spensaur Posted March 22, 2010 Share Posted March 22, 2010 Hey guys, I know this is hybrid Z and should pertain to Z cars. But I wanted to see if anyone had experience with RX3's in the past. I'm looking to pick one up and I was wondering if anyone knows about how easy/hard an engine swap is for it. I have decent experience, and my friend has dropped a sr20 in his 240. I'm just wondering if I could get a little info on the subject before I make the leap of faith and buy an rx3. I apologize again for making a topic about an rx3 on a z forum but I don't know of a hybrid rx3 forum haha. Thanks again if anyone has info on the subject. Quote Link to comment Share on other sites More sharing options...
yetterben Posted March 22, 2010 Share Posted March 22, 2010 (edited) I got crap tons of experience with them find a sp drop a 20b in it dont murder a uber rare rx3 i know i know hybrid z but a 20b is where its at man. If you need help with a bridge port or perphial port or even a 4 rotor let me know. Look for one with a 13b not a 12a twin dizzy. The 13b 4 port has r5 nitride irons that are worth some serious mula. Seek out wackeyracer on rx7club.com under the other rotary section thats his orange one Edited March 22, 2010 by yetterben Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 22, 2010 Author Share Posted March 22, 2010 I really really love the way they look. And I really want one as a decent car that I can drive a few days out of the week. The only thing I'm afraid of is my lack of knowledge with Rotary engines. I was thinking of putting some type of new-er engine in it, an sr20 maybe. But the engine bay seems very compact. I really want an SP but it's hard enough to find a normal rx3 I doubt I'll ever find myself an SP. I'm also on a tighter budget than most seeing as how i'm 19 and paying for an STi. I kind of wanted to pick up a junk/roller and work on it with my free time over the years. I will definitely be in contact with you if I purchase one. Thank you very much for your help. I actually found one on craigslist. 1973 mazda rx3 salvage title 1/2 bridge 13b-48 dellorto, limited slip diff, 5speed transmission, mallory coils, holly fuel pump, 15x7 mesh rims, 5''tach, original lime green color needs some body and interior work no major dents ,daily driver,up to date tags The salvage title doesn't really bother me that much as long as the frame is in tact. I plan on doing some body work and restoration as well as trying to make it a decent "hybrid" unless the 13b / 20b is a better idea. Thanks. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted March 22, 2010 Share Posted March 22, 2010 Technically a 13b is a hybrid. And as a self-confessed rotard, I personally would love to see more triangle powered Rx-3's. They're some of my favorite cars from the area. If only I could find one around here. Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 22, 2010 Author Share Posted March 22, 2010 Right, because the 13b wasn't originally in the 73 rx3 right? I wanted to know if it was possible to put a more up to date motor in it. Quote Link to comment Share on other sites More sharing options...
yetterben Posted March 22, 2010 Share Posted March 22, 2010 (edited) 13b was always a option from rx2-rx5 cosmo sedan. twin dizzy 12a where put it the rx2 and early rx3. The 13b was not ironed out until the rx4 came around. I have had a 4 sa/fb 2 fc and one rx4 wagon of doom lol. Anytime anyone on this board needs help assembling a motor please let me know can be anything from a floor sweeper from used apexs to a all out 20,000 4 rotor i can even do 3 rotor with renesis irons. Rotarys belong in rotary vehicles i am uber anal about it look up on rx7club where a guy is building a trick nova with a 3 rotor in it to piss off all the v8 guys that drop sbc in rx7's Edited March 22, 2010 by yetterben Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 22, 2010 Author Share Posted March 22, 2010 Great, thank you yetterben. What do you guys think about the rx3 i posted above? If I don't go for that one there's one on JNC nearby that is just a roller. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted March 22, 2010 Share Posted March 22, 2010 Great, thank you yetterben. What do you guys think about the rx3 i posted above? If I don't go for that one there's one on JNC nearby that is just a roller. We cannot respond to a 2 line description on a car, pics would really be the key providing any useful feedback. Also check www.japanesenostalgiccar.com under Mazda lots of RX2 and RX3 restoration threads underway right now. Yasin Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 22, 2010 Author Share Posted March 22, 2010 I'll contact him soon to get pictures. His ad unfortunately doesn't have any up. Yeah, I've been reading a few threads on JNC. Thanks. Quote Link to comment Share on other sites More sharing options...
