Do new cylinder heads need to be resurfaced?
Cylinder heads may need to be resurfaced; to restore flatness or to just improve the current surface finish. A cylinder head may need to be resurfaced; after welds or other repairs have been made; or milled to increase the compression ratio.
When does it make sense to replace a camshaft?
A warped cylinder head could theoretically also warp the cam shaft but i would not just replace it, i would check it first. Place the cam in a set of V blocks. Put a dial indicator on the bearing surface and spin the camshaft. Watch how much the dial indicator deflects. The appropriate engine manual will have the warpage specs.
How can I tell if my camshaft is warping?
Place the cam in a set of V blocks. Put a dial indicator on the bearing surface and spin the camshaft. Watch how much the dial indicator deflects. The appropriate engine manual will have the warpage specs. The more subtle problems arise from lobe wear. A valve that does not open all the way could cause strange problems.
What kind of damage can a cam do?
The first damage seen would most likely be oil boiling out of the bearing surfaces causing metal to metal contact damage. Heat damage that was enough to warp the head would almost certainly have destroyed the piston rings also. Possibly a seriously over heated cam, maybe from a lack of oil.
Can a cam lobe be reground to regain lift?
Theoretically the worn cam lobe can be reground to regain the lift. The problem with this technique is that not every valve train can compensate for the reduced base circle. Any car with adjustable valves can usually tolerate this. Any car with only hydrolic lifters normally can’t.
A warped cylinder head could theoretically also warp the cam shaft but i would not just replace it, i would check it first. Place the cam in a set of V blocks. Put a dial indicator on the bearing surface and spin the camshaft. Watch how much the dial indicator deflects. The appropriate engine manual will have the warpage specs.
Are there two camshafts in a four cylinder engine?
So in an inline four-cylinder engine with a SOHC, there would simply be a single camshaft in the engine’s head. But in a V8 with SOHC, there would be two camshafts overall (one on each side of the V). The most extreme camshafts come in the shape of those featured on the Bugatti Veyron.
How are camshafts and crankshafts different in a DOHC engine?
While a SOHC system has a camshaft that completes both the intake and exhaust stroke valve movements, a DOHC system has two camshafts above each bank of cylinders – an intake camshaft and an exhaust camshaft. So in an inline four-cylinder engine with a SOHC, there would simply be a single camshaft in the engine’s head.
Why are the valves on a camshaft spring loaded?
This allows the air/fuel mixture to enter the cylinder and then the exhaust gases to leave the cylinder at the required time. The valves themselves are spring-loaded, meaning that once the lobe has done its job of opening the valve, it naturally closes as the spring becomes uncompressed.