P80 Burned Valve Discussion Thread - attendant with Data set

greg850r · Post by **greg850r** » 22 Mar 2019, 10:09

Upon cleaning things up I found numbers around the tip of the valve stem. I pulled out an old head I know was from a turbo and robbed a valve. It differed only by one number. donor valve stamp - 'N5 1366490 UT'. The ones out of the head I'm doing - '05 1366490 UT'.

Also all valves in the failed head had similar build up on the stems, with most of them showing black spots at least 1/3 of the way around on the mating surface of the seats.

Post by **erikv11** » 22 Mar 2019, 13:03

abscate wrote: 22 Mar 2019, 08:56
erikv11 wrote: 22 Mar 2019, 07:33
tardcart wrote: 22 Mar 2019, 04:32 I wonder if the bare casting is the same? I think the higher compression of the NA is from the pistons. ...
Yes, same casting, yes it's from the pistons not the head. You can swap heads NA<>turbo the fitment is perfect, however as discussed the turbo head has sodium exhaust valves the NA doesn't so the swap should only go one way, turbo head unto an NA is ok.

Those Volvo Turbo exhaust valves with Sodium (not NA ) are a scant $85 each by the way - thats $850 in valves if you replace them all.

9454610

Or about $50 if you grab a head from the scrapper.

Post by **abscate** » 15 Mar 2021, 04:52

Picture of my burnt and pied #3 exhaust valve on my T5 at 260k. Root cause, badly worn stem seals

Recommend against 15F fir this job.

Azik09 · Post by **Azik09** » 20 Mar 2021, 07:11

erikv11 wrote: 22 Mar 2019, 08:37 The head castings are identical ...

Wrong. Combustion chambers in NA and turbo heads are different.

Post by **abscate** » 25 Dec 2025, 02:57

Those are indeed different.

On a 1999 2000 also complicated by having to match VVT

1999 NA no VVT
1999 2000 exhaust VVT
2000 NA intake VVT.

Cylinder head has to have the oil ports for the VVT solenoid, of course

2025 DeC update. Sodium filled turbo valves are no longer available new