yetterben Posted March 22, 2010 Share Posted March 22, 2010 (edited) I will say this rotaries are not YOUTH friendly cars. You have to be prepared to shoot a apex seal out the tale pipe and any given time. A half bridge/street port is probally gonna idle at 1,500-2,000 rpms. BRAP BRAP BRAP sounds good but its loud. Sucks fuel and pisses off neighbors. Rotaries are fantastic engines. But there finicky. You need to be ready to premix fuel with good two stroke oil or idemitsu oil from japan. Idemitsu is 7 bucks a quart. Never ever ever ever trust that the mop works(oil injection) Rotaries can not be quick started and shut off they will flood. I have bought many a rotary engine casue it wont start. Outside of apex seals flying out the tail pipe towards on coming traffic hehehehe coolant seals can go if the keg is stressed or overheated. You ever driven a rotary with a 2 barrel idf.....not street friendly its basically wot or noting. Not saying its not tuned for street driving but it wont be loads of fun on the street. I think unless you have deep pockets to not go near a rotary until you are older wiser and have more cash. What turns alot of people off about them is they break they dont know how to fix them and then they say its junk from lack of knowledge. once a rotary blows usually on the back rotor the apex seal spins inside the housings tears it all to **** and renders that whole section junk. So they cant really be REBUILT so to so to speak unless you get a new housing. Often a new rotor and new apex seals etc etc. It can get pricey fast. Edited March 22, 2010 by yetterben Quote Link to comment Share on other sites More sharing options...
PR280z Posted March 22, 2010 Share Posted March 22, 2010 I have a friend that has a sp same as above.I`ll visit him this week and post some pics for ya. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 22, 2010 Share Posted March 22, 2010 I will say this rotaries are not YOUTH friendly cars. You have to be prepared to shoot a apex seal out the tale pipe and any given time. A half bridge/street port is probally gonna idle at 1,500-2,000 rpms. BRAP BRAP BRAP sounds good but its loud. Sucks fuel and pisses off neighbors. Rotaries are fantastic engines. But there finicky. You need to be ready to premix fuel with good two stroke oil or idemitsu oil from japan. Idemitsu is 7 bucks a quart. Never ever ever ever trust that the mop works(oil injection) Rotaries can not be quick started and shut off they will flood. I have bought many a rotary engine casue it wont start. Outside of apex seals flying out the tail pipe towards on coming traffic hehehehe coolant seals can go if the keg is stressed or overheated. You ever driven a rotary with a 2 barrel idf.....not street friendly its basically wot or noting. Not saying its not tuned for street driving but it wont be loads of fun on the street. I think unless you have deep pockets to not go near a rotary until you are older wiser and have more cash. What turns alot of people off about them is they break they dont know how to fix them and then they say its junk from lack of knowledge. once a rotary blows usually on the back rotor the apex seal spins inside the housings tears it all to **** and renders that whole section junk. So they cant really be REBUILT so to so to speak unless you get a new housing. Often a new rotor and new apex seals etc etc. It can get pricey fast. It appears you're have a lot of problems with rotaries in the various builds you're tried. I've spent a reasonable amount of time with RX7 racers and none have had the issues list above (shooting apex seals out the tail pipe?) Are you exaggerating to tell a story? Quote Link to comment Share on other sites More sharing options...
auxilary Posted March 22, 2010 Share Posted March 22, 2010 I have a 13b from cosmo, if you want to buy it it's already converted to drop into a 1st gen rx7, which I think uses the same mounts as an rx3. You'll need to supply your own turbo, exhaust manifold. I also have a couple of turbo 2 transmissions to go with it Quote Link to comment Share on other sites More sharing options...
