|
|
Post by Donald on Apr 9, 2016 10:07:34 GMT -5
Was hoping my first thread here would have been more upbeat. Just taken the proper unit apart due to a low compression and sticky Apex seal and got a bit of a shock when I looked at the rotor housing. The Plating has failed and is lifting at the exhaust port area. I have yet to have a really good look but I don't think the casing has cracked, just the plating has lifted. Attachment DeletedHad tried to add a photo but not sure how to so if you open the document you can see the damage. So has anyone any experience of try to get these re-plated and then ground back to the proper shape? Or does anyone have a spare usable rotor casing available? Thanks Donald |
|
t140v
3rd Gear
Posts: 422
|
Post by t140v on Apr 9, 2016 18:35:02 GMT -5
You are in uncharted territory as far as I am concerned try Jess or Rog who have done rebuilds before or ROC, who do a molibydebum disulphide coating .
Regards Stuart
|
|
|
|
Post by re5rotary on Apr 10, 2016 1:42:20 GMT -5
Hi Stuart the moly coating you are talking about is for the side plates not the rotor housing and I think that is what Donald is talking about. regards Terry
|
|
|
|
Post by goandy on Apr 10, 2016 1:51:13 GMT -5
Side plates are moly coated. Very early ones were totally coated, most have the spiral pattern coating. The Rotor housing is nikasil plated.
That's what has flaked off on your rotor housing.
You could get it replated but would have to find someone willing and able to do it.
Good luck! May be easier finding a good used housing. Jess, other members here or ebay. Try to get one with no cracks either side of the spark plug hole.
|
|
|
|
Post by Donald on Apr 10, 2016 3:00:02 GMT -5
Thanks Goandy.
I have been doing some research and I can probably get the housing coated easily enough but it will be the grinding of the Trochoid that will be very tricky and would need a CNC grinder and a wee maths equation.
If I have to go down that route I will also have to remove the spark plug shield so does anyone know how that is actually held in place?
I am hoping that I can source a usable housing as it would be the simplest solution.
Cheers
Donald
|
|
|
|
Post by re5rotary on Apr 10, 2016 3:45:05 GMT -5
The spark plug insert is pressed in to the main housing regards Terry
|
|
joe
1st Gear
Posts: 49
|
Post by joe on Apr 10, 2016 5:11:47 GMT -5
Hello Donald,
Norton Motors had some rotor housings re nikasil plated some years back. Unfortunately though after grinding the internal running surface the sides of the housing also require grinding. I'm not 100% sure why but I think it is to acheive a pefectly flat surface for sealing. Once the rotor housing sides have been ground the rotor will also need to be ground along with the tip seals other wise the running clearance will be reduced and you'll wreck your engine.
A couple of years ago at a Wankel Treffen in Neckarsulm Germany I met a chap whom reground and re plated NSU RO80 housings, they have a similar sparkplug arangement. The seller didn't mention haveing to remove the sparkplug insert.
It can be done but much easier to find an alternative rotor housing.
Over the years many manufactures have produced Wankel engines but none seem to be 500cc ala Suzuki RE5. Many are two rotor with 588cc (2 x 294cc) some are single rotor 600cc but i've never forund anything which comes close to the Suzuki size. Maybe one day I'll look into having soome made and without the sparkplug insert and a more convenient thread size.
Not sure this help, just rambling.
Regards, Joe.
|
|
|
|
Post by goandy on Apr 10, 2016 6:14:45 GMT -5
Once the rotor housing sides have been ground the rotor will also need to be ground along with the tip seals other wise the running clearance will be reduced Regards, Joe. Err, no. If the apex seals are within spec they can just be reused. The side plates should be ground flat if they have a step on them which is beyond the permitted amount. The whole point of replating and grinding the rotor housing is so that it will be back at its original size. You never reduce the width of the rotor housing- that would certainly reduce the clearance between the rotor and side plates/housing. You never grind the rotor... You could get the apex seal tips moly plasma sprayed as moly is a really good material to run against nikasil. |
|
joe
1st Gear
Posts: 49
|
Post by joe on Apr 12, 2016 14:49:37 GMT -5
There seems to be some misunderstanding on what I am trying to say. I'm not talking about machining end plates, this is normal practise to recover either worn or damaged end plates and also to bring them back to within tolerance after re mollying. I'm saying Norton Motors did and probably still do on their engines (although they are now only for aviation and UAV's so possibly not) reduce the rotor housing width. This was done for various reasons sometimes just down to poor control during manufacture. In any account the rotor and apex seal must be reduced accordingly. The rotor housings come in three sizes, Standard, Grade A and grade B. with the sizes shown below.
