Jump to content


Photo

Anyone know a rotary engine buff please help


  • Please log in to reply
34 replies to this topic

#1 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 12 November 2012 - 10:41 PM

If you know someone resonably well i hope that is good with rotary engines expecialy 12a please send me the details.

Got few issues with it and need some advice.
Other rotary forums dont have the answers and not many replies.Bit desperate and need answers quick.
now even considering replacing it with sr20det  ;D  :P

Thanks in advance

#2 peter mc

peter mc

    The 1000+ club

  • Members
  • PipPipPipPipPipPip
  • 1,573 posts

Posted 12 November 2012 - 11:03 PM

Anthony at maztec in melb is a gun tuner and rotor man and a nice bloke

#3 zzzzed

zzzzed

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,691 posts
  • Location:south australia

Posted 13 November 2012 - 06:45 AM

Jazmac mt barker

#4 dat2kman

dat2kman

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 4,029 posts
  • Location:Newport Waters Qld
  • Tagline:going sailing, see ya later!

Posted 13 November 2012 - 07:43 AM

Wot u wanna know?

I got a 13b sports sedan, and access to some cluey blokes up here, as well as some good documentation.
I got a bit of stuff on the Group C race cars.

See,,,  i am not all Datsun !!!

#5 MaygZ

MaygZ

    The 1000+ club

  • Members
  • PipPipPipPipPipPip
  • 1,456 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,7841.0.html
  • Location:Springfield, Victoria
  • Tagline:We all started somewhere. Where are you Lurch???

Posted 13 November 2012 - 09:55 AM

Try DAZDA here on this forum.

#6 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 10:28 AM

Unbelievable you guys ROCK!

in less than 8 hrs I get 4 responses.

THANKS HEAPS.

warning long boring read. but details are there for a reason.

I spent lots of time trying to work out what the problem is. some things are hard to explain and don't make sense and no similar example to be found on the net.

Well spent considerable time sifting through crap on the major rotor forums. Don't get me wrong there's couple of smart guys there but very hard getting response from them. over 2 days still not a decent educated or valid response.

I got a smoking issue with my stock 12A carby with stock exhaust. ( ill explain later why exhaust is important)
Only smokes when revved harder or when under load after few kms and starts smoking when back at idle. than smokes for a while and eventually reduces but lightly present.

now from what i've read from the forums in summary.

White smoke cane be : condensation, coolant or brake/trans fluid.
Black blue smoke: Can be too rich with fuel smell
Blue smoke: Oil burning with distinct oil smell

very similar to piston engines.

other: things that seem repeating when rotaries smoke.

White: condensation or failed water seals (indicated by loss of coolant), also failed seal in master can suck up brake fluid or in autos trany fluid.
NOT in my case for last 3 brake fluid hasn't moved and its manual so no auto fluid. coolant level hasn't moved so white smoke at cold is condensation in my case which goes away when normal temps are reached.

Blue/Black fuel: running rich blowing black smoke when floored.
This was true in my case. initially new spark plugs were quite black. cleaned them and put them back in and reduced the mixture. After over 1hr running time pull the plugs out and were cleaner than when i put them in 3 out of 4. 4th one was bit wet assuming its where in the cycle it stopped and hasn't ignited the fuel.

Blue smoke oil. This can happen when oil control seal fail, Oil Pump Metering (OMP a small oil pump that injects small amount of oil into carby to lube the apex seals) is stuck on full and injecting too much oil in the fuel.
When lightly stuffed seals when cold engine will blow bit of blue white smoke. on more stuffed it will blow smoke when cold than go away and come back again when hot.

My scenario is slighlty different.

No smoke when cold. or for at least 40min of idling just steam for few minutes till normal temp reached. also evident by water droplets from pipes.

