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backwards running engines ?

Discussion in 'The Hokey Ass Message Board' started by 57 3100, Jun 25, 2010.

  1. 57 3100
    Joined: Apr 9, 2010
    Posts: 344

    57 3100

    thanks for all the info guys. my bad on wording it "backwards running engines".
    now i know better.
    i know it must take a lot of extra work and money to run them this way, and just thought it was cool, different.
    isnt that what we all want to be, different ?
    thanks again guys.

  2. Holman Moody boat engines from the 60s rotated in the opposite direction, So I guess my question would be SUCK or BLOW ?? >>>>.
  3. fab32
    Joined: May 14, 2002
    Posts: 13,985

    Member Emeritus

    Just be thankful that it's the only recorded incidence of a waste of time in automotive history. Otherwise we would have an uncountable number of these "experiments" that lead to nothing.:eek::rolleyes:

  4. pdq67
    Joined: Feb 12, 2007
    Posts: 787


    Please hunt up an old copy of HPBooks, "How to HR SBC's" and find the pic on page 148 of Mr. Crowers under 300" Chevy V-8 that has the intake ports installed on the outside of the heads along side the exhaust ports with the exhaust ports feeding up and over the top of the heads into a top center mounted turbo.

  5. RichFox
    Joined: Dec 3, 2006
    Posts: 9,981


    leonard; Do I want to be different? yes, that's true. But I could be different by wearing very large red shoes, Oversizes green pants, a yellow hat with a flower in it. And a red nose. I would look different but people would call me a clown. Any simularties between clowns and people who loose performance to look different by reversing intake-exhaust ports is coincenadental
  6. Piewagn
    Joined: Mar 25, 2009
    Posts: 1,106


    Damn Rich, your comedian too?!? That's some funny shit right there!!
  7. lippy
    Joined: Sep 27, 2006
    Posts: 5,277

    from Ks

    The old 2-stroke putt putt rail cars ran backwards and forwards. Thats how the car changed directions on the track. Lippy
  8. I had one of those.
    It was an inline 6 cyl that stood vertically on end.
    I thought it was called the "suicide drive".
    A little tricky to ski behind without any neutral.
    The distributor would turn around 180 degrees and the starter rotate backwards for a minute. That was reverse.
    That was my favorite motor for skiing except for the awkward launch.
    Very powerful for the small weight once you get away from the stupid three-lobe cam in the distributor and added an electronic ign.
    Yes, you sure don't want 110 HP in full reverse while at the dock.
    I can only imagine what that would be like.
  9. 57 3100
    Joined: Apr 9, 2010
    Posts: 344

    57 3100

    wonder if dan lost any performance going with his set up ??

  10. 117harv
    Joined: Nov 12, 2009
    Posts: 6,590


    It seems that i heard somewhere that the exhaust would cook and finally break the windshield, depending on the confiuration. That should help get attention with the look at me crowd.
  11. shoveled71
    Joined: Jun 3, 2007
    Posts: 159


    I seen a panhead with reversed intake and exhaust at an antique show and swapmeet. Back in the 70s I drove a dump truck with a Detroit Diesel that would run backwards when you lugged it way down, it would reverse rotation and pull air thru the exhaust and blow it out the intake, we would do it to clean out the air filter,it would blow up a dust storm out the intake. Spike
  12. von Dyck
    Joined: Apr 12, 2007
    Posts: 678

    von Dyck

    On twin prop boats running inboard engines, one of the engines must run the crankshaft in the opposite rotation to the other so that the boat moves forward in a straight line without having to constantly "rudder" it straight. Affects how the boat steers as well!
  13. Bill Slater had one in his modified back in the 1960's, figured it would give him some advantage in the turns. Stock Car Racing magazine had an article on it some years back. The car was largely successful though and only a few people knew about it.

  14. Mr48chev
    Joined: Dec 28, 2007
    Posts: 28,147


    You still do. Unless they run a reversing gear box. These are on twin engine boats to have the props turn in opposite directions.
  15. '54Caddy
    Joined: Sep 11, 2009
    Posts: 929


    You seriously would run it backward on purpose!? You do know that when its running backwards the oil pump is running in reverse and you have no oil pressure. How could you see the dust coming out of the air cleaner through all the black smoke?!
  16. RichFox
    Joined: Dec 3, 2006
    Posts: 9,981


    I seriously doubt the engine reversed flow. Detroits have no intake valves. They are a 2 stroke with ports in the cylinder for intake. Because the design will not allow the normal crankcase and transfer port intake they use the famous GMC 71, and other, series air pump to provide intake pressure. As in most two strokes I guess that a Detroit could be made to run backwards although the timing is set by the injection and if it was firing right about TDC I guess it would run pretty much the same. Oil and fuel pumps running backwards would seem to be a limiting factor. But the blower would be running backwards also. It would become a sucker. Maybe it would reverse flow?
  17. Chris 50
    Joined: Feb 1, 2002
    Posts: 443

    Chris 50

  18. SlamIam
    Joined: Oct 8, 2007
    Posts: 409


    Some Sprint car classes allow reverse rotation engines to prevent torque problems in turns, but they do not swap intake for exhaust.
  19. woodhawg
    Joined: Apr 11, 2009
    Posts: 1,019

    1. S.F.C.C.

    When I was a kid about 50 years ago, some will say I still am, there were dirt track circle racers that ran motor in reversed rotation to push chassis and inside wheel into the dirt for better traction. They sounded the same but went pretty good in low traction conditions. Probably not worth the effort or everyone would have do it.
  20. Fro
    Joined: Sep 3, 2007
    Posts: 124

    from Joplin Mo.

