Learn me: rebuilding the rotary...

I have an S5 engien that has a blown coolant seal. the engien ran and does run well other than loosing coolant. I want to rebuild it.

I have the atkins rebuild video.

What parts are suggested to make sure I have a long lasting engine. Please be specific. What parts are mandatory to rebuild this engine? What parts would you replace as "insurance"?

Any special tools required (I have the flywheel socket).

Thanks!

Rob R.

When I rebuilt mine, everything I found said that replacing pretty much everything remotely soft/wearable was the smart way to go- which meant getting the 'Master Rebuild Kit' from Atkins. But I also wasn't at all certain of how good of condition the apex & side seals were in, so figured replacing them was wise. Does jump the price up by a factor of about 3 though (overhaul kit is only $350, master rebuilt is $1k). Re-using the apex/side seals may work just fine- but you'll also likely need to rebuild it sooner than if you replace them and have all new internals.

Tools-wise, the flywheel socket was a big one (literally) to find. Do you have the tool to lock the flywheel in place to use the socket? (steel bar-looking thing with 3-4 teeth and holes to bolt it to the engine) With as much torque as it took to break the flywheel nut free, it helps to have the flywheel locked solidly in place. Otherwise, I seem to remember not needing any particularly special tools besides the ones I already had on hand.

I was surprised once I got the engine torn down at just how easy it really was to rebuild it.

IS there a specific brand or type of Oring that is better than others? I have heard about goopy performance and some others that sound okay.

Any more input?

Thanks!

Rob R.

Fidelity pick up the white phone please

Question for you, are you rebuilding for performance or just to get it back to stock conditions?

Atkins has been a go to for many years and has a lot of experience in the field, goopy performance are good people and seems to be a good alternative to those on the east coast.

This would be for our Chumpcar. So reliability is the main concern. The car will be on stock electronics with stock ports and stock manifolds (except header).

I am not sure what type of performance I could get with different seals.

So, I guess my answer is stock type conditions.

Better seals- especially the apex seals- primarily matter when you're trying to put more pressure into the engine, e.g. boosting. So if you're running it stock (especially if it's NA), stock seals should do just fine.

I don't know anything about Goopy- I'm not sure they were around/very well known when I was looking into rebuilding mine. Pineapple & Atkins were the only real ones around. If you're confident that the hard seals are in decent shape, you MIGHT be able to get by with just the Water Seal kit- http://www.pineappleracing.com/hdwatersealkit-fcs45re1986up.aspx

You're almost certain to get more longevity out of the engine if you use the full rebuild kit and replace all the seals, but if only the coolant seal is a problem that is a much cheaper way to get it running again- and it may well run many thousands of miles more with the original hard seals...

Here's what's in mine:

new OEM side seal

new Atkins solid Corner seal set

S5 Hardened stat gears w/ bearings

Atkins Apex seals w/ springs

New Rotary Aviation wet seal kit

FD side seal springs

Corner seal springs

mazdaspeed oil control ring springs set

http://atkinsrotary.com/store/86-95-Rx7-Basic-Engine-Closing-Kit-ARE146.html

Is this basically everything I would need for the inside of teh engine?

I am not sure about oil control rings or oil control ring springs. The engine did not smoke at all...

Thanks!

Rob R.

That looks about right- looks like it has everything but the oil control rings/springs, and those are generally less prone to having problems since they're heftier than most of the other seals involved.

The kit looks good for what you need. I would order the mazdaspeed oil control ring springs - don't think they cost too much. The actual rings are probably fine, wouldn't buy them unless you confirm the existing are bad by inspecting them.

As far as other parts, a 3rd gen rear oil pressure regulator is a cheap upgrade to get you higher oil pressure which is good for high rpm use.

You might also want to change out the e-shaft check valve oil jets for the racing ones that always flow - mazdatrix will have them and they're cheap. You'll have lower oil pressure at idle, but better lube at high rpm.

During the rebuild - closely inspect to make sure the water seal channel hasn't given way - there is a thin section that can fail, and your rebuild will be a wasted effort if you miss this. Check Mazdatrix tech section for photo's of this.

Also make sure you get the front cover oil passage o-ring installed correctly - there are a couple different types, and you need the right one or you won't make oil pressure.

Also an oil baffle plate is recommended for racing applications - don't know if they are totally needed, but I have always run with one. You might need slightly longer oil pan bolts if you add this. Don't over-torque these bolts - easy to snap the heads off.

The middle iron had a blow out of the water seal due to the metal breaking out of the thin area.

Are s5 na and s4 turbo middle irons interchangeable? I have a good condition s4 turbo iron that looks really good that I could use for the rebuild.

Thanks!

Rob R.

Can I use digital calipers for the necessary dimensions or is a micrometer the correct tool?

What are people using for a straightedge to check wear / flatness on the irons?

Is there a brand or type of feeler gauges that are prefered?

Thanks!

Rob R.

Straightedge: https://www.mscdirect.com/product/details/02674026?item=02674026 or similiar.

Feeler gauges: https://www.mscdirect.com/product/details/62246335 or similar.

Personal preference on mic vs calipers, but it depends on what you are measuring and where.

Cheap is good, because when it comes down to it, they all have a documented standard deviation, whether you spend very little or way too much.