Was rich initially when high revs or under load black smoke no oil smoke.

when backing off and back to idle once warmed up (realy well or revved to 5k+ or under spirited driving) it start bellowing smoke at the back blue/white for next 20-30sec. than reduces. (from what ive read if oil control seals it wont reduce just smoke till driven again)

Disconnected the OMP lines so no oil goes to carby. OMP works not exessive but smoke still present.
Point back to oil control seals.

after 5min shut down when heavily smoking, engine started and no smoke for over 5min idle. started driving no smoke for 5min than comes back.

bit of a irregular pattern here not corresponding to rotary heads on the forum.

as i stopped and shut the car of and lifted the bonnet i noticed smoke bellowing from the tunnel accross the engine for next 5min.

checked under the car and there was an oil leak from one of the pollution pipes that are from the thermal reactor going back to the front pipe. big nut thats t pieced into the main exhaust.

HMMM where the oil coming from?

checked the engine and leaking from the front out of the OMP than seeping along the sump, getting on this pollution pipe.

Theory 1 was, oil is going through the exhaust and that its cooling and liquifying near the connector due to lower pressures and temps and seeping down. ok. sounds possible.

At this stage i pulled the plugs out see if the black or oily and as previously mentioned they were clean. for that much smoke to be poring out i'm certain it would have been black. theory 1 is bit ?????

i decided to remove that pollution pipe and to inspect it. after removal the flanged end that is hooked to reactor was clean just carbon build up.
the pipe inside seemed clean as well all the way to the nut that has a seal similar to brake lines. this nut has been on the car for over 30year. initially was thinking it be impossible to remove. but it was easy and almost loose.

On the front pipe side as i removed the pipe and nut. on the inside of the nut there was lot of oil. and roughly about 3mm inside the small pipe. i inspected the front pipe and had oil covered on the T extension. I inspected to see if any oil in the front pipe. there was none. seemed clean and dry just carbon build up.

so


My pressure theory is not that great so all this may sound stupid or myth.

But trying to explain how oil gets into the exhaust.
Kinda explains in general if oil gets into the exhaust wont smoke till the pipe gets hot than it starts smoking. from the little pipe i couldn't see evidence of oil in the system. so must be inserted somewhere along the line. when under load more heat heats the exhaust + oil present = smoke.

now how does oil get in Theories:

1. Oil control rings leaking and entering combustion chambers gets shot out the exhaust and Theory 1 is valid as previously      discussed. Issue with this is No evidence of oil in the pollution pipe or on the spark plugs, no smoke when totally cold at start up as expected with damaged seals, there is oil evident at the muffler though.

2. Oil leaking from OMP at the front of engine (leaking a fair bit actually) seeping along the engine running down the pipe near the loose end. pressure differences (somehow create a suction) and oil gets fed into the front pipe. once exhaust gets hot +introduced oil =Smoke. Sounds far fetched to me. but supports the evidence of no oil in the pollution pipe before the nut connection and clean plugs.

now its either the oil control seals are stuffed and engine needs a rebuild.

or

this OMP leak is getting in the exhaust. and burning when gets hot.

i'm going to pull the reactor off tonight and front pipe and inspect if oil residue is present before or after the reactor pollution pipe. if clean at the reactor but oily after the pipe, clean plugs, relative easy starts, after 5min of cooling didn't smoke, No smoke at start up all point to supporting  theory 2.

confusing mysterious and plain annoying. was lucky the police didn't pull me over last nite smoking them out of the rear vision mirror. was my lucky nite.

as i said detailed steps I went through trying to figure out this thing. maybe i'm dillussional and refuse to believe engine oil seal are gone.

sorry for the long arse read but I think devil may be in the detail.

do have pics of most of the stuff i dribbled ill upload them when i can.

Help greatly appreciated. any new theories or flogging mine as insanity and stupidity is quite welcome.  ;D

Thanks MaygZ ill PM DAZDA bit later.

DAT2KMAN what u make out of this???

Thanks Mick im hoping to find someone local that isn't a shop a Guru that knows from experience and not interested in ripping ppl off. Don't mind paying for services but like to learn along the way.

Contacted few shops and i will refrain what i think of them for time being.

Peter ill try calling but from what i've seen from local guys here,advice is very hard to get.

just want to figure what it is before jumping to the deep end. not backing out worse case scenario will be shoving an Sr20DEt for 50% power increase and economy and 100% reliability for the same cost of just buying the seal kit for the 12A. paying 4K for rebuild for a 75kw engine is bit silly.
may even get a good 13B turbo for half the price of rebuild. last me 2yrs ill be happy.  but rather just keep the original stuff.

cheers









#7 MaygZ

MaygZ

    The 1000+ club

  • Members
  • PipPipPipPipPipPip
  • 1,456 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,7841.0.html
  • Location:Springfield, Victoria
  • Tagline:We all started somewhere. Where are you Lurch???

