www.RX7fb.com

gt_james wrote:who's jon newman?

Nice man, Own a rx3 and think he sold his sa22 last year.
he still got many 13"x 6" TWR alloys and rare rollcage for £500+something like that for sale.

apexheid wrote:

gt_james wrote:who's jon newman?

Nice man, Own a rx3 and think he sold his sa22 last year.
he still got many 13"x 6" TWR alloys and rare rollcage for £500+something like that for sale.

Oh right I've spoken to him about buying the rollcage and some other bits and pieces from him. Small world. He said he had a 12A 6PI but it wasn't for sale I think. I thought he meant he was talking about a 13B He was a helpful guy for sure, he told me he sold his RX3 some years ago. I keep forgetting to get back to him!

I have now got the engine and gearbox out the car. I can confirm the engine is a 12A 6PI.







The gearbox needs some bearings changing, I haven’t really decided what I’m doing about it yet



Here’s the rare beast I’m quite excited just because I really wasn’t expecting this engine, and as far as I can tell it’s a rare and interesting piece with technology that was first seen on the engine before being used on the later 13B 6 port. It is also a bit mysterious, it has found its way all the way from japan and into my car and I have owned the car for over a year and had no idea.








Now unfortunately the engine is really ugly. Its vile.



Sooo much grime and corrosion



This is what my normal 12A 4 port looks like



This is the manifold off the 12A 6 port


One of the rotating sleeves that open up the 5th and 6th ports



I got the carb off the manifold. Unfortunately the 5th and 6th ports have not been working on my car so I have had it all to bits



You can see the weird butterfly valve in one of the runners. It seems like someone has poured Loctite into it, which is annoying, but I can’t see that it does much anyway.



There is a rather rubbish looking blanking plate on the manifold with only 2 bolts holding it down. It leaks. I will have to try and sort this out.





I got the plate off the butterfly, but the spindle is Loctited or something and stuck in.



I cleaned the manifold up and removed the valve that should control the butterfly. I have started to make an inlet manifold gasket, and have some “O” rings.



Is this exhaust gasket like normal 12A ones?



The housings are the same as the 12A turbo. Here’s the exhaust port. There are two small holes under it. The exhaust port really is tiny! I used the torch of my phone and tried to look through it into the engine but I don’t know what I’m looking at. I think the engine is probably tired, but It ran fine before and started hot and cold.



I cleaned the engine up a bit with a wire wheel and wire brushes. The rear housing literally looks like the surface of the moon



There’s like craters and caves, I half expected some tiny clangers or rotary pixies to crawl out






The engine is really really badly corroded externally. Its horrific


I’m not sure but the water pump looks different, could someone tell me if stock 12A pumps are different? It just looks big and clumsy to me, the engine doesn’t look clean with it hanging off the top right at the from





I apologize for the really rubbish pic, this is the back of the engine and flywheel. I’m concerned as the nut is all mangled and burred which suggests the flywheel isn’t original and could be the wrong one. I know the rotating mass is the same as the 83-85 12a (S3). I presume this means that If the flywheel is wrong then it could be causing damage to the stat gears and bearings The car was running a 215mm clutch.



I’m going to clean up the distributor



As the rotor housings were so bad I filled the deep holes with JB weld. This might horrify you and the clangers, but I couldn’t stand seeing such bad pitting on the housing and thought filling it would be a good idea.



I cleaned up the engine and painted the water pump and that’s as far as I got.





















Also I need an oil cooler, anyone tell me if this will be any good?

http://www.ebay.co.uk/itm/221885734687? ... EBIDX%3AIT

Note the engine mount studs on the centre plate and the tiny primary ports. IIRC the 6 port actuators are vacuum controllled so check the system.

12A exhaust gasket is regular 12A.

Water pump looks normal.

You have a S2 flywheel on the back there. No point to change it unless you can be sure which rotors you have.

Take the sump off and get me pictures of you front counterweight and I can tell you which front weight you have so at least you'll know the counterweights match. Rotors you can assume to be the same as the counterweights.

Housings are Jap spec 12A, not 12AT. 12AT housings have oil injector ports.

HB Cosmo motor, 100%

I thought all 12A 6PI engines had the S3 rotating mass, so if it's an S2 flywheel it's wrong I imagine. I wasn't planning on dropping the sump. I've cleaned up most of the manifold and the actuators so hopefully I'll be able to get it all working again. The ports are minuscule :|

Important the waterpassages of the engine are clean and not rotted as the housing outside James.
Thanks for sharing such exotic details of an 12A very interesting.
Thomas

I forgot to say, I need a pilot bearing, mine is completely knackered. Where can I get one quickly? Are they a standard bearing I can get from a bearing supplier or a specific Mazda item? Can anyone tell me if they are all the same or different between flywheels/engines/E shafts?

They are all the same.... Don't forget the seal as well... I bought mine from a Mazda main dealer.... Only cost a few quid.... Check out page 2 of the parts numbers section of the forum for the parts numbers James

gt_james wrote:I thought all 12A 6PI engines had the S3 rotating mass, so if it's an S2 flywheel it's wrong I imagine. I wasn't planning on dropping the sump.

Yes, as I said earlier 6 port motors should be S3 rotating assembly.
Who knows if Mazda built a few specials or not.


You're assuming it's never been rebuilt. There's no way to know what's in there without tearing it down.