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Rotary Engine Pages - FAQ
I have decided to go full width with the new FAQ section as it needs all the room it can get.
I think it will be much better this way.

You can go back to the questions form on the Ask Us page here.

quick-jump index

  1. ...operating temperature of a 12a...
  2. ...car has been sitting, wont start up...
  3. ...porting a 6 port 13b...
  4. ...1973 RX2 coupe for sale $1800... (pics)
  5. ...reliability of the rotary engine...
  6. ...which RX car should I buy...
  7. ...just a few comments... (pic)
  8. ...what do I look for when buying an RX...
  9. ...can I put a 1987 engine of mazda rx7 into mazda 1985...
  10. ...will Miata get a Rotary...
  11. ...seized rotary engine...
  12. ...autocad drawing of the 13b... (pic)
  13. ...rust in car...
  14. ...improve the performace to my Rx3 13b...
  15. ...hydrogen powered wankel engine...
  16. ...smoke, lots of it...
  17. ...rotary for my homebuilt airplane...
  18. ...which gas you recommend...
  19. ...my page is on go-karting...
  20. ...where do all the rotary mechanics learn their qualifications...
  21. ...like the page...
  22. ...and how much will it run to fix it...
  23. ...shot of my 88 convertible...
  24. ...can I run the factory cpu...
  25. ...materials used for rotor construction...
  26. ...is a wankel engine ruined if it gets flooded...
  27. ...how long will the engine last...
  28. ...it surges like it is trying to die...
  29. ...it loses power...
  30. ...i dont think i have seen anyone port like that...
  31. ...why does the rotary stall...
  32. ...brothers old car has problems...
  33. ...escort with a rotary engine...
  34. ...what could it be, a seize...
  35. ...could not get it up to revs...
  36. ...will it start leaking collant and oil afterwards...
  37. ...blow's black smoke when leaveing a light...
  38. ...pilot bearing fails on me in just 2 months...
  39. ...fuel pump cuts after 5 seconds...
  40. ...gears will not shift...
  41. ...where can I get a R26B engine...
  42. ...which rotors are best in the RX3...
  43. ...rotary sounds please...
  44. ...12A engine in a Suzuki Sierra...
  45. ...turbo into an '86 RX7...
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posted on 1 July 98 by niner 1

What is the normal operating temperature of the 12a with the air condition on and going 80mph?
Also it appears that when I drive in town the temperature on the gage appears normal. Only when I am going down the highway does it get warm (210 degrees F.)
I have just finished rebuilding the engine and every thing is new.

The only problem I see is that maybe the oil pressure is too low at higher rpms.
Oil pressure at idle is about 20in/lbs. At 3000 rpms the book calls for oil pressure to be from 64 to 85 in/lbs. mine is only about 45 to 50 tops. When I start it the most that I get is 60in/lbs.

Could this be the source of my heat problem? Is the rotor not getting enough oil pressure causing heat at higher rpms. If it is do you think it is the oil pressure control valve, the pressure regulator or the oil by-pass valve? My car is 1983.

Regarding the operating temperature at 80mph with the airconditioner on, it is impossible to answer without more data.(e.g. ambient temperature outside?, stock or modified?, radiator type?, coolant type?, oil system details)

Regarding town and country driving, in the country the revs are constant and this can churn the oil into a foamy, air filled mixture like an egg beater, resulting in a drop in pressure and less cooling ability, in the town the revs go down to idle occasionally, giving the oil a chance to liquify again. This would usually only cause problems in high reving performance engines but it can happen to anyone.

Try a more viscous oil or go the whole way and fit a baffle plate in the engine sump.
I have a template for a 13b plate but not a 12a. (13b template could be easily modified)
Also you could use a higher pressure regulator valve and/or high performance oil pump but be prepared for possible increased oil consumption if you do.

Check the oil cooler elements, oil filter condition (especially after a rebuild - first one clogs fast !), condition of pump (tolerances etc from manual), if running water - use coolant instead.
Turn off air your conditioner and roll down your window :)
To assist further we would require more information about your set up.

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posted on 20 July 98 by greg

I just bought my first car a 1978 RX7.
We have been trying to get it started but it won't fire.
The car has been sitting for about six months.

What can I do to prime the engine?

To start an engine you need three things.
Fuel, Spark and Compression. If you've got these 3 things, it should start !

Check them quickly as follows...
Remove a spark plug from the front housing, hold your finger or thumb tight over the hole an crank the engine. It should go "puff, puff, puff" agianst your finger with enough pressure to blast past it.
If it goes "puff, puff, fart" or "puff, fart, fart", there is a internal seal problem indicating a rebuild is required.
(check with a proper compression tester first, of course !) You should get 3 even puffs.
Repeat this quick check for the rear housing.

While you have the spark plug out, stick it back on it's HT lead and ground it somewhere handy
(and dark preferably).
Crank the engine and inspect for a good strong spark flame.
Chech the other plugs the same way in their own socket.

This one is the hardest to be sure of.
Check fuel bowl sight glasses on each side of a standard carby are full to the mark.
Clean and test injectors (if fuel injected).
Look down the carby to see if a good fuel mist is created by a good pump on the throttle in BOTH sides of carby.

