Rotor Tips

[Moulinex]

whats the difference between 2mm/3mm rotor tips when rebuilding a engine???

regards moulinex

[Fish]

COST!

The 3mm seal tips are said to be able to withstand a couple of DET\'s.

There are a couple of different make seals. Mazda have just released a new 2mm seal that is 2 piece. There is a lot of talk that they are the same material as those found in the RX-8.

Then you have the Hurley 3mm seals, that you need to get the rotor\'s milled out to hold.

Then you come to the daddies. Ianetti\'s! These are cermic, 3mm and said to be the best you can buy.

I was going to be using the Ianetti\'s on my build, but have been advised that they are not necessary, so I am having the 2 piece 2mm newMazda tips instead.

Best speak to Carl on here, he builds rotary\'s for a living.

Dan

[Carl]

Hi Moulinex,
good to have you on board with the club.
Danny is right about the seals.
3 mm are stronger than 2 mm but also heavier so you cannot rev your engine so high as the lighter 2 mm seals Mazda make.
Mazda have recently changed the design of the 2 mm seal from 3 pieces into 2 pieces which in my opinion is better,this is because you can retain the lightness but have a little more strength.
The Iannetti seals are at least 5 or 6 times more expensive than Mazda seals but are very good in hi power engines and if setup up right then they do not wear too quick,they are primararily used for racing applications but can be for road use too.They are very good seals and Mazda competition parts in USA sells them.
Of course the subject could have a book written on it but suffice it to say that any rotary specialist can enlighten you further if you would like to know more.
Kind regards
Carl
:wave

[20B_boy]

Isnt tuning the important bit?

Form what I\'ve read here, there/where ever - and the little I\'ve seen during the time I\'ve spent at my chosen rotary workshop - stock FD 2mm\'s are probably up to the abuse that most people will subject them to - as long as the car is tuned COMPETENTLY.

Just a shame few people seem to be able to do this in the UK at the moment. What\'s the point of fancy motors and seals if hardly/no one can tune em so they last longer than a thousand miles!???

I wouldnt use Ianetti\'s unless I had money to burn while the state of the uk rotary tuning scene is as it is at the moment. I\'ve seen what happens to a set when they go. I think one side housing was reusable! They are far from detonation proof thats for sure - but then what seal is!

Until the UK is 10% as far along the rotary evolutionary scale as say they are in Aus - as far as engine building and tuning is concerned - then flash motors and real high outputs are for the seriously rich i.e. those who can afford a new motor every month or so!

A little blighted view perhaps, but it\'s JMO of course...

Dont get me wrong, I\'m a rotor-head to the core. I live for the time when rotary engine builders and tuners are 2 a penny in the UK!!

R.

[Carl]

Hi Richard,

Yes I have the seen the engine in question and would say that I agree with what you have said up to a point.
Don\'t forget that steel apex seals when they fail also damage the housings too.
The engine in question had side plates that were lapped more than once so they would have had no hardened nitrided surface left on them which would not have helped.I know that they were low because the water seals had to be smaller in order for the engine to go together,so alot of material had been removed!
BTW I did not build this engine but have spoken to the man who did and he is a very competent engine builder.
The main thing is though that the engine obviously broke the tips for a reason and this does not mean that the Iannetti seals were at fault.What is that reason?This is the key.
These apex seals can withstand more detontion than most but they are not indestructable and the makers have allways said that is the case, and as you have rightly pointed out the engine needs to be tuned right to prevent their destruction,but I am convinced that if that same engine had steel seals in it then it would have gone wrong earlier.The seals may have  masked another problem.The engine must still be built to an uprated spec to handle more power too.
It is of interest to note that in Oz and USA people are getting good hp with steel tips but so are people who are using Iannetti seals.The only diffrence is that when an engine is rebuilt with the ceramic seals they can(and have been) be reused many times as they do not wear any where near as much ,whereas the steel ones do.Out of the above broken engine 3 seals were intact and they have no wear at all.
Abel Ibarra is using Iannetti seals and has well over 1000 hp in his RX7triple that runs 7.01 1/4 at 199 mph!
You may have noticed that Danny said that he is having 2 mm steel seals now,that is due to the fact that they are now 2 piece and I consider them to more than adequate for the approximate 400 flywheel hp that Danny\'s engine will produce,if only 3 piece were available then I would have gone the Iannetti route.
One question for you Richard,have you seen the damage that steel seals cause when a major failure takes place?the rotor housings get shot and side plates often get damaged to but maybe not quite so bad as Iannetti\'s but still not reusable.And they do damage the turbos just like Iannetti\'s.
I hope that this helps and apologise for the long post.
Kind regards
Carl

[20B_boy]

Hi Carl,

Sorry, I wasnt suggesting that Ianetti tips are bad, on the contrary; like you say they probably held up longer than steel seals would\'ve in the same engine. And yes, I\'ve seen a few nicely nuked housings that steel tips have destroyed - uggh!!

