Recoating housings?

m1tch · March 13, 2012, 08:23:52 PM

Hi all,

I just wanted to ask about recoating housings with the plating, I am guessing its nikasil plating like that used on 2 stroke engines etc that can get worn away and I know you can recoat piston related cylinders.

I am just wondering about if this is done that much or is it cheaper to buy new/good used. I don\'t need any housings for my engine, but I am just wondering going forward, surely it will come a point where worn housings can simply be replated for them to be used as new again.

I also have a question on simply not recoating them much like many piston engined cars, and put some honeing markings on the surface as the apex seal works like a piston ring to seal the gap with the housing.

If a used housing was \'honed\' it would be a bit like an oversized bore, with a piston engine you would have to run an oversized piston, with a rotor surely the extra few thou clearance will be taking up by the spring/seal - if not could the spring/apex seal be \'shimmed\' slightly to take up the gap?

I am just wondering all these things as im just curious, its probably be done before with bad results lol but I thought I would ask, especially with parts like the 12a engine not being produced anymore, you can\'t simply buy new parts.

Brett · March 13, 2012, 09:50:01 PM

In theory it can be done, but the cost has always been prohibitive and you would be encoutering all the development costs etc.

m1tch · March 13, 2012, 10:20:47 PM

What about simply honing the housings like you would do with honing a cylinder?

rx7boy · March 14, 2012, 12:21:13 AM

There is a company in Canada that can remove the old chrome insert and reinsert a new one, or add their own Cermex version which has a 90% less friction. Can\'t remember the name of the company but if you search ceramic coating housings they should come up

Grant Monkhouse · March 14, 2012, 03:04:40 AM

Think they\'re called goopy?? The liners are chrome, not nikasil. I think it\'s a bit late in the rotary engine history for people to start re chroming them. Just think of all those scrapped housings, and all those 10A motors that could have been saved to make some great PP 10A\'s

The guy that has made the 12 rotor has made his own inserts but machining cost to put his insert in are near enough the same price as new housings, especially after all the fancy coatings he puts on them for super wear resistance.

Prof · March 14, 2012, 07:22:46 AM

The original mazda coating was also porous, and a teflon like substance was allowed to fill the pores. The idea was that if it did run \'dry\' of oil, the increased heat would melt out this extra coating and provide a few minutes more lubrication before you scraped your housings to death.

m1tch · March 14, 2012, 07:41:19 AM

Quote from: Prof;815921The original mazda coating was also porous, and a teflon like substance was allowed to fill the pores. The idea was that if it did run \'dry\' of oil, the increased heat would melt out this extra coating and provide a few minutes more lubrication before you scraped your housings to death.

Mazda also let the engine rev to 4k rpm from cold just to warm the cat up quicker :rollin

rx7boy · March 14, 2012, 03:33:06 PM

http://jhbperformance.com/services.php#rotor_housing

Goopyperformance · March 28, 2012, 09:35:17 PM

Goopyperformance.com

Grant Monkhouse · March 28, 2012, 10:05:59 PM

Quote from: Goopyperformance;817885Goopyperformance.com

Can housings with hair line cracks be fixed? I have an rx4 13 b engine in pieces and wonder if the housings are worth keeping for someone that may want an original engine

Goopyperformance · March 30, 2012, 04:40:49 PM

Quote from: Grant Monkhouse;817888Can housings with hair line cracks be fixed? I have an rx4 13 b engine in pieces and wonder if the housings are worth keeping for someone that may want an original engine

Those are very nice old school housings..the look really nice polished.
but to answer your question.

Most housings have some A lever of repair..the question is where is the crack and what are your intentions with the housings after repair.
you can email a few pics to info@goopyperformance.com and we will let you know.

Grant Monkhouse · March 30, 2012, 07:30:10 PM

Quote from: Goopyperformance;818059Those are very nice old school housings..the look really nice polished.
but to answer your question.

Most housings have some A lever of repair..the question is where is the crack and what are your intentions with the housings after repair.
you can email a few pics to info@goopyperformance.com and we will let you know.

the crack is only very small at the spark plug hole, cant remember which plug hole it is though. i will most likely be selling the housing along with the plates and e shaft as i have a bridge port turbo motor for my rx4.

i will take some pictures this weekend and get them too you.