How To Resurface Rotary Engine Housings - Its Like a Cylinder Hone... But Better! 

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@@RADPotential You're the first name I recommend to anyone who even brings up rotaries

Thanks Man!!

The plating is way thicker than what he is sanding.. he is just re surfacing it oh and rob dahm does the same thing to his housing just with a flap wheel and a drill press.😮😊

so i posted this comment before watching the whole video. i'm pretty sure nickel plating is done to different classes of thicknesses and hardnesses. i don't know what would happen if you send a nickel plated housing without chrome plating on top of the nickel. but nickel can get chrome plated. problem is back in the 80s everyone chrome plated, and dumped the waste water down the toilet. the epa didn't think that was very funny. anyone who chrome plates nowadays probably has their own water treatment facility. so it's going to be pricey. i used to know a guy who did nickel plating. this guy only dealt with parts machinists messed up and undersized. he'd charge them 2/3 what it cost to make the part, to plate it to proper thickness. also i don't know if you're cool with it, but there's a place in maryland that does nickel plating. not sure if you're cool with name dropping, let me know.

Hit or miss. Sometimes I do sometimes I don't, If its not warmed up all the way, I for sure do.

They do not. They resurface them with a similar result.

It doesn't so much matter the depth of removal, apex seals are spring loaded, so they will just slide out to accommodate the thinner area. its more important to not sand through the chrome plating on the surface.

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You can't. But you can watch someone fuck them up with this goofy approach.

@@funone8716 yeah I thought there was a coating on the inner surfaces? one you can't just 'fix'? lol

​@funone8716 rob dahm does this to his 700 hp tenth ae rx7 if it's good enough for him it's good enough for anyone 😉 oh and the chrome plating is 0.03 thick you can see how thick it is when looking at the edge of the housing!

I'd really like to know that also. I would guess at the most 320 grit????

120, I know it sounds really abrasive but you see the results. it works great.

Yea man!! I have seen that video. I'd be interested in trying that over top of surfacing them!! Super cool!

WPC has been around for a while, Mazdatrix offers the service, its essentially shot-peening that dimples the surface to create pockets for oil to sit. It doesn't replace the factory coating. (oem housing is a steel (or iron?) sleeve in an aluminum casting, with a chrome alloy electroplated onto the iron. WPC would probably be a great addition to a housing surface, though the lining has a level of oil retention already. What i'm the most interested in personally is goopy's chrome-replating service.

@@1OMEGA111 Ah okay that makes sense. I didn't do any research on it, but I just heard about it. Sounds interesting.

Rob dahm does the same thing with a flap wheel and a drill press... his engine is making Over 700 hp... seems to work great 👍 👌 🙃

Housings are Chrome plated. Nitriding is done to the side plates, not the Chrome plating (altough you can nitride chromium)

Thats awesome man!! I would find a shop that does the work, and try to become a fly on the wall and learn what you can. Most people will be more than willing to teach somebody who shows a genuine interest and passion for their work!

It's an oscillating spindle sander. Used mainly for woodworking but looks like it does a good job on the housings.

@@rmreid83 Appreciate that bro. Just found one on Amazon 😁

​@@rmreid83"looks like" is the words today. You can't fix damaged chrome by sanding it away !

​@@stevecarlisle3323hopefully no one is taking away the idea that this makes it the same as new... It'll run though I'm sure.

​@@stevecarlisle3323the chrome is over 0.03 thick he's only sanding a little off rob dahm does the same thing.... and he's running 700 hp thru his... check out the video of the 10th ae he flap wheel sands his housings down before rebuild... same exact process... ya hater

Any honest shop would probably recommend new housing. Shop rates by hand would be more than a new one. I feel like it's nice for a cheap personal project to around with. I wouldn't want my name attached to it for a paying customer though!

Yes. I used 180 grit on an orbital sander, then Valve Grinding Compound. Per a forum. It worked well and knocked down the shine. The irons don't last as long...etc etc

Harbor freight oscillating sander... 99$ your welcome 😊

Its like running a ball hone on a piston engine. Just enough to take off some of the grooves, and provide a good surface for the new seals to bed into. It does thin out the housing, and I wouldn't expect a refinished used part to perform as well for as long as a brand new part.

@@RADPotential I would compare it to a piston engine. There must be a cylinder of exact geometric circle. Here, the geometric inaccuracy doesn't matter so much.

Isn't this what the spring is for, behind the apex seal? That micro amount taken off is all it's going to have to expand. This seems like a good idea for just having a spare motor to set aside for emergency, or to just beat the hell out of on a track for a day until it's done.

It really shouldn't have any low spots. You should be able to feel them with your finger nail or a pick. Just keeping an eye on the color change from shiny to dull should be enough

@@RADPotential cool. We totally had one of those machines but didnt know what it was for so we dropped it off at goodwill. Regrets

Sometimes its just easier to do it that way for sure!

@@RADPotential yeah, getting rotors machined too for weight reduction. Plus a street port.

Lol same thing as honing a cylinder wall... he's not sanding past the hardened chrome lining he's just re surfacing the ruff patches and getting rid of the polish from apex seals... if you question it watch rob dahms video of the 700 hp 10th ae rx7 he does the same thing to his housings only with a flap wheel and a drill press... seriously stop being a hatter

@@jo-qp7mz it is? Anyone willing to share the RA, RPK, RV, crosshatch angle, etc that these housings are being “honed” to? Those are standard values that are adhered to when honing cylinders, do you think that’s the case here? Do you think anyone could even share what those values are for a stock housing? I don’t really care what Dahm does, he’s not an authority on anything and frequently gets technical information wrong. It’s a reflection of the poor state of the rotary tuning industry that “professionals” in the field look to him. Demand better.

No, the RX8 engines use a Multi Side Port Exhaust, vs the Peripheral Exhaust of the early 13b's.

no