I already did a search and read some good posts, but I want to know some specifics that weren't answered.

I'm rebuilding my 87 T2 right now. I have the engine already stripped all the way down.
My questions are all about what I need to replace and what to reuse. I'm not on a super tight budget, but I don't want to spend more than I have to.

What do you usaully need to replace? bearings, housings, seals etc...?

How can I tell if my housings are ok. rotor, front intermediate, rear

The apex seals were carbon locked on my back rotor and it had no compression consequently. So there are no cracks, chips or brolen apex seals.

This is my first rotary overhaul so bear with me

Thanks a ton, Ed

 

Try rotaryresurrection.com I think there is a big write- up on that.

 

Thanks I'll try that site.
Anyone else have any input

ed

 

ALWAYS DO:

apex seals. they make it go, theyre cheap, theyre a must. About $200-250, I like a 2pc.

oil o-rings. just the rubber, not the metal. about $85-100, get genuine mazda for the best fit and easiest installation, though atkins work fine theyre a bit hard to install and I have a problem with them breaking the metal rings due to oversizing.

gasket kit. contains all internal o-rings and external gaskets, a must. About $270 for a turbo II engine, due to the expensive metal turbo exhaust gaskets. IF yours are still in good shape, along with your manifold gaskets, you can use a cheap NA kit for just the internal water seals and save about $125. Best to get the right one though, unless all your old ones came off perfectly intact.

oil pellet replacement for eshaft. Reliability mod can sometimes raise oil pressure on an engine with a partially failed thermowax pellet. $15, atkins or mazdatrix or revolutionrotary aftermarket part only.

Everything else is generally reuseable. IF you ahve money, side seal springs and FD corner seal springs are nice.

Note that you can leave out the rubber corner seal plugs with no ill effect of the runing of the engine, but new ones are about $25 so if you have the funds go ahead and get those too.

In my book, other than time and effort, there is no reason not to do a large streetport on an engine that is apart. That, or lack of a good compressor and diegrinder. IF its your first time, either get some spare irons to play with first or take it really slow, or youll be looking for new irons. Stick your fingers behind the ports and get a sense of how much material remains before you break into the passage behind...

BE sure to use hylomar on each side of the coolant seals when installing, this will ensure a good seal as well as keeping them in place when doing those blind iron-drops where you cant monitor what the seals are doing really easily. Also be really sure and careful with the front cover o-ring placement and that it will be held in place well. See the mazdatrix.com homepage under FAQ for information on this. A screwup here can cost you 40psi of oil pressure later, and make you have to pull the front cover back off...

 

Thanks a lot. Thats exactly what I needed to know!
got a couple more questions though
Should I replace the side seals and corner seals?
Whats your rule of thumb on reusing housings (rotor housings and side)? Should I get the side housings lapped or are they generally ok?

thanks again, ed

 

Also about the street port I am going to have my boss (I work at Japan American Auto) do the port. He used to be the lead mechanic in tokyo for the Prince Skyline sports coner. Nissan bought out prince and stole the skyline Anyway he has tons of practice porting motors. He has rebuilt two rotaries, but they were 12A's and it was a long time ago. Thats why I'm asking all these questions.

ed

 

Generally, side seals do not wear very significantly; reusing them is fine.&nbsp Corner seals also do not wear very significantly, but you need to replace the center rubber piece - Mazda does sell just the rubber center by itself.

The "fingernail method" works well for me - sliding the fingernail over the housing surfaces should not catch in any groove.&nbsp I do not lap housings - lapping them usually requires getting a new/taller spacer to keep e-shaft play within spec.&nbsp If the housings need lapping, they are usually caused by abuse or too much mileage - either/or reason is justification for getting a new set of housings.



-Ted

 

I took apart the rotor today. The rear rotor had a ton of carbon deposits. Two of the three apex seals were completely frozen as well as a couple of the side seals and corner seals. I broke a couple of the side seals trying to get them out. The corner seals were equally hard to remove on this rotor.
I think it would be better in my case to replace all the seals on my rotors (apex, side, corner, oil) Given the condition of the rotors being so carbon locked. I think the carbon wears down the parts more than an engine that is cleaner that got better oil changes.

So here's my parts list to date for the overhaul.
Apex seals/ springs
Corner seals/ FD springs
Side seals/ springs
Oil rings and gaskets
Gasket kit
Oil pelet replacement for eshaft
Street port template (where can I get this)

Am I forgeting anything?

Thanks for all the help,
ed

 

bump

 

Mazdatrix sells the porting templates. Click here for info on them.

 

What should I use to clean and polish the housings that won't damage them? (chemical and tool)
Are there any other suggestions on anything thats good to replace during my rebuild or any other tips for me?

thanks, ed

 

You may want to check into Bruce Turrentines videos available from atkins.
http://www.atkinsrotary.com/enginevideo.htm

 

Replace everything that you have money for

I cleaned and polished my housings with a steel wire brush hooked to a drill , worked great. (on the outside)

Also rememebr, use HYLOMAR. Using vasoline will bite you in the *** if you have to take the engine apart again. I learned that the hard $60 way

Its much much much easier if you have someone helping you too. Especially when you have to invert the housings, they can keep an eye on the o rings and make sure they dont fall out of place.

For all paper gaskets on the engine I would recommend using Hylomar as well. It wont harden like RTV and it stays in a more or less "liquid" form so it wont harm your oiling/water system should some get loose.

A light coat of spraypaint can make the engine look nice and pretty too

 

Now you know why they say "one look at a used rotor and youll want to run premix"

 

I clean engine external parts with aircraft remover then pressure wash in 10 minutes, then I paint them. I clean the mating surfaces with a die grinder with a wirebrush(meant for a drill) and it works great, and wont damage anything.

 

I will have my boss help me assemble the engine to watch everything. He has done a couple rotaries before, but it was a long time ago. I will also use the Hylomar sealant on everything.

Do you mean it's ok to use the wire brush on the parts of the front rear and inter. housing that the rotor touches?

I am planning on removing the oil metering unit and premixing. Anyone know if I will be able to pass smog running premix? Can I run leaner or will I still fail in CA?

ed

 

No, only on the outside parts of the housings.

As for the premix: in theory its supposed to burn cleaner than engine oil so I dont think emissions are a big deal.

 

Ed, what part of California are you in? I have racing beat street port templates and a "clean" chip for the ECU to pass smog, they both worked perfect in my car. I am not going to ship these items to anyone ... but if you are close enough to Stockton you are welcome to borrow them. Theory being ... if you are close enough to pick them up, you are close enough to be tracked down if they don't make it back

 

I'm in Yuba City near Sac. Thats not too far from stockton. That would be great if I could borrow the street port templates and ecu chip. Thanks for the offer.
So this ecu chip plugs into the ecu then you go smog and then remove it?

ed

 

Yup, thats just how it works. If you don't street port you don't need it .. but if you decide to street port I would sugest using it.