I was using a pair of old metal rings as per the FSM to press them in.

Scathcart makes a good point about the thicker rings not being able to move freely as well, maybe thicker isnt better?

I did have multiple problems with the viton water seals. I try to save money and it winds up costing me more. Really, I haven't heard of too many people melting oil seals, compared to low oil pressure problems. I'd stick to the stock. Proven in race cars for how many years now? I can see if they were alot cheaper, especially in gas prices these days though. ?!!

Nothing wrong with amending the FSM to cater to aftermarket components. :)

I've never had new stock rings to compare to the viton ones, but I think the main difference isn't in dimension, but in hardness of the material. The viton rings are 75 durometer where the stockers would likely be 65 or less if they were rated.

I understand the idea about the stiffer material not moving as freely because of increased friction against their bores, but mine have always moved in and rebounded very freely after installation when I checked them for free movement. Ditto for an engine I just pulled apart after 1500 miles (turbo failure related).

Maybe he used a different variety of o-rings than those currently offered by atkins. I know the inner rings that I sourced out were definitely too thick.

So you can reuse the oil seal o rings as long as they're viton? Im currently rebuilding my 12a and all i need left are the o rings, the original ones were oem but i snatched some viton ones from an extra 13b i have, should these be fine then? Ive been using a good grip of 13b parts on the 12a haha

Also my apologies for resurrecting an old thread:dunno:

if they're not extremely squared off, yes.

alright then ill have to see whats up with them then haha thank you:crackup:

for water rings I just use oring cord. 2.2mm NBR for outers and 2.4mm Viton 75 shore for the inners. Ive been doing this for the past 6-7 years on track and street engines and upon disassmbly the rings are flattened a bit I didnt have an occasion yet where an engine devloped a leak.

for the oil rings last years I seem to have issues with stockers (black renesis ones) on oir 13B PP. Maybe due to the oil used being full synthetic? (Total HTX 860 10W60) or premix (Idemitsu) not playing together?

on disassembly the orings come out on multiple pieces and oft also the rings are damaged/cracked.
https://cimg3.ibsrv.net/gimg/www.rx7...768ae9e1d.jpeg

https://cimg4.ibsrv.net/gimg/www.rx7...e55206110.jpeg
https://cimg9.ibsrv.net/gimg/www.rx7...52c9ffe95.jpeg

In a used rotor I bought I found a orange inner o-ring. It was remarkable soft/low shore, softer then the mazda green ones.

anyone has a clue where it originated? Fit was perfect.


https://cimg2.ibsrv.net/gimg/www.rx7...adb521f73.jpeg

still searching for these.. upon disassembly auf our 13B PP one of the inner green oring was also swollen/expanded. it had like 5mm slack when slid over the inner oil control ring. This is after about 5 hours of race use. the other green inners and black outers were still fine. this orange ring I also had in the engine and it was still perfect soft w correct fit.

We switched from full synth total quartz 10w60 oil to 15W50 MOTUL Classic oil hoping that the additives were the cause of the early failure of the orings. As premix w still use the idemitsu oil

I did come across these where the outers appear to be the correct colour:
https://www.ebay.co.uk/itm/122102482548