Let's fire it up !
Take out all the plugs and crank it over to blow out any crap, fuel, oil or whatever.
Put 'em back and give the throttle two quick ones to the floor and crank straight away with NO throttle and plenty of choke.

If it still doesn't fire then you need to check everything again but this time properly with the right tools and a Manual.

All rotary owners should have a manual for their engine. You WILL need it eventually.
To assist further we would require more information about your set up.

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posted on 29 July 98 by austin

Is it capable (sic) to do a street port on a 6 port 13b ?

Yes, most certainly.

A six port 13B will take very nicely to a bit of opening up.
Be careful though as the walls of the housings can be different in thicknesses from 4 port motors. Just make sure there is enough material behind where you want to grind to accomodate the port and away you go.

Also, don't take the top (extra port up too high or you will have trouble with overlap). See if you can find someone with a porting template. Main thing is, it can be done.
I know a guy who is doing one now. (sorry, no template here either)

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posted on 1 August 98 by cameron

I have a 1973 rx2 2door with a ported 13b racing beat intake and carter 625cfm carb.
I would like to sell this car, the reason is that it's not a volkswagen.
I'm asking around $1800.00 or would trade for volkswagon bug or bus.
I've also got a rotery powered fiberglass buggy. I attached a pic of the rx.

Thanks for the pics. Glad you liked my site.
You didn't ask a question so I'll just run your car specs and photo's. I like these easy ones !

Camerons RX 2
Camerons RX 2     Camerons RX 2

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posted on 11 August 98 by ralph

I am looking at buying a 1983 RX-7 and am concerned with the reliability history of the rotary engine.
This particular engine has 250,000 kms under its belt.

How much more can a person expect from it?

In the early days, as with any new device, the Rotary engine was unreliable.
That was in the fifties and sixties and unfornunately people still try and tell you this today.
These days it is simply not true.

New materials, better manufacturing methods and about thirty years of practise and experience means a modern Rotary engine, taken proper care of, should have a life span at the very least equal to a conventional reciprocating engine. 250 000k's is a pretty good dig for any engine but it can be checked over a bit before you buy.

Having said that, when someone comes to me and says,"I'm getting out of Rotaries, I'm sick of mine blowing up on me !". The first thing I ask them is what were you doing at the time. They inevitably answer..."Oh, a burnout at seven and a half" or something equally as stressful like donuts.
What I'm trying to say is take care of any car and it will take care of you, Rotary or otherwise.

If you drive it like a race car.....expect to have regular pit stops :)
PS Are you really never coming back ? How will you read this ?

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posted on 16 August 98 by sunarto wijaya

hello I'm a big fan or an Rx-7 I mean I'm totally obsssessed with it that I almost killed myself cuz my parents aren't buying me one. well I have this question...I was wondering what type of Rx-7 is there out there from the year 93 and above. I'm wanting to get one and now I'm choosing between 2 Rx-7s. one they ask for 17000$ ..its 1993 turbo, 5 speed, air, PW, CD player, alloys and more ..60k milleage color is black coupe and the other one ask for 19500$ its 1993 color is red...49k milleage...bose sound system, power sunroof and more its a five speed. I was wondering what's the difference between Rx7 and Rx7 coupe...and would you advise me which has better deals on either 2 of these Rx-7 thanks

It's very hard to say which car you should buy from here as there are so many things to consider whith buying any car. I would at least have to test drive them both first. Models are many and varied and can even include local dealer initiated custom options so it isn't easy to say what was or is ever available. Mazda Australia sold different model variants than did Mazda New Zealand or for that matter did Mazda Ethiopia.

My point being, that no-one knows exactly what was or is available in total. I can help you with what came out in Australia though if that is any assistance.
This of course is impossible so I can't really advise you there, but as for your other question, the difference between an RX7 and an RX7 coupe is zero. All RX7's are coupes unless there is a four door sedan variant that I am not aware of :)

It is probably just the guy who wrote the advert. Last week he was probably selling trucks.
Personally, I would go with the non turbo but that is just my taste.
All the best !

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posted on 19 August 98 by jack clair

thank you for a great web site, here is a picture of my first rotary.
i've had a total of 5 but none now.
i had a great time in this car, i got it in 1978 and of all the cars i've had in my life no other car ever attracted as many street races, or suprised as many people.
firebirds were a special target and easy prey.
it's a shame these cars are so rare now, i would like to own one again.

WOW someone actually had the SP pin-stripe model !

I have only ever seen one photo (it's on my site) from a Mazda promo.
Old Rotaries are not so rare, depending on where you are. For example, here in Oz, between myself and a mate we have 5 1974 RX4s at the present time.
(2 roadworthy, 2 straight shells and a trashed one for spares).
Yours is exactly the mentality that I love, unique to Rotary fans, that driving Rotaries is simply great fun.
My best driving memories have been in my Rotors. The other cars I have had, some slow, some fast, are all so boring to contemplate compared to hopping in my RX.
Glad you liked my site.
Catch ya....

Jacks RX3 SP
Jacks RX3 SP

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posted on 26 September 98 by kris

First of all you have the best roto site, the best multimedia !!! (thanks - Glenn :)
I'm looking to buy a base model RX with 75K for CANADIAN$5000. Is this a good deal ?
What do I need to look for ? What do I keep my eyes open for ?
What do I need to check B4 I buy it ?
What life expectancy can I expect under regular use ?
Please give as much info as you can.

