What did you do to your Volvo today? Topic is solved

Post by **Sveedy** » 23 Jul 2025, 16:26

(You're preaching to the choir, in my case.)

Post by **abscate** » 23 Jul 2025, 19:06

Dr Oetiker here…you will assimilated! Clamping resistance is futile…

Post by **bmdubya1198** » 23 Jul 2025, 19:33

abscate wrote: ↑23 Jul 2025, 19:06 Dr Oetiker here…you will assimilated! Clamping resistance is futile…

Post by **Sveedy** » 24 Jul 2025, 15:32

Started back on rebuilding the head for the 850. Thanks to that evil Dr. Oetiker

, I have some new valves on the way, so my schedule has moved up a bit.
A couple of the other valves also had quite a bit of carbon build up on the stems, so looks more and more like bad stem seals.

Post by **abscate** » 24 Jul 2025, 20:16

Be careful with those broken valves. I’m not quite sure where the Metallic sodium is but that is not to be played with

Post by **abscate** » 26 Jul 2025, 06:01

I’ve always wondered what exactly happens here. Does a poor seat inhibit heat transfer and the valve metal softens to failure? What causes that gouging, is it hot gas acting like a torch or melting again?

Chieber · Post by **Chieber** » 26 Jul 2025, 12:01

Gained 10hp with an added spoiler!

At the cost of even more fuel consumption?

DennisCA · Post by **DennisCA** » 26 Jul 2025, 13:26

I took a pause from the 850 after I did some filler work and I needed to get some supplies too for painting. But tonight I got most of the stuff i needed and I've put a seal coat of 2k epoxy on one fender to start with.

So the idea is to let the epoxy cure, scuff it with P320 perhaps, then go to a high build primer, then metallic base coat, then 2k clear coat.

A lot happening tonight, a person dropped by and sold me these aluminum link arms too

Post by **Sveedy** » 26 Jul 2025, 14:19

abscate wrote: ↑26 Jul 2025, 06:01 I’ve always wondered what exactly happens here. Does a poor seat inhibit heat transfer and the valve metal softens to failure? What causes that gouging, is it hot gas acting like a torch or melting again?

My uneducated guess is that oil seeps down the stem when the engine is not running and sits there. Then when the engine fires up, that oil cooks off, but maybe leaves a little bit of residue. Repeat and repeat, and the build-up must get thick enough to retain the heat till one explosion and it blows that piece out. I'm imagining something like an oxyacetylene torch when you hit the oxygen lever.

Post by **volvolugnut** » 26 Jul 2025, 14:50

Sveedy wrote: ↑26 Jul 2025, 14:19
abscate wrote: ↑26 Jul 2025, 06:01 I’ve always wondered what exactly happens here. Does a poor seat inhibit heat transfer and the valve metal softens to failure? What causes that gouging, is it hot gas acting like a torch or melting again?
My uneducated guess is that oil seeps down the stem when the engine is not running and sits there. Then when the engine fires up, that oil cooks off, but maybe leaves a little bit of residue. Repeat and repeat, and the build-up must get thick enough to retain the heat till one explosion and it blows that piece out. I'm imagining something like an oxyacetylene torch when you hit the oxygen lever.

It sure looks like result of torch.
I think the sodium is in the stem only.
volvolugnut

What did you do to your Volvo today? Topic is solved

Re: What did you do to your Volvo today?