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


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Well that's an all out drag car with an open down pipe. So I started looking for more 20B vids. Heres the stuff that I found that made me drool

 

 

 

 

 

 

Those should be some good examples of what a 20B can sound like.

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I think that I shall never see

a YouTube as musical, as a 20-B

 

 

Because the sound of nine plus grand

gets better the closer that you stand

 

(with thanks and apologies to Jim Downing, wherever you are)

DLY-PLM.jpg

(LOL @ BellSouth Mobility)

Somewhere my youngest brother has a chunk of the body off of this car from the 1997 October Speedfest at Sebring, signed by Jim Downing and his entire team.

:2thumbs:

 

EDIT Okay wrong car, the car in the photo is the FOUR rotor.. my brother got a piece of the three rotor car at sebring.

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yeah, rotary engines have a distinct sound.

the 20b is a sick engine.

the 4 rotor engine you're talking about is the 26b.

i've never been in the presence of a 20b or 26b.

i imagine the first time i will be it will be mine.

the z engines are still amazing though.

after i get myne restored perfectly.

i think i might do a rotary engine.

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3.5 litre rover V8, ali engine, up to 4.5 in the later models, designed by buick but sold to rover when the buick suits decided small V8's wouldn't sell, just before the 70's fuel crisis hit :P

 

Theres plenty of english racing mods to be done to the rover V8, and they're compact and light.

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3.5 litre rover V8, ali engine, up to 4.5 in the later models, designed by buick but sold to rover when the buick suits decided small V8's wouldn't sell, just before the 70's fuel crisis hit :P

 

Theres plenty of english racing mods to be done to the rover V8, and they're compact and light.

 

But they don't have an exotic sound - classic V8 wuffle - don't have a flat plane crank, don't rev to high heaven, and cost serious money to get real power out of.

 

Cheers,

Rob

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After reading the post Josh817 made (#21) in this thread:

 

http://forums.hybridz.org/showthread.php?t=133931&page=2&highlight=piston

 

I think it might be easier than I thought to find someone who can make a flat plane crank. It seems like they carve the cranks out of steel billets. I tried to find "Hank the Crank" as mentioned in the article, but I haven't found a number yet. Does anyone know if it is common practice to make custom billet cranks? Well, more importantly how difficult is it for them to change the CNC program for a flat plane setup... hmmm. I wonder. Thoughts?

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I think it might be easier than I thought to find someone who can make a flat plane crank. It seems like they carve the cranks out of steel billets. I tried to find "Hank the Crank" as mentioned in the article, but I haven't found a number yet. Does anyone know if it is common practice to make custom billet cranks? Well, more importantly how difficult is it for them to change the CNC program for a flat plane setup... hmmm. I wonder. Thoughts?

 

Its really not that hard. There are plenty of companies that would be willing to build a custom crank for you. Its big companies like Scat that don't want to do it because of the large amount of time and labor going into the design only to sell 1-10 crankshafts...

Smaller companies can make a billet crank with the same quality as the big boys and maybe even be better.

www.kingscrankshaft.com

www.customcrankshaft.net

 

 

"How hard is it to have a CNC flat plane made up?"

 

You just plug your CAM/CAD file into the CNC machine and let it go. The coming up with the design is the hard part and there are MANY decisions to be made in the crankshaft design process. A flat plane V8 crankshaft is VERY different than a standard crossplane V8 crankshaft. Much more than rotating the journals inline and hitting print on the billet sculpter machine. ;)

Some of the considerations:

 

Are you after very quick revving/race motor or longer bearing life(i.e. 100,000+ miles) and fewer refreshings?

 

Any fancy drilling to remove weight?

 

Bearing oiling designs?

 

Bearing design?

 

Journal size?(crank strength and bearing surface area.)

 

Connecting rods? some OE rods or custom ones?

 

How much stroke?

Less stroke=stronger crank, rev higher, less vibration, less stress on rods, more efficient rod/stroke ratio which means less frictional losses...

 

Counterweight design and percentage of counterbalance. (lol)

 

As you can see, there are many questions to answer and these are about .02% of them.

 

Now, If you have a finished design and take it to one of these custom crankshaft companies it will most likely be cheaper than having their engineers design the crankshaft for you. But if your not an engineer well versed in rotational harmonics and vibration then good luck! :-D

Or you can school yourself... (!!!)

 

It also helps to have some good F.E.A. programs like GTcrank (pricey) and a quick computer.

 

OTM

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Guest Still_Good

As long as I can remember I've wanted to build a high revving low displacement V8 - while I don't have a problem with displacement, I find forced induction, and making good power with limited resources much more rewarding.