I'm not sure if CA$5000 is a good deal because of dollar conversions etc.
If it was OZ$$ I would say "Can you get me one too" as that would be a huge bargain here.
Otherwise, it's hard to say for obvious reasons.

Your question about life expectancy of a Rotary is sort of answered above in a previous enquiry and regarding what to look for when shopping for a new Rotary, please see our new department Buyers Tips, recently added to address this popular question.

Oh yeah, thanks for your generous comments. It makes all the difference when someone get something out of visiting our site.

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posted on 5 October 98 by davis

Can I put a 1987 engine of mazda rx7 into mazda 1985?

Hi Davis
Firstly, let me say that you can put ANYTHING in ANYTHING if you have the budget. I assume you mean with few or no modifications involved.
Well, a 13B out of any Mazda rotary should fit where any other 13B has been regardless of model or year. Same with 12A to 12A or 10A to 10A.

Legals are something you will have to investigate in your part of the world.
If you are going to change a piston Mazda to rotary power you have a little bit more work to do like changing the front crossmember/engine mount, changing/moving the gearbox mounts, and where I'm from you would have to upgrade the brakes and possibly the driveline and a few other things.
Hope this info helps.

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posted on 9 October 98 by andy

I just purchased a 1999 Miata, and I have heard from some people that I've talked to that Mazda is thinking about making a rotary engine for the Miata.

Is this true? If it is then when will it be out?
As you can tell from my name a also own a VW, I enjoy the Mazda alot more!
Thanks for your time.

Hi Andy,
I am not sure about the new Models being available in Rotary powered versions but we can dream I suppose.
If you want my opinion they (Mazda) should offer a Rotary variant in all models.
I will endevour to find out more.
Try the Mazda web site in your area for more Model info.

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posted on 10 October 98 by steve

Is there any way to free up a ceased motor ?
What would cause a rotary to cease up ?
Do I need to replace my motor or can this one be saved ?

Hi Steve,
A Rotary should turn fairly freely by hand when not connected to a gearbox.
If a Rotary engine is ceased it is not a good sign.
Sometimes, but rarely are they able to be rescued, especially if it has been standing for some time.
If you or whoever else was driving it at the time when it ceased, this is even worse.
Chances are you have thrown a seal and it has done a few destructive laps of the housing before you got the clutch in. If it is not a seal it is obvious that something else is either broken, bent or has moved out of place.

Either way an engine rebuild is unaviodable.
Sometimes the parts in one of the two housings survive undamaged as the problem was isolated to only the front or the back housing.
If you have bent the main eccentric shaft then who knows what else has suffered.
Get a good book and some spanners and have a look.
You will soon see the problem.
Good luck

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posted on 20 October 98 by knot

Looking for an autocad drawing of the 13b, any help would be great. ?

I am not sure if this is what you wanted but I have been looking everywhere and could not find much else. Let me know some more specifics and I may be able to help some more.

the picture (click for a huge picture)
click for a larger picture

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posted on 27 October 98 by ngoc

How are you? Would you please help me ?
I love my car very much....It is a 1985 Mazda Rx7 gs.....
I want to keep it forever, but right now it's got a lot of rust under the car ( I mean that alot of rust at the bottom of the car).
I want to take it off.

Would you please show me how to take off the rust at the bottom of the car by myself ?

By the way....
Is that the body shop they do to take off the rust at the bottom of the car ?
I am waiting for your message....Please help me.
Thank you very much.

Where do I begin ?
I could approach this one of two ways.

I could write a sizable book on car body repairs or I could give a quick guide in point form.
I think I will go with the second option.

If the rust is in a piece that can be taken off. (eg. door, fender etc) - replace it.
If the rust is in a fixed section (eg. floor, lower sill etc) cut out the rust with a grinder and weld in a new piece of metal sheet. Then finish with some filler and paint.
If it's in the floor, sometimes it is more practical to cut the entire floor out and weld in a replacement.
If the rust is structural (eg. chassis, framework etc) it can still be repaired if not too advanced but is sometimes better to scrap the vehicle if it is dangerously rusty.
It all depends on where the rust is, how bad the rust is and how much time and money you want to spend getting it fixed.
All the Best

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posted on 29 October 98 by jay

What could I do to improve the performace to my Rx3 13b ?
How much hourse power could i get it up to ?
Please send me some information on engine products and mechanic tips.
Thank you

Hi Jay,
It would take an entire website to tell you what you can do to make a Rotary more powerful but I will try and give a few tips anyway.
Starting from a standard, stock engine. Do these things in this order.
(until you run out of money :)
External -
1 - Improving engine breathing will be a huge first step.
    a. Fit a mandatory Sports exhaust system.(the bigger the better)
    b. Fit a high volume competition Air Filter.
2 - Fit a late model Electronic Distributor - ex RX7 13B (a must for clean reving)
3 - Fit a bigger, performance carburettor. (eg. Webber, Holley etc)
4 - Fit aftermarket electronic fuel injection and engine management system.
5 - Fit a nitrous oxide injection system.
6 - Fit a Turbocharger. (or two)
7 - Paint the car Red.
Internal -
1 - Fit a high volume or competition oil pump and filter.
2 - Remove collets from exhaust outlets. (carefully !)
3 - Porting of housings to mild, extended, bridge, extended bridge or peripheral.
    (or anywhere in between)
4 - Fit competition seals and anything else you can get your hands on.
5 - Cross drill eccentric shaft.
6 - Fit competition style lightened Rotors.
etc etc etc etc .

