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-   -   Chrome flaking between plugs – OK to rebuild? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/chrome-flaking-between-plugs-%96-ok-rebuild-1135222/)

derSchwamm 04-18-19 07:48 AM

Chrome flaking between plugs – OK to rebuild?
 
I've been looking hard for a replacement housing and I found one in good shape except for a small bit of chrome missing between the spark plug holes. How big of a deal is it to be missing chrome there? My other housing has a tiny bit of chrome starting flake between the plugs on the opposite side, so I feel like they'd be relatively well matched.

Is this one worth using in a rebuild?

https://cimg9.ibsrv.net/gimg/www.rx7...058b6d056b.jpg

Ckforker 04-18-19 10:12 AM

Are the edges just dirty? It's hard to see them, but if they are good, the little bit by the plugs doesn't look bad.

Others will weigh in with more rebuild experience..

derSchwamm 04-18-19 10:16 AM

I think a lot of it is dirt, but chrome is missing along the left edge right on the 'hump' between the two plugs and that's what concerns me. This is my first rebuild so I don't know enough to say

t_g_farrell 04-18-19 01:16 PM

Usually you see chrome missing on the edges down right before the exhaust ports. Never seen it between the plugs. Its on the left edge in the picture correct?

derSchwamm 04-18-19 01:53 PM


Originally Posted by t_g_farrell (Post 12342454)
Usually you see chrome missing on the edges down right before the exhaust ports. Never seen it between the plugs. Its on the left edge in the picture correct?

Correct - left edge about in the middle of the plugs. I haven't seen it here either and the chrome is all intact in the entire rest of the housing. I am unsure how chrome missing in this section would affect compression and since it's uncommon I'm not turning up much searching on the forum

chuyler1 04-18-19 03:11 PM

I'm no expert, but I'm guessing it has little effect on compression as the apex seal will pass over this area at the absolute beginning of the compression cycle, which is the same time that the seal is crossing the spark plug holes as well. Will it run? Yes. Will it be faster than someone with better housings? No.

LongDuck 04-19-19 09:56 AM

If you think about the peritrochoid motion, that's also the slowest velocity point of apex seal movement, so I'd not expect to see flaking there and not somewhere more common, usually on the sides of the housings near the exhaust ports.

derSchwamm 04-19-19 10:24 AM


Originally Posted by LongDuck (Post 12342628)
If you think about the peritrochoid motion, that's also the slowest velocity point of apex seal movement, so I'd not expect to see flaking there and not somewhere more common, usually on the sides of the housings near the exhaust ports.

I know it's strange, but I have pictures of the rest of the housing and I don't see other chrome flaking, not even at the bottom

derSchwamm 04-22-19 05:54 PM

Bump....

Anybody know how this housing would be in a build?


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