 

Obviously the dinosaur technology of pushrods, with two valves per cylinder is gonna impose some limitations on how fast you can spin a motor if you don't have alot of money to spend.

 

I'd like to go with a SBF and take the stroke all the way down to 1.25" for 2098cc displacement, but to capitolize on what that would allow, I'm guessing expensive DOHC 32V heads would be required.

 

So, what I want to know is, how fast can you get away with spinning a setup while still using the OHV configuration?

 

Could I use solid roller lifters, upgraded valves and springs to eek out 10,500rpm?

 

All my experience is with the Mits 4G63, so pardon any ignorance I might be flaunting.

 

I think it'd be badass to spin a twin turbo 2L V8 to 10.5 - I've never seen anything like that on the street, and I think it'd be fun to build.

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10500 is a lot. I know Nascar runs 9,000 or so. I hear rumors of Windsor based engines hitting near 14,000 for Indy (probably with OHC heads) and Coates heads hitting about the same. I would think you would need DOHC to get those RPM's. Maybe take a Porsche 968 head and start splicing. I think the bore spacing is too big though. The Nissan V8 bore spacing is right... but then why not just use the Nissan V8... heh. 4 Cylinder heads on a small block is a better idea imho since a 4 cylinder performance car must flow more out of the box to be competitive.

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Highest I'ver ever even heard of a OHV engine going was 10k, but like Chris said, nascar does 9k.

 

You'll probably need a custom crank to get a stroke that low right? So why even start with the SBF? I love the SBF so don't take this the wrong way, but if you're going to rev past 10k you should start with an engine that's been known able to do it.

 

My only issue with this (I'd thought about doing this same thing more than a year ago, and discussed it quite a bit with rudypoochris) is that it's still going to sound like a SBF, and you're going to need parts that match those RPM:

 

Camshaft

Intake

Exhaust

Valve Angle (probably less important, but it's a factor. Maybe braap can chime in here on how much valve angle will have an overal impact on where power is made in the RPM range)

 

Either a nissan or toyota V8 would be a much better base IMO. Then you just have to worry about the fact that your 2 liter engine weights 400+ pounds and barely fits in your engine bay...

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With all else being equal, you have to have 3 more custom camshafts made for a flat plane DOHC V8...

Now is it worth the extra $750-$1000 to have the extra couple cams?

 

Maybe, maybe not...

For a boosted V8 a Ford Windsor block might be a great choice. They can withstand supposedly 700hp which is plenty and there are always many head options... just getting the valvetrain to live at high RPMs will be a challenge.

 

The good about the Nissan VH45 is that it is rather light weight for the size. The block weighs MUCH less than an L6 block. The heads are ~53 pounds each minus valve covers. If you strip it down to just the bare essentials then I bet you could have it to be a 400 pounder or even less. That isn't too bad at all.

 

You remove about 25 pounds by not having a 90 degree chankshaft...

Remove the stock VH intake and all of its emission junk- another 20 pounds saved.

build a custom thermostat housing- 3 pounds saved

build light weight thin aluminum valve covers- 5 pounds saved

smaller alternator mount-4 pounds saved

power steering delete- who knows how much....lol

 

The VH45 is a heavy beast from the factory...but there are LOTS of things that can be done to shave off lots of weight from its fat belly.

Just have to get it to go to the gym and work out a lot, lose weight, pick up a new crank and cams....and boom!

 

With the VH I think the only things to worry about are possibly new timing chain tensioners and replacing the HLA's (hydraulic lash adjusters) with solid ones so that at HIGH RPMs you don't get valve(or rocker arm) float from soft or bad HLA's.

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i dont know much about the vh45 but i would say that the 1uz would be a pretty descent candidate as well. They are 4 liters and 290hp stock with a bullet proof aluminum 6 bolt main block.

 

I agree on not going with the a sbf, unless you chose a 351c which would be awesome if you got an aluminum block/heads. I know people will run them up to 8k in the stock 4bolt main blocks, but i think they extra 2k will be hard to get.

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  • 1 month later...

So has anyone mentioned the Hayabusa V8s being built in the UK yet?

the latest version runs to somewhere up to 10500RPMs with 455hp at only 2.8L! It's about the size of your average I4 and only weighs 200lbs, leaving you plenty of room in the engine bay and a beautiful power to weight ratio.

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There's been talk about the H1V8, but I'm not sure if that's the engine you're reffering to. I wasn't sure where they're made.

 

Main issue with that motor is cost. An aftermarket crankshaft is cheap. There's not a ton of cost in the matierials, just in the machining and designing.

 

If we could either find a flat plane crank engine to work with, or find someone to machine some for us, that could be a much cheaper solution.

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