Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

rotory engine history

Discussion in 'The Garage' started by Tabb, Apr 7, 2007.

  1. Tabb

    Tabb ROLL TIDE! AGAIN! GMOTM Winner

    Joined:
    May 2, 2006
    Posts:
    3,566
    Likes Received:
    21
    Location:
    Heart of Dixie
    A freind and I was talking about the Wankle rotory engine yesterday and I discovered a little known fact about it's history. In 1974 Mazda offered this engine in their PICKUP TRUCK. I had always thought it was only available in the RX, they only sold about 1500 trucks in 1974 and in 1975 only about 700 in the U.S so they stop offering this engine in their trucks after only 2 years.
    I know this has nothing to do with this web site, but I thought it was a interesting fact and just thought I would share it
     
  2. Kyle Strong

    Kyle Strong 1/2 ton status

    Joined:
    Sep 26, 2005
    Posts:
    280
    Likes Received:
    0
    Location:
    Eugene, OR
    ya, it's pretty interesting. Lounge material though, but you don't have a membership yet...
     
  3. atho

    atho 1/2 ton status

    Joined:
    May 14, 2003
    Posts:
    1,115
    Likes Received:
    0
    Location:
    Wayne County, Ohio
  4. ntsqd

    ntsqd 1/2 ton status

    Joined:
    Nov 28, 2002
    Posts:
    3,381
    Likes Received:
    0
    Location:
    So. CA
    Not just the pick-up's but also in the RX-2's and RX-3's in addition to the RX-7's.
    Saw one of the pick-up's at El Mirage Dry Lake for an SCTA event many years ago. Rotaries are naturally loud, a high pitched - goes right thru you kind of loud. Takes some tricky muffler work to quiet them down. This truck didn't have any of that. :eek1: At the 1/2 way point down his 1 mile pass the noise quit being painful.

    BTW, rotaries first came to the US in NSU's, way b4 Mazda brough them in.
     
  5. surpip

    surpip 1 ton status

    Joined:
    Apr 7, 2004
    Posts:
    10,877
    Likes Received:
    0
    Location:
    sacramento ca
    buddy in HS had a rotary pick up, loud as heel, and it would back fire like crazy, sounded like a bomb going off
    good times
     
  6. fireplug

    fireplug 1/2 ton status

    Joined:
    May 3, 2005
    Posts:
    1,692
    Likes Received:
    0
    Location:
    Toronto, Canada
    "This forum is for the general discussion of almost any truck-related topic." ;)
     
  7. blind driver

    blind driver Registered Member

    Joined:
    Oct 9, 2004
    Posts:
    11
    Likes Received:
    0
    Location:
    Louisville, KY
    Gm experimented with rotaries too. They even built a 5.0 liter monster.
    Rotaries suck the gas and don't have the torque
     
  8. rx7gslse

    rx7gslse 1/2 ton status

    Joined:
    Nov 4, 2002
    Posts:
    362
    Likes Received:
    0
    Location:
    DFW, TX/Mexico
    Yep, Mazda used them in their version of the Ford Courier for awhile.. but they don't have much torque, don't do well at low RPMs and suck gas... So I can kinda see why they didn't stick around in trucks for long ;)

    They've been brought to the US in bikes, Many Mazda cars, Cosmo, R100, RX- thru RX-8.. Now they're actually pretty commonly used in the homebuild aircraft hobby as well (when they break, they at least keep running somewhat, I guess that's good..)

    Yeah, that's my other hobby ;)
     
  9. FRIZZLEFRY

    FRIZZLEFRY 1/2 ton status

    Joined:
    Apr 20, 2001
    Posts:
    3,271
    Likes Received:
    134
    Location:
    Clovis CA
    I had a friend that I used to race with at LACR that had two early or mid 70s 2 door little cars.Both rotary powered.One ran low 10s and the other low 11s :D
     
  10. vortec

    vortec 1/2 ton status

    Joined:
    Jul 22, 2004
    Posts:
    1,472
    Likes Received:
    0
    Location:
    fort worth, texas
    on old friend had 2 rx7s and a rotary pickup. the rz7s were fun, but the truck was a total waste of space. i don't honestly remember if it was the same displacement engine as the cars, but it felt like a real dog in a truck. couldn't haul a dang thing, and it always sounded like it was about to fly apart.
     
  11. BlazerBud

    BlazerBud 1/2 ton status

    Joined:
    Jun 14, 2006
    Posts:
    473
    Likes Received:
    0
    Location:
    Chattanooga
    Rotaries have a near linear torq curve as there is no valve train timing. The torq just keeps going up the faster you spin them until they have catostrophic failure.
    I think I even heard a Texas tall tale of someone getting almost 10,000 miles out of a rotary engine before it became useless. Why bother with them? You can take a conventional V-8 and abuse it for decades and it still runs, maybe poorly but it runs. A rotary engine is a piece of jewelry, it runs good on a test bench, but abuse is not good for it.
     
