ZR8ED Posted October 21, 2002 Share Posted October 21, 2002 Yup a Flat crank. Saw/heard an older buick regal tearing around the track (Mosport) a number of years ago. Thing sounded like some kind of impossible rotary engine... till the sight of the Buick making the noise. Heard from the guy that he had a "flat crank" and that his V8 was actually firing 2 cyl at the same time. Anyone ever heard of this? never seen or heard anything of it before or since... I have Zero other info about this engine.. zero. Was it a custom one off? talk about torque! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 21, 2002 Share Posted October 21, 2002 Talk about vibration.. Quote Link to comment Share on other sites More sharing options...
SpeedRacer Posted October 22, 2002 Share Posted October 22, 2002 I think all current Formula 1 engines are flat crank V10's. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 22, 2002 Share Posted October 22, 2002 Was this the early 3.5 lt buick v8 or a steel block one? There are a few flat plane cranks around for the ali ones, have a look at some of the dicussions about 180 degree headers. This achives the same thing. I have never been able to find a answer on if it makes more power but it seems that it might make more torque. It would be cool if someone could explain this a bit better. It seems that there must be more power in there somewhere. Why would they bother otherwise. 180 degree headers and flat plane are out lawed in lots of class' or circle track racing as well. Douglas Quote Link to comment Share on other sites More sharing options...
Guest Ian turbo240 Posted October 22, 2002 Share Posted October 22, 2002 Don't quote me on this, but I think this is how Ferrari does some of thier V8's. It is really like 2 4-cylinder engines bolted together at a 90 degree vee and sharing the same crank. If you were to take the heads off, 2 cylinders on one bank would be at TDC and the other 2 would be a BDC just like a 4-cylinder. On the other bank, all the cylinders would be at 90 degrees from top or bottom (the pistons would be halfway down or up the cylinders). This is why Ferrari V8's have such a unique sound. Ian Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 22, 2002 Share Posted October 22, 2002 The motors sound neat like that. It sounds like a pair of four poppers but just throatier, I donno. I'd imagine that they would have a vibration problem, its basically 2 large 4 cyl engines at that point and the throws sound as if power is more important than economy and urban barge smoothness. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 22, 2002 Share Posted October 22, 2002 A flat crank 10 cylinder would be a whole different animal. To reduce vibration you want a power stoke at regular intervals, say every yeah many degrees of crank shaft rotation. That is why, as one magazine put it, the V8 came off God's own drawing board. They have a nice regular beat. That is also why a V6 is a tougher engine to get smooth. A 90 degree V doesn't lend itself to a regular firing interval (unless you do like GM did and with their even fire V6 and use split journal cranks). A 60 degree V gets you closer, but is still not perfect. But my guess the reason to go with a flat crank V8 is expense. Most forged V8 cranks start out as flat cranks then get twisted into the natural alignment. This is the easier way to forge them, but has some compromises in strength. I know a few years ago the car magazines wrote many articles about no twist cranks and how they were stronger for flat out racing applications. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 22, 2002 Share Posted October 22, 2002 Thats a good point Jim. I had never thought about the strenght aspect. I wonder if that would make a flat plane crank cheeper to make. I dont care so much about the vibration, just love the sound. Douglas Quote Link to comment Share on other sites More sharing options...
spdsk8r Posted October 22, 2002 Share Posted October 22, 2002 Yup, I remember our neighbor behind us, back 30 years ago. He owned the local neighborhood garage. I remember he was in his seventies back then. He drove an old '46 Chevy pickup. He had a 327 with a flat crank, at least I think it was, it fired two cylinders at a time, I remember that for sure. He also used cut off driveshafts for tailpipes. 3" exhaust before it was cool. There wasn't a Corvette, Camaro, Mustang, or Cuda in all of Grand Rapids that could touch that old truck, and remember, GR is the home of the Berger copo Camaro's as well as many others. All I know is no one dared run against "gramps K". Quote Link to comment Share on other sites More sharing options...
Guest mongrel Posted October 23, 2002 Share Posted October 23, 2002 One of the benefits with using a 180 crank is that the headers can scavange the exhaust pulses more efficently. 3 cyl on one side fire in sync with one cyl on the other side on a regular layout, a 180 crank adresses this since its (as previously stated) works as 2 4 cyl engines. Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted October 29, 2002 Share Posted October 29, 2002 I think an advantage that I have "heard" (no facts from me right now) is that the flat crank makes the motor more "rev-able" (the faster you can turn it the more power right?). perhaps it just sounds that way. Also I know that Audi had been banned from IMSA racing in the early 90's because they where using a flat crank in thier V8 sedans.... Quote Link to comment Share on other sites More sharing options...
TimZ Posted October 29, 2002 Share Posted October 29, 2002 Ferarri does it because it make more power, not because it's cheaper. As already mentioned, the even firing pulses per bank make it easier to make efficient headers. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted November 1, 2002 Share Posted November 1, 2002 Here is a quote from the latest "racetech" mag, on the IRL chevy engine: "With the flat plane crank we could optimise the intake pulses to better effect. The engine became more receptive to subtle changes of intake and exhuast lenghts. We gained perhaps 15bhp from the switch (from 90 degree cranks)." The engine was making 660 bhp so this represents a 2.2% change. I guess a 180 degree header would do the same providing the lenghs were not to long. As much as I love the sound, It doesnt seem worth it. I am still very interested in exhuast design. I have Been through Burns Stainless, Headers Buy Ed, many of the circle track suppliers and have read the Vizard books. There is a lot of different inf. out there. Any one else know of any other sites on exhuast? Cheers Douglas Quote Link to comment Share on other sites More sharing options...
Drax240z Posted November 1, 2002 Share Posted November 1, 2002 Doug, if you want to really delve deep into the exhaust design stuff, check out "scientific design of exhaust & intake systems" by Philip H. Smith & John C. Morrison. Its quite a bit above all the other books I've come accross on the subject. (not recommened as a 'light' read however) Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted November 1, 2002 Share Posted November 1, 2002 Thanks Drax, I think I thumbed through that one in a book store a while back. It was very expensive here. Might see if they have it at amazon. Douglas Quote Link to comment Share on other sites More sharing options...
Cable Posted April 15, 2008 Share Posted April 15, 2008 Another run at the top for new comments..... Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted April 15, 2008 Administrators Share Posted April 15, 2008 This thread linked below pretty much took off and ran with the Flat crank/single plane/180 degree V-8 crank concept. http://forums.hybridz.org/showthread.php?t=122238 Quote Link to comment Share on other sites More sharing options...
evtech Posted April 20, 2008 Share Posted April 20, 2008 One of the Dad's of a Guy who races over here, got this style of crank sorted in his V8 Morgan, turning out around the 500 mark it made for a formmidable beast to chase up the hil, agree it was an 'odd' sound, but if you blinked you'd missed it:twisted: Nige Quote Link to comment Share on other sites More sharing options...
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