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Exotic "SOUNDING", high revving V8! Read "ENTIRE" thread before posting!!!


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So whats the chance of finding a flat-plane crankshaft, for an SBC/SBF? That and a custom grind bumpstick and EMS should work. I did a search on Google and read this on Wikipedia

 

"In 1992, Audi left the German DTM racing series after a controversy around the crankshaft design of their V8-powered race cars. After using the road car's cross-plane 90°-crankshaft for several years, they switched to a flat-plane 180° version which they claimed was made by "twisting" a stock part. The scrutineers decided that this would stretch the rules too far."

 

So technically you could make your own out of a Dual plane crank?

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  well, we all know there needs to be custom thing to do, but to me this is the closest thing to a Flat plane I could ever get, plus I don't intend to reve this thing past 6K I just want t

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I seem to recall that a couple Nascar teams played with single plane cranks in the mid 90’s. I haven’t heard of or know of any other forms of Motorsports where people were playing with flat cranks in domestic V-8’s. I’m sure there has to be and as such, those used take out cranks have to be floating around somewhere and be still more than capable to run in a mild to moderate street application.

 

Personally, I have been wanting to build one of these flat crank V-8’s for myself and every once in a while over the past 10 years or so, I’ll do a search for "take out" 180 degree cranks for SBC or SBF, (not picky, I’ll take one for either in ANY stroke). The idea of a domestic 16 valve engine with that sweet crisp exhaust note under the hood of Z car is quite alluring. From what I understand, Bryant built a few and they are floating around, though I have yet to see a used one up for sale.

 

You can always have one manufactured from one of the major aftermarket crank manufactures such as Cola, Bryant, Callies, or other high end crank manufacture that produce billet cranks, (not Eagle or Scat). In going that route, prepare to spend lots of money for that custom billet exhaust note…

 

I have also thought about a forging. Some of the lower cost aftermarket forged cranks are a “twist” forging. They come out of the forging die as a single plane crank, then they are twisted while still hot so the crank pins end up at 90 degrees. I’m not sure that the crank pin config of the non twist forgings are in an acceptable arrangement though. Those cranks come out of the forging dies in the pin config circled in BLUE below. All the 180 degree cranks I have seen have the crank pins in the drawing circled in GREEN, (same as the inline 4 cylinder cranks.) My guess for the specific crank pin arrangement in a 4 cylinder and 180 degree V-8 crank is to mirror the fore and aft crank pins to each other in an effort to reduce couple induced vibrations. That is my hypothetical guess any how.

 

All the major cam manufactures can grind a cam to match the revised firing order for just a little more than an off the shelf cam. Spark plugs wires are easy to swap around, but of course, we would use EFI and DIS right?

 

I’d gladly trade my Eaton M-112 Super-charger straight across for a single plane domestic crank…

 

CrankpinsCustom.jpg

 

 

Then top it off with one of these intakes…

 

350CHEVYfront.jpg

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finished single plane crank also exist in the configuration circled in blue. See attachment. The pic is narrow cuz the attachment size limit is 19.3Kb

 

The crank configured in green needs two small counterweights in the middle to prevent the crank from bowing toward the 3456 direction. The crank in blue configuration does not require the two small counter weights since the adjacent journals are on opposite sides.

flatplanecrank_thumb.JPG

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After reading that I wonder if you could use a single plane for a I6? Like instead of 1,6-2,5-3,4 make it 1,2,3-4,5,6 or something of the like. Sorry if thats a stupid question.

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You probably could... I don't think you would want to. I was under the impression that the crank ideally should not have the firing order travel down or up the engine block. This twisting of the crank is not good. Might be able to retain a satisfactory firing order with a 180 degree crank, but it might run rough even after it is all figured out. I would be interested if someone who knows alot of this stuff could chime in.

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the I6 already has evenly spaced exhaust pulses as is. The main goal for using single plane crank in V8 is to get exhaust pulses evenly from each bank :

 

left

right

left

right

left

right

left

right

 

With cross plane crank, there are consecutive pulses from each bank (left,left and right,right), that gives a rougher/wilder/impure sound.

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I was doing a little digging on the internet for domestic flat plane cranks and I came across this:

http://www.ferraris-online.com/pages/carintro.php?reqcardir=LL-332-BLANK

 

A lola 332 with a flat plane SBC in it. I can't even imagine how fast this thing must be. Here is a picture of the 180 deg. crank used in this car. This crank is apparently made by Crower.

P032Web.jpg

 

Amazing. He says he only has a bit over $30,000 invested in engine parts.

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"Horsepower should be in the 550 hp range with a useable rev range of 5500–9500 rpm."

 

Wow, never heard of a OHV standing revs that high.

 

Interesting. I wonder how high NASCAR engines rev. Granted they are on 98 octane at 12.5:1... but they do make up to 150hp/liter. That would indicate revs of atleast 9,000... I would think any way.

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