I would not worry

[19Fordy]

You are "Good to go."

The 1949-51 Mercury Manual, Vol. 1 on page 72 states the following re: crankshaft pulley to crankshaft torque:
5/8-18 x 1 1/8 " cap screw: Mercury CM 130-145 ft. lbs. I believe 8CM applies to 1949 and 50 Mercury engines.
1951 Mercury 45-55 ft. lbs.
I have tightened my 1953 Ford 8BA crankshaft bolt to 55-65 ft. lbs for the last 50 years with no problems.

Here is a Bolt Torque Specification chart for grades 2,5 and 8 SAE 5/8-18cap screws.
I believe Ford used mostly Grade 5 bolts to save $$. https://mechanicology.com/sae-bolt-t...rade-5-grade-8

Don't worry, your use of an impact wrench did no harm. However, next time, use a torque wrench if you have one. If not, just tighten that bolt good and tight with a socket wrench plus a dab of blue Loctite. Here's an explanation of the difference between BLUE and RED Loctite.
https://www.bing.com/search?q=streng...CTS&showconv=1

If you use a breaker bar, don't go crazy. Just make it TIGHT like a stock Mercury headbolt which uses 65-70 ft. lbs.

You will notice that Ford did not state a torque valve for the crankshaft bolt. Look here:
http://vanpeltsales.com/FH_web/flath...ecs49-53V8.htm

[Working Class Zero]

Thank you for the reply! I do of course have a good torque wrench but not sure of best way to stop motor from turning over as attempt to torque. Familiar with loctite types, and could use blue… should I be attempting to check torque as it sits after impacting it on or take bolt out, loctite and torque? Or leave it? Haha. Any tips on how to torque in place in car without turning motor over is appreciated! The huge discrepancy in torque and what to torque it to is the other question mark!

[cas3]

To lock up the motor, you could remove one shift rod from the tranny, and put it in two gears at once...it will not turn over then. For this job, may be easier to just put it in gear with a block of wood under the tire. I do believe though, you are done. no need for locktight, or a torque wrench.

[19Fordy]

The discrepancy in torque values is probably due to the design and performance changes Ford made in the Ford and Merc. engines over the years such as horsepower, motor mount design, crank pulley and keyway design plus engine balancing and "time on task" during manufacture. Keyways affect torque.
Here's some good reading on the effect of keyway design and torque values required..
https://www.bing.com/search?q=does+a...ANAB01&PC=HCTS
and
https://www.bing.com/search?q=does+a...&ghacc=0&ghpl=

At this point, just for curiosity, I would place a torque wrench on the bolt and get a reading to see the amount of torque your impact applied. Then, decide if you want to leave it as it is or go higher if needed. To stop the crankshaft from rotating I put the transmission in gear as cas3 described. No need to undo the bolt and apply Loctite.

I torque the crank pulley on my 8BA to 55 foot pounds and all the while paying attention to how tight it feels as the bolt gets tighter. My goal is not to see how tight I can get it.

As you have not yet damaged anything, don't over think and open a can of worms.(Been there. Done that.)

[Bored&Stroked]

That big ole' bolt will take a lot more torque than 60 lbs - though the washer that goes with it may deflect. I would not worry about it in the least. If you're nervous, check it with a torque wrench.

I've never had one loosen in the last 50 years - and you'll probably not be the first guy to experience it.

[Working Class Zero]

Well I put torque wrench up to 70 ft pounds and clicked immediately. I know it is tight enough put my concern is that it’s over torqued and if that’s harmfull. I decided to try and take it off to reinstall and locktite at a torque but can not budge it with breaker bar! Car in park and wheels blocked, literally will spin tires on shop floor before it can come loose! Radiator is in so would have to remove it to get impact in again to remove….. hmmm

[19Fordy]

70 ft. lbs is not harmful. I have a gut feeling it's best to leave it alone.
BUT, if your determined to loosen that bolt:
Is the emergency brake "On?
Did you fit a pipe over the breaker bar to extend its length?
Are you using a long 5/8 impact socket on your breaker bar so as to avoid the use of a short extension?
Watch these videos:
https://www.bing.com/videos/rivervie...6BA7&FORM=VIRE

[3twinridges]

If you break the head off that bolt you open yourself up to a whole really big can of worms. I am sure that is obvious. I wouldn’t try to get it off until you can get an impact back on it. If it doesn’t turn with a breaker bar no telling how many lbs of torque is on it.

JB

[3twinridges]

BTW if using a stock radiator on a truck 48-52, they have a hump so you can get a socket and some extensions through. Not sure if your setup has that or not.

JB

[19Fordy]

3twinridges's #16 post info. merits attention.

On the brighter side, it makes sense that if you used an impact wrench to install that bolt, you will need to use an impact wrench to remove it.

Reminds me of trying to remove the big nut on the front of a generator or alternator.

[Working Class Zero]

Ok here’s the update. Decided to take the bolt back out for peace of mind because I had no idea what torque was put on with impact. Removed radiator to be able to get at it again with impact. A few raps and it came off no problem. No damage to bolt threads or anything. But a dap of blue loktite and back in and torqued it up to 55 ft pounds. Was able to do that torque with it in gear and brake on. Not sure why it didn’t come off with breaker bar and pipe! Hope that’s enough torque seems like not much but… so all should be well now yes?

[Working Class Zero]

It’s a 1950 Ford Shoebox by the way!