Itsdaveonline

I was just wondering. Im inheriting a 85 rx7 with easily over 350k miles. To be exact i think its in its early 380,000. Its always been cared for and is regularly maintained. Its always that car parked at the end of the lot where no one else parks. My fathers car is in great condition and will run like a champ.

Anyways i will be getting the 7 soon and was wondering if there should be anything that should be tended to besides the regular stuff. Are there any problems i should be looking out for due to the mileage?

thanks!

Rogue_Wulff

This kind of mileage is rare, but not unthinkable. The 1st gen RX7 had the most durable engines of any Rotary powered car. They were built with 3mm apex seals, which have not been used since the end of production in '85. The turbo guys are always "Upgrading" from the stock 2mm seals, to 3mm seals.
If I understand what you are saying, this has been your fathers car since day one, which means he has likely maintained it meticulously. Continue to follow his lead, and it could last you for a good long time.

clean85owner

I have almost 290,000, and I'm on my fourth motor....

Mazda12AGS

I had 400,000 on an older Civic I had on the original motor, but my RX-7 only has 130,000.

no_name

I have about 200 000 miles on the orginal motor. The car was not taken care of to well when I got it. It seems to be leaking a bit of oil. The leak looks like an oil pan problem.

Even if the motor dies on the car you will be enhariting, a new used 12a engine is like 300$ including tranny.

bliffle

Don't let it overheat. I think it's a good idea to add a little premix to each tank of gas. I use about 6-10 oz. of 2-cycle moto oil, MMO, or Idemitsu: they burn clean, lube inaccessible engine parts, and the detergent in MMO helps clean engine internals. Use a good lube in the transmission: I like Redline MTF, which makes shifts smoother and lubes well.

Junia

My dad's old 93 escort got 550,000 miles before he traded it in so I'm pretty confident that a 12a can get 350,000 with the proper care and maintenance.

notveryhappyjack

iTrader: (4)

at 350,000 miles your bushings will prolly all be tossed and need to be replaced

joecoolly14

ive got almost 250,000 and im on my 3rd engine...lol but the 7 WILL NEVER DIE AHAHAH

DwArF

My 2nd got 266k RIP!

and my 3rd (Daily Driver) has 236k, but it just got a new used motor in it

Itsdaveonline

Yeah i cant wait to recive the grocery getter. It sounds like i will need new bushings which sounds logical. It also will need a gearbox adjustment. Are used 12a's hard to find? Im thinking of rebuilding the engine, i learned the basics of doing so using mitchel1 at my automotive school. Is it worth rebuilding? im sure its has a shitload of carbon buildup.

the only problems so far with the 7 is:

-vinyl is popped of the door... I belive this is common with 7's
-grinding in 2nd gear when car is not warmed up, (happens sometimes, not serious grinding..)
-very small oil leaks, from engine compartment, maybe like a size a dime accumulates over about a week.
-floor mats are super fucked up, there torn. Where can i get a set of brown ones?

is it true that 12a's are more reliable than 13b's i would sure like the power but more importantly i want too keep the car running. If so how much would a good 13b cost, used or new.

one last question the 7 has been retrofitted to work for r134 but has not been filled with freon in about 3 years. Should i replace the o rings before refilling? or do you think i should be safe?

joecoolly14

umm to tell you the truth most of the people i know with 12a's dont want to give them up, ive gotten more offers on 13bs they have sitting in there garages than any 12a

iceblue

3mm seals is only an upgrade the undedicated perform. I am surprised it has held together even more so with 3mm seals. There is a reason Mazda only ran 3mm seals for one year.

I am glad to see it kicking. My take is doing everything he has been doing and drive it the same way. I have one with 220k original with strong compression and I know it would make over 300k 1982 FB. I don’t know if it will because my uncle dose not take care of it and drives it into the ground.

