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Discussion Starter · #1 ·
I just realised that there is no forums here for the older Mazdas... maybe some of this is a bit off-topic, but dunno where else to post it :)

Currently in the driveway I have a '95 Eunos 800M (Millenia S) and the GF has a '91 121 bubble (a much better car than it *looks*). But on the front lawn and in the garage are 2 "wierder" beasts...

First was my old "good" car, that unfortunately died due to rust and lack of interest - a '75 model 121 coupe. Dunno what they were called overseas, but they were popular here in Australia - same body as a RX5 (Cosmo?), but piston motor. I remember drooling when they were first released, so I bought one a few years later...

I got that (somewhat boring, conservative) car coz I wanted to get something slower to save my licence - years of driving fully worked 6's and 8's meant that I still didn't have a full licence and I was well over 25 years old...

The stock 1800cc 4 cylinder was OK at first, but pretty soon the thirst for grunt overcame me... so I spent heaps for ported head, custom-ground cam, extractors, 2" exhaust and twin DCOE webers (anyone remember what they are?) and numerous other mods. The guy who built it prepared the race motors for some famous rally driver.

After considerable dyno time and a heap more tweaks I got just over 120hp at the wheels, which at that dyno shop was about the same as a strong mild-port 12A. I had great fun with that motor - chirps into 3rd gear, amazing fun ! That thing couldn't really do a burn-out as such (rear disc brakes made it hard to hold), but from a standing start it could leave a good pair of 100 yard ******* (rear drive, remember), and second gear sideways in corners was awesome fun :)

But the Mazda (MA block I think) had a long-stroke engine - and apparently they don't really like big revs much...

Each day on the way to work, I passed this school - I always turned into that street, went past the kids then wound it out thru 1st, 2nd and 3rd. After a while the kids would wait outside to watch me... I could hit about 140km/h by the end of the street in 3rd, before braking for the T intersection at the end.

One weekend I spent hours changing the venturies and jets in the carbs (larger) and had advanced the ignition and changed the cam timing. The car was spitting and farting badly down low (this was a VERY excessively hot motor for a street car) but over 5,000 rpm it was pulling really hard...

Past the school at about 40km/h, then drop it back to first and dump it. Thing goes absolutely ballistically sideways (nice long fat marks from the 225/50x14 toyos), eventually hooks up and I flat change it at about 8,000 - yeehaaa, it's got itself sideways into 2nd !

Into third at (guessing, coz I was off the tacho) 8500 rpm and I get a good solid screech - I'm thinking at this stage that maybe I can put up with the almost undrivable bottom-end inflexibility, this is great fun ! Normally I was pulling about 140km/h and 7,000rpm in third at the end of the street - I start braking and notice that I'm WELL over 160 (got knows what the tacho said), but I just screech to a halt just in time, and wait for the traffic.

Then I hear this ticking - which is common on those motors after a thrash coz the rockers had a tendency to flex a bit and throw out the valve adjustment.... then it starts going tick TICK T-I-C-K click CLICK C-L-I-C-K clunk CLUNK C-L-U-N-K bang BANG B-A-N-G - and there is quite a large amount of exhaust smoke...

I knew I had [email protected]#ed it, so I kept driving for a few weeks on 3 cylinders while I got the parts together for a proper re-build... When I pulled it down I found that I had broken the top ring-land (cracked the top edge off the piston)

The next motor was absolutely ape-shit - especially when I would have been smarter to just drop a turbo 13B in there, gosh some people in Oz were even dropping 289 and 302 ford windsor 8's in them... but I was young and rich and had a point to prove. Anyway, the idea was to get it to hang together - so I got a shop that prepared speedway and drag motors to build it. Remember that this is back in the early 80's and the hi-po stuff was hard to find, turbos were really a problem back then...

