Rotary Engine Side Plate Lapping and why it's important for RX7 RX8 builds, Mazda Kyle Mohan Racing

[@Shrouded_reaper]

Really makes you wonder how far rotary engines could have gone with the same kind of development that went into piston engines.

[@Deanozdirect]

I'm from Australia and rotary technology is still moving forward with billet plates and is looking to billet housings also we nitride the factory plates

[@MrRotaryrockets]

Kyle way back when in 1995 I asked the rep from Mazda Canada about rebuilt Engines.. he told me that before he started with Mazda he had the contract for Rebuilding Rotary Engines for them and had built 5000 engines for them .. I asked him about lapping Plates.. he told me he lapped every one and he only had a 1 percent failure rate on his re-builds.. I like the Idea about the Micro shot peening for friction reduction and surface hardening. Thanks

[@KyleMohanRacing]

Sounds about right, thanks for posting

[@smokielw]

I was just going to say that cleaning is one of the most important part of the build especially after side cutting. Great video.

[@KyleMohanRacing]

truth! generally the easiest big mistake is not cleaning well enough.

[@logainzerik316]

Great video thank you for sharing this. I am about to use the procedure outlined by Lynn Hanover to surface my irons and I was not aware of how important the cleaning process is but now I am thanks to you. What is the failure modes of an engine built with improper cleaning?

[@thomasnwilcox4537]

Oh I just wanted to say great job on all your videos

[@andrewfilippone6245]

Thanks for the video and info, I’m in Australia and have just stripped my 13b and need to get me plates lapped hopefully I can find someone who knows what they’re doing🙏 can you recommend best way to thoroughly clean plates at home so I can do that part myself? Cheers.

[@AndyDufresne4]

Great stuff, keep it coming!!

[@KyleMohanRacing]

Thanks

[@OndrejMuran]

how many milimiters can i lap from rx8 side plates, they have been water damaged, i need to lap something between 0.1 0.2 mm is it possible?

[@brentbaker954]

Hey, so basically you're saying that nitrating or another harder for the irons is not really necessary? 100,000k out of an iron is more than enough for me lol. Also how many thou can you safely remove without compromising the coolant seal on an s4? Any clarification would he greatly appreciated!

[@AndyDufresne4]

If you could pick the perfect numbers, what would you want oil/coolant temps to be? 210/180?

[@khasehendricks640]

I see that in the process of lapping you lose the gasket seat. How do you make a new gasket seat? Do you grind a new seat? Or do you use a sealant?

[@KyleMohanRacing]

No.... thats incorrect and would make no sense. Some side housings have the water O rings in the side housings some side housings have the water O ring in the rotor housings. We generally only cut a couple thousands off. To lap or grind a water O ring groove off of a housing would completely ruin it and would make no sense. Please go watch and educate yourself on the rotary engine.

[@douglasfurlong1]

Do you think removable side plates are better or are solid housing is better? I would think that iron plates with aluminum would cause temperature difference issues---do those side plates ever leak? have that removable plate scares me...I was wondering for high hp applications would removable side plates hold up?

[@RedBatRacing]

Do you have the capability to do the wpc yourself or do you send them out to be done?

[@KyleMohanRacing]

The wpc headquarters is local to us and we have worked directly with them for years

[@gaspererjavec7108]

just found your channel, instantly subbed. Awesome

[@KyleMohanRacing]

thanks so much!

[@gonzomaniarotary280]

have you new nitride?

[@hokayuuu777]

That's great information, thanks for sharing!

[@AvoiidTheVoiid]

Where do you have your shop located? I’d be really interested in getting mine done if I can go directly through you rather than mazdatrix etc

[@KyleMohanRacing]

I'm associated with Mazdatrix. www.kylemohanracing.com is directly to me. Happy to help

[@AvoiidTheVoiid]

@@KyleMohanRacing thank i appreciate it, fingers crossed you’re close by in Florida. I’d drop off everything literally tomorrow

[@erikwahlstrom7826]

What is WPC treatment?

[@danalcala7907]

What is the maximum thickness you would suggest on a 71-85 front intermediate and rear housing??

[@ThreeTreeDog]

This is a little off topic, but if cooling is all important (i agree) its not that far off. Why wouldnt you apply a sealant on the whole water jacket? what would be the effect, other than a oversealed coolant pathway? Ive asked on forums only answer i get is try it and see how long it lasts.. not very informative unless I follow through, if I had the money i would lol

[@JoseMaldojado]

Lapping is always a good thing. It will give long life to the engine. Race or street.

[@knowitalls8079]

Can you just surface the side plates with no nitrate/ wear treatment stuff and just run it bare/ raw?

[@KyleMohanRacing]

Yep

[@makiikedandrew]

@@KyleMohanRacing Is it recommended to Lap the Center Plate considering light corrosion?

[@KyleMohanRacing]

@@makiikedandrew in most cases yes

[@stuntdrvr]

kyle..I have some water damage to the surface @.001".. is that lappable??

[@KyleMohanRacing]

yes we should be able to clean it up

[@stuntdrvr]

@@KyleMohanRacing sweet

[@servisrx8mazda277]

@@KyleMohanRacing What is the maximum for lapping?

[@rotaryworld8446]

Hello What’s your shop location ? I have a Rx8 irons that need resurface

[@KyleMohanRacing]

I work with Mazdatrix. Generally I would say ship them there and we will get it handled I'm just the one who does the lapping. Feel free to email me if you like.

[@rotaryworld8446]

@@KyleMohanRacingok

[@arjaydiamse1460]

Can make my 07 rx8 6speed high port can you help me make mine reliable I've had 3 engines already! Please

[@nikespeedempire]

Nice videos!!