    I've done allot of research on 60's drag bikes, which you would see allot of inverted heads, the engines would still turn the same direction basically you just flipped the head around and ran custom cams, they did this to get a supercharger in front of the bike where all the good air is and there was no real performance gain otherwise.
  21. Heo
    Joined: Jan 8, 2010
    Posts: 524


    No beacuse this is a completly different set of
    heads compared to stock Ford
    generaly a head flow about 75 percent of the
    intake flow on the exhaust side so the idea
    swaping sides on exh-int on a regular head
    is stupid like it is stupid to modify a engine to be
  22. granny
    Joined: Apr 1, 2009
    Posts: 56

    from WA state

    I built/drove a couple reverse rotation dirt late models back in the '80s, ran real good when the track was slick. You had to drive it different though, which seemed to make it harder to run in a close group of std rotation could go in much harder and deeper than the other cars, but if you had to let off in a corner for some reason it was easy to get into trouble.

    It was all a homemade low buck deal (more time than money). I did it by just turning the 440 Mopar around backwards, and making a transmission to drive off of it's crank snout. The 1st car/rear was just an 8-3/4 Mopar turned upside down, which lasted 2 races before i ripped the double center out of the RR wheel and barrel rolled it several times. The 2nd car was much more successful with a quickchange that i modified to put the ring gear on the other side of the pinion...even won some features with that one...


    The car just had a flexplate for the starter on the front(rear?) of the engine, and plenty of room up there to get creative. I always wanted to make a simple single stage straight vane impeller out of the flexplate and build a housing to turn it into a simple centrifical blower. Diameter and tip speed would have been in the ballpark so that a stepup drive system would not be required. Rules were damn near gone at that point, but i caught the rotary engine bug and decided to put two rotaries together to make a low buck 4 rotor engine, which was standard rotation.
  23. Morrisman
    Joined: Dec 9, 2003
    Posts: 1,600

    from England

    That bike is from the school of 'Desperate to be different' There's nothing to gain, no advantage, doing it that way, just maybe a few more points in the competition circuit.

  24. KK500
    Joined: Dec 29, 2006
    Posts: 354


    Why does it has a licence plate? It was never build to drive, not with a tie rod that shape!!
  25. gimpyshotrods
    Joined: May 20, 2009
    Posts: 17,899


    I have built several vehicles that have a curved tie-rod. All 4x4 stuff that is regularly abused. Several have over 20k miles on the very roads you drive.:D

    It works just fine, properly built, out of the right stuff.
  26. No, because the built the cylinder heads with the explicit intention of running the exhaust and intake in this manner. There were a few Indy/Formula v-8's done this way and it had to do with exhaust packaging vs available room to run it out the back.
  27. This flat head in my friend Chuck's dragster has exhasut ports in the valley of the motor - right next to the intake!
  28. Landseer
    Joined: Aug 19, 2006
    Posts: 154

    from VA

    I bought surplus pair of 350's from a twin engined boat and took them apart, trying to end-up with a single marine engine.

    Difference: timing chain on one, vs meshed timing gears on the other. That's it.

    Unfortunately, they were 87 vintage and used in salt. Virtually nothing was left to the interior of their respective blocks. Completely corroded. Massive loss of metal. And time on my part.

    (I realize this thread is about something different, but this question also came up so I wanted to address it)
  29. I started to say that the guy with the bike did it so he could run two carbs but he didn't do that so there is really very little advantage to his doing it other than for shock value.

    A lot of harley guys used to do it to run two carbs. And the exhaust valve being smaller is not a problem on a pan head or a shovel. One really old (since the inception of the shovel head) hot bike trick was to run a shovel intake valve in all 4 holes. Makes them breath a lot better.

    Anyway like most things to make one breath backwards more often than not is for shock value. Sometimes in a rear engine config like an X class Can Am car it makes it easier to build your headers 180 degrees. So lets say you owned a car called a Edsel Alley Ostrich and it was chebby powered. You wanted to compete with a car in the same class that was running a high winding Lambo. You might rear mount the engine make it breath backwards so you could easily plumb an exhaust that extracted (scavenged) spent gasses to the optimum and stick your carbs out in the breeze where they could get plenty of cool fresh air. next you might even try putting a mechanical wing on it up high so you could take advantage of the down force when needed and move it so it didn't make much drag when down force wasn't needed.

    Blah blah you catch my drift right?

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