yetterben Posted March 22, 2010 Share Posted March 22, 2010 (edited) i have never lost a apex on one of my builds but on others and including factory junk 3 piece apex seals yes i have had them come out the tail pipe. When they dislodge then can float around the housing until they get smashed and embedded in a rotor face or they can fly out the exhaust port. I am trying to make it known that rotaries are amazing engines but are not for the timid or someone who is not willing to spend serious cash. The longevity of the rotary has long been a topic heated in fact of discussion. When nsu first released felix's design in the spider apex seals where only lasting 2-5,000 miles. Mazda started to perfect his design and really did not succeed until the later 12a models. The 10a and early twin dizzy 12a where basically junk and the nitride coating in the housings and on the iron faces where not up to bar for the high demand. In 79 mazda did a massive recall on all Sa's for chucking apex seals. The fd is notorious for chucking them at 50-60,000 due to there crappy 3 piece design. My only thing i wanted to convey is rotaries are not for the timid or casual mechanic. They are very very specific and must be treated with care. The owner MUST be willing to take care of it in a specific fashion. People give rotaries a bad name cause they flog the piss out of them and leave them high and dry. One who understands how the 3 moving parts work and create compression on there otto cycle and what must be done to make them reliable sees great success and is rewarded with the best sound and performance in the world per liter ratio bar none in the world. I was not trying to post dis belief or mis understanding only hat can happen when not taken care off. Mis used. Just cause the the tach says 9 grand and pulls to 10 does not mean it should be done. Often people over rev a rotary not relizing that the seals in the housings are chattering at that speed wearing the plating off and causing a bigger tolerance inside. Care full modification to the ecentric shaft and oil galley must be made to have long life above 8,500. Often the Oil injection system is broken or the hard line are starving the apex seals off oil Hence the pre mix statment. Anyserious rotard pre mixes fuel as to never trust the oil injection. Pictures below of What a damaged housings looks like after the inevitable a apex seal failure. (Thanks to Aaron Cake for pictures) My point here is to inform and help the young lad make a decision on if he is ready to walk this road its a fun road and rewarding but can be long and painful if you fall a stray. ROTARD FOR LIFE BABY!!!! Some good info on Kevins site http://www.rotaryresurrection.com/2ndgen/tech_engine_int_damage.html Edited March 22, 2010 by yetterben Quote Link to comment Share on other sites More sharing options...
Globerunner513 Posted March 22, 2010 Share Posted March 22, 2010 I love the magic dorito motors. A good friend of mine is a die hard RX-7 guy (FD's in particular). They have lasted him pretty well. But as stated above, if you're just getting started in mechanics, or don't have a lot of funds to keep it in good running order, stick with pistons. Otherwise, just run the motor super rich and enjoy the smoke/fireballs that ensue Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 22, 2010 Author Share Posted March 22, 2010 Yeah, I've read and heard how expensive rotaries can get. It's the main reason I've never gone near buying one. Here's the scoop, sorry for the rant beforehand. I work 12 hour shifts as a network tech and the only reason I work those hours is so I can afford to pay for my expensive hobby, cars. I love them and everything about them. My plan is to have a solid daily driver (My STi) and a great weekend car (rx3 / 240z), not something I push to 9k rpm's all the time just something I can build up and be proud of. Not only to enjoy, but to hopefully pass it on to later generations as well. I know that rotaries are pretty pricey and they need a lot of care but I am willing to spend the time and effort to keep a classic car like this going. I also have an ex-co-worker whom I still keep in touch with very much that owns 4 RX7's, two of them are doner cars. So I've spoken to him about it and it seems like he's willing to help me in my troubles. More pics of an SP would be fantastic, I absolutely love the way they look. I love the big front air dam. Although, I'm not sure where to buy one other than Yahoo Japan so I was thinking of making a template out of wood then molding a large piece of sheet metal to the wood. Yeah, I would buy that 13b if I need to get my hands on one, they sound like they're the best choice. Perhaps second to yetterben's suggestion of a 20b. Unless someone knows if I can drop an engine little easier to take care of that isn't rotary? I was thinking an SR20 since they're cheap and readily available. i'm not looking to restore this thing to it's original state, I kind of want something different. Which is why i've come here! Haha. Thanks guys for all the helpful information. Quote Link to comment Share on other sites More sharing options...
yetterben Posted March 22, 2010 Share Posted March 22, 2010 (edited) Hybridz is hybridz but to take a rotary out of anything that says rx is removing its soul and why its a rx. You will ruin the car make it worthless. you wanna butcher a rx butcher a 7 there are not many 2 or 3's left. In the end its your car your money and just yours but there is no point in getting a rx to remove the rotary NONE. go get a 510 or another little banger that is well suited and swap it out. Edited March 22, 2010 by yetterben Quote Link to comment Share on other sites More sharing options...
spensaur Posted March 23, 2010 Author Share Posted March 23, 2010 I understand the fact that well.. there's not to many rotaries out there anymore. I see few rx8's, even less rx7's and I've never seen an rx2-4 in person before. And I know that the rotary is the heart and soul of the car but I'm just looking for an easier alternative to allow me to drive it often. I always think cars are meant to be driven, it's nice to have a nice car in your garage but what use is it sitting there? I was also thinking about trying to mount up a newer rotary in my rx3 to make it a little more reliable. I'm all for learning I just want something a bit more reliable that's all. Thanks again! Quote Link to comment Share on other sites More sharing options...