There are soooo many other things you can do but this lot should keep your busy (and poor) for a while yet.
Other tricks include running a different ratio in the differential to improve torque and acceleration although a reduction in terminal speed will also result. (Drag cars do this)
As I cannot advertise or promote products on a Geocities website, I can offer recomended engine specialists to you located in Australia if you want to ask me by e-mail

About the most horse power possible ?
People set records everyday so it's hard to say. I have heard of around 400 for a twin rotor race/drag engine with the works but let me just say that a stock rotary screams so any improvement is a bonus.

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posted on 1 November 98 by j

What can you tell me about a Hydrogen powered Wankel engine, and where can i find more information on it ?

Hi J,
I can tell you that it is the VERY REASON that rotaries will one day rule the world of engines. This is why.

Reciprocating engines, like normal rotaries, run on fossil fuels. Petrol/Gasoline, Kerosene, Diesel etc.
(I know, I know, Indy cars run on methyl alcohol, made from plants !)
The RX01 was released as a concept car by Mazda to showcase it's new Hydrogen powered 13B engine. They have almost as good performance specs as a normal 13B but suffered problems early in developement with the method of fuel storage.
The problem is hydrogen is extremly volatile. Stuff has to be stored as two separate compounds in special cells(I can't remember their names:) and mixed bit by bit, producing a chemical reaction that gives hydrogen. Supplying an engine meant controlling this process acurately enough to make only the amount of hydrogen needed by the engine. This is very complicated indeed.
Why I say it will take over is simply this. The intake, compression, combustion and exhausting all occurs in the same place in a conventional engine. (the piston bore)
A rotary however has a cold and a hot side and intakes/exhausts on the cold.
My point being, Hydrogen will ignite on the instant it contacts a hot metal surface like anywhere inside a piston bore. This makes the timing of ignition in a conventional engine impossible.

In the RX01 13B engine the hydrogen is taken in on the cold side and doesn't strike hot metal until it is time to fire anyway. This basically make the rotary suitable for hydrogen fuels.
I have a few articles etc on the RX01 but can't find them anywhere !
Have you been to any official Mazda sites ?
I'll keep looking.

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posted on 2 November 98 by chris

How are you? Like the site.

I just bought a 1979 RX-7 w/rotary motor 45k miles for $100 us. The car is in good shape.
The girl I bought it from let it sit for months and could not get it started. I just push started it, fired right up.

Some minor probs (may need a new starter and a new driver seat).that I can fix on my own.
The main problem is Smoke, lots of it.
The motor runs ok but white smoke from the tail pipe I'm talking James Bond style smoke screen. Bad seals? gaskets? Its definitely burning oil. :(

Any ideas on what needs to be done? Cost?
Did I just waste my $100 dollars? Or is it worth keeping and fixing or should I sell it to my local salvage yard? Any feed back will be most appreciated.

Thanks much.
Wannabe Rotary fan.

Hi Chris (007),

Smoke 'em up they say.
OK. Inside a rotary there are separate oil and compression seals.
You can very easily have a defective oil seal without affecting the compression a great deal and therefore still receive good performance.
Your $100 was well spent in any case (bargain here :). It should be nothing more than a rebuild, replacing defective seals and anything else that looks suspect.
If you do it yourself it should only cost a few hundred for the gasket kit and new seals etc.
Also check the seal springs (you get new ones in the kits anyway).

Good Luck with it.

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posted on 2 November 98 by kelly

Where can I find a Wankel Rotary for my homebuilt airplane.
Saw Atkins Aviaion, but wasn't impressed.
Would like to find about 160 - 200 hp.

Hi Kelly,

I have seen some speedway cars with single rotor engine making about this much power but I don't know where you would get one.
Try finding an old 10A Mazda engine.
They are reasonably tiny and can still be worked for power. Cheers

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posted on 4 November 98 by joe

I have recently acquired a cherry 84 gsl-se(completely stock).
I would like to know which gas you recommend to use in it ?
High octane (92) or regular (87) ?

Hi Joe,

I have used Standard (regular) before the days of unleaded fuel here in Australia and now use the lowest octane Regular Unleaded now.
It has never been necessary to use high octain fuel in a Rotary engine unless you are running a special purpose performance engine.

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posted on 10 November 98 by james

your site is so cool!
What html editor did you use? i need to get a good editor, because I use coffee cup html, and it cant produce a really professional page.
My page is on Go-Karting, and you can check it out at


Hi James

Thanks for the comments.
I mostly use a HTML editor called Lorenz Graf's HTMLtool2.0.
It's a shareware program that I found at one of the download sites (can't remember which).
It's not WYSIWYG but remember that I make web sites for a living so this program might not be for everyone. I love it and you have seen the results it can make. To use it properly you will have to have a pretty good grasp of HTML 4.0 but it comes with good reference material and the net is full of stuff as well.
By the way, they have just built an international standard karting circuit about 1 mile from my house and I am that close to buying one myself. As you may have noticed from my movies page, I am an avid F1 fan and most of my driving heroes came from karting in Europe etc. I think Michael Shumacher is the greatest driver alive at present. His parents own a karting track in Germany? where the Schu brothers learnt their craft.

