3K Cross Plane Crankshaft

[love ke70]

Ill sell you my statesman for 4000, you can then keep the other 500 and buy yourself a great night on the town. And your life will probably be better than going through the trauma of why you spent 4500 on a crankshaft alone for an underpowered shit heap corolla engine ;)

 

You have to put these costs into perspective, it makes no sense

[ke70dave]

I have been doing some research on this cross plane crankshaft, and its alot cooler than i originally thought....

 

http://www.ashonbikes.com/cross-plane_crank

 

Howeever it seems you would also need a custom made camshaft to get the valves to open at the same time, how much does that cost?

[philbey]

Camshaft is easy enough to get made up, but they will have to grind from a blank, couldn't use a factory one. They just need to know how to index each lobe when they set it up in the grinder. Will still cost a bomb.

 

I'm interested why one would bother with this in a car though. Bikes are hard coupled (ignoring cush drives) from the gearbox to the single driving wheel, so they are susceptible to torque pulses breaking traction.

 

Bikes revving at 12000rpm will also get much higher pulse forces than a 7000rpm car, although this is offset by likely lighter pistons. (Incidentally, the link above has completely miscalculated crank torque due to piston speed)

 

A car with even traction to both driving wheels means that the force of each pulse is HALVED at each wheel. Plus friction is a function of mass, so your car being heavier will have a higher friction force to overcome anyway.

 

In other words, why put all the effort in using a cross plane crank to improve traction when you would be better off spending it on diff and suspension mods to acheive the same thing.

[ke70dave]

oh yeah, when you look at how much it costs to retro fit its not worth it.

 

But if you ignore that its pretty damn cool :P

[GJM85]

I think if it was gonna be beneficial someone in the car industry would be using it.

 

 

[snot35]

Except production costs are likely a lot higher than a flat plane crank, for minimal benefit to the general public. Sport bikes are quite a different market.

[KO 10]

The cam isn't to hard find some one who grinds from blanks it's the same for anyone wanting a custom race cam no need for big budget stuff but the crank will need to be custom made there's no worry about the counter weights they just work the same the tricky parts the distributer when I was working out the points positions I found the only way is with a V8 electronic dizzy grinding off the lugs leaving 0 ,270,180,45 if there's real interest ill post the timing positions and cam degrees

Ps

for anyone thinking the K motors a pice of shit well let's look at from my point of View there cheep simple and can have a lot of mods without big dollars and no need for engineering the K motors a good platform for this build there used in everything ,road, hill climb,open wheel ,rally,there's even a thread with one in a side car so power isn't an issue it's the application that is

PPS

I still think this needs to be done to a 4AGE for no other reason other than every thing else has been done

[KO 10]

I've mixed up my cam angles there a bit : (

[skuttle87]

The issue (and speaking just for myself) is not a case of a smoother torque curve or any of the gains that my bike attains from such a crank, but purely the sound and originality that would come from such a feat...

I dig this forum and power to KO 10 for an idea that's tickled my fancy since hearing a crossy for the first time, I see the reasoning behind the for and against opinions.

Perhaps a 4age would be the better option, It's just I have a few K's laying around, and money isn't a huge concern...

While this is all hypothetical at the moment, you all can't deny (as much as you all see the 'why would you bother factor') that this wouldn't be awesome, especially being that as far as I'm aware the first Crossy 4 banger car engine, in of all things, an early Rolla...?

[love ke70]

Id still rather see you spend the money and put a thousand horsepower through it while retaining handling capabilities and track it. the cost would be similar me thinks...

[skuttle87]

If it was about costs and achieving ridiculous HP, a 2J or 1U would be the topic of discussion.

Or would you rather see someone have a go at something that hasn't been done yet...?

[love ke70]

not if it is really just a waste of resources ;)

[KO 10]

not if it is really just a waste of resources ;)

Well close your eyes and play with your push rod v8

Simple !!

[love ke70]

As opposed to your push rod I4?

Very astute of you, but the only pushrod V8 I own is in my stateman and it needs no playing, just abusing. and you would not have known about that unless you really did some research.

as you will find in my signature I have a project which uses no pushrods.

and my pushrod powered diesel will likely make more HP/L than your crossplane 3K, because I invest my resources in appropriate ways instead of contemplating cutting and shutting a crank...

 

so please, carry on, but understand that not everyone will wet themselves with excitement about an idea that is likely to yield large financial and time losses and result in no more HP than the original crank and a possible power delivery improvement in a vehicle that will likely never be driven so close to the edge that it will have a marked difference.

 

but please, do go on...

[---Pimp-My-Rolla---]

Yo Love ke70,

 

Chill out mate, they are just engines!!

 

Peace :)