Guest Laocoon Posted March 23, 2010 Share Posted March 23, 2010 I understand the fact that well.. there's not to many rotaries out there anymore. I see few rx8's, even less rx7's and I've never seen an rx2-4 in person before. And I know that the rotary is the heart and soul of the car but I'm just looking for an easier alternative to allow me to drive it often. I always think cars are meant to be driven, it's nice to have a nice car in your garage but what use is it sitting there? I was also thinking about trying to mount up a newer rotary in my rx3 to make it a little more reliable. I'm all for learning I just want something a bit more reliable that's all. Thanks again! I sold my '86 fc last month to a buddy of mine. I rebuilt the engine after 187k miles of hard driving (both me for 5 years and the previous owner for plenty more). A little bit (read: ALOT) of weight reduction (dry curb weight stock:2700lbs down to under 2400 with oil/coolant/full tank of gas) put the car into the low 13's with an open diff and on street tires (205/50/15's *stock vert rims to decrease the rotating mass of the wheel/tire* wish I had slicks after the extra loss of weight and the rebuild...). When rebuilding the engine I reused the old apex seals cause they haven't "flow out the exhaust" yet lol. Rx3's have a curb weight of 1949lbs, that's 450 lbs less than my gutted fc. I ran a pineapple racing streetport template, and a rebuild that cost $750 through mazdamotorsports parts program. I switched to pre-mix (removed the oil metering pump chain ect.. using castrol or super tech *walmarts version of castrol from the same assembly line* 10w30) during the rebuild only for having less rotating mass/running synthetic oil. I had the water pump and alternator as the only things the engine had to move besides the flywheel (which I never got around to replacing with an 8lb) for less rotating mass. I had a racing beat header, Y-pipe (racing beat turbo), and mufflers (racing beat turbo) and a presilencer between the header and Y-pipe that was handed to me. Intake was cone filter then ported all the way down to the block and six port actuators/sleeves removed. I was on the stock computer, and the timing was set by ear advanced just slightly. My suspension isn't important to your questions, however the 13B six port engine can be found for $100 through a junkyard or wherever and the rebuild cost me $750 (a extra couple hundred and I could have had new apex seals but they were unnecessary in my case). Add a computer (megasquirt for cheap), fabricating a couple simple mounts, and running any old fc tranny (can handle the power out of a n/a 13b just fine), and probably a bit more fabrication in misc. places and you should be easily in the high 12's range (extra power from the computer, a couple hundred pounds less *adding oil/coolant/gas to the curb weight of the rx3*) in a *VERY* street-able and reliable rotary powered rx3. When you add the turbo(s) to the engine, you drop reliability quickly. A couple rules you then HAVE to follow: Let the car warm up to normal operating temp before you push it. Make sure to remember to put oil in the gas tank before you fill up. Drive it at least 2x a month to keep the oil mixed in the gas tank. Used as my daily driver (read: car I raced around town everywhere all the time to get where I needed to go on a daily basis...) I smoked a lightly modified (computer/intake/exhaust) T2 fc (turbo) at the drags. I bogged as I hadn't launched in a long time. And he jumped me at the line. By the time I got over bogging at about 2500rpms, he had 2 car lengths. I beat him by about 6 car lengths by the 1/4mi. My wife raced a 05 350z (intake/exhaust/???) who had a 13.6 time slip. She didn't bog as I told her to launch at 4k instead of 3500, and had him by a car length at the top of first. She missed 2nd, missed it again... missed it again... by the time she found second, the 350 had roughly 4 car lengths on her and I thought it was over, but both she and the driver of the 350z said she was within 2 car lengths at the 1/4 mile.. The day was over before they had their rematch, and drag season isn't here yet (my buddy is gonna take it out this year!). Since I live in California, I was worried about state ref tickets for my completely smog illegal car. I sold it to a friend who can register it in Oregon. I was doing research on the presmog s30's as I am hoping to pick one up in a day or two. I wasn't gonna register yet as I was just busy reading over everything, but I saw the RX-3 topic and couldn't resist a look. It was full of misinformation, and idea's that would cost 10's of thousands of dollars (20B = $15k-$20k to drop in there without a rebuild, 26B *aka 4 rotor* isn't even an option if money is an issue lol). If you are really interested in building a n/a 13b to put in there, I have years of research and rotary knowledge for building specifically naturally aspirated performance 13b's. Drop me a text (or call if you must) (707) 502 - 2RX7 (2797) lol... I really miss my 7 after a month of not having it.. Quote Link to comment Share on other sites More sharing options...
