I'm having a fundamental disconnect as to exactly what the difference is between the side seals in the S2 that make them better/more reliable compared to the S1's (this comment was made in more than 1 thread I was reading recently, sadly I can't find and quote the exact post - as this basis for my misunderstanding could be completely incorrect to begin with).

From what I've been able to find - the "extra long" side seal (#N3Z5) was added to 2008 model year cars, as well as the S2's thereafter. However, I don't see how this set up is more reliable/better in any way than the S1's? Is it not so much the side seal itself but how its lubricated in the S2's that makes it a "superior" design/less likely to fail (theoretically at least)? Should I be looking at differences in the side seal springs and not the seal itself?


I do apologize for this question, and perhaps it should be asked in the dumb questions thread, especially since ASH8 has gone through the enormous effort of posting all the parts diagrams and differences between the different series (which I'd like to say THANK YOU for doing!).

Sorry for my ignorance and I appreciate the help.

 

AFAIK there is no different side seal spring (11-C17B-N3H1) just the side seal itself. The longer side seal helped remedy issues with clearances that were initially designed as far too loose. Ideally, one would get an uncut side seal and cut to the exact clearance they need, but i think that the goal here from mazda was to get as close to spec as they could as they reassessed clearances over time.

 

Incorrect..on all accounts

For the record, MAZDA (Japan) has never recommended cutting/filing of Side Seals for Renesis Engines, they still do not, yes it was done for most older RE's, the Mazdatrix website is wrong/misleading where some here get their information from.

All Renesis Side Seals are size coded (Mazdatrix also has this wrong with their made up (group turned around) Part Numbers/List) depending on manufacture of Rotor SS groove length @ the time of making of Rotors, every Rotor is stamped with an ALPHA letter, you then match correct Side Seal to the stamp letter on Rotor.

Mazda Japan introduced another new Side Seal (taking the size variety from 4 to 5) from production date of November 1, 2008.

Side Seal Springs..

There are only 2 different Side Seal Springs, one with Blue marker paint and the later with Pink paint, the later (pink) is the stronger SSS.

All Renesis used the blue tagged N3H1-11-C17A (including Series II) up until production date February 1st, 2009.

From Feb 1, 2009 the pink N3H1-11-C17B was used in production and is now the only SSS sold.

N3H1-11-C17A supersedes to N3H1-11-C17B.

************************************************** ****************************************

THE correct Side Seal Part Number List and Rotor Use.

N3Z1-11-C10D Side Seal for Rotor letters.. F,G,H & I
N3Z2-11-C10D Side Seal for Rotor letters.. J,K,L & M
N3Z3-11-C10D Side Seal for Rotor letters.. N,O,P & Q
N3Z4-11-C10D Side Seal for Rotor letters.. R,S,T & U
N3Z5-11-C10 Side Seal for Rotor letters.. V,W,X & Y. From Series II Renny Production date November 1, 2008

 

Ash, you should change your user title to "Rainman for Rotaries"

 

they don't recommend synthetic oil either ....

or "Reads From Product Catalog"

 

At least I can read...

 

lol

 

Technically that's MNAO, not Mazda Japan.

 

You wouldn't expect Picasso to paint by the numbers, just kindergarten kids. Now translate this to the average Mazda service personnel and you have a more accurate read on the situation. A real professional won't use a straight file either fwiw.

 

I guess there isn't any chance that Mazda uses the newer side seal in their re-manufactured engines?

 

And obviously some people can't even handle painting by teh numbers ....

 

FWIW Obviously you have never re-man any rotary as Mazda has been using paint (also alpha letters and numbers) to mark internal Rotary parts for the past 40+ years. .paint-blue, white and now pink.

Pick up some oil control ring springs also and see the small colour paint marks on the END of the spring tip also used to identify the part.

Yep Mazda Japan are very unprofessional.

WTF Picasso has to do with it...the Paint and Letters is for component IDENTIFICATION @ manufacture assembly and after market reman and parts supply and correct Side Seal cut length.

 

that has no reference to the thread subject, but whatever

 

If there are benefits in the sealing upgrades then is it worth upgrading to S2 rotors in a S1 engine?

 

There has been no change in Rotors since April 1 2005 production (S1)

S2 uses the exact same Rotors...what did change was an additional (new) Side Seal cut length in 'some' manufactured rotors and updated Side Seal Springs for all rotor use.

One can use the latest SS spring, but you only use the new side seal (without adjustment or filing) in Rotors stamped..V, W, X and Y which is new in 'some' S2's ONLY, used from November 2008 production.

There has been no data to prove that a tighter (longer) fitting Side Seal has any benefits (like blow by, or 'better' compressions)...can also give problems.

