Can a camshaft be bent?
The camshaft is hard, but it can still bend. With the reciprocating stresses that occur, it is a possibility at elevated temperatures.
How do you change the camshaft on a BMW?
With the head out of the car, you turn the camshaft until a particular valve is open. Then, wrapping the valve with rope, you rotate the camshaft and let the rope compress between the valve and the seat. My attempt at this is shown in Figure 4.
Where does the rotation of the camshaft come from?
They come from the preloading of the valve springs. The camshaft can rotate, obviously, through 360˚ of motion. During 100% of this time, there is at least one pair of camshaft lobes pressing down on valve lifters and compressing a pair of valve springs.
What kind of force does a camshaft put on a valve?
During 100% of this time, there is at least one pair of camshaft lobes pressing down on valve lifters and compressing a pair of valve springs. Transmitted through the lifters, the springs place a tremendous amount of force on the camshaft.
Is it safe to remove camshafts on BMW 3 series?
The problem lies with the tension that is placed on the camshaft by the valve springs. Reduce or remove this tension, and you should be able to safely remove the camshafts without them breaking. How to achieve this?
What’s the proper way to install a camshaft?
Assemble the timing chain and cam sprocket while aligning the timing marks properly, and torque the cam sprocket bolt or bolts to the proper specifications. Next, lubricate and install the lifters, always using a new set of lifters, for proper tappet-to-cam-lobe contact (Fig. 2).
What should I do if I cannot find the timing marks on my camshaft?
If you cannot find the timing marks, DO NOT remove the camshaft – consult a motor manual. After removing the timing chain and lifters, place the cam sprocket back on the camshaft and revolve the cam in the block by hand and observe how freely it turns. Your racing cam should also turn this freely in the block, when installed correctly.
How do you replace stock spring on camshaft?
After removing the stock spring, place the new spring retainer and split locks back on the valve and pull up on the retainer, to simulate the tension of the valve spring. Now, measure the amount of free travel between the top of the guide and the bottom of the retainer.
Is the exhaust valve open on a radical cam?
(Both intake and exhaust valves are slightly open at T.D.C., and for up to 60 degrees on either side of T.D.C. on a radical cam.) In the early days, any unintentional overlapping was considered detrimental.