Posted 13 November 2012 - 10:40 AM

Perhaps oil isn't getting INTO exhaust.  Is there a chance it is an external leak with exhaust contacting outside of exhaust?  Or is the smoke definitely coming from pipe?

No turbo, right?

Consider dropping off the exhaust, possibly at the manifold or the first join.  Miles from you neighbours (or mine) and with ear plugs in, take it for a drive.  You may be experiencing oil residue from a previous problem.  There may be oil sitting in one of the mufflers. 

I too, like you, am trying to think of the bizarre to avoid what seems like the obvious and more expensive reality.  ;)

#8 dat2kman

dat2kman

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 4,029 posts
  • Location:Newport Waters Qld
  • Tagline:going sailing, see ya later!

Posted 13 November 2012 - 10:47 AM

You're not gonna like this.
How many K's on motor?
Have you owned it since last rebuild?
Answers
Lots
No

.rip it out and run a full rebuild kit through it.
Pay carefull attention to any scoring or wear to the chrome plating inside rotor housings, and look at getting all side plates lapped.

You've got a few issue happening, mainly due to very slight weepage at various places when both hot and warming up, also as things move about internally there is a bit of weepage of fluids.

Yes out she comes, sorry!

#9 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 10:51 AM

Perhaps oil isn't getting INTO exhaust.  Is there a chance it is an external leak with exhaust contacting outside of exhaust?  Or is the smoke definitely coming from pipe?

No turbo, right?

Consider dropping off the exhaust, possibly at the manifold or the first join.  Miles from you neighbours (or mine) and with ear plugs in, take it for a drive.  You may be experiencing oil residue from a previous problem.  There may be oil sitting in one of the mufflers. 

I too, like you, am trying to think of the bizarre to avoid what seems like the obvious and more expensive reality.  ;)


heheh so im not the only one with bizzare theories woohohoo. did it ever work?

No turbo all standard with all the emission gear bit of a dogs breakfast.

yeah basically planning to do what u said besides driving around neighbourhood or you. dont worry im like 750Km+ away . just inspect the pipes and clean them . fix the oil leak and hope for the best. but don't like my chances like DAT2KMAN is explaining.

smoke seems to be more evident from the polution pipe ie 3 pipes at the back of the car.

Twin tip muffler and a single p shooter welded next to muffler. this is the pipe that has the oil near the connection. but occassionaly does smoke out of the muffler and seems bit oily deposit on the tips. so not looking good.



#10 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 11:05 AM

You're not gonna like this.
How many K's on motor?
Have you owned it since last rebuild?
Answers
Lots
No

.rip it out and run a full rebuild kit through it.
Pay carefull attention to any scoring or wear to the chrome plating inside rotor housings, and look at getting all side plates lapped.

You've got a few issue happening, mainly due to very slight weepage at various places when both hot and warming up, also as things move about internally there is a bit of weepage of fluids.

Yes out she comes, sorry!


cheers. yeah i didn't think i was going to like it.  ;D

some anwrs for u.

no idea on the KMS, car had two previous owners (both females) last owner had it since 89. at some stage motor was replaced as its not genuine one from original paperwork. not sure when and what has been done. car is done around 350k kms.
still original exhaust beats me how that survived.
seems to be serviced regularly but it has been dorment since 2005. where history stops. Radiator seems reasonable new brake rotors look newish as well. so seems to had some money spent on it. and to own it for 16 years must have been in love with it. though interior was shot and body had better days when i got it.

no didn't own its since rebuild or replacement.

yeah was thinking of doing it myself as i don't realy want to spend 4k on rebuild. they don't look that complex. only risk is its 1.2K worth of seals good enough gamble for me if i got someone to guide me if i get stuck than its worth the gamble. also need a car badly as im still hitchiking to work via few workmates. I realy only expected 3 month out of it and than if it blew didn't care. fix it in my spare time.

ill try the above fix the leak clean the exhaust and see what happens cheapest option at the moment. if its waste of time well at least i tried.

any recommendations where to get the seal kits from? ie price only ones ive seen is mazda for 1.4k or phils rotaries for around 1.1k

thanks

#11 MaygZ

MaygZ

    The 1000+ club

  • Members
  • PipPipPipPipPipPip
  • 1,456 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,7841.0.html
  • Location:Springfield, Victoria
  • Tagline:We all started somewhere. Where are you Lurch???

