Rotaries in Zeds

Discussion in 'Technical' started by Chrispy, Nov 25, 2012.

  1. Chrispy

    Chrispy Pretentious Upstart

    Because I'm an idiot and can't stop faffing about with things, I'm thinking about putting a rotary in the zed :eek: :rofl: :br:

    20B's are rare and rather pricey, but will fit reasonably well. 13B's are much more common and priced accordingly.

    There are about a bajillion aftermarket parts available for them and you can get as much power out of them as you want. Provided you can get enough fuel into them :rofl:

    I think it would be a quite easy conversion, much, much easier than that stupid VH45 :p *May* need some sump work, but with a late model RX7 'box and new driveshaft, mounts, FMIC and a bit of wiring it should be right to go.


  2. Anti

    Anti 14.7 x 14.7 = 44.1

    I agree on 20b, go hard or go home.
  3. Jamie

    Jamie Jamie The Hobbit

    If you were successful in doing this and were able to make a kit up/extensive build thread, i'd probably follow suite. Or buy the Z you've done the conversion to once you get sick of it :p
  4. beaver

    beaver southern zeds

  5. pmack

    pmack Member

  6. stumagoo

    stumagoo Active Member

    I would go the 13b for a start, it would be a lot easier and I think the results would be worth it, I would however say that a S6 / FD engine would be the better choice than a FC, single turbo on either is no issues. Every one acknowledges that weight saving on a Z is as important as HP increase and I think this is where the 13b is going to huge dividends (around 120kgs + ancillaries). it is not unusual to hear the rotary guys talking about 350~400RWHP but the fuel consumption is through the roof with these engines. The end result is a very supported engine with crap loads of aftermarket parts etc. And a Z that is going to sound off the hook....... I can hear that bridgy already :br:

    QLDZDR ID=David

    If you want the look of driving a 300zx just change the Mazda head lights with the crappy 300zx lights and leave the engine where it belongs.
    Driving a 300zx Z32 at night is a unique dtiver's experience.
    Nothing much wrong with the look of the final RX7.
  8. Madcow

    Madcow Active Member

    Dont like 20b? Consider building a 13g... ;-)
  9. Chrispy

    Chrispy Pretentious Upstart

    Yep, 20B's are not cheap. Haven't really seen one for under ~$6K :eek: and you really have to budget for a rebuild. Kit alone for the parts is over $2k...

    And the other thing is I've got a lot of VG bits already. I've got ported heads/plennum/manifolds, bigger cams, forged rods, arp studs, haltech platinum sport 2000 and 28R's in the cupboard. All I need is pistons and a gasket kit and take it all to Eric's. That would certainly be the sensible thing to do.
  10. Jamie

    Jamie Jamie The Hobbit

    We don't want to hear about the sensible thing, we want to hear about the cool thing to do :p
  11. Romonski

    Romonski And Justice For All

    da rotary was one of my options before i decided to go 2j, would have been interesting.
  12. mungyz

    mungyz Well-Known Member

    I was going to mention there is a place in NZ pretty switched on with the 26B quad rotor set ups.

    Forget the 13B or 20B, 26B and I would be glad to see it done, I looked in to the 20B about 12 years ago and it wasn't going to be any better than a VG30DETT stock for stock.
    13B way to small, kind of like the guys that have fitted SR20DETs etc, fun but not smart IMO.
  13. foremannz

    foremannz New Member

    No matter what Rotary you put in it, your build cost is going to be more than a VG30DETT AND your reliability factor is far more dependent on how it is looked after and the money you spend on it. I am also in constant contact with a Mazda dealer and he has warned me against using a Rotary car if I use it for short trips - he has had many Rotarys, even RX8's, come in with seized engines because they weren't driven for long enough per trip, and it takes hours to get them working again (engine doesn't need to come out though)

    Weight wise, after you swap the VG30DETT for an 13B, its probably going to be pretty similar to an FD, but forget having fun without torque, and it might be a bit understeery.
  14. Peter Black

    Peter Black Active Member

    There is a lot of talk in this thread about 'sensible' and 'value for money' and such.

    Do any of you actually know Chrispy??????
  15. mholt

    mholt Member

    hey we had three rotaries at king edward hillclimb doing much better times than youd get out of a 300zx but here was afunny one, one of the RX7 S6 on start up miss fired and the only way the owner knew how to gain compression again was to put auto tranny fluid in it to get it started, ie up the compression then just warm it up and away she goes, what a nightmare eh
  16. stumagoo

    stumagoo Active Member

    No I dont know Chrispy, but I am not promoting value for money or sensible or any thing other than what I would personally do/like to see done. I personally love the idea of a 26b or a 20b in the Z, and while there is never a true replacement for displacement I believe that a 13b would be a great option (and a 20b would be better), I just dont have the cash to do the swap. although I very seriously considered it along with a v8 swap when I found my engine was dead. the only reason I did not do this was due to the ease (read cheaper option) of obtaining a VG to go back in.

    For Mungyz' and others in NZ, I know how rife rotaries have been over there (especially hamilton) and I know that like our engines a lot are getting unloved attention and long in the tooth but just like the unreliable claims that go with the VG a lot of the bad press about rotaries can be attributed to poor maintanance. the RX8 engine is the least reliable of the rotary since the abandoned the twin dizzy on the first RX2's (and that is due to ancillary issues) but any thing from RX7 range if treated correct can last easily as well as any other performance engine.
  17. black baz

    black baz black 'n blue Bazemy

    Spot on Stu ..... when i first came to the G/C in late 1998, i purchased an 1984, S2, RX7 from the original owner ... 185,000 Kms on the clock ... drove it like Hades until 230,000Kms ... and never had a single issue with the vehicle ... !!!!

    then stupidly sold it thinking that it was due for issues and bought Black Bess ( and quickly found issues) ... !!!

    had also owned an S1, purchased new in 1982 ($17,400 on the road) ... drove it hard for 100,000Kms as well as two x 2 year stints in storage ... never an issue.
  18. Wrathlon

    Wrathlon Member

    I would love to have been privvy to the thought process that arrived at "Dump some auto tranny fluid into it".
  19. Madcow

    Madcow Active Member

    we all own zeds here. We are all tarred with the same brush. Lol
  20. Jinxed

    Jinxed Moderator

    id love to see it done, 20b is obviously better but i think the 13b would be simpler and obviously much cheaper....

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