Anyway, all the best and thanks for visiting

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posted on 11 November 98 by james

Where do all the rotary mechanics learn their qualifications ?
I have written to most of the top workshops around Australia, and only Pac Performance wrote back with useful information, because i am interested in beconing a mechanic on these wonderful engines.
Do you know what is going on ?

sick page man!

Hi James,

I'm catching up my mail.
As far as I know, all the rotary mechanics that I have ever met have actually called themselves Rotary Specialists and this is where the distinction lies.
In most cases these people are self proclaimed rotary mechanics and hold no special credentials other than a claim to specilalist knowledge of rotary engines.
Some are not even qualified motor mechanics at all and still operate successful and usually very busy rotary only repair workshops.

There is an element of Rotary theory contained in the regular trades course for motor mechanics but nothing beats experience and background.
Some of these self proclaimed rotary specialists, qualified and not, are recognised as genius in rotary and motor racing circles, others however can be very shonky and dubious indeed and should be avoided. I can think of examples of both.
My advice to you is to get a couple of good books, some spanners and go for it. It is not really that difficult if you are patient.


PS - your quiz score was 5 out of 10

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posted on 12 November 98 by ironman

WOW! Really like the way you have changed the page, looks great.

Now I have a great place to send friends when they say,
"No pistons! How the hell does that work ?".
'91 TII
'86 w/ 161,000 miles bout the only high point with that 7

Hi Ironman,

Thank heaps for your generous comments.
This new layout will allow me to add stuff more easily so it can only get better.


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posted on 13 November 98 by luis

I have a 86 rx7 non-turbo 13b with 154k miles I bought to fix it up.
I change the tranny and the car turns on and drives perfecly but it smokes white smoke excessively through my exhaust. People tell that the corner seals are worn and they need to be replace.
Other tell me the engine needs to be rebuild. And some tell me that I shouldn't even bother with the car and get rid of it but I like rx7's and the unique engine and would like to keep it.I would like you to tell me what would be the possible problems and what would I have to do with it to get the problem fixed. And how much will it run to fix it ?
Or am i better off getting another engine

Hi Luis,

About your smoke problems. You should see the posts a few up. They sort of answer your question I think.
As for your friends, don't listen to them, they are just jealous of your rotary.
Like any engine that is playing up, you always feel like ditching the car, but when it's going properly again you think "I'm glad I got this fixed....This is GREAT !".
Need I say more ?

All the best.

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posted on 17 November 98 by paco

hey, i really like the page. i got the addy from a newsgroup post in rec.autos.rotary, and since you need pictures of RX-7's, i'll gladly submit a nice double-angle shot of my 88 convertible. (soon to recieve a new top) hope you put it up. i'll check back!


Hi Paco,

Thanks for you visit.
Yes your car will be in the RX7 section soon. (very nice indeed:)
I am very busy with work at the moment and haven't had a chance to work on my site or answer any mail.
Today is catch up day.
Glad you like my site.


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posted on 18 November 98 by dan

I'm installing a 86 13B with fuel injection into another car, it will be for off road purposes only.
My question is can I use the factory cpu, to control the fuel injection and the timing or do I have to get a aftermarket cpu and timeing management cpu that I see on alot of others rotary powered cars?
In other words can I run the factory cpu (EGI) in a barebones way, as I'm trying to shoe string this for the first year or two?
Second if so what can I remove?


Hi Dan,

As far as I know the factory CPU needs all the sensors and crap fitted to operate efficiently.
I think this is one of the reasons the aftermarket units are popular because they can be configured in many different ways including as you say, a bare-bones, only what I need set-up.
The aftermarket units are only a few hundred and there are heaps to choose from depending on the application.
Hope this helps.


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posted on 20 November 98 by aaron

I am a mechanical engineering student working for an engine company in Canada.
Pistons have been made of steel, cast iron, aluminum, composites, ceramics, etc. Why not Wankel rotors (the Mazda rotary, in specific)?
Thermal loading or temperature reasons? Vibration? Strength, combustion pressure? Machining and casting complexity? Gear strength? Lubrication?

Or is it something more obvious, like cost (steel = cheap)? Or Mazda not wanting to mess with something once they finally got the sealing problems solved?
Or perhaps a different material could be used and it isn't being done because of a general lack of Wankel research in industry?

I have found little help from mechanics, Mazda, industry, etc. and thus went fishing for Wankel experts, that's how I found you guys (by the way, informative site and straightforward).
Thank you in advance for your opinion or any available help

Aaron Lockwood

Hi Aaron,

I'm sure I read somewhere that Mazda have tested ceramic rotors and I think they were aiming at using them in variants of the RX01 13B Hydrogen Engine.
Cost is another consideration and cast is cheap to build with. As far as weight saving goes. I think Mazda (and others) purposely left the rotors heavy to smooth out the pulsing at idle which in it's production form wasn't good for sales.
Ever driven a stocker ? They were marketing it as a Smooooooth power delivery and having two heavy rotors acting like extra flywheels helped enormously. This is one of the reasons PP engines were abandoned early by Mazda because of the rough idle and low torque at low revs and the peaky power when it came. This is all just my opinion if you like but it sounds reasonable to me.

