I am waiting on my heads to finish my new motor. Machine shop just called and said excpect an extra week because all the intake valve seats were trashed. The exhaust ones are fine. He said they were way too loose to run them as is, and that he had never seen any beat up that bad.

I would assume this is why my car has been so inconsistant and a dog for years, but what would cuase it in the first place? Just 120k rough miles?

I would have gone 2.02/1.60 on my valves had I known I would be paying for seats anyways.

 

did the engine lose a piston?

 

Spring pressure or heat.

 

No, I spun #7 & #8 rod bearings.

Too much or too little seat preasure? My machinist said that my springs are good for my cam, however I ran them without checking install height or anything, just threw them on. He of course will be shimming them properly.

 

Could be either. Too little the valves will bounce,too much and they pound the seats. A bad valve job will make them thin and too much porting in that area will make them thin.
High chamber temp will do it too.

 

A vacuum leak will beat the intake valves and seats up because like LR said it creates a lean condition and very high heat for the intake valves...look for blueing on the stem for an indication of a temp problem.