Your bushing and suspension are trashed at these miles. all I would do is replace bushings wheel bearings, ball joints, and struts. Call it a day well spent.

trochoid

iTrader: (6)

Iceblue, I'm not sure where you find your misinformation, but 3mm seals were run in all of the 1st gens and earlier engines, after they moved away from the 6mm seals.

Some of the 2nd and 3rd gen guys go 3mm believing it will give more protection from detonation in high boost applications, or to save rotors that have worn slots, making the 2mm seals too loose in the groove

iceblue

Ahh yes I wasn’t paying attention when typing. So maybe when someone with a good bit of knowledge says something you may want to be a little bit less evasive.

Like I said performance guys only move to 3mm because they do not know. The recycling of worn rotor grooves is a larger practice of 3mm seals. This was more vital back in 3piece seal days. 3 piece seals are my fave as they provide the most sealing potential to date and least amount of resence. The more the grove warn the 3 piece seals tended to roll in the grove thus moving to 2 piece was a more durable solution. The more mass you have on the surface matter the more chatter and wear you obtain. The whole act of 3mm seals being stronger in the motor is a bunch of bunk. They hardly withstand detonation any more and any ping of a nice bit will take out both 2 and 3 mm seals. Not to mention the hardened rotor ends from 86+ that get destroyed when milling.

Mazda has spent so much money researching seals there is a reason they are running 2mm in the FE. Who else has ran sensor on the actual apex seal?

Rogue_Wulff

All 12a's ever produced had 3mm (or larger) apex seals. The first time 2mm seals were used (in production engines), was in the '86 up 13b. Even in N/A form, those engines rarely made it beyond 150K before losing compression. Prior to the '86 13b, they used 3mm seals, as well. The older engines, such as the 12a, are known to go well beyond 200K with decent maintainence, and can make well over 300K with exceptional maintainence.
A well maintained 12a, with 250K or higher, usually shows decent compression numbers, even though the housings are getting very worn. I have seen some rotor housings from a 12a that had very little chrome plating left, yet the engine was still running prior to disassembly.

iceblue

It all has to do with maintance and how the car has been driven and if it was boosted. I have had several FC's with 200k on them. The fact that Mazda chose to stick with 2mm seals again with the FE speaks volumes IMO.

Rogue_Wulff

2mm seals will seat in faster, and seal better than 3mm seals. However, they wear faster.
The FE (RX8) is not designed to last over 200K. No car is designed to last that long. If all cars lasted that long, they wouldn't sell as many as they do. Prolly has a lot to do with the demise of the 3mm seals from the factory......................
Designed obsolecence. IMO.

iceblue

It is a give take. I think only Mazda knows the full truth. I find it funny because the americans do it so different then the japanees. I trust the Japaneese more personaly.

razorback

i have stock 13b rotors in my garage with 3mm seals, also have(had) 3 different sets of 3mm 12a rotors.

jgrewe

iTrader: (1)

I made it 274,963 miles on an '84 that was given to me when it had 257K miles on it. And I mean GIVEN. The guy bought it new, gave me his folder with every receipt in it and I gave him a ride home to his Tll. Original engine. I had to sell it last fall, I had to many cars laying around waiting for me to work on.

calvin

I am on my second high mileage 85 GSLSE (13B first gen, with 3mm apex seals stock). The first one got 320,000 miles on the original engine, then it lost an oil control seal. It still ran fine, but produced a huge cloud of smoke. I changed engines and drove the car until 360,000 miles and the car got totaled due to someone elses fault.

I replaced the chassis with another car I found. When I got it, that car had 190,000 miles and now it has 340,000 miles. I put the engine out of the totaled car into this one when I got it. I should point out that I autocross and run these cars on road courses. So they don't live "gentle" lives. I do take care of them, but the over rev buzzer goes off regularly.

First car :


second car :

calvin

the 12A's are in most first gens, but the 13B is in the 84-85 GSLSE. Here is info on the engine parts:

http://mrmazda.no-ip.com/interchange.html#ENGINE