VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Main bearing torque specs 216 engine

Originally the size of a spanner related to the size of the nut or bolt. Obviously the spanner got longer as the nut or bolt increased in size. If you extended the length of the spanner you risked snapping or at least stretching. This system worked for many centuries and basically still does. The latter day use of the tension wrench is just refining matters, particularly when it comes to things like cylinder heads where it gives that added accuracy and security.

Note: This is longer than it should be. Is nonsense. You may want to skip it. You've been warned.

Okay. I've been shot down.

Just answer me this? When was the last time you tore down a 216 (for instance) and found a main bolt loose? You know when you went to loosen it you found you could turn it with your fingers? Or found some of them in the bottom of the pan.

I still say that "muscle memory" is good enough and "tight"means tight without approaching the elasticity of the bolt. If you haven't had the experience of tightening bolts over a long period of time, then, a torque wrench is essential.

No matter how much you screw down on the bolt in the main cap the clearance is not going to change.

The crank is balanced and is just sitting there. When the engine is running the weight is evenly distributed through 360 degrees. I think that is about right.

So next time you put the mains back in your car just tighten down on the bolts. If you break one just grab a spare and don't exceed what broke the first one. You
muscles will remember and start to shout, "ease up, idiot, That is tight enough!"

Amaturs use torque wrenches. They have nice clean garages, tool chests so high they need a step stool to reach the top drawers and trash cans located here and there.

Professionals use recently calibrated torque wrenches. They have all the above but don't use the torque wrench unless the boss is looking. It stays in its little tray until the next calibration. They have drink machines and pictures of some "heavenly
Helens" on the walls.

Old timers use "muscle memory." (Just as good on mains and much faster.) Their tools are scattered and it takes time to look for the proper wrench. If they have one they don't know where it is and its out of calibration anyway. They have dogs lying around and have to watch where you step. There are tobacco stains on the unfinished concrete floor and the missus smokes a pipe.

Charlie

Well I have put a couple hundred miles on the car since changing the rear main seal top and bottom halves using the Sneaky Pete tool. I am happy to report that it appears as though we have stopped the leak. When I first installed it and put everything back together and test ran the engine with the car up on stands, it did seep out a little. I was really disappointed thinking all this work was a waste. I figured I would drive it for a while and see just how bad a failure it was. It turns out that it has sealed up and after 200 miles the rear main cap is dry! I am happy to report back that as of now it seems to have been a success. Hopefully it lasts. Now to fix the leaky transmission and torque tube.

Thank You Everyone for all your help!!

RM,

If it hasn't begun to leak after 200 miles, it means you did something wrong. You may need to tear it down to find out just what it was before the pistons begin to swap holes.

The transmission and drive line are supposed to leak as well. They cannot be sealed. Not supposed to be. Without those leaks and seeps the DOT won't know where the bumps are in the road and the signs that say "bump ahead" will just sit in the warehouse and gather dust. Yes, all those dark spots on the road are caused by Chevrolets marking their spots like a new puppy on your neighbors flower beds. You get the picture.

Just thought you ought to know,
Charlie