Posted 13 November 2012 - 11:08 AM

Might as well go 13B (or 20  ::) ) for that sort of money.

#12 thriller

thriller

    Advanced Member

  • Donating Members
  • PipPipPip
  • 398 posts
  • Location:Adelaide Hills
  • Tagline:New Member

Posted 13 November 2012 - 11:48 AM

I have a haynes manual for the FB series, has the usual 25-odd-page guide on engine rebuild if you end up needing it and don't have one already. But for 1.2k on rebuild parts, that's halfway to a Silvia halfcut ;)

#13 Ledge

Ledge

    Senior Member

  • Members
  • PipPipPipPipPip
  • 869 posts
  • Website:http://www.customandclassiccars.com.au/
  • Location:Mount Barker
  • Tagline:PMC RB28

Posted 13 November 2012 - 12:40 PM

As Mick said Jazmac mount barker.
He is a rotor nut, has dyno there also.
He tunes my race Z and is the only guy
I would trust.


#14 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 01:59 PM

thanks guys.

here are the prices from local guys.

4.5K
4.5k
4.5K

see a pattern?

called revs, jazmac, mildrens etc......

freaking OUCH.

though Jazmac was most helpfull thanks Ledge and Mick. As much as i don't want to hear it got to get in terms that the oil control seals are gone.

DAT2KMAN so you suggest to just get the seal kit and rebuild it myself? seems the cheapest and quickest option. Seem easier than piston engine.

i rang another privateer that is good with rotaries, and same answer as jazmac and revs oil control seals. still looking approx 4weeks waiting and not much return of 2K if my housing rotors and side plates are ok. which is a big Question.
knowing my luck im going to assume its stuffed.

no idea what to do. risk 1K+ of seals and do it myself it be like those drink driving jokes.
Drink and drive u bloody idiot. Drink and drive and make it home you are legend.
that be same with me.
rebuild rotary yourself and you an idiot. rebuild it and works you are legend.  ;D

got to joke with the bad situation.

just wrong timing for me to rebuild the motor. no time.

maybe try some of the band aids and hopefully reduces smoke for few weeks till my other project is complete than rebuild the motor at less pressured time. that way i can give it a good shot and not stuff anything up.

buy another 12A in good condition but how do u trust it. fit a 13B found one through jazmac rebuild but 3.5K still ouch.
or buy a Sr20DET for 1.5K and have it screaming over a weekend.

dillema. now wished i never bought the damn thing and stuck with datsun/nissan.



#15 DAZDA

DAZDA

    Advanced Member

  • Members
  • PipPipPip
  • 190 posts
  • Location:Datsun Mafia Headquarters (Canberra)
  • Tagline:Brap Brap Brap

Posted 13 November 2012 - 02:30 PM

now its either the oil control seals are stuffed and engine needs a rebuild.

or

this OMP leak is getting in the exhaust. and burning when gets hot.

Or Both.

Based on this comment,

... was lucky the police didn't pull me over last nite smoking them out of the rear vision mirror. was my lucky nite.

I'd suggest the oil control seals are on their way out.**  It's unusual for an external leak into the exhaust to cause that much smoke to be burnt.

Rebuilds are expensive because of the labour (same with piston engines, but perhaps less time intensive???)

The SR20DET will cost significantly more than 1.5k once you do all the conversion (there are lots of posts on here about ballooning costs with conversions).

I don't think there is a cheap, easy, simple, reliable answer for you, sorry.
A variation on "Cheap, Fast, Reliable"  in this case "Cheap, Simple, Reliable - choose any two. "  ;)

If it was me, and assuming I had the time I'd rebuild it, if I didn't have the time I'd see if I could pick up a cheap second-hand 12A engine off Ebay.  It's pot-luck but I could probably buy several for the price of a rebuild and one of them is bound to be fine.