Some re-builders outside of Mazda like to fit-file a tighter tolerance Side Seal, Mazda does not and never has for Renesis, to the very last MMC Japan produced Renesis engine made in 2012 they still used the exact same Side Seal for Rotor alpha table for Side Seal length I posted above.

Nothing else has 'changed'..

 

I assume an engine that has been hand built and properly balanced can afford to have tighter clearances. This is something that cannot be achieved in a mass produced factory.

 

Not in relation to Side Seals,

IF it is too tight normal expansion of side seal when hot (remember Side Seals get way way hotter than any previous peripheral ported rotary engine Side Seal) between Corner Seals can actually jam SS in tight allowing little to no movement when engine is hot, long term the Side Seal Spring is compressed and weakened..longer term Side Seal failure = Engine failure.

IF Side Seal is too loose when hot then reverse occurs, but, while blow-by (@ CS to SS) might be higher the Side Seal Spring cops and even worse hammering, basically it (wears out) breaks and end result can/will be Side Seal failure...hence updated PINK SS Spring for all new engines and rebuilds.

I had this recently confirmed by WW @ MA, many here (in US) who do rebuilds (privately or non Mazda) will not agree about Side Seals gaps.

Please don't get me wrong I believe Mazda did have SS tolerances incorrect in earlier Rennys @ production level inspection and laser measurement and letter stamping of Rotors which was rectified from late 2005.

Is it perfect..NO...will it ever be...NO (IMO), not while Side Seals are exposed to hot (higher) exhaust temps...Mazda has no alternative, Peripheral Exhaust Porting will never happen again, unless there is a different fuel/combustion process.

Maximum allowable gap (cold) between SS/CS is 0.2mm (0.008") for each end of Side Seal to Corner Seal, or 0.4mm (0.016") combined gap.
If "gap' is greater Side Seal is replace from above alpha parts graph (Rotor stamped) with factory pre-cut Side Seals.
Minimum all new is 0.2mm (0.008) combined gap.

 

Sometimes a proper compression tester like mine (# see pic) can show 'where' an issue is.

You can have 2 good (fair) compression numbers (PSI-kPa-kgf/cm2) for 2 of the 3 Rotor faces*, and 1 with a lower number (fail).
This usually always means there is an issue with Side Seals or Corner Seals...usually Side.

If you get 1 good-fair compression number and 2 with poor (fail) numbers this can also point to a worn/bad Apex Seal(s) and or 2 Side/Corner Seals or both even...also usually hot start issues.

*For one of the two Rotor banks.

There are exceptions and other variables..
I have seen 5 out of 6 faces pass good with 1 fail, engine starts OK, even goes OK, but gets a crappy gas mileage...usually 'a' slow engine death with a bang/crunch (a total Side Seal failure on that fail face) in the end.

# OE Mazda RE (USB) Compression Unit can test both Rotors (1+2) at the exact same time, which only needs one engine crank (starter) turn over, results can be emailed/printed/saved.

 

[QUOTE=ASH8;4475877]Not in relation to Side Seals,

IF it is too tight normal expansion of side seal when hot (remember Side Seals get way way hotter than any previous peripheral ported rotary engine Side Seal) between Corner Seals can actually jam SS in tight allowing little to no movement when engine is hot, long term the Side Seal Spring is compressed and weakened..longer term Side Seal failure = Engine failure.

IF Side Seal is too loose when hot then reverse occurs, but, while blow-by (@ CS to SS) might be higher the Side Seal Spring cops and even worse hammering, basically it (wears out) breaks and end result can/will be Side Seal failure...hence updated PINK SS Spring for all new engines and rebuilds.

I had this recently confirmed by WW @ MA, many here (in US) who do rebuilds (privately or non Mazda) will not agree about Side Seals gaps.

Please don't get me wrong I believe Mazda did have SS tolerances incorrect in earlier Rennys @ production level inspection and laser measurement and letter stamping of Rotors which was rectified from late 2005.

Is it perfect..NO...will it ever be...NO (IMO), not while Side Seals are exposed to hot (higher) exhaust temps...Mazda has no alternative, Peripheral Exhaust Porting will never happen again, unless there is a different fuel/combustion process.

Maximum allowable gap (cold) between SS/CS is 0.2mm (0.008") for each end of Side Seal to Corner Seal, or 0.4mm (0.016") combined gap.
If "gap' is greater Side Seal is replace from above alpha parts graph (Rotor stamped) with factory pre-cut Side Seals.


Sorry for resurrecting this old thread. Was hoping to verify the Minimum side seal to corner seal clearance of 0.2mm when using all new seals. I have the manual, but it only refers to the maximum gap (0.16mm) as far as I can see there is no mention of a minimum.

 

Whatever you do, don't use a flat file. An old rotor can be made into a nice jig ...



(Pic credit: therx7kid09)

 

awesome tip

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