godsboss

here's the story, the next paragraph has the actual issue if u want to skip to that:
Last weekend i drove to a friend's place, about 380 km away; everything was good; drove around the area all weekend without problems, then heading home. everything was working great for the first 60 kms then i was passing somebody and only at 7800 RPMs suddenly the car starts slowing way down and running very um not-right. shut it down and towed it home. checked compression. no compression on the rear rotor.

so i just got around to tearing it apart and the rear rotor has a broken apex seal which scarred up a piece of the housing near the exhaust port and one side of the rotor has some pretty big scars too.. the engine has less than 40k on it. the rotor doesn't have much carbon built up at all and the housing doesn't have any. the metering pump is functioning properly and there's proper amount of oil in the car

i see lots of people talk about apex seals and which ones they prefer.. but my question is.. which ones wont break easily? .. Wear is FINE by me. i wouldn't mind replacing seals even if i had to do it every summer. but i DON'T want to see them break and ruin everything they contact...

i haven't owned this car long. and i've never owned one before it. so i don't exactly know where to source these parts or which ones are better than others.
Can you please tell me which apex seals are best for NOT breaking, and where to look for housings and rotors that are in good shape. preferable affordable. i'll probably have to buy everything online since i live on the east coast of canada (new brunswick) and i've yet to find anyone around who specialize in rotary engines.

Also, i HAVE searched and searched the forum and i know there's a lot of good information out there. but i can't find everything i'm looking for.. so i'm asking. and yes i'm new... please be kind. thanks.

my car is a 94 fd3s single turbo

fendamonky

iTrader: (6)

There is no magickal seal that will resist breaking, but also not cause undue wear on the housings. Your tune, supporting mods, fueling, etc., etc., etc. have as much (more) to do with engine survivability as your apex seal. If not more...

An abnormally strong seal is NOT a solution for a bad tune or poorly set up machine.

Sorry to be the first to say it, but there is no simple, cheap, solution

I hate to break it to you, but your best bet is going to be A) research your *** off to learn about these cars (there is 15 years worth of information hidden away on this forum...) and B) travel outside of your local area to find a REPUTABLE specialist. (it is NOT unheard of to travel 5+ hours for a good shop... I used to drive halfway across the UK for a specialist when I was posted there)

More details? What turbo, what ecu, what fuel system(injectors/pump, etc.), what intercooler, exhaust, etc,. etc., etc...

H_M

iTrader: (7)

There is no one east of Montreal that specializes in rotaries. The closest rotary specialty shop is Derwin Tuning in Montreal.

However...

John Boyd in Saint John can rebuild your engine. He's done a few in the past. I own his old FD. He rebuilt it about three years ago and it hasn't broken yet. He uses Goopy apex seals and mentioned that they have a little more bend/flex in them so they won't break right away and chew up your housing or rotor. I don't know how much he charges. I recently bought the car from someone else who had bought it from John Boyd.

I'm in Fredericton. I rebuilt the engine in my second FD about two months ago. I read a lot and watched many videos. The rebuild was very easy. I used the rebuild kit from Atkins Rotary. They ship USPS and it takes about 5-10business days to get the parts.

There's a guy in Halifax that works on rotaries too. He owns a shop called Scotia Tint and Audio. I don't know how much he charges. I've tried contacting him because I wanted to buy one of his air pump delete kits but he doesn't reply to phone calls or emails very well.

Those are all the people that I know who have worked on rotaries.

A few tips:
- call around to shops and see if they have good condition used housings. Many shops will have some for reasonable prices. S5 t2 housings will work as will the 89-91 NA housings but they need to be ported (I think).
- if you're close to the border, buy parts from US shops and have them shipped to Calais or Houlton. That way you don't have to pay ridiculous shipping charges and just have to hop accross the border to pick up your parts. Have your receipts ready because you'll be charged 15% HST when coming back in to canada. I use Shire Town Package Receiving in Houlton but have also used Johnson's Hardware in Calais.
-Jimmy's in the UK was a huge help to me when I did my rebuild. They have an ebay store (spiritrx7 ... I think) and they have many used parts that i couldn't find here or were too expensive in North America. They're shipping prices are very good too. I think that I paid $360 shipped for an excellent condition used rotor.

Feel free to message me if you have more questions. I'll try my best to help.

fendamonky

iTrader: (6)

It would be one hell of a hike, but you could also look into dragging the FD down to one of the shops in the US if you're completely out of good options in New Brunswick...

H_M

iTrader: (7)

There are no good options in NB. Depending in where in NB he is, the closest shop is 6-11 hours away. Going to the US is pretty much out of the question unless he's got a ton of money since the Canadian dollar is worth less than dirt right now.

Now, if you need yer lobster boat fixed up in a jiff then this is the place to be.

