I have a 1979 12a engine, and this is its first rebuild do to "leak of death". The original seals completely filled the channels they where in.
I got the 79-85 12A Rx7 Engine Gasket Kit (N201-89-100B) from Atkins, and was test fitting things last night and noticed that the water seals do not fill the width of the grooves. There is enough space for over half of another seal.

Water Seals do not fill channel

I've already found out that this kit is not actually for 79-80 SA engines, it's for 81-85 because it comes with the wrong intake and exhaust gaskets. So, is this also an issue of the channels changing size between the 79-80 and the 81-85 SA engines?

 

its the same part number water seals from Mazda, are there any Mazda tags on the stuff they sent you?

 

Could the gap be for compression of the o-ring and space for the Hylomar?

 

if the seal fit the groove, it would try to squeeze out between the housings as they compress when the housings are stacked and bolted together.

 

I just checked the Parts Catalog, and the number in there does match the Part number on the package the o rings were in, so I guess the space is for the compression. I got some hylomar to put in there too.

 

Well, looking stuff up on youtube, and Im not so sure now. In this video, they are building a 13b, but still, the seals more fully fit.

 

If the seals fit the full width, they would not be able to compress.

The old seals "fit" because they had taken a permanent set when compressed. They looked like your new seals when they were new.

 

Thanks for the info, I got the keg back together yesterday.

 

Damn good looking motor! Nice work

 

Let's hope it runs

 

One thing you could do to test the seals before installing it would be to do a leakdown test on the water system. This will test those seals.




Cooling System Pressure Tester (CSPT)