Supercharger from SLK

[alexanderfoti]

Hi all.

Im sitting here, looking at the impposible to find amr300 supercharger, thinking would a slk supercharger:

http://www.ebay.co.uk/itm/Mercedes-slk- ... 3a6ac2242b

or even better a bmw mini supercharger (1600cc)

http://www.ebay.co.uk/itm/Mini-Mini-Coo ... 2a10e37d2f

work with a 406 yanclome. Im thinking if its underdriven by approx 3.93:1 it should work no? (1600/3.94 per rotation = 406.09

Does anybody else think that will work?

[alexanderfoti]

As I am an ejit, it appears as though the supercharger calculations are a lot more complicated:

http://www.ehow.com/how_7953457_size-cu ... arger.html

I will some calculations and post em up here.

[alexanderfoti]

Right, some numbers:

the 186 has an air flow range of 21.5cfm to 26cfm across its usable rev range.

The pressure ratio is apprx 1.4:1 and the adjusted cfm is:

30.1cfm or 0.014m3/s @ 3000rpm

and

36.12cfm or 0.016m3/s @3600rpm.

Now, any ideas where I can find a supercharge with this low a flow!

[nanno]

The mini-cooper supercharger is quite often used on all sorts of blown motorcycles, e.g. on Kawa Z1000s, but they tend to spin it with more than engine speed. Considering that, you either have to knock up some really wicked transmission (i.e. 4-times engine speed) to be in the effective range, BUT (and now comes the good part) people are complaining, that they tend to overspin the supercharger.

Sorry, that I can't be any more specific. Theoretically with the correct pulleys, it should be possible to adjust the boost to what you need.

Hope this is of any help to you.

Cheers,
Greg

[alexanderfoti]

No worries.

Having a look at most of the compressor map, the only worry I have is that I wont be able to spin the supercharger fast enough to build any boost. There will defo be enough flow!

Im sure I can pick one up somwhere and have a play with it, should be able to knock up some sort of boost

[nanno]

Any boost is better than none, I suppose

Cheers,
Greg

[alexanderfoti]

Defo!

Consdering a 186 engine, what would be the best way to drive it, bolt a pulley to the center of the flywheel side and run it of there with a belt, or convert it to chain drive and drive it off the primary drive?

[pietenpol2002]

Here's an option below. Quite capable of providing all the boost the little 186 could handle. But you'd better start saving your pennies.

http://www.hscsupercharger.com/

Do the calculations on this page and you'll see the Yanmar clones fall well within the range.

http://www.hscsupercharger.com/faq1.html

BTW, how many pounds of boost are you planning.

[nanno]

I'd do it with a belt from the flywheel side, because on the gas-guzzling bikes, it's always a problem of putting too much load on a single bearing, i.e. if you run the alternator, clutch and blower all from the same side, because it will overload the bearing on cylinder No. 4.

Actually, if done right, I suppose, that the bearings will last longer, because you have (more or less) equal strain on both sides of the crank.

Cheers,
Greg

[alexanderfoti]

Here's an option below. Quite capable of providing all the boost the little 186 could handle. But you'd better start saving your pennies.

http://www.hscsupercharger.com/

Do the calculations on this page and you'll see the Yanmar clones fall well within the range.

http://www.hscsupercharger.com/faq1.html

BTW, how many pounds of boost are you planning.

Ohh now that is pricey! Is there a downside to using an oversized supercharger (other than extra load on the engine?)

I was planning to use about 7psi which should bring me up to 15bhp.

http://www.ebay.co.uk/itm/AMR500-Superc ... 356wt_1396

That would be prefect, but how would I get the intake to supercharger and supercharger to engine intake made?

[alexanderfoti]

Heres the same, but with the manifolds, and much better priced!

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 063wt_1396

Its in australia, but I have Family members there who could forward it on if need be.

[alexanderfoti]

I'd do it with a belt from the flywheel side, because on the gas-guzzling bikes, it's always a problem of putting too much load on a single bearing, i.e. if you run the alternator, clutch and blower all from the same side, because it will overload the bearing on cylinder No. 4.

Actually, if done right, I suppose, that the bearings will last longer, because you have (more or less) equal strain on both sides of the crank.

Cheers,
Greg

Sounds like what I would do anyway to the space available etc.

Right, I can really see this coming together in my head now, the only thing I need to think of is how to attach a pulley to the flywheel. Could I weld a pulley onto a metal collar, then weld this onto the flywheel, or is it a no no?

[alexanderfoti]

Looking at the flywheel of the 186, it has 4 threaded holes in the center:



I could screw 4 standofs into the threaded holes, then attach the pulley to that somehow, should give me the clearance needed at least.

[nanno]

Sounds reasonable (and doable) to me... One might also expect, that those 4 holes are properly centered. (No further balancing necessary)

Cheers,
Greg

[alexanderfoti]

Coo, the only thing Im getting stuck on is now finding the pulleys and sizing them. On ebay it states:

On a 500cc four stroke, with the blower being driven 1:1 times crank speed,
it would produce approximately 14 psi boost.

now im looking to make 7psi boost. So im assuming I need to drive it 1:2

Ie, one crank revolution, half supercharger revolution.

So assuming a 3 inch crank pulley, I would need a 6inch supercharger pulley.

If not, can anybody assist in the calculations.

Also, where the ell do I get the pulleys, they seem impossible to find on the internet!

[pietenpol2002]

One might also expect, that those 4 holes are properly centered

Please note that those 4 holes are indeed the same distance from the center, however they are not equally spaced on the radius. The pull start coupler that utilizes those 4 mounting holes could be used as a reference I suppose if you were planning on mounting some other coupler.

[nanno]

I'd still drive it 1:1 because thinking of my XT500 the Diesel will make about half the revs, i.e. 3500rpm there being about the middle of the range.

So if it does 14psi at 1:1 on a gasoline engine, it will do about 7psi on a diesel...

Cheers,
Greg