Mind you, the first thing I do is b-port an engine to get the beating idle back ! :)
One last thing, Mazda is at the fore-front of Rotary research. Their R+D lab isn't protected by high security for nothing.
Hope this helps.


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posted on 22 November 98 by dave

Is it true that a wankel engine is ruined if it gets flooded?
My daughter has an 87 RX7 that would not start , the mechanic said it had been flooded and there is no way to start it. Is there a way to fix this if this the problem?

Need help ASAP

Hi Dave,

I can't see why it would be damaged provided the water didn't stay there too long. It would be mandatory to drain the sump, blow out the oil and water galleries and basically give it a damn good clean up. Throw some light oil in the plug holes and disconnect the exhaust and just spin it on the starter until you blow all the offending liquid out. A new set of plugs and she should fire up if the ignition system and carby are undamaged. A brief flooding has not stopped me from a first go start-up on a few occassions provided I did a good job of cleaning up first.
If it still doesn't start, there is obviously something else wrong.
Hope this helps.


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posted on 18 November 98 by skip

My 83 RX-7 has the Normal oil leak by the Mazda emblem between the front rotor and front plate.
It also leaks a little coolant on the other side under the carb.
It has 96thousand miles and runs great.
How long will the engine last ?
Where can i get another 12A ?

Skip Robinson

Hi Skip,

All engines, rotary or otherwise, with age will show a leak or two.
The engine will last as long as it lasts. It would be great if everyone new how many miles we will get from an engine, but unfortunately, you never know. The only thing I can suggest is to look after it and see if you can keep it at it's present condition.
As far as getting a 12A engine. You didn't say where you are but here in Australia they are easy to find as they are now not as popular as the 13B have become.
It's a bit hard to help much more from the few details you have supplied.
Good Luck


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posted on 23 November 98 by bill

We own a 1985 RX-7 GSL-SE with the 13B engine.
We've had it since it was new and it has always had TLC and has run great, until today. If the throttle is released, the engine dies. It restarts, but acts as if it is flooded and so must be nursed into running. It accelerates fine, but when the throttle is lifted to maintain speed it surges like it is trying to die and then catching itself.
It has also started emitting a bit of black smoke (unburned fuel?) The plugs were pulled and were all black with soot. New NGK plugs were installed (and were black within a couple of minutes of starting the engine), but didn't help. The air and fuel filters have been replaced, and the dirtributor cap and rotor were cleaned.
If you can't help me, I guess the next stop is the Mazda garage (poor pocket book).

Hi Bill,

It looks to me like something minor has let go in the engine. It may be a rubber component such as an oil seal or maybe even a metal seal has broken up.
I would say it was water getting in somewhere, only that you said black smoke not white.
If it is not a mechanical problem then I would look closely at the fuel system. Too rich by the look of it. This could mean a blockage or even a leak allowing atmosphere into the mixture. I would check this out first but otherwise, if it is internal/mechanical then it will only get worse.
Something is depositing on the plugs. You just have to work out what.
Sorry I couldn't help more.


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posted on 24 November 98 by a morales



No, no head gaskets, in fact no heads. But, there is an area around the outside of each housing where the water jacket is separated from the combustion chamber by a rubberised seal. If this seal is breached anywhere the engine will loose water to the combustion chamber and affect performance while it's at it.
To fix it means an engine rebuild. Not good news but that's how it goes.
Good Luck With It
(PS - there is no need to shout :)


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posted on 26 November 98 by matt

I was looking at the motor parts and i dont think i have seen anyone port like that, is this something new or are the holes that are drilled there just a guide to be ground out ?

Hi Matt,

I was wondering how long it would be until someone spotted the drilled bridge ports. No they are not a guide, that's how they went into the engine.
Reason - To add a slight top end improvement without loss of down low torque, but mainly to get rid of that smoooooth standard idle. I recomend it to anyone who wants that good ole' Rotary Wah Wah Wah Wah Wah throbbing idle.
It's more cosmetic than performance related.


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posted on 28 November 98 by gman

I have a 1987 Rx-7 and recently purchased a new engine. I love my car. However, I notice two problems that always seem to occur with a rotary engines.

Problem 1
When starting the car, why does the rotary stall, or never cranks over smoothly. I sometimes have to hold down the "GAS" to make it turn over. I have to be careful not to FLOOD the Engine. What's the problem, I talked to over 10 madza RX-7 owners and the also notice this same problem. Need Help???

Problem 2
Please explain what these madza dealers mean by the phrase: "It's the compression".
Before I purchased the new 13 B engine, My mazda dealer said that "the compression is low"
Even though my car ran great. Starting the rotary engine was the only problem. They tested my rotary and said the compression is too low and a new engine is needed.
They have also told this "story" to 4 of my other RX-7 owners.
How can a car run so well, but have starting problems due to "compression". Please inform us of this problem.
I feel Madza is ripping people off. What's the deal?



Hi Gman,

I've got three words for you, Apex Seal Springs. I just bet that this is the problem. I'll breifly explain.

