Apex seals. How precision!?

[leeroy_25]

Just having some thoughts about rebuilding my FD3 engine. What are the apex seals made out? I presume they are cast/extruded high carbon steel that has been precision ground to size? What is stopping me making some new ones myself that are slightly thick hence stronger? I have read you can get thicker ones anyway but being that they cost quite a bit if I get a man with a surface grinder to do some? surely? What say thee? maybe there is more to the seal than I think? to be honest I have not properly seen one in the flesh.. hence I am asking? If they are just a solid piece of steel I am sure this is something I could get done? Also I have heard some rumours about coatings that are being experimented with that I think could help prolong the life of the apex seals.

[20B_boy]

If they were so simple to make stronger/better/break proof, I reckon Mazda\'s R&D budget would\'ve cracked it by now

[leeroy_25]

Haa Haa! LMAO! :evillaugh

I didn\'t mean I could do a better job of making them! I meant that potentially I could get a set made just the same but cheaper than joe public can buy them for as I am in the manufacturing/design line of work and have a lot of contacts! From what I can see so far (although I might be missing something) they are very expensive for what they are! Maybe Mazda have designed them in such a way that they don\'t last on purpose! Unlikely! But I do know for a fact that there is a coating being tested in aerospace that could be beneficial?? I am trying to find out more but obviously the industry is a little hush hush! That\'s by-the-by anyway.. My first point is trying to make some apex seals myself.. Now I think from memory standard ones are 2mm thick and you can get 3mm competition ones which I assume are stepped to fit into the groove on the rotor?


Lee

[ro284]

Now I think from memory standard ones are 2mm thick and you can get 3mm competition ones which I assume are stepped to fit into the groove on the rotor?

No they are not stepped, as far as i know, the grooves are machined out to take the 3mill seals, i would not try experimenting with this personally, it would be all too easy to wreck the housings trying to save money!

they are very expensive for what they are! Maybe Mazda have designed them in such a way that they don\'t last on purpose!

i think it unlikely Mazda would make something inferior that would not last, i think the idea is to make rotary engines as reliable as possible

[Timmy]

Yeh other companies make seals and they don\'t last any longer.
As for material i got a feeling they are softer rather than a harder material, also ceramic seals are also availble.
And yes the rotor is machined out to take the larger seal.

[Stevie Boy]

I thought i read somewhere that the "thicker" 3mm seals create more resistance of the rotor as it rotates in the rotor housing, therefore having an undesirable effect of reducing the engines ability to "Rev-up".

[arrouk]

please use the search as this has been covered soo many times

matt

[noyzboy]

If they were so simple to make stronger/better/break proof, I reckon Mazda\'s R&D budget would\'ve cracked it by now

As these are crucial to the engine, I think you should rely on the tried and tested products and put your money and effort elsewhere.
 If you came to sell the car, and it came out that the seals were home made, any buyer would knock £3K off the price for a rebuild.
They would also start to wonder what else you had "prototyped". Don\'t do it.
Would you buy a "boinger" with home made piston rings

Martin H

[sadgoth]

Apex seals aren\'t exactly the most expensive part of the rebuild, housings , rotors and endplates are far more costly and the risk of damaging any of these more expensive components makes saving a hundred quid on seals less appealing IMHO

[stuart wizy]

Just having some thoughts about rebuilding my FD3 engine. What are the apex seals made out? I presume they are cast/extruded high carbon steel that has been precision ground to size? What is stopping me making some new ones myself that are slightly thick hence stronger? I have read you can get thicker ones anyway but being that they cost quite a bit if I get a man with a surface grinder to do some? surely? What say thee? maybe there is more to the seal than I think? to be honest I have not properly seen one in the flesh.. hence I am asking? If they are just a solid piece of steel I am sure this is something I could get done? Also I have heard some rumours about coatings that are being experimented with that I think could help prolong the life of the apex seals.

making them is not the problem like you say, I could make them from bar but the problem is i dont think any producer would give the secret away regarding carbon content heat treatment process etc etc , they are most definatly heat treated, but im sure this is just stress relieving after the tips are milled down to size leaving 10 thou all round and then finish ground to size after the stress relieving, i used to make rotor milling tips from bar this way but they was  hardened then stress relieved then finish ground to size.
 apex seals arnt hard because u can file them quite easily, if you took a tip to a metal specialist (corus are good) maybe they could work out what it actually is if you really wanted to have a bash yourself, i reckon we could saw and mill down a set in a couple of hours from bar but then you have to find out the heat treatment process, if u can find all that out start producing lol:Laugh

[leeroy_25]

Thank you for a like minded engineering reply!

Regarding materials and hardening. I have read that ceramic ones are not all that.. They are soo hard that they do not get as good a seal with the housing. I think that the apex seals are Cryogenically treated? i.e cold treatment rather than heat treatment. I also read on a US forum that pineapple racing cold treated all off the engine components on a pikes peak car. Halfway down the run the car lost all it\'s cooling fluid but made it to the end of the run and on inspection the engine hadn\'t suffered any serious damage! How true this is I am not sure!?

I Have been looking around a lot the last couple of days and I see the seals available vary massively in price. So maybe I saw a really expensive set first off! It also depends who you get them from.. but they appear to be anywhere from £100 a set to £1000 per set! The ones I had seen were somewhere in the middle??! How do you know which ones are best? They are also available in 1 peice and 2 peice? What is the reason for splitting the seal in two?

Cheers
Lee

[20B_boy]

I Have been looking around a lot the last couple of days and I see the seals available vary massively in price. So maybe I saw a really expensive set first off! It also depends who you get them from.. but they appear to be anywhere from £100 a set to £1000 per set! The ones I had seen were somewhere in the middle??! How do you know which ones are best?

Stock Mazda apex seals are unlikely to cost you more than 120-150 quid for a set of 6. Aftermarket seals range in price massively, some of the cheap american seals like like rotary aviation and atkins rotary are not much different in price to stock. Hurleys arent much more expensive. Then you get the \'big\' named brands like Ianetti, NRS, PTS etc which you\'re talking upwards of 500, in some case a 1000 quid a set. To say any apex seal is indestructable is essentially ********, I\'d say if theres some thing amiss with the cars setup some where or the tune is out - regardless of what your apex seals are made of - you are going to end up with some expensive mantel peice ornaments...

[leeroy_25]

Cheers..
Talking of Aktins Rotary and Rotary Aviation.. You say these guys do \'cheap Seal\' do you mean cheap as poor quality? I have seen both whn I googled the other day and that is where I got the lowest prices! Are they better or worse than stock? is there a brand at a reasonable price that anyone would recommend particulary? And likewise for the rest of the bits needed for a DIY rebuild. is there one particular company that do a good price and quality balance on the lot?

Cheers
Lee

[nikp]

Yeah....Mazda.

[stuart wizy]

in my fd ive used atkins 2mm apex seals and just bought mazda side and corner seals and springs, also bought all mazda o rings. they arnt that expensive, your rotor housings and plates can be expensive if you need them and maybe a rotor if its dragged a tip out.
Ive built a fc drag engine with atkins 3mm tips and milled the rotors out to 3mm, but not run it yet. 1 rotor dragged a tip but cleaned up fully when i miled it out to 3mm
the yanks seem to like using atkins seals and ive had no probs with my fd with them as of yet !
they used to sell full rebuild kits on ebay, dont no whether they still selling on there