Supercharging my diesel motorbike!

[alexanderfitu]

Hi all

Nlot sure if this is the right place, so sorry if it needs moving

Im looking to supercharge my Diesel motorbike engine( a 1 cylinder 406cc 4 stroke diesel).

I have bought an amr500 supercharger which apparently makes approx 14psi boost at 1:1 drive ratio on a 500cc.

I am looking to produce around 5-7psi boost.

According to some calculations, I think I need to underdrive it by 0.61:1 crank ratio.

I used this site to calculate this:

http://victorylibrary.com/supercharger/super.htm

Can anybody confirm?

Also, If I am correct so far, where do I get drive pulleys from, it appears that its very hard to find one site that sells a variety of pulleys sizes!

Many thanks for everybody's help

[Michael]

Hi and welcome to SCH.

Your project sounds incredibly interesting... and quite unique. A diesel motorcycle?!? I'll admit I'm not a motorcycle expert, but I've never heard of a diesel engine-powered motorcycle. And one that's only 400cc in size?!? That's TINY!!! Post pictures if you can... I want to see this!

As for the supercharger, I've never heard of an AMR500 supercharger. Who is the manufacturer?

Pulley sizes are difficult to find for even some of the most popular superchargers, let alone a supercharger that isn't very well known. In your case, you may need to have a custom made pulley to suit your purposes.

[alexanderfitu]

heh, yea its pretty unusual, there is a whole community of us over at dieselbike.net

some really crazy/wacky combinations, mine is a an old honda with a industrial diesel

looking something like:

http://www.suckindiesel.com/thingy/d...=735&mode=view

apparently its an Aisin used on small nissans in japan and america. This is all I can find specs wise:

http://superchargersunlimited.com/specs.html

A custom pulley shouldn't be a problem, just finding somewhere to make them!

[Michael]

I had no idea that such a sub-culture existed! Increcible! I never thought I'd see the day when diesel engines would make their way onto motorcycles...

That Aisin supercharger is very cool too. It's TINY in comparison to what we're used to seeing in automotive applications. Funny... I just bought a 2011 Chevy Cruze Eco. It's got a 1.4l, and if it wasn't turbocharged, I'd be looking into something like this Aisin supercharger as a means of building some nice power.

As for the pulley, any competent machine shop could easily machine one for you. If you aren't in a big hurry for it you can swing a deal with the shop owner to make you one in his spare time. The best thing you could do would be to take him one you already have so he can use it as a template. Otherwise, you may need to leave the supercharger with him so he can test fit the pulley to the blower.

[alexanderfitu]

Yeah its pretty cool, in the UK (where im from) Diesel cars outsold petrol cars over the last couple of years due to the stupid fuel cost ( 7+ dollars per gallon for diesel + gasoline in the uk)

So it gives me great pleasure just riding around un used veg oil for free! (plus I get 150+ mpg)

It would be nice to coax some more power of the engine hence the supercharger, this one appeared to be the best size for this engine type, impossible to find though!

Even a little bit of boost will clear up some smoke as well.

Just a) I have no idea if my ratio is correct, any thoughts? Im looking for 4-5psi, up to around 7 psi if all goes well. Problem is, its running a 21:1 CR!

If I run a 3inch pulley from the crank shaft, what size would you recommended for getting 4-5 psi boost?

Hopefully my calculations are in the ball park figure.

There is a guy who helped me with my taper lock busing who could probably machine some pulleys up for me :)

Many thanks

[vinces427bb]

if you have a 3" crank pulley and need to it to underdrive the sc @ 61% then you would multiply the 3" by 1.39 = 4.17" pulley size for the sc-ratio you asked for.
since this SC will only compress the air, i'm wondering how you will enrich the fuel delivery for the proper mixture when the boost pressure rises??
larger or extra injector or increased fuel pressure referenced to the boost?

[alexanderfitu]

Ah , I was told that the diesel would make less boost so I should run it 1:1. Any issues with that? It would be easier as well.

With regards to the fuel, it runs a governer with a fuel stop, I can adjust this to overfuel up to 100% more and seing as the sc should always produce boost (and it's a diesel) it shouldn't matter if I over or under fuel that much. Thanks for your help