An apex seal rocks back and forth slightly in it's slot sealing on one edge, then the other as it spins to different parts of the cycle. Centrifugal force, combined with the combustion gasses, apply pressure to the seals to force them into the sides of the slots as well as into the housing surface they are sealing against. What happens is that at low revs (or even slower cranking/starting speed), these seals are not forced against the housing very hard and so leak gas past into the next chamber. (Gives BAD compression readings at cranking speed !)
To overcome this, Mazda (and others) have installed small, coathanger shaped springs underneath the apex seal, pressing the seal against the housing for starting etc. The springs are relitively redundant after the engine revs up a little. You can have a PERFECT running engine, with plenty of power that is just hard to start if these springs are worn out. Lay an old one next to a new one on the bench and you will soon see the difference.
I had this exact problem, replaced the seal springs and it was all perfect again. They are cheap to buy but require a re-build to fit them.
Hope this helps


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posted on 8 December 98 by mark

Great web site!!!

Do you know of any good Mazda repair places in Los Angeles. I have a 85 RX-7 I inherited from my brother after his death and want to fix this to mint specs.
Currently it has an oil leak (front engine seal) and a small noise in the defferential.

Hi Mark,
As I am based in Australia, my knowledge of the Los Angeles area is restricted to a small school atlas, therefore I cannot recommend repairers in that area.
As for the problems you listed.
The outer front seal can be replaced without an engine re-build with some patience and a good Mazda book. Check the oil level in the differential and if OK you might need to get a replacement center. They are not rare or expensive. Try a auto-dismantler or seconds dealer.
As for your honorable efforts, I can only hope someone will keep my Rotarys going should I meet an inconveniently early end.

All the best

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posted on 17 December 98 by escort man

I have a 1979 Ford Escort Mk 2 (4 door) and was wondering how hard it is going to be to put the 13B Rotary in it.
Has anyone done this before? or am I the only person stupid enough to try it?
It would be great to hear from you with any suggestions and information you might have.

Briefly. Yes it can be done.
I have seen this exact combination years ago but do not have an photos or info on that particular car. Rotaries are so small they tend to fit almost anywhere and the escort engine bay hs plenty of room.
I am just guessing but I would say at very least you will maybe have to move a few things like the steering box, brake cylinder and whatever to suit the new engine.
Get a front engine mount/crossmember from another rotary or dismantler and adapt it to the esky. It will save a lot of fabrication.
The price of this advice is a few photos when you're finished building it.


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posted on 18 December 98 by vince

I have an 83 rx7 with a 12a..I started it up last night in the cold.After awhile suddenly the engine locked up...What could it be..A seize?
I am a mechanic,but no nothing of rotatry engines..


Hi there,
Doesn't sound good Vince.
Does it turn by hand with the plugs out.
If it is locked up with the plugs removed and is not hydro-locked (full of liquid - unlikely), then something solid must have moved/broken and it means an engine split just to see the problem.
You can sort of check the apex seals with a torch by looking in the exhaust port as you slowly turn the engine. (not much good if it wont turn though!)
Hope this helps.


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posted on 19 December 98 by richard

I own a 1983 RX7 with about 114K miles on engine.
Engine started running rough at idle and over a months time would barely run at idle but "up on the pipe" o.k.. Finally could not get it up to revs. Local mechanic said Apex seals shot.
However, the engine never smoked/blew oil through any of this.
Could this engine problem be other than Apex seals?

Hi there,
A common misunderstanding is that apex seals are like piston rings in that they seal the compression area (dry) from the sump and crank area(wet).
Not the case.
Apex seals have a compression area(dry) on BOTH sides. This means that when an apex seal is worn of fails completely, It does NOT cause oil smoke.
It does however give symtoms very similar to those you have described in your question.
It sound like it is worn out to me.
Hope this helps.


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posted on 22 December 98 by vince

i have a 86 non turbo rx7 with a rotary changed 3 yrs ago. And i am planning to take the car up north with me.
Can the rotary engine withstand those slope hills and long 7 hours drive?
will it start leaking collant and oil afterwards?
thank you for the info.

Hi there,
I don't know where in the world these hills are you speak of but my Rotary looks forward to hilly roads.
I have driven my Rotaries for 1000's of miles on long journeys without any trouble at all.
Are you worried BECAUSE it is a Rotary ? Hell, I'de prefer to take a Rotary on a trip over a conventional car anyday. I am a little biased though.
Basically if it is in good condition it should go fine.
Like any car that is well looked after, being a Rotary has little to do with it.
By the way, north of where, 7 hours from where ? (we are in Australia)
Hope this helps.


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posted on 2 January 99 by darin

I was just checking out most of the sites i could find and found you guy's.
I have a couple of rx3Sp's neihter of them running at the moment. but i took the rotary that was setting around and put it my 1986 mazda b2000 p-cup.
for the most part it runs great. but I cant seem to get to run correct.
I have a holley intake and carb on it and a header,light'n flywheel ect. the problem i think is in the carb. it loads up but doesnt foul the plugs. the plug's look good when pulled, but does'nt perform like it should.
I had it on a scope and did'nt find anything wrong but it smells real fuely (too rich) and blow's black smoke when leaveing a light. over all it runs great turns alot a heads and will do about 130mph...
any ideal's would help i'm out of them...
happy new year!!!!!!!!!