Motor #2 - list of (remembered) mods :
Bored 1mm, block X-rayed, oil galleries relieved
Rods polished, shot-peened and re-honed, converted to full-floating pins
Custom pistons (from Isuzu blanks), domed up (std they are dished), heat treated
Even wilder custom cam - lobes welded up to get more meat ! Not as much duration (tried to get the peak power revs down under 8000)
Custom-made adjustable cam sprocket (to adjust cam timing)
Forged aluminium rockers, modified oil pump
Port matched manifold with the old twin 45 DCOE webers
Extractors, new exhaust system
Fully ported head, chambers cc'd to get 12:1 compression (with the amount of overlap on that cam, you needed at LEAST 11:1 to even get it to run, it never pinged even on pump gas)
Lightened flywheel (from a 1600 capella), 1 ton pressure plate and custom clutch plate (sprung hub)
Webers had ram-tubes, inside a custom plenum chamber, with a cold air intake (unheard of at the time)
... definitely more, it's been almost 20 years !

Anyway, that motor was not as much "fun" but it lasted a lot better - I vowed not to take it over 8000 (std redline was 6000 and it was a haul getting them up to that). The new one had even more torque and power, but not quite so much revs were required to do it.

But the most amazing thing was that the thing was tractable, I lost my licence again and loaned it to a friend for a few months and he never even realised it had a hot motor in it ! It idled under 1000rpm and felt like a stocker up to about 3500, then it just pulled and pulled and pulled...

Putting that into perspective, another fried has an old '70s Honda Civic (the original ugly ones) - with a full-house Jap import Mugan Racing 1300 in it - a wicked thing, 9000+ rpm no problem, and such a light car ! But my heavy 121 with 1800cc's absolutely KILLED it in accelleration, and the top-end in his felt so.... um... lame !

I also had it lowered, custom-valved adjustable Konis all round, urethane suspension bushes, braided brake lines, all the crap. Now days you can buy most of these things for popular cars, I had to have most of it custom made... even the wheels (14x8 w/ 235/50 rear, 14x7 215/50 front) were custom - took ages to work out how to get that much rubber under the guards, and at the time those tyres were like HUGE man !

Anyway, I never raced that Mazda - I couldn't afford to do anything like that with my driving record... but that didn't mean I didn't use it to absolutely scare my friends (with their big V8's, RX's, etc) witless... "comeon, let's go for a spin in the green Mazda" - I have never had so much fun in a car, it was the perfect sleeper !

That's a rave about the first car, which is now rotting in my front yard (the GF can't unverstand why I keep it for sentimental reasons, when I can't drive it).

The one in the garage is a RX5 convertible - and since this post is so long, that one is another story !


PS: anyone wanna buy some performance parts for a RX5 / 121 ?

2,693 Posts
I mentioned that there ought to be a "classics" forum to Shayaan, but so far it seems you and me are the only ones who'd be there. Maybe later...

Anyway, your cars sound like a hell of a lot of fun. I don't think we ever did get the 121 here in America, but we did receive the RX-5 Cosmo from 1976-1978 or so. It was never very popular here though, especially with V8-powered American compact coupes costing so much less at the time.

In short, here's Mazda's early history in the States (and without my references, I'm fuzzy on the years):

R100 (Familia rotary), 1971-73
616 and 618 (Capella piston), 1972-74
B-series (piston pickup), 1972-76
RX-2 (Capella rotary), 1972-74
1800 (Luce piston), 1972-73
RX-3 (Luce rotary), 1973-76
808 and Mizer (Familia piston), 1973-76
Rotary Pickup, 1974-76
RX-4 (Savanna rotary), 1974-77
Cosmo (rotary), 1976-78
GLC (Familia piston), 1977-80
B-series (piston pickup), 1977-84
626 (Capella piston), 1979-82
RX-7 (rotary), 1979-85

These are all rear-drivers - later on, the GLC and 626 switched to front-drive, but the absent 929 (Luce) reappeared for 1988 as a rear-driver. And apart from the Xedos 6 sold in Europe, most of the other worldwide Mazda car models found their way here in one form or another. (For instance, our Ford Festiva of 1988-93 was a rebadged 121 built by Kia.)

Duncan :D - so there's a classics forum coming, right?
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