Night Moose CARNAGE!!!!

[seawalkersee]

Loctite or any other brand of thread lock doesn't do anything for torque... it's function is to stop the nut or bolt from backing off the torque given. Dirty nuts and bolts will not give a true torque reading. Clean and dry , or clean and lightly lubed gives you a better shot at making your number. If you want to be exact, anything on the bolt/nut changes the actual tension vs torque indication.

I agreed with you 'till this point. I have personally had loctite on a thread and broke the bolt with less than 30 lbft. It had no sign of tightning down either....

Next, I wonder if there was a difference in the pitch of the flywheel and the rear flange of the crank. Not sure how much it has to be off, but f it wobbles, even enough (for example) .00059 when tollerance is .00055, can that cause the failure?

Saleen has been building 400 lbft/HP engines for years. They said on some of their higher HP engines that they could use as few as 3 bolts for the flywheel with no problems.

SWS

 

[Agnem]

...It's my opinion that the "Lucky Mod" puts bolts in a position where they are placed at or near their failure limits not from torque on the nut, but load from the flywheel forces that are added to the torque load with every piston stroke "shock". That's why the DMF springs fail after use,,, and defeating the DMF with solid bolts gives the hammer of the diesel power shock no where to run.

That seems illogical to me when other SMF's are subjecting their bolts to the same hammering affect. Also, why would it break first on a light truck that never tows anything and after only 8000 miles, where as I have a 16,000 pound rig that has been modded for 6 years, and has probably at least 25,000 miles on the lucky mod?

I think this is just a failure to torque correctly. Seems pretty simple to me.

 

[subway]

I agreed with you 'till this point. I have personally had loctite on a thread and broke the bolt with less than 30 lbft. It had no sign of tightning down either....

Next, I wonder if there was a difference in the pitch of the flywheel and the rear flange of the crank. Not sure how much it has to be off, but f it wobbles, even enough (for example) .00059 when tollerance is .00055, can that cause the failure?

Saleen has been building 400 lbft/HP engines for years. They said on some of their higher HP engines that they could use as few as 3 bolts for the flywheel with no problems.

SWS

i share this same opinion, looking at formulas and dealing with real world bolts lubrication changes the coeficiant of friction. granted differant lubrication will give differant values, hech differant plating and machining quality affect torque. but the bottom line is it all has an effect.

ask icanfixall with his head studs, those NEEDED the proper oil just to set in correctly.

but like mentioned unless you are near the edge with your design it is not rocket science and 99% of people have gotten by just fine with a torque wrench or even less working on there vehicles.

 

[icanfixall]

It sure would be nice to have a factory new crank bolt tested to failure. Then test a used bolt to failure. Finding out if there is a differance might cause a Ford stampede for new crank bolts for the clutch guys.. Maybe not....