hi,

Im relativly new to the forums so let me begin by introducing myself. My name is sean maloney and i live in ontario. Im an avid grassroots racer and all around car guy. ive taken the last two years of school off and will return in september for mechanical engineering. during this past summer i purchased an srt-4 that i daily drove and tracked on the weekends. I must say that a dual purpose machine escpecially a newer one is not ideal. after the summer i sold the car. mostly beacause A) i couldnt afford to drive the car daily because of gas prices and B) one more summer like that and the engine would have surly popped. so i spent $2000 on a hyundai accent i now drive daily for peanuts and i am investing the rest of the money from the srt-4 into my track occasaional weekend car.



I've always loved the inherint simplicity and genious of the wankel rotary. I have been studying them since i was 14 but never owned one. so i took this oppurtunity and bought one. i now own an 86 base. I began my quest by searching for a motor for my car. at this point i got in contact with joe ferguson at R.P.M. we arranged to get a 13b-re motor which now resides at his shop. We have been discussing some ideas as to how to build the motor and have settled on this so far.



full bridgeport

t2 exhaust sleeves

balanced

clearenced

9000 rpm redline

@15-20psi



The point joe and myself find ourselves at now is trying to determine exactly what internals to go with. Im sure once the motor is built futher questions will arise but im going to take this one step at a time. I've been reseaching for about 2 weeks now on what internals to use and have found such a wide variation in results its staggering. reliabilty is the key to this project with power taking a back seat, followed by price in the trunk! the only thing im not willing to shell out money for is ceramic apex seals. its just too much money for such a vulnerable part. I also dont want to throw money away at things that give negligable results for large amounts of cash. not saying ceramic apex seals fall into this category, but if they go thats not a small amount of money lost. But the million dollar questions are what apex seals to run? ive read so many differing opinions on this it makes my head spin. solid corner seals or stock ones without the rubber? some say solids crack more easily and cause exponetial wear while others say the same for the stock ones. cermeting? some say its worth its weight in gold while others say its a gimmick.



Now i know most the responses im going to get to these questions are just going to be more opinions, but maybe since the questions are posed with my exact goals stated the results will be more detailed. As the project begins to pick up ill photo document the progress. Thank you for your time and input!



sincerely,

Sean M.

 

okay lets start with this:

"reliabilty is the key to this project with power taking a back seat"



Few things about a bridge port:

you dont need a bridgeport to hit 400whp.

bridgeports generally lessen the life expectancy of the motor.



Depending on what turbo you are going to run, i'd say all you need is a mild street port and a relatively routine rebuild. Replace anything not in spec, make sure to measure everything. for reliability most people say to use the stock 2mm mazda seals.



I've never seen or heard of a solid corner seal breaking, I am running solid atkins corner seals with FD corner seal springs.



I also have cermet B coated rotor housings, only one person on the internet forums has had problems with the cermet coating, and if you read into that story you see it wasn't completely the cermet coaters fault, they made a mistake, offered to fix it for free, consumer decided to fix himself basically by grinding down the high spots of the cermet, and had a catastrophic disaster. No one else has reported any serious problems from cermet. Most people report quicker "break-in" with the housings building compression quicker after the rebuild then just the stock housings.



All-in-all, for reliable 400whp here's what i'd focus on:

Good oiling system, go the extra mile and buy a brand new oil pump for the rebuild, many people offer "oiling mods" that can be done to the block that will be worth it. And make sure you have a good oil cooler.



Also focus on the water cooling, get a good radiator and a new waterpump.



Keeping it reliable is all in the small details when it comes to the rebuild, focus on all the specs, measure twice, etc.



kevin.

 

Stay at 7k rpm redline for reliability.



And learn about boost and what it actually is. Its not a badge of honor like most rookies think. And doesnt nesessarily mean you make more power, or are faster than a car at 14 psi. Try to make power with less boost.

 

thanks for the input!



The 400 hp mark is my own conservative number in my head so i dont get too crazy of expectations and get let down by the dyno. by no means is it a limit to what i want to reach! I set it this way in my head because when i tune the motor im going to tune it quite conservativly to avoid catastrophie. I hadn't heard that bridgporting actually had a negative affect on reliability. What is the reasoning behind it? just to make clear the bridgeporting joe and i discussed is relativly mild; were not going to cut the housing and we're going to leave a much larger bridge on the primary sides so that a two piece apex seal won't fall in.