**  I reserve the right to be completely wrong  ;)

#16 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 02:47 PM

cheers Dazda..

i know what you saying. but still. i think the labour cost with rotaries is very overinflated.

regarding SR20DET conversions. not a big deal done a few. know to do most of it so biggest expense is getting motor and gearbox with loom and ecu air flow meter etc....1500-2000 pending on model
second cost is tailshaft to be made to suit approx cost $250
fabrication can do myself. wiring can do myself. fuel pump and surge tank. if have all the bits i recon it be in and running in 2 days.

regarding back to the 12A.

im going ot fix the OMP leak put it back together tonight and see what happends. may change the oil for something thicker. see if anything can prolong it for few weeks.

try find another 12A or 13B so i can replace it as soon as the current one start to blow again. (that's assuming thicker oil and fixed OMP is successful for short term) if cannot find anything and seem to hold together still hopefully gives me enough time to fix my other car.
than if it blows don't care, pull it appart check it and if seems fixable buy the seal kit and rebuild it properly.

invested enough time and money in it not worth abandoning it now. if parting it now i loose too much. may as well keep the sucker. do like the car intrigued by the rotary and always wanted to rebuild one. just not right now.



#17 zzzzed

zzzzed

    The 2000+ club

  • Members
  • PipPipPipPipPipPipPip
  • 2,691 posts
  • Location:south australia

Posted 13 November 2012 - 07:15 PM

Wack an l20b in it  8)

#18 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 13 November 2012 - 11:22 PM

Shhhhhhhhhhh.......

Not saying anything yet.

#19 gav240z

gav240z

    Administrator

  • Administrators
  • 12,386 posts
  • Website:http://www.viczcar.com
  • Location:Sydney NSW
  • Tagline:Jack of all trades, master of none.

Posted 14 November 2012 - 02:01 AM

Buy some of the rebuild DVDs it does look relatively straight forward but would help to have someone with experience watch over you.

I think 4.5k is reasonable to be honest if its an expert and guaranteed work. You'll get many more years of use out of it if you take care of it. Second hand engines are unknown quantity so if you plan to keep the car I'd rebuild.

Might wanna go 13b since parts can still be obtained I think 12a is harder to get parts for also Mazda made many improvements to ports that will give you more HP.

Would you consider a renesis 13b? Would go like stink in an FB. Otherwise I highly recommend the 13b few out of the FD ;) over an SR20 but I'm a converted rotary nutter.

Maybe keep driving as is then rebuild a second hand motor on the side? Is it really smokey?



#20 Fairlady Z

Fairlady Z

    Advanced Member

  • Members
  • PipPipPip
  • 497 posts
  • Website:http://www.viczcar.com/forum/index.php/topic,12313.0.html
  • Location:South Australia
  • Tagline:Sports Cars

Posted 14 November 2012 - 09:26 AM

Gav yeah its really smokey.

what gets me its not smoking at all when cold and OCS issues first seem to pop up when cold. confirmed over and over.

but still early days. did some work on it last nite. not going to say the results just yet in-case i was dreaming and wake up to the nitemare.

regarding 4.5K cheap for 75kw engine i think its out of this planet.

gaskets/seal kit is 1.1K so u telling me on a rota there is more work than on 6cyl piston engine with performance parts . and 3.4K labour cost? ridiculus.
i think they just milking it cause of the niche market and everyone is scared of word rotary. bit like when you mention turbo to some ppl.

Noticed lot of rotary owners don't know anything about them. They just cough up the $$$ for crazy prices for work on their simple engines.

what pissed me off is i saw a GTR for sale with fresh rebuild with performance parts with reputable shop costing 5K. this for an improved engine not a stock rebuild. this upgrade gained performance and cost 5K. this thing gain more kw than the total rota has.

everyone says rotaries easy to work on than piston but yet they charge ridiculous prices. What tha?

anyway few things to confirm tonight than we have a little game: Guess the issue?

it be fun.

PS Gav, whats going with donations??? not working ,wanna chip in.







0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users