Hi there,
Carbies are hard to get right. It sure sounds like fuel mixture. I can only suggest a Holley expert or going to the more popular and easier to set up Weber carbs.
Some people have had good success with Holley but from my memory they always seemed to be tuning them.
I have the calibrations for a 48 IDA Weber if you need them. Also for the Niki carby.
On your Holley the mixture screws are either side of the metering block.
To lean go clockwise, to richen go anticlockwise unless there is a tag on the metering block telling you otherwise (some go the other way). Hope this helps.


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posted on 22 December 98 by vince

i have a 86 non turbo rx7 with a rotary changed 3 yrs ago.
And i did my own clutch replacement couple months ago. I changed the pilot bearing, clutch disk, housing. But the pilot bearing fails on me in just 2 months.
I wonder why it fails so easy.
thank you for the information.

Hi there,
I'm just guessing but there must be a vibration, misalignment or something around the gearbox input shaft to cause early failure. It's hard to say.
Not a problem I have ever seen.


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posted on 8 January 99 by mark

i have an 86 rx7.
the car starts and then for some reason the fuel pump relay trips off... no fuel to engine . what is causing this to happen?
the car will run for 5 seconds or so. before it cuts out.
i am also looking for the feul system wiring diagram without buying the shop manual, any suggestions?


I don't know what the problem might be but I can offer a solution.

Firstly, I can't think of any situation where the fuel pump needs to be switched off. Therefore I would hard wire it to the ignition so it's ALWAYS got power. Easy.
Also, I only have old manuals for the RX4 models. (my favorite).
You should buy one. Every rotary owner should have a good workshop manual.

Thanks for your visit.

Glenn - REP

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posted on 12 January 99 by vince

hi, my 86 non turbo 2nd generation Rx7 is playing trick on me.
Sometimes i cannot shift at all. What i mean by that is when i try to shift to any gears, the shifter won't go into any gear slot. The only one i can get into is the reverse gear, but when i shift to reverse, gears grind each other causing that nasty noise. After i got into that gear in reverse, i can be able to shift to first gear right the way. But the problem persist sometimes.
It happens to me quite of times...i dont know what is causing it.
I had my clutch and housing and throwout bearing replaced recently. I believe its the pilot bearing that is cauing all this...but i am not sure bout anything.
thank you for ur knowledge on the topic

It certainly sounds like a clutch problem.
It isn't dis-engaging fully and is still spinning the box. Unfortunately, the clutch area is not a strong point in the design. I would pull it out and check it over as it will wreck the gearbox before too long.
Maybe the bearing is binding or something. Good luck with it.

Thanks for your visit.

Glenn - REP

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posted on 13 January 99 by paul

Hi I was just wondering if you knew where I could get an r26B engine from

Isn't the R26B a special that Mazda made for the 787B Le Mans cars of 1991 ?
If there were any left in the world I would think they would be very hard to find and lots of money to buy.
Unless of course you want one of the two I have in my garage. (dreaming of course).

Thanks for your visit.

Glenn - REP

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posted on 21 January 99 by ellis

I have an RX3SP.
Unfortunately, I spun a rotor bearing and need to replace the rotor. I'm looking for a source for used RX3 rotors. Also, I'm interested in information about which rotors are best in the RX3.
The stock rotor with a retangular combustion chamber or a later stock rotor with elongated combustion chambers ?


As a general rule, the later the design, the better refined the design.
That means that I would use the later model rotors by preference as long as they are dimensionally the same. You may have to machine the seal slots if using different seals with the later rotors.

Did you know you can pin the bearings so they dont come loose.
Good Luck with it.

Thanks for your visit.

Glenn - REP

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posted on 21 January 99 by paul

How are ya ?
Im good, my name is Paul Samulski ( WKD - 12A ) and i went to your page ( which i love )
and it said that youll be able to send me rota sounds if i ask.
So im asking please...:) ! Can u just zip em up and send me em ?
Regards Paul

Thanks for your comments.
About the sound files, I'm finding them now. Wont be long.....promise.
Thanks for your visit.

Glenn - REP

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posted on 26 January 99 by grizbear

I have a Suzuki Sierra 4x4 (also known as Geotracker / Samurai depending on your part of the world) and I was looking for something to replace the original engine that will provide adequate performance on the beach/sand as well as in town.
I have considered a 4cyl, but want something different.
Would the 12A be a suitable engine or should I opt for one of the regular conversions.

As far as fitting a rotary 12A to a Suzuki Sierra, you will probably do some serious modification to get it right but it would be excelent for the task.
All depends on your budget I suppose.
If you do it, I want to know. (pictures too :)

Glenn - REP

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posted on 13 February 99 by oak

I have a 86 non-turbo rx-7 and the engine is blown.
I am going to by another engine for it and I am putting it in myself.
When I am looking for an engine what years are compatibale with my 86.
Also is it possible to put in a turbo engine instead.
If so is there anything speacal that needs done?
thanks, and your web page is great

Thanks for your comments.
Any rotary of the same capacity should fit easily.
If its a turbo you have a bit of extra work to do. If it's a factory turbo engine then it's not so hard but get a good book first.
The wiring can be tricky but patience will see you through.
This conversion has been done thousands of times. No worries.

Glenn - REP

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