Mazda Rotary Club

Was going to order my rebuild kit other day. But found out the engine was ported I thought I best measure the tips. Toke one to workshop turns out they are 3mm tips.
I know the rotors have to be machined to take the bigger tip, but what is the reason for this, also do you use a single spring with them?
Only reason I can think of is you get 50% more tip size over 2mm, what else?
Are these alot more expensive over 2mm tips
Thanks guys
Sean

Are they 3mm in terms of depth or width?

If its depth, then i guess they\'d lose compression rather than get forced out of the rotor when it all goes tips up (excuse the pun)

Width, i have no idea, maybe better against det

3mm break just as easily as 2mm.
 
I think when they first started doing 3mm, it was thought the extra material would give strength for boosted engines, but in reality the modern 2mm seals will allow revving higher and take just as much punishment.
 
Cost wise, there doesn\'t seem to be much in it - not for performance seals.
 
I thought 3mm also used 2 springs, well my old engine certainly had a notch back cut into the seal and used 2 springs.

Just saw on old skool 10A stripped back ready to be rebuilt with stock 5mm seals lol

Quote from: BlitzBoy;737359Just saw on old skool 10A stripped back ready to be rebuilt with stock 5mm seals lol

You mean 6mm

Quote from: HaywardRotary;737370You mean 6mm

Probably I didnt measure them, but they look very prodigious lol

Hi Sean,

Do you know who built the engine before you stripped it as it may be an idea to find out if the tips used were Mazda or aftermarket ones as your rotors would have been sized for the tips that have been used

Flippin heck, 6mm apex seals?! :2eek

yes, the famous Apex Barriers :D

Hi

I used 3mm seals in my 20b when I first did the rebuild..in my previous engines (13bs) I always managed to blow the apex seals  :(

But in my previous 20b engine, last year, I experienced such a sever detonation that the side seals were half disappeared and the single spring under the 3mm apex seal was straight as ruler because of the heat-not only I experience that but the rotors had dents on them...But guess what, the 3mm seal never broke..it was straight as hell not even bent..I do strongly believe that 3mm seals are stronger coz I have a proven record..I still have the rotors and the 3mm seals for reference..

I am using 2mm at the moment on my new rebuild..but do believe that 3mm were stronger-many would say that when a detonation occurs nothing stops the seals from breaking and I share the same thoughts...but given what I said earlier, I think 3mm does helps..  

syed

I had 3mm seals det in a 13b - so they do break - and they make bigger holes in the rotors too :rollin

In most cases I\'ve only ever seen 3mm seals used where there is wear in the slot, and milling out the slot to take a new 3mm seal would reduce the risk of 2mm seal rolling and wedging.  As has been stated by others, I\'ve not seen a great deal of evidence to suggest benefits either way.

Usually material is a bigger factor, but different materials are quite pricey! :Giggle

3mms respond to det just as bad as 2mms, they cause more damage when they crap themselves too, if anything the weakspot with 3mms is the cornerseal


....e pic but you get the idea, i tested 3mms to destruction(note detonation ;) ) and were far worse than 2mm\'s in terms of damage caused as most of the 2mms went out the exhaust (note detonation ;) )
(http://i47.photobucket.com/albums/f170/mx1311/SP_A0115.jpg)
(http://i47.photobucket.com/albums/f170/mx1311/SP_A0116.jpg)
was all done on a bone stock block and same tune  :)

colum

Quote from: mx1311;737560....e pic but you get the idea, i tested 3mms to destruction(note detonation ;) )

Detonation noted :eek: Damn, that\'s a big dent, dude :2eek!

cheers for the info guys starting to understand it all know haha
 

Quote from: clive;737384Hi Sean,
 
Do you know who built the engine before you stripped it as it may be an idea to find out if the tips used were Mazda or aftermarket ones as your rotors would have been sized for the tips that have been used

it was an american company that built the engine before i got the car, found there company sticker on the block.. pettit racing.

3mm is a much stronger seal than 2mm end of story. They can take much more detonation before breaking be it in Ferrous or Ceramic materials.

Where 3mm is inferior is chamfer wear on the leading edge.

3mm generate much more rubbing friction and heat, and they bow much easier due to this, as they do then they preferentially wear in the middle on the leading edge, when the engine cools the apex seal is missing a chunk out of the middle of it and the compression and power suffer, some to the point of not being able to restart the engine.

2mm is best
3mm is strongest but needs some other running parameter changes to make them durable due to the extra friction.

I agree wid u Pete, I have witnessed this in my 20b..

Exactly wat u said above is wat happened to my previous engine!! I had sever detonation but the 3mm seal survived without a single breakage or bent..

Cheers
Syed

cheers for all that help guys..
any one know where in the uk is best to get 3mm corner seals from?
cheers
sean