I Need Some info on the 6mm 72 rx2 Motor???
02-04-09, 03:36 AM
#1
I Need Some info on the 6mm 72 rx2 Motor???
Well i just cracked open both of my 1972 mazda rx2 motors...I knew they came with the 6mm setup stock from the factory but whats the history on this? How rare are they? How long was this set up made? One thing i did notice is that on the front plate there was a built in bolt up oil tention guide that was spring loaded, the block weighs almost triple the weight of the newer 12a blocks, the intake ports are smaller the exhaust ports are smaller, the apex seals are solid one peice, with sold pac man's NO rubber inserts, and one peice solid apex seal spring per apex seal...I also notice that the weight on the apex seals were very light in weight...So im wondering if the seals were made from carbon?
Also in stead of the rotors having 6 side seal springs per rotor there are 12 side seal springs per rotor...
Any of the older ol'schooler cats got some good info i could run with, so i can make a good posting on ebay with the best information possible? thanks
teddy....
Also in stead of the rotors having 6 side seal springs per rotor there are 12 side seal springs per rotor...
Any of the older ol'schooler cats got some good info i could run with, so i can make a good posting on ebay with the best information possible? thanks
teddy....
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02-04-09, 08:34 PM
#8
sorry bro. I never had a chance to work on them motors but I can refer you to my bros @ Sidepex since he just rebuilt one of these motors last year for one of his customer and for his stock/orig RX-2 as well (PM me and I will give you his #). Yeah, try doc or look at the links down below.
02-04-09, 11:25 PM
#10
info hope this helps
Well i just cracked open both of my 1972 mazda rx2 motors...I knew they came with the 6mm setup stock from the factory but whats the history on this? How rare are they? How long was this set up made? One thing i did notice is that on the front plate there was a built in bolt up oil tention guide that was spring loaded, the block weighs almost triple the weight of the newer 12a blocks, the intake ports are smaller the exhaust ports are smaller, the apex seals are solid one peice, with sold pac man's NO rubber inserts, and one peice solid apex seal spring per apex seal...I also notice that the weight on the apex seals were very light in weight...So im wondering if the seals were made from carbon?
Also in stead of the rotors having 6 side seal springs per rotor there are 12 side seal springs per rotor...
Any of the older ol'schooler cats got some good info i could run with, so i can make a good posting on ebay with the best information possible? thanks
teddy....
Also in stead of the rotors having 6 side seal springs per rotor there are 12 side seal springs per rotor...
Any of the older ol'schooler cats got some good info i could run with, so i can make a good posting on ebay with the best information possible? thanks
teddy....
what you have looks to be an early 72 12a due to it having the oil pump chain tensioner. Yes engine heavy, very heavy, also notorious for having bad oil seals and smoking, 6 mm apex seals one piece and yes they are carbon although impregnated with steel look close you will see it.
It does have 2 side seals as compared to the later engines one so for each rotor you will have 12 side seals. now the nitty gritty, the intake/carb, emissions, water pump, alternator, starters, flywheeels, rear engine cast iron are all specific to the pre 1974 engines, this engine also should have 2 distributors one for leading one for trailing. What is it worth, a boat anchor, no seriously most people don't want them unlike me who has a couple
02-05-09, 02:02 AM
#11
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I have owned a few twin dizzy motors over the years, been very reliable - never had one drop it's lollie - higher milage ones can lose compression, especially at cranking speed, making it a little hard to start. Still lots of parts for them over this side of the world if you look around.
You can replace the rotating assembly with a later model 12a parts... the rotor housings tend to be in good condition due to the carbon seals, but won't last long with steel seals (so use late model 3mm carbons). The end plates are not nitrated as well, anything this old will be worn, but with a freshen up and a little porting, there is no reason it won't go hard for a very long time!!
You can replace the rotating assembly with a later model 12a parts... the rotor housings tend to be in good condition due to the carbon seals, but won't last long with steel seals (so use late model 3mm carbons). The end plates are not nitrated as well, anything this old will be worn, but with a freshen up and a little porting, there is no reason it won't go hard for a very long time!!
02-05-09, 04:34 AM
#12
wow...that is great info...these two twins dizzy blocks weigh a **** load...I also noticed that instead of the exhaust sleeves being pinned from the side of the housing like the new 12A's there bolted in from the inside of the exhaust with huge *** allan bolts and then hex bolts on the bottom....
02-05-09, 04:39 AM
#13
one more pic, i will post pics of the irons as i get them cleaned, and the rotors and the e shaft and all the other bull ****...that flywheel weights a good damn LB!!!**** is stupid heavy...I also have the twin dizzy front oil cover with the dist. on it, one cap is broken...really just making this thread for my on personal gain in new knowledge and who ever the hell else wants to gain from this...
02-05-09, 10:16 AM
#15
No distributor? No thanks
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By the way, I spoke to Rick Engman last weekend regarding twin-dizzy 12As. 6mm apex and dual side seals apparently aren't any better or worse. They run just fine, as long as they're in good shape and they've got good springs. Mazda moved away from them only because they proved unnecessary. If you want to run it, I'd recommend throwing an FB front cover on it with electronic dizzy and call it a day.
02-10-09, 12:16 AM
#22
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I think that they quickly worked out that one side seal does the job fine - plus a little less in the way of moving parts. Side seals in a twin dizzy motor are not known for causing problems. The last of the 10a twin dizzy motors (and maybe the 12a ones, can't recall) used single side seals.
02-10-09, 03:22 AM
#23
And yes we all know, i pushed my car at seven stock...yes we know this already...
Anyways back to the info thread stop clustering my damn thread with useless bull **** talking...