[@philip_james]

What is the maximum you can take off by lapping and how much does it change endfloat? I once had an engine lapped and the person who did it took so much off I had trouble fitting the inlet manifold because the engine was shorter.

[@KyleMohanRacing]

sounds like bad work... dont use them again

[@philip_james]

@@KyleMohanRacing Must have been. So can you please tell me what the maximum you can take off please?

[@KyleMohanRacing]

@@philip_james That can be a technical question, it depends on the year of the plate. Some of the info is proprietary. Cant give every secret away.

[@Skyrexx7]

@@KyleMohanRacing 😂

[@dlwmotorsports]

now you make me want to pull the rx8 motor out and rebuild it lol

[@alexlevy4581]

Would it make sense for higher reliability to lap the plates and then re-nitride them? Without nitriding, wouldn’t the wear skyrocket? As you say in the video, the nitriding lasts for 20-50 thousand miles, by lapping alone you are reducing the life of the plates overall. I get it for a racing application with wpc and other treatments, but for a long living motor like you talked about, I don’t see it. Let me know if this is right or if I’m missing something, would love to learn more.

[@KyleMohanRacing]

Generally in 20 years of rotary service I generally don't see a big difference between lapped, new, or nitrided wear in parts. I think the internet is a little off on what nitride does. Ive built many lapped motors at mazdatrix that went as far as new parts with no re nitride and zero had issues. Generally I see assembly, break in, and parts cleaning mistakes as the leading cause of issues when its not done correctly it causes failure. Lapping a part to far can also cause issues. So answer is no. I don't think there is a big difference in wear or lifespan.... I'm not saying re nitrided parts are bad. I just don't think its nesasery like its portrayed in all cases. . Also FYI. The nitride process can warp a part. So it may not be flat anymore after the process and may need more 🙃 machine work. I know shops that lap new housings to make them flater than factory... I think adding all this info should help people make better choices based on their build needs.

[@KyleMohanRacing]

Another thing to consider is side housings are generally not a fail point if in good condition. Lapped or not... ive never seen a block come in that had lapped housings and they where dead from wear or the fail point because of wear and other parts where still in great shape. There are a lot of parts that generally wear faster than the side housings even if lapped. The side housings generally are not the big issue or why a motor comes in for a rebuild. Good questions. Hope this information helps and makes sense.

[@jo-qp7mz]

@@KyleMohanRacing I just had my irons lapped and ported! I also re surfaced my housing adam a rec Did a great job! I will consider your services also for a future build! Also got the rotors lightened and balanced clearance also. I had two irons that the metal between coolant and seal was gone!! So I kept em on the shelf until I find a solution for em...do you have a solution for that? Thanks a bunch your videos our supper awesome and very useful info!

[@danielcordi7519]

@@KyleMohanRacing how do you know when its been lapped too far? I have a set of RX8 side housings that have been re-lapped twice but I was never given exact dimensions of material removed each time. Both times they were re-nitrided. I now have a 0.003" wear line on my rear iron as shown at 5:45 in this video, and it was burning oil with scraper ring wear beyond all usability on what were new oil control rings and scrapers about 3k km ago. What is the leading cause of that wear line? looks like corner seal riding area, I had initially thought it was from the scraper ring but it doesn't extend that far out into the side housing. Thanks for this video, it was very helpful in me diagnosing what happened to this engine, I'm still perfecting this craft but getting better each time 👍🏻

[@dubbleA100]

Hey Kyle I see the website is still being updated. How much does it normally cost for lapping and WPC for a turbo ii motor?

[@KyleMohanRacing]

100 per face lapping, 85 per face WPC

[@dubbleA100]

@@KyleMohanRacing awesome! I know where to go when I start my big boy engine

[@7sins979]

haha found you on youtube lol small world in the rotary scene.

[@dubbleA100]

@@7sins979 bro that's wild!! I'm actually going to try fire up the FC right now

[@7sins979]

I think lapping is a good thing, not only does it true up the surfaces but provides a fresh surface to bed seals into. the hardened surface is important for wear characteristics, there is no way a ductile iron surface wears the same as a hardened surface. the process is less important imho and i am curious about nikasil coating. nikasil could be built up to .030 then machined back to factory new spec and provides are porous hardened surface that will retain lubricant while maintaining good wear properties. 2 stroke guys line their cylinders with nikasil and swear by it.

[@KyleMohanRacing]

Everything comes down to cost. just getting new sides is the best but if you cant afford it then lapped or resurfaced is better than just used... lapped sides can go 100k in normal application with proper engine maintenance. i see people spend money on nitride then put used sides seals and rotor housing in. Doesn't make any sense.

[@efaracing4000]

Interesting to see the wear its like reading a trees age in a way🤷‍♂️😂

[@KyleMohanRacing]

Yep. Shows what the motor has seen. Lol

[@andrewlashko]

"I see that in the process of lapping you lose the gasket seat. How do you make a new gasket seat? Do you grind a new seat? Or do you use a sealant?"

[@KyleMohanRacing]

No.... thats incorrect. Some side housings have the water O rings in the side housings some side housings have the water O ring in the rotor housings. We generally only cut a couple thousands off. To lap a water O ring groove off of a housing would completely ruin it and would make no sense.

[@Indi_DevJames]

I can lap it on a glass pane and sandpaper 😀 just like heads to piston engines

[@JoseMaldojado]

Always laying is a good thing.

[@JoseMaldojado]

Auto correct sucks, Hahahaha

[@thomasnwilcox4537]

If you're watching a video and it's pixelating then the Playing speed is too slow or stream rate is too low