Sunken Valve Seat

[RDWizard]

I just bought an 1988 Spider with 47,000 miles.
The cylinder head was removed when I bought it.
The dealer diagnosis (they left it in the glove box) was as follows:

• Vehicle towed in – won’t run – function check
• Fuel, ignition, engine
• Very low compression cyl’s 1+2
• Removed cylinder head / analyze engine
• Cam timing has changed- all 4 exhaust valves
• Show signs of hitting pistons – strongly suspect
• Failure of auxiliary timing gear
• Exhaust cam has bad lobe #3 cyl
• ______ valve seat sunken deep into head

My question is this.
What can I do for the sunken valve seat?
I can easily replace the cam and valves.
I want to get the car running before I spend more money on it.
Should I jump in and buy a rebuilt cylinder head or just fix the things wrong with mine?
The car has such low miles I wouldn't think that the engine has much wear.

[Alfaguy35]

Replacing a couple of sunken valve seats should not be a big deal. My question is what caused the seats to sink? I've only seen seats replaced because they had been ground to many times or they were taken out to do major port work on a head.

[RDWizard]

I am assuming that the previous owner revved the engine too high and that is what caused the timing to jump and the cylinder to smack the valve and valve seat into the head. This senario fits with the dealer diagnosis.

[alfaparticle]

Timing does not jump due to over revving these engines. The bottom end breaks. Look at the timing chain and sprockets and then try to explain how it can "jump". If the timing was off it was because someone set it up incorrectly.

[Alfar7]

Repairing 2 liter heads is more costly than replacing it. Most likely cams or chain improperly set-up. But valve seats typically do not sink. They are cut that way improperly.

[Alfar7]

Repairing 2 liter heads is more costly than replacing it. Most likely cams or chain improperly set-up. But valve seats typically do not sink. They are cut that way improperly.
Chain on lower cam drive is often left hanging with only the back teeth of the sprocket engaged,( because of engine tilt) then tightened leaving the failure a matter of record.

[rcess]

Quote:

Originally Posted by Alfar7 Chain on lower cam drive is often left hanging with only the back teeth of the sprocket engaged,( because of engine tilt) then tightened leaving the failure a matter of record.

[RDWizard]

I was just guessing about the over revving.
I don't know enough yet about engines to say so.

Ok. So if over revving would not allow the timing to jump,
then what would cause "Failure of auxiliary timing gear" as the dealer noted.
And what would be considered the "Auxilary timing gear"?
The valve is definitely sunken and the lobe on the cam is now flattened or deformed.