Nor was I suggesting that you built the motor btw, although as you say it was put together by a well-respected engine builder.

I was trying to convey that while there are few tuners in the UK that can look after a high power rotary at the moment - I would not go to the expense of using ianetti\'s; if the car isnt tuned properly (this is my point) then the seals will fail sooner or later - be they steel or other material. May be using steel seals in the engine in question would\'ve provided a better clue as to the reason for its failure - like you say the ianettis being as good as they are may well have shrouded the problem that was underlying. My gripe is with the tuner, not the seals. I honestly believe, rightly or wrongly, that the REW engines are not unreliable as long as they are looked after properly - and in the case of higher output motors - TUNED COMPETENTLY.

Hope this clears up the short comings of my previuos post!

Cheers,
R.

[Carl]

Thanks Rich,
Thats great,ps hows the triple going?TOTB?
I have put up a post on the "down under" header to ask of their experience of longevity on hi power engines.
I hope to get a response.
Kind regards
Carl

[20B_boy]

Will be interesting to see what they say...

20B is coming on, albeit slowly. We are trying to do it as \'properly\' as possible so time isnt a real factor - though I\'m champing at the bit of course! The engine mounts are being machined and will hopefully be ready this week....

To expect this kind of conversion to be done overnight successfully is ridiculous - as some one else in the UK has found out already I think! I at least did a lot of background reading and research and spoke to a lot of people prior to selecting components and concluding how things would be done. We\'ve spent MANY hours planning and replanning the project. This way I will hopefully have a driveable car with good (not over the top by any means) power. I honestly want the torque and the 20B\'s sound more than big HP - so I\'m confident that we will acheive our goals using the stock motor. When we\'ve learnt a bit about the engine and got every thing installed satisfactorily then we can think about swapping the stock motor for the street ported one and start \'trying\' to snap drive trains :-)

More than any thing I want to hear that motor and turbo singing!

R.


R.

[DRAGON]

WHOS ENGINE WENT KAAABOOOOM?

[Iwan]

Carl, I\'ve heard abot RX-8 seals are made of ceramic.

Do you know something about it?

Regards

Iwan

[Carl]

Hi Iwan,
i have heard so many stories about RX8 seals that I will wait and see when I get an engine.
Sme  say they are 6.5 mm deep, others 4.5mm and 2 piece.I have not heard if they are ceramic or not.
Kind regards
Carl

[Moulinex]

carl as a follow on

so does the selection of rotor tips affect performance, as in selecting a cam for a piston engine or polishing and porting, or is it just there ability to handle the power from say an increase in boost etc/ abuse.

Moulinex

[Carl]

Hi Moulinex,
Well if you were to use Iannetti seals of the 2 piece design for a naturally aspirated rotary then there is a hp gain due to the fact that the friction losses are lower.
The main reason for using these seals though is about control/handling of the power in big hp engines.Of course many opinions are around on this so you take your choice from your engine builders advice.
Regards
Carl

[Fish]

Carl, who are you getting your advice from? You are amongst only a couple of people on the UK that are building rotary engines, so where are you getting/checking idea’s/information?

I understand that you will not give away any trade secrets, but I anlong with some of the others here would be interested in who you are talking to.

Dan

[Carl]

Hi Danny,
I have alot of my own expertise that I have gained through the years in road and racing engines, and have also gained much knowledge through reading technical books on all kinds of performance engines,much of which can be applied to rotaries.

I have met and spoken on occasion to Rick Engmann in the states about various ideas I have had and he has given me good advice,Rick is probably arguably the top naturally aspirated rotary engine builder in the states if not the world.

I have also a couple of very good contacts in OZ one of whom has sponsored Dyson rotary some time back and was very succesful.Currently based on principals of this contact there is a car with a 13b in OZ doing 7.9 1/4s with 800 hp on methanol.I am currently involved in building an engine to attain over 600 hp on race fuel with some of the good advice given from this source.

I speak to Francesco Iannetti from time to time who makes the Iannetti seals.

Of course there is Pip in this country and on this forum who is also willing to share info with me.I think that he is the only other person in the UK who has a reasonable idea of how to modify a rotary.

I do have many radical ideas on how to modify rotaries of my own,one of these radical depatures been racing on a 12a for 3 years with class wins and championship wins for the past 3 years.

If I am trying something new then I will try it on my own engine first such as the 600 plus hp engine above which I am sponsoring the driver with the engine being lent to Him for "Ten of the Best".

Is this what you are looking for?


Kind regards

Carl

BTW have been into rotaries for over 20 years and got into them in New Zealand where I lived for 10 years.