What would cause a valve to hit piston?

Valves hitting pistons means a timing issue. If the car has a solid metal chain and not a rubber belt the chances of it ever going out of time as a result of driving habits are so low it’s probably not measurable.

How can you tell if a valve is hitting piston?

Registered. Compression test all the cylinders, listen for “popping” through intake and exhaust. If a valve hit your piston you will know it.

Do valves touch the Pistons?

Cam lift and timing can put the valves dangerously close to the piston. and piston crown design, it’s possible that the valves can touch the top of the piston as it reaches TDC on the intake stroke.

Do Pistons close the valves?

Normally, the intake and exhaust valves close as the piston comes to the top of its travel in the cylinder. This is good because there is very little space between the piston and the valves at this point.

Does the piston hit the spark plug?

When a timing belt slips, it can easily take out a valve and leave it sitting on top of the piston. Then on the next rotation, the piston(s) has a nice sized foreign object to force right into the spark plug.

What causes a broken valve stem?

Most often, this fault is caused by a toothed belt that has jumped a tooth or is incorrectly adjusted. This causes the piston to collide with the valve, which has not yet completely closed (Fig. 2), during operation. When this happens, the piston and camshaft exert major forces on the valve stem.

Can an engine run with bent valves?

As mentioned previously, bent engine valves will affect how efficiently an engine runs (if it runs at all!). If one or more valves have been damaged by something like a broken timing belt, this will affect the performance of the engine, especially at low speeds or when idling.

What happens if valve clearance is too large?

Too much or too little valve clearance can result in poor performance or a rough idle because the engine can’t “breathe” normally and operate at peak efficiency. Too much clearance means the valves will likely clatter and, over the long term, cause damage to the valves, camshaft lobes or rocker arms.

How do you increase valve clearance on a piston?

Examples include resurfacing the deck of the cylinder block or cylinder head, going to a thinner head gasket, increasing the ratio of the rocker arms or installing a high-lift camshaft. Opinions may vary between piston and valve manufacturers, but a popular consensus is a minimum clearance of .

Are both valves closed at TDC?

It’s up to you. Both valves should be closed if it’s TDC at the end of the compression stroke. If it’s TDC at the end of the exhaust stroke, you should be in the valve overlap zone, with the intake valve partially open and on its way to opening fully, and the exhaust valve partially open on its way to closing.

What causes bent sparkplugs?

Two things that cause bent electrodes. Either physical bending caused by piston contact from piston/rod assembly stretch or softening due to high combustion temps or the plug heat range is too high or the reach is too long.

Why do spark plugs Bend Hemi?

Something either hit the spark plug or the head gasket might have gone out and filled the cylinder with water then smashed the plug which may cause white smoke. Or whoever put the plugs in May have dropped it before they installed it and bent the electrode.