In reply to Ranger50:

Are those ones that you have used when rebuilding a rotary? I ask because there are specific items that need measured in specific ways for the rotary.

As to the mic vs calipers, I am measuring all of the seals to see what needs replaced. Some of the tolerances are pretty tight!

Thanks for your help!

Rob R.

wvumtnbkr wrote: The middle iron had a blow out of the water seal due to the metal breaking out of the thin area. Are s5 na and s4 turbo middle irons interchangeable? I have a good condition s4 turbo iron that looks really good that I could use for the rebuild. Thanks! Rob R.

I had the exact same problem with the engine that I rebuilt- and found out the hard way that the S4 & S5 (at least the NA ones, I'm assuming it would be similar with the turbos) center irons are NOT the same- the exhaust ports are a bit different, IIRC the S5 has one more or it is located below where the exhaust manifold bolts up. For the first month or so I was hearing a massive exhaust leak until I looked really close and saw that the S4 manifold and the S5 iron didn't match. I think the front and rear irons are essentially the same and that just the center one is different (the S4 also has the EGR which the S5 eliminated IIRC). If you have an S4 exhaust manifold you may be able to use it and have everything work fine.

Yep, the s4t and s5 seem to have the same exhaust port on this iron. I should be good there.

okay, my apex seals look liek they are atkins seals. (from looking at images on Google).

They measure 7.5 to 7.8 mm in height. They ALL have some tapering of about .20 mm across the top.

Are these reusable? They look like they are in good shape to me.

Thanks!

Rob R.

Anybody?

Also, it seems the corner seal plugs were not in the engine. Is this normal? Do they disappear?

How do you remove the oil control rings without damaging them? I cant get them to pop out and I don't want to pry on them!

Thanks!

Rob R.

Technically, anything is reusable- it's just whether you're willing to take the risk of them failing, since the apex seals are the most common seal to fail.

I don't remember how I got the oil control rings out, sorry.

I actually messed around with the oil control rings and used a guitar pick to get them out. They were alot stronger and more resistant to bending than I thought they would be.

When I was looking at them, I figured one little pry on them would bend them. Nope!

They are out and the parts are cleaned up a bit.

What apex seals do people recommend? Holy crap they can be expensive!

Rob R.

Apex seals are definitely not cheap, I can understand your desire to re-use them. I just ordered the whole Atkins rebuild kit, so had theirs from the kit.

Another issue. Totally different engine...

I just picked up an engine for all of its anciliary parts (manifolds, water pump housing, wiring, etc...)

The engine actually seems to be in good shape (passed coolant system pressure test and visual inspection of apex seals).

However, the top ear on the front iron is broken off where the water pump bolts on. Is there a way to fix this without replacing the iron? Do I need to fix this?

I will try to get a pic...

On the left upper part of this pic, there is a stud coming off a triangular piece (with "3 legs")of the casting. This entire triangular piece broke off.

DO NOT BUY ATKINS! I dislike their product, only after using them. I dislike the customer service and their terrible build quality and I am not looking to use them again. Having said that, mazda is god. Typically follow what they did throughout the development, port shape/rotors/bearing/oil etc. I just like to update them.

Places to get good parts (aside from mazda) is Rotary Aviation, Pineapple Racing, Banzai Racing (for misc things) and Mazda.

The rotary aviation and atkins rebuild video differs a little bit, I tend to watch both when I build one but I always use rotary aviation o-ring kit the viton seals are excellent.

Do your rules forbid porting? streetport wouldnt hurt and the stock electronics can handle it, if they do. I would source t2 block and run NA rotors. the 6 port isn't as good as the 4 port.

I would replace all the springs, the apex seal springs can be bent into spec. I re use oil control rings because they are expensive but I still replace the o-rings in them.

Pineapple racing used to have VERY good videos on their site but their hosting is bonkers and they don't work anymore and they haven't said that they will release a CD/DVD of the videos, although for years I heard they were coming out with it...

S5 NA and S4 T2 center irons are interchangeable.

corner seal plugs tend to burn out or fall out and this is normal they don't really do a whole lot once the engine is assembled.

Oil control rings are a PITA but a flathead screwdriver works if your careful. Or a puddy knife.

I like OEM apex seals ($$$$$$$$$$$$$) and rotary aviation, my RA ones stood up to some serious abuse since it wasn't getting fuel at high rpm it wasn't getting oiled either. plus they come at a good price and come with springs which is a nice feature and if your already getting o-ring kit from there it saves on shipping.

I would measure your apex seals they are the 2 piece correct? if they are 3 piece toss them out, you can't even buy that style from mazda anymore they tended to wallow out the apex seal grooves on the rotor.

Your SOL on that front iron if that ear broke off. unless your good at welding cast iron.

I wish I could rebuild one with you/for you but I am stupid swamped with day job and current projects that I don't even have free time :(

Crap.

I already bought my stuff from Atkins. The old seals in it were Atkins anyway.

I guess I will get some experience!

I am going to try to do the "hammer weld" repair on teh front iron. - Weld small part and hit it with a hammer to stop the shrink. Weld small part and hit it with a hammer... repeat....

I will follow up once I try it out tonight.