  12. mosesburb

    mosesburb For Rent Premium Member GMOTM Winner

    Joined:
    Apr 20, 2003
    Posts:
    2,175
    Likes Received:
    132
    Location:
    Phoenix AZ
    I'd disagree with that statement. When properly maintained, they can last for a long time. I have a couple buddies who are Wankel Nuts. One held several track records for his class with his GT3 RX7 and never had one come apart. Before they released the new RX8 Mazda sent another buddy of mine a couple engines to see what he could get out of them. Pretty impressive numbers (by V-8 standards). This is the same guy who has one of the rotary powered Mazda pick-ups that is just stoopid fast. Pound for pound, they are hard to beat.
     
  13. ZooMad75

    ZooMad75 1/2 ton status Premium Member GMOTM Winner

    Joined:
    Apr 5, 2003
    Posts:
    1,007
    Likes Received:
    609
    Location:
    Pueblo, CO
    There was some dude running a wicked RX-2 at Bandimere speedway in Denver about 15 years ago. Uncorked and loud as a friggen top fuel rail. Just more high pitched. That guy would constantly rap the throttle as he rolled up to stage. The echo off of the tower and moutainside were just as bad. IIRC he was running low 13's at the mile high altitude. Strange little beast for sure.
     
  14. FRIZZLEFRY

    FRIZZLEFRY 1/2 ton status

    Joined:
    Apr 20, 2001
    Posts:
    3,271
    Likes Received:
    134
    Location:
    Clovis CA
    High pitched cuz they can spin at 8000+ rpm :D
     
  15. ntsqd

    ntsqd 1/2 ton status

    Joined:
    Nov 28, 2002
    Posts:
    3,381
    Likes Received:
    0
    Location:
    So. CA
    In stock form I believe they were limited to less than 8K according to the stock tach. Not to say you couldn't wind them past that, but the stock intake & exhaust were pretty restrictive.

    The reason they are loud is they are similar to a 2-stroke, the gasses are still burning in the header. They can have insane EGT's if you're not carefull. High enough to make a turbo-diesel guy go "dude......" and walk away rapidly. Easiest way to quiet one down is to turbocharge it. :D :D Also makes them more efficient.
     
  16. vortec

    vortec 1/2 ton status

    Joined:
    Jul 22, 2004
    Posts:
    1,472
    Likes Received:
    0
    Location:
    fort worth, texas
    considering what fails on them, i think the flaw is not in design, but in build. great on paper, but using cheaper weaker parts to save money leads to failure, or just plain crappiness. the two guys i know who have had them (they were cousins, as if that matters) had to add oil all the time. they might as well have mixed the oil with the fuel, like old 2-strokes.
     
  17. ntsqd

    ntsqd 1/2 ton status

    Joined:
    Nov 28, 2002
    Posts:
    3,381
    Likes Received:
    0
    Location:
    So. CA
    A little oil in the intake is necessary to lubricate the seals of the rotors, particularly the apex seals. There is a tiny pump on the pass side front of the 12A's and 13B's that pulls a tiny bit of crank oil out of the pan and injects it into the intake near where it bolts to the rotor housings. There is a barrel valve on the pump that controls the oil volume based on the throttle opening. If that throttle cable's adjustment is off then they can inject more oil than needed, which makes them look (& run) like oil burners.

    Most road racers that can't afford the oil-less & spendy solid carbon apex seals do away with the little pump and run 2-stroke oil in the fuel. No idea at what ratio, but I'd guess it to be pretty lean.

    Rotaries are a different critter. You can't judge them fairly by 'normal' V8 standards.
     
  18. vortec

    vortec 1/2 ton status

    Joined:
    Jul 22, 2004
    Posts:
    1,472
    Likes Received:
    0
    Location:
    fort worth, texas
    true, but you have to draw the line somewhere. they were using 5-10 quarts per 3000 miles, and it smelled like pure motor oil, on hard acceleration. not ideal for any engine, i'd say.
     
  19. BlazerBud

    BlazerBud 1/2 ton status

    Joined:
    Jun 14, 2006
    Posts:
    473
    Likes Received:
    0
    Location:
    Chattanooga
    I didn't say I didn't like Rotaries, just that they can't take abuse. And your opening statement..."When properly maintained"...verifies it, yes I know that they can last if maintained, I've read all the stuff about how to make them last and how to build them strong because I was going to get one a few years back.

    But there is no way that a rotary can withstand the abuse, I meant to say neglect that a conventional motor can. You have to know how to take care of them and they can be pound per pound better than any conventional engine for power output.

    But we've all seen some rotary guy with 10,000 miles and busted seals cuz he was stupid. And we've seen an equally stupid person with 300,000 miles on a V-8 that barely has compression left but still works.
     
  20. roadnotca

    roadnotca 3/4 ton status

    Joined:
    Sep 16, 2005
    Posts:
    5,433
    Likes Received:
    1
    Location:
    Redondo Beach, CA
    I remember when the RX7s came to Riverside. You did not want to be any where behind one, and they were running megaphones too! It hit everybody by surprise; stuffing race day program in our ears:doah:
    I had an RX2. Scarry at the top end in fourth, car was too light.
     

Share This Page