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Crankshaft nut torque setting

higgins

Senior Member
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Hello there,

what is the ideal/correct Torque setting for the Crankshaft nut on an Harmonic balanced pulley. I've ordered a Pro/race for my 100/6 BN4 model.

regards
 
70 ft/lbs.
 
If you're installing it as part of the engine build process, and the oil pan is still removed, place a block of wood between the counterweight closest to the front of the engine and the inside of the block.

If you're doing it while the engine is inside the car, well, good luck! Put the trans in reverse (highest multiplication) and set the handbrake. You may still need someone to STAND on the brake pedal to keep the engine from turning.

I had to turn down the neck of a socket in order to get it to fit inside the ProRace dampener:

dampener_socket.JPG


dampener.JPG
 
Randy Forbes said:
If you're doing it while the engine is inside the car, well, good luck! Put the trans in reverse (highest multiplication) and set the handbrake. You may still need someone to STAND on the brake pedal to keep the engine from turning.

Hi Randy,

I have the luck of installing it with the engine in the car :cryin:

Are you wishing me luck for getting the damper onto the crankshaft or tightening the nut :confuse:
 
One other thing to remember about the Pro Race damper. Soak it in hot water for 15 minutes (I think) to allow it to expand. Goes on much easier that way.
 
GregW said:
One other thing to remember about the Pro Race damper. Soak it in hot water for 15 minutes (I think) to allow it to expand. Goes on much easier that way.
I put mine in the oven, 200 degrees. I was able to handle it well enough wearing welding gloves (the really thick ones that make you wonder if you still have fingers, as you sure can't feel anything).

Apparently, it cools really fast, but I was able to get it on far enough to engage a few threads and draw it up with the bolt. If I ever had to do it again, I would source the correct thread in a longer stud (so there's no threat of pulling out the threads in the crankshaft) and draw it on with a nut and washer.

If it gets stuck halfway on, I'm not sure what you could do to get past that dilema?!
 
Oh if it gets stuck get the torch out and impact wrench. A flame protector behind rhe samper will protect the other engine parts. --Keoke
 
The Pro racer arrived today; good looking stuff.

One last question, though. Should I use the standard lockwasher for the Crankshaftnut or is there a special recommendation from your side?

regards

Higgins
 
higgins said:
The Pro racer arrived today; good looking stuff.

One last question, though. Should I use the standard lockwasher for the Crankshaftnut or is there a special recommendation from your side?

regards

Higgins
I don't see a depression to set the locktab washer into on the dampener, so it would be prudent to use some thread locker. I'd recommend the Loctite "blue" so that it could be disassembled without needing to be heated.
 
Looked into these, and was basically told off the record for a 100/4 they wont do much unless you are pulling a lot of revs
 
Got it in today, but what a job!!!

Did it exactly the way you described and like the instructions said but it was definitely a tough job with the engine in the car.

I do have one question as a novice as the guy who checks everything for me is away for two weeks so, please excuse my ignorance, but:

How can I be sure that the damper is completely in?

regards

Higgins
 
zblu said:
Looked into these, and was basically told off the record for a 100/4 they wont do much unless you are pulling a lot of revs
Isn't the 100 engine "dampenerless"? If that's the case, then adding one probably won't make much difference.

In the case of the sixes, a dampener was originally fitted, but by now, most have already delaminated or aren't trustworthy to use. I know of one failure firsthand (Layne Perkins BJ8) that when the dampener came apart, it broke the crankshaft at the 1st main journal. That was fully 20 years ago, and those rubber fillers have not gotten any younger.

Really, it's more a case of cheap insurance than a performance upgrade.
 
Randy Forbes said:
zblu said:
Looked into these, and was basically told off the record for a 100/4 they wont do much unless you are pulling a lot of revs
Isn't the 100 engine "dampenerless"? If that's the case, then adding one probably won't make much difference.

In the case of the sixes, a dampener was originally fitted, but by now, most have already delaminated or aren't trustworthy to use. I know of one failure firsthand (Layne Perkins BJ8) that when the dampener came apart, it broke the crankshaft at the 1st main journal. That was fully 20 years ago, and those rubber fillers have not gotten any younger.

Really, it's more a case of cheap insurance than a performance upgrade.
Randy,
Do you think it's best to have the dampner rebuilt if the engines out or even so if it has never been out. '67's are 42 years old this year.
Patrick
 
If it wasnt for the weight/cost I'd probably put one on for the incremental improvement, but in your case Patrick67BJ8 I'd replace as you say its a few decades old now and probably gone hard
 
I agree; replace it. At that time, Layne's engine had never been out of the car, so it was completely as original. Can't blame the failure on rough handling during a rebuild.

Wile it's possible that southern Louisiana (Lafayette) heat could've contributed to the rubber's demise, I can't imagine it being <span style="font-style: italic">that much</span> cooler in Dallas.
 
zblu said:
If it wasnt for the weight/cost I'd probably put one on for the incremental improvement, but in your case Patrick67BJ8 I'd replace as you say its a few decades old now and probably gone hard
I was given a source for a rebuilder and was thinking of going that way. I think new ones(performance brand?) are about $400 and to rebuild is less than half with shipping.
 
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