What causes an engine to drop a valve seat?

overheating is the main cause of dropping a seat, simple way to prevent it….. Don’t overheat it.

Why do valve seats drop Hemi?

Overheating greatly increases the risk of something warping and allowing a valve seat to drop. In fact, almost all valve seat drops are on an engine that’s overheated once in its life.

How much does it cost to fix a dropped valve?

It might take 7 hours (very rough) to replace the one head that has the broken valve, so 7 hours of labor is roughly $630. So, adding in a little for the incidentals, at minimum, it’d cost at least $1,000 if you just replaced the head to solve the problem but that assumes that no other damage is found.

What does a dropped valve seat mean?

Valve seats drop because the area where the seat is either too big or the aluminum head expands quicker than the steel. Once you have dropped a seal, its then up to the machinist to get the fit correct, hopefully the seat didn’t do too much damage, enlarging the recess. There is only one size seat for the valve size.

How many valves does a 5.7 Hemi have?

The 5.7 Hemi engine has aluminum cross-flow cylinder heads with two valves and two spark plugs per cylinder. The HEMI-shaped chambers now have a flatter design with squish shelves on both sides, increasing efficiency and reducing emissions.

What does a burnt exhaust valve mean?

Burnt valves occur when the valve can no longer seal correctly after excessive temperatures have damaged the material of the valve. The typical causes of burnt valves are allowing the vehicle to overheat or incorrect fuel being used.

How long does a valve job take?

Pros bill for half an hour to an hour. If you haven’t done it before it’s going to take you longer than 20/45 minutes. The time going to vary based on how many are out of spec. If you have to adjust all 16 it’s going to take you longer than if you only have to do 2.