Rotor Housing width, Standard 68.19 to 68.21mm, Grade A 68.09 to 68.10mm, Grade B 67.98 to 68.00mm
Air Cooled Rotor Width, Standard 67.77 to 67.79mm, Grade A 67.66 to 67.69mm, Grade B 67.56 to 67.58mm
Water cooled Rotor width, Standard 67.86 to 67.90mm, Grade A 67.77 to 67.79mm, Grade B 67.67 to 67.69mm
Apex Seal assembly overal length, Standard 68.13 to 68.19mm, Grade A 68.03 to 68.07mm, Grade B 67.93 to 67.97mm.
I hope this help resolve any confusion.
Joe.
|
|
joe
1st Gear
Posts: 49
|
Post by joe on Apr 12, 2016 15:46:51 GMT -5
Just to add to my comments above. Norton Rotary engines are either air cooled or water cooled but in both cases the rotor is air cooled rather than oil cooled in the Suzuki, Mazda, Citroen/Van Veen and many other engines. The principle is the same though. DKW/Hercules and Sachs also fall into the air cooled rotor category where filtered air laden with oil is sucked through the eccentric shaft and rotor internals prior to feeding the carburettors via the plenum chamber. The race engines do not feed warm air via an plenum chamber to carbs. In this case an extractor exhaust is used and air is sucked through the rotor and shaft straight to atmosphere. The carbs (or injectors in my case on my race bike) are fed with clean filtered air and additional oil is fed into the rotor bearings.
Not relevant for a Suzuki but I thought it may be of interest to someoe, just rambling.
Joe.
|
|
|
|
Post by jm0406 on Apr 12, 2016 18:15:05 GMT -5
Here is what filtered air laden with oil going through your rotor shaft looks like:  |
|
|
|
Post by timpa136 on Apr 12, 2016 20:08:02 GMT -5
Proves that clean air is just as important in an air cooled rotor as it is in our peripheral port oil cooled rotors.
|
|
|
|
Post by goandy on Apr 13, 2016 1:37:39 GMT -5
There seems to be some misunderstanding on what I am trying to say. I'm not talking about machining end plates, this is normal practise to recover either worn or damaged end plates and also to bring them back to within tolerance after re mollying. I'm saying Norton Motors did and probably still do on their engines (although they are now only for aviation and UAV's so possibly not) reduce the rotor housing width. This was done for various reasons sometimes just down to poor control during manufacture. In any account the rotor and apex seal must be reduced accordingly. The rotor housings come in three sizes, Standard, Grade A and grade B. with the sizes shown below. I hope this help resolve any confusion. Joe. Thanks Joe- confusion is now gone! Didn't realise that Norton did that. I've only rebuilt Mazda and Suzuki rotaries and we never touch the width of the housing other than to ensure it's within spec. Same with the rotors. Some Mazda builders have 'clearanced' the sides of the rotors for super high power applications but that introduces other issues and is still using the standard width housings/ apex seals. |
|
|
|
Post by timpa136 on Apr 13, 2016 21:00:59 GMT -5
Here is what filtered air laden with oil going through your rotor shaft looks like: This might be a good time to go to Help FAQ and enter the air filters we are successfully using in the different parts of the country. Wayne has volunteered and I hope is ready to compile this portion. I have previously entered my recommendation. re5rotary.proboards.com/thread/2149/help-faqsTim |
|
|
|
Post by wayne on Apr 14, 2016 17:24:50 GMT -5
Here is what filtered air laden with oil going through your rotor shaft looks like: Wayne has volunteered and I hope is ready to compile this portion. I have previously entered my recommendation. re5rotary.proboards.com/thread/2149/help-faqsTim Noted Tim, can't promise in the next few days but I'll make Air Filters my next FAQ with all the hints and tips you guys have contributed. |
|
