R3 side seals

[AndyBrad]

Just a quick and easy (i hope) question.

I read that with the R3 the sideseals were coded to the rotors so you didnt need to cut them. Is this correct? If so is this a reason for the apparent side seal failures ive been seeing on facebook?

Is there a difference between them and the S1?

[delta0]

I had a random long startup when warm last week which spooked me. Hasn’t done it since. Should be with Aston in the next couple weeks for a caliper change so I will investigate. Compression was done around 1000 miles ago and looks fine but these things can deteriorate quickly..

[AndyBrad]

aye im ok (touches wood) atm but im seeing loads of people mention it.

[13Black]

It's not an R3 specific thing.

S1 rotor side seal grooves are stamped with their respective length's letter so that Mazda can just pop in a certain length seal from a tray and they'll know that it's not too tight.

IMO this isn't ideal - you can't beat a hand-cut seal to the perfect tolerance.
There's about 10x as much gap between a just-right seal and the maximum allowable.
Gap is power and longevity you're wasting.

[AndyBrad]

ah
so its no r3 specific. ill go away then...

[13Black]

Nooo, pls stay.

I don't know if they did it any differently on R3's but I'm not aware of them changing their ways.

What deez R3 side seal failures you're hearing aboot anyhoo?

[AndyBrad]

he i didnt mean it like i was taking my bat and ball home

just seen a few on the facebook page of the r3 owners. dans had a few, someone said that RR had told them side seals were a weak point on the r3. im just wondering why. i.e. if you had an r3 like me is it worth rebuilding early to upgrade something and prevent failure?

[warpc0il]

When this "pattern" was first raised there was some speculation that it might be triggered by the increased oil pressure of the R3 engine, though I was never convinced.

However, it might be the changes in the engine block breather system, aimed at reducing oil burps, that's a contributing factor - or not

[AndyBrad]

hmm

it appears that there is something though.

on the plus side the bearings last longer but it just seems to have moved the issue.

[AndyBrad]

basically this is me waiting for the inevitable wondering what (if anything) could be changed on an r3 when its rebuilt to ensure longevity.

[geofftl1000r]

It's called "rotary paranoia" - and there's no cure

[AndyBrad]

[350matt]

well apart from having a spare engine in the shed ...

[AndyBrad]

this is what i am contemplating

buy a knackered one off ebay and build it in my spare time.

[kopite72]

Park it up and use as a weekender, guaranteed to triple the life of the engine

[AndyBrad]

thats cheating.

and means ill need to sell it to buy a golf or something

[kopite72]

yeah but you'll have a pristine car

[Dr. FrankenRex]

*waves*

Yep, I've had a few, although the more I investigate, the more I think it's down to external factors rather than the engines themselves.

My first one had recently been moved from one car to another, shortly after (less then 4k miles) it popped a side seal. I never bothered to tear it down, so don't know the cause specifically, other than it was side seal failure.

The second side seal boom was on my current R3 that had a broken vacuum line on the UIM. This is, as far as Josh @ RR can see, the main cause for failure as the rest of the engine seemed healthy - to the point I could have just had the seals replaced and the engine re-assembled and all would have been fine.

I think, personally, the reason side seal failure is taking R3 engines isn't that they are specifically more common, but that other types of failure are less common on the R3. For example, there are very few instances of failed stat bearings on the R3 - most likely down to the increased oil pressure. Likewise sudden apex seal failure appears to be less frequent, as well as lost compression, due to the 3rd injector. I'm not sat here saying the R3 engine is bomb proof, we all know it isn't infallible, but I think that the number of failures due to other factors is lower - as such the side seal is potentially getting the blame as Mazda 'fixed' a couple of the weaker points of the S1 engine.

[warpc0il]

That's been my logic in this regard.

Improve reliability in some specific areas and your remaining common failure mode is going to rise to the top.

[AndyBrad]

good point.