Guest Laocoon Posted March 23, 2010 Share Posted March 23, 2010 I was not trying to post dis belief or mis understanding only hat can happen when not taken care off. Mis used. Just cause the the tach says 9 grand and pulls to 10 does not mean it should be done. Often people over rev a rotary not relizing that the seals in the housings are chattering at that speed wearing the plating off and causing a bigger tolerance inside. Care full modification to the ecentric shaft and oil galley must be made to have long life above 8,500. Often the Oil injection system is broken or the hard line are starving the apex seals off oil Hence the pre mix statment. Anyserious rotard pre mixes fuel as to never trust the oil injection. Not saying that you are completely wrong. You seem to have done a bit more research than anyone else in this thread, however... I disagree with your reasoning on why the rotary engine fails at high rpms... Apex seals while they are metal, still flex minimal amounts just like anything. It's this flex that ends up putting the middle of the apex seal ever so slightly into the peripheral exhaust port on rotation. Notice on every engine pulled open the scaring above the exhaust port as the apex seal is forced back in from it's flex. I have not done any research on the renesis engine wearing, however the exhaust port is no longer a p-port, and rather a side port like a stock intake port. I am sure this helps the stability of the apex seal a bunch (thus the ability for mazda to release a reliable engine turning 9k... ). You are right about requiring some oil flow modifications to turn higher rpms. And yes these are not all able to be solved using premix (thus the modifications)... The problem is not with the oil pump is not the failing point, but rather the brittle oil injection lines that need replacement like vacuum lines. The lack of oil in the engine causes the metal seals on the metal housings to create friction/heat. This heat will warp the housing causing points where the metal can catch on like the apex seal in the exhaust port. Also at extended high rpm's the water in the water pump cavitates causing the water to not circulate correctly. Or the belt on the water pump slips causing the water pump to not turn at all which again, no circulation. If the water in the engine can't cool the engine, expansion takes place. The engine is a combination of aluminum and steel which expand at different rates causing the same issue as not letting the car warm up before getting on the throttle. This can be fixed with an electric water pump though. Even with all this fixed and running an apex seal which doesn't flex as much (ceramic... less weight which means less centrifugal force causing the seal to flex). High rpms will destroy a rotary engine due to the e-shaft (basically a crankshaft for the rest of you) being pulled around as it rotates and flexes in the middle. Imagine looking at the rotor from the side and adding and subtracting camber as the center of the e-shaft flexes. You can see how the seals would not keep a perfectly even surface anywhere... However the good news is the Australians developed a center bearing which supports the middle of the e-shaft allowing tons of rpms! Last thing to think about for high rpms (besides hardening of gears/lightening and balancing of rotors and e-shaft because all these forces mentioned above don't disappear, but instead get minimized by the fixes, oh and fuel delivery/spark ect...) is the drivetrain. Most flywheels can't handle over 10,500rpms. Anything that turns 9k+ rpms is required to have a scatter-shield installed around the transmission through the NHRA. Also, the balancing and protection of the "3" moving parts in the engine is nothing compared to what you would have to do to the transmission. Instead you would have to have a gear reduction to the transmission. Say a 2:1::Engine:Transmission... Build and engine that can push 18k rpms, idles at 2k... Transmission would seed 1k idle and a 9k rev limiter. The rotary engine is full of rumors and superstition, mainly because if a mechanic at a shop doesn't understand what is going on, he tells his client what he thinks, and they tell someone else and they tell someone else..... and another mechanic hears about it and sees something similiar and decides it's the same thing as he has heard about... I have talked with even the rx8 mechanic at the mazdaspeed dealer close by here and couldn't hold a legitimate conversation with him cause he didn't know 1/2 of what I was talking about... I have put in YEARS of research to get rid of the rumors/superstition and get down to plain old fact... But I can't tell you much of anything about a piston engine! lol Quote Link to comment Share on other sites More sharing options...
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