How bad is this? Only appears to be on the front housing, along the bottom section. Worst in the center, tapers out near the edges.



Useable? Fixable?

What would cause this?

I'll grab some better pics shortly

 

more pics






I lied, it's on the top section too:



Sides look OK tho:





you can see corresponding wear on the apex seals where the chatter was worst right in the center



and the other housing is way better






any opinions are appreciated!

 

both housings above the exhaust port look rough, are they smooth? can your fingernail catch anythjng? they both look fairly reusable, just above the exhaust port is what i question

 

im pretty sure it was smooth above the exhaust ports, just looks discolored, but i'll double check that tomorrow, thanks

 

how high were you revving it?

did it ever run hot or actually overheat?

 

never overheated that i know of, but it was a used engine i bought, i only ran it for half a season last year, probably put under 2k kms on it

i never revved it very high either, maybe 7.5-8k tops. s5 internals

 

take a dowel pin wrapped with 150-220 grit wet sandpaper. 3m has some clear stuff at home depot that works realy well. keep it nice and wet and sand it down. I smoothed out some housings I thought were unusable.

 

theres a very small indent right at the center immediately above the exhaust port, nothing too major i don't think

 

interesting, thanks for the idea

 

Click here:https://www.rx7club.com/build-thread.../#post11852880 to see the after, and before. i run my fingernail over it and after some sanding the ridges go away so it definitely works, even though the camera still shows some there. something is better than nothing.