What is this buildup on my valve seats?
Thread Starter
Launching!
Joined: Dec 2015
Posts: 246
Likes: 1
What is this buildup on my valve seats? After I pulled my head off and took it apart, I found a weird substance in the exhaust ports and on the seats. Cant say I have seen something like this before. I first thought it was rust but it really doesn't seem like it is. It feels more like sand then anything. Does not leave the normal orange residue on my finger when I touch it like rust normally does. Not only that, but there are white chunks inside the exhaust ports too. Not all the ports, only a few.
What is it and what caused it?
Quick recap on the engine. No its not an LS but that shouldn't matter.
- Has around 350 miles on it
- Exhaust valves were bent and not sealing
- Guides were wasted
- 91 octane only no additives
- No signs of a blown head gasket
- Blower with 10 psi boost. 11.7 afr
- Pictures were from after an auto-x event. Ran it hard, shut it down and pulled it apart
What is it and what caused it?
Quick recap on the engine. No its not an LS but that shouldn't matter.
- Has around 350 miles on it
- Exhaust valves were bent and not sealing
- Guides were wasted
- 91 octane only no additives
- No signs of a blown head gasket
- Blower with 10 psi boost. 11.7 afr
- Pictures were from after an auto-x event. Ran it hard, shut it down and pulled it apart
Looks like rust to me...maybe some other by-product from high temperature combustion of hydrocarbons. I have seen white on exhaust valves alot on turbo cars. It must be the product of carbon deposits burning off? Let me ask the chemical engineers here at work....I am just a mechanical engineer that designs the engines.
Thread Starter
Launching!
Joined: Dec 2015
Posts: 246
Likes: 1
Thanks. That would be awesome! And BTW, there was nothing like that on the valves themselves. Only the seats and ports. There was nothing in the header either. Just trying to figure out what causes this. I mean if this is only after 350 miles, what is it going to look like in 5000 miles? I am hoping it was due to the valves not sealing letting stuff pass by. Maybe I did have a blown head gasket? The piston that was in the same hole as the above pictures was a little wet and all the others were dry...
