Is it better for bent valves and damaged cylinder heads to be repaired at a machine shop, or should they be replaced with new cylinder heads instead?

Depending on how extensively the damage extends and the level of knowledge that your mechanic has, it might be necessary to replace damaged cylinder heads or else repair them at a machine shop where they are bent valves. Remember to see an expert in order to make a suitable choice based on your case scenario. Here is some information on both choices:

Repairing At A Machine Shop:

1. Extent Of Damage: When there is little damage to the valve head and cylinder surface and this can be corrected by machining, the solution could be repairing at a machine shop at a low cost. This usually involves re-cutting valve seats and resurfacing so as to put them back into shape.
2. Price: The price of fixing damaged components in a shop is much cheaper than buying new heads as much as possible. Consider what it will take in terms of costs versus replacing.
3. Experience: Machining process that makes use of advanced machinery with experienced technicians happens only in machine shops. This situation works well if no change has been done on the original parts’ integrity or performance during rectification.
4. Compatibility: Having existing cylinder heads repaired would ensure compatibility with engine and other existing components; which is very important for best engine performance.
5. Time: It may take longer to repair damaged parts at machineshop because they are disassembled, machined and reassembled again. Think about how long you expect your car not to be used while making such decision as this one.

Replacing With New Cylinder Heads:

1. Extent Of Damage: Cracks, severe warping or multiple bent valves signify massive damage that implies replacement for cylinder head. The structural integrity of the cylinder head becomes compromised due to heavy damages which would make repairing impossible.
2. Performance And Longevity: Your engine will have no lingering concerns over rebuilt parts when installed with new heads; fresh start approach does it all!
3. Warranty: In most cases warranties come with new items like those found in cylinder heads thereby making someone less worried about same problem in near future.
4. Time: As compared to machining and repairing existing ones, replacing cylinder heads by new ones is a faster alternative hence this decreases vehicle downtime.
5. Upgrades: Replacing cylinder heads could provide an opportunity to have some upgrades done on the performance of the vehicle which may not be possible if older repaired parts are used.

To sum up, decisions about whether to replace damaged cylinder heads or repair them at machine shops will rely on various factors such as your engine’s specific circumstances and professional advice. For minor damages, they can be fixed but for major ones replacement may be required. Its aim is to ensure a safer and more efficient engine operation so seek advice from specialists that will work best with your car needs as well as your affordability.