RotaryEvolution

iTrader: (30)

i've written lists of which seals are brittle and which ones are soft and "unbreakable", the soft seals all tend to cause wear to the seal and housings, if that is an acceptable risk then there are many options for soft bendy seals.

some people live by OEM, some people hate them because they trash engine parts. there never has been a clear way to go. i've seen enough broken seals that i tend to avoid the brittle OEM type seals.

some people even say ceramic is the way to go in turbo engines, i say that could not be less true.

misterstyx69

iTrader: (142)

there are a couple members such as Halifax FD,RedShift and Pink Racer that may be able to help you with some sourcing of engine builders..even parts.
They all hail from NS.

godsboss

really appreciate the replies, thanks a lot.
I've decided that i'm going to rebuild it myself. Never done a rotary engine before but i figure the first one has to happen before the second.. and if something isn't quite right then the second one will come a lot sooner than later haha. Previous owner said he had it rebuilt in new jersey. dunno by who.
anyway, i read through A LOT on this site after seeing the replies about the seals i decided that the slightly-less prone to break seals aren't worth it.
now.. even though i'm building it myself i'm still going to have to travel somewhere to get it tuned Any suggestions would be good. between newbrunswick and toronto.
--> on that: Before i bought the car i had to wait two months because it wasn't running and he didnt want to sell it at a not-running price since he'd already chipped in money with a few others to fly some guy from somewhere in ontario down to halifax and tune the car... soo i figured it would have had a good tune. maybe i could contact him n get the name of who did it and check him out.

what would make a seal break with not much miles on the engine and there was really no carbon build up on the housings. a bit on the rotors though. as i said i was only at 7800 rpms.. but i was trying to see how fast it would go... only got to 245 KILOMETERS and hour, not miles.

i'll list what i know about the car.. but i didn't build it so i might miss something.
stock primary 550cc, and 1680cc secondary injectors. walbro 455lph fuel pump. aem fuel pressure regulator.
precision 6262 turbo. tial 44mm wastegate running 17psi boost.
hks twin power spark. gm map.
apexi power fc+commander
and i think when it was tuned in may he said it put about 320 to the wheels
and has a "mild street port" as he put it --- but after looking at the ports it looks very DIY and not done with a template. resembles my first 2 stroke dirt bike port job i did when i was 16 lol.

I really need to find a rear rotor housing and a rotor or two. I'd prefer to spend less than $2000 for two rotors and the rear housing. any ideas where i can find some let me know.. anywhere that will ship or any local shops between here and toronto (if i can't find them for less than 1200 each then i'll just buy one and have the assembly balanced... unless someone says that's not ok)

RotaryEvolution

iTrader: (30)

usually a crappy tune or misleading stories. maybe the car wasn't tuned to the boost level you ran it to, or it was tuned years ago and stored away in a garage, which means things get out of whack and something may have weakened and caused it to run lean.

invest in a wideband

GoodfellaFD3S

iTrader: (213)

That turbo will make over 400 at the wheels at 17 psi with no issues, and that's a lot of boost if you're running 93 octane pump fuel with no water/aux injection.

godsboss

already have the wideband, forgot that one.

annd GoodFellaFD3S maybe that's the whole problem then.. I just drove the car as i got it, on pump fuel as he did... but here in NB we don't even have 93 octane at the pump. ours highest octane at the pump is 91

Howard Coleman

iTrader: (6)

before you get into the rebuild process (and in your situation it might be best to build it yourself) i suggest you focus on what caused your problem.

rotary engines don't just break. apex seals don't just break.

engines break because of a bad tune or incorrect support systems.

your car is not set up properly.

you start w understanding the turbo. size everything for max air from the turbo.

your fuel is inadequate.

the turbo will make 500+ rw rotary hp.

you need at minimum 5300 cc of injector. you have 4460.

all single turbo rotaries need AI.

it does not have to be super sophisticated...
the new AEM or a Coolingmist running around 500 CC works fine.

stock coils above 400 rwhp will probably generate some misfires but unlike fuel are not generally life threatening.

the rotary is a small displacement motor that breathes like crazy so it is capable of generating huge combustion chamber pressures, even around 400 hp.

there is no room for error. do it right and you will be one happy guy. do it 90% and you will be looking for a tow.

all the info you need in the form of posts or contacts is here on the site.

fixing your engine is a fairly simple process.

straightening out your support systems and tune is JOB ONE.

good luck,

Howard

godsboss

hey thanks for the reply. just a few questions.
why do i need 5300cc combined injectors.. how you calculated that number would be VERY helpful.

what do u do about fuel? additives?

Howard Coleman

iTrader: (6)

start w max air from your turbo...

say 66 pounds per minute... Precision doesn't hv compressor maps so figure backwards from approx 500 Rotary rwhp (diff than piston).

figure you need to do 10.0 AFR (you won't run there but there are numerous potential deducts so use 10.0)

66 pounds of air, 6.6 pounds of fuel.

go from pounds to volume...

6.6 / 6.35 (weight of gal of gas) = 1.04 gallons per minute

1.04 GPM to cc/min = 3936 CC per minute X 1.35 to adjust for lag and 85% duty cycle = 5313

you are O K on gas (even 91) around 500 or less... as long as you use AI.

see my thread:

https://www.rx7club.com/3rd-generati...fd-fix-806104/

written a while ago... the basics are there and you can discount the parts about a higher level system... the AEM and Coolingmist basic systems work fine w 500 CC of whatever.. water, water/meth, meth.

Oh, premix w your gas 1/2 ounce of any 2 cycle oil per gallon for street and 1 ounce for track.

see my thread:

https://www.rx7club.com/3rd-generati...-motor-887275/


Howard