I 100% agree about regular rebuild intervals. I believe this is probably the single most important factor in protecting the motor. The rebuild interval im aiming for is at most once per competition year. as it is probably as much as i'll be able to afford if neccasary. im really unsure of the average motor life when pushing this much power. Does anyone who competes have any experince with how many hours it'll last safely?



Im glad to hear that your experince with solid corner seals has been favourable. It seems like a much better route for my build then the stock ones but i still would like people to post there experinces on them just to get a better consensus. what brands of solid seals are you guys using?



As far as the cermet coating goes, I also haven't heard too much negative feed back on it and am quite interested in it, but i would like to get a better idea of if people think it is an effective tool, or if its abilities are just being overstated.



In regards to the oiling and cooling system, absolutly no expense will be spared! very careful attention will be made when it comes time to attack this part of the project, but as for right now i would like to focus on the mechanical internals, specifically the sealing mechanism of the combustion chamber, as the importance of the oiling system has been addressed.



do you think that the mazda apex seals are up the the task at these levels of output? This is the area of the build im most unsure about right now. Anyones experinces with high output rotaries and apex seal brand life is much appreciated.



Again thanks for your input and keep it coming!



sincerely,

Sean M.

 

thanks for your input.



I am quite familiar with boost and how it works, but i appreciate you trying to look out for my well being . I actually have an excellent book called forced induction tuning and principals by A. graham bell. extremly indepth highly recommended! the idea behind the higher redline and bridgeporting was exactly what you are suggesting. to make more power with less boost. I figured do to the design of the rotary it is better suited to handle rpm's then torque so i had decieded that if i spun the engine faster then i could reduce the combustion chamber pressure and help protect the apex seals and still reach hp levels im happy with. I feel that with proper oiling and clearincing, the rotary is more then capable of this high a redline. Am i mistaken? Also I was under the impression that 15 psi was relativly modest for these engines, but if i start to see hp numbers i like at lower boost numbers then by no means is the boost going to make it up that high during tuning. actually when i think about i have to say lower boost numbers are a badge of honour, if im making the same horsepower with 10psi as someone else is making with 20psi then ill definatly be proud that the engine combination i tried is more efficent!



thanks for the help!



sincerly,

Sean M.

 

Pretty much what kevin said covers everything.



Bridgeported motors tend to eat up the side seals, not the apex seals. I have heard of tuners running over 600rwhp on the stock mazda 2mm apex seals. Make sure everything is clearenced and within specs.



Good luck, and keep us posted on your progress, we love projects here at nopistons.com. Welcome to the forum by the way.

 

thanks i appreciate it! i certainly will keep everyone posted on my progress. hopefully all goes well. im hoping to have the motor put together in fairly short order, though im still no closer to knowing what brands of internals to use. so far it seems stock apex seem to be the way to go judging by peoples input thus far. Any more info on this is greatly appreciated!

 

my $2!



i would build a nice tight stock sealed engine. (mazda apex, side and stock corners), street port, keep the water and oil and intake air temps in check, give it enough fuel, and you should have something that lives a long time @400hp. there are plenty of people breaking 400 rwhp @15psi on street port engines.

 

Go with s4 or 5 turbo engine . Medium to large street port. A good proven turbo , there are many just check out what other guys are using , i use a turbonetics 62-1. In fact a t3 with a big enough compressor can make 450+ rwhp. I would personally have the rotors slotted to take earlier 3mm apex seals and use the 12a turbo corner seals with the rubber insert. As for solid corners been better we just pulled down a full bridge port s4 engine that got a bit hot at the drags every single solid corner seal had cracked and broken. Apex seals looked like they had hair line cracks but none had broken.

 

No matter what, there is always going to be debating on which apex seals to use. They both work fine, but it depends on what your needs are. I am not 100% sure of the differences though.



I would also go with the S4 or S5 turbo motor. Seems to be a good motor to work with. I believe the S5 pushed a little more power.