Off Topic ah but can you super charge one??

[Renrut]

To humour the original post, lets say we did want to supercharge a cento engine. Nothing is impossible so what would need to be done?

Biggest hurdles seem to be:

1) Drive to supercharger as crank pulley key is made of toffee.

2) Where to put it.


I've got an idea (and bear with me on this one) why not mount the supercharger on the front of the engine near the exhaust. You could even drive the supercharger from a turbine using exhaust gases rather than off the crank and use some of that waste energy. Problem solved, just gotta go out and find one of these special turbine superchargers :idea:

 

[cartledge_uk]

The problem - which everyone is trying to point out - is that there isn't space to stack an extra drive on the crank and even if you did the crank end can't take the load. From personal experience the end of the crank (the woodruff key) is a pretty fragile arrangement. I had to get some parts made up for mine as it disintegrated after just a couple of minutes on the dyno during the initial mapping session. Having talked to other people in the serious tuning field this is a common problem and they've all had to solve it.

A turbo might have its own set of problems but in practical terms it is easier to fit in the space available.

You can run it off the std pulley, you don't need an additional one on the front. woodruffs can be made from high tensile material. its really not that much of an issue.

 

[cartledge_uk]

I wouldnt say its easier.

oil pipes are nothing. the feed pipe is an off the shelf part that can be made up for about £15 from any place that sells hydraulic hoses

the sump just needs a drain welded in. which is just a 1inch bore tube


Imho a SC would be a lot harder as you might need to look into the crank pulley (not the crank itself as people keep saying)
then you have pulley ratios and belts.

the pipe work from charger/intercooler/tb would be more complicated then a turbo as its all close together.

Be interesting to see a supercharger on a small displacement engine.
you would never make the power of a turbo
turbos basically make use of waste energy while SCs use power working power... IIRC i remember reading that use a quite large percentage

hence why a lot of proper production SCs disconnect depending on load/rpm

Id say for what its worth and what you would get from a sc it would be easier to fit a small turbo with a huge waste gate.
you would get very low lag (my GT15 turbo had no noticeable lag but killed the engine at high rpms because the small wastegate) and free exhaust flowing at high rpms.

What are you actually talking about with pipework issues? almost every possible bend is available off the shelf. you can relocate the throttle body to where ever you want. And most of the time, you won't need an intercooler.

Having owned turbo and supercharged cars.

And having turbo'd an N/a car and supercharged an N/a car, its easier, granted it wasnt a 'cento' but the concept is the same.

But then this is an internet forum, so clearly all the people who haven't actually used a supercharger know more than me :bang:


If I had a cento at the moment, i'd supercharge one over christmas (with the two spare superchargers I have sat upstairs) just to show you all how easy it is. Maybe thats one for the future. hmm.

 

[Eklipze3k]

Feel free to come and Supercharge mine

 

[cartledge_uk]

I would like to add, as stated above by craig, you will get more power from the turbo. And there are more off the shelf items for the turbo's.

And yes roots style chargers will take more 'power' due to the drag and are also incredibly inefficient.

Twin screws and rotrex chargers on the other hand are a different story.

 

[whitz]

http://i46.tinypic.com/so4ymt.jpg

not much you can do to the end of the crank

so you would need a nice strong pulley to go onto that

Ash

 

[Brooky]

What if you milled six flats on to it? Or any number of flats and made a pulley to suit.

Or mill 3 more slots in it for woodruffs? So you have one at 3,6,9 and 12 o'clock

There's loads you could do to it if you had a milling machine and a slotting machine, and a spare crank if you have a woopsy

 

[whitz]

What if you milled six flats on to it? Or any number of flats and made a pulley to suit.

Or mill 3 more slots in it for woodruffs? So you have one at 3,6,9 and 12 o'clock

There's loads you could do to it if you had a milling machine and a slotting machine, and a spare crank if you have a woopsy

you offering ?

machining the crank for another 3 slots seems the best way imo, you could probably make them abit deeper too to give the keys more to hold on

Ash

 

[Brooky]

Nope. The slotted isn't working, missing it's drive belts

Edit: is the key a woodruff or is it just a straight key?

 

[whitz]

Nope. The slotted isn't working, missing it's drive belts

Edit: is the key a woodruff or is it just a straight key?

iirc its a straight key

i think it would be pretty hard to machine around the sides of the keys, would probably be easier to have it cast for the centre then machine it down

Ash

 

[Brooky]

Fitting an extra key/keys would be simple.
End mill down the crank. Get a machine shop to slot the pulley then make a key and fit it The standard way using Slip gauges, mic's, files/surface grinder, blue and a lump of key steel

 

[jimbro1000]

You can run it off the std pulley, you don't need an additional one on the front. woodruffs can be made from high tensile material. its really not that much of an issue.

It isn't just the key - the whole pulley goes but as you've pointed out the problem isn't that significant. Our solution was to replace bits with high tensile material parts that someone else had already made for that purpose.

I did look into this about a year ago and after some rooting around trying to get a plan together it was abandoned as a bad idea largely down to cost as I would have to replace the pistons in my engine as it is a stupidly high compression NA spec. - all of the problems I was getting have (apparently) been sorted out (I'll decide when I get the car back).

 

[craigb244]

i think everyone is thinking to much!

If i was to do it i would make the cambelt/alternator/sc pulley as one unit made from billet.

the "problem" lies in the weak thin cast alloy cambelt pulley not the crank.

there is enough "meat" on the crank end for it to work. the key is only there for location... the end of the crank is a tapper fit

 

[craigb244]

What are you actually talking about with pipework issues? almost every possible bend is available off the shelf. you can relocate the throttle body to where ever you want. And most of the time, you won't need an intercooler

I was talking about the oil feeds for a turbo... ive heard more then once people saying they like the idea of SC as they dont need oil feeds(do they need oil feeds? I would of thought something running from a crank at high speed would need oil)
but oil feed and drain is just a tiny part of fitting a turbo and maybe one of the easiest and cheapest parts

I know boost pipes can be off the shelf bends... I was just saying that if a sc was fitted at the rear of the engine and needed an intercooler it would take more pipework then a (my) turbo which is literally made from for 90degree bends

 

[Brooky]

i think everyone is thinking to much!

If i was to do it i would make the cambelt/alternator/sc pulley as one unit made from billet.

the "problem" lies in the weak thin cast alloy cambelt pulley not the crank.

there is enough "meat" on the crank end for it to work. the key is only there for location... the end of the crank is a tapper fit

Is it worth getting a batch of pulleys made?? Maybe with the option of bolting on another pulley for a s/c.

Is this problem with the pulleys only a problem when a s/c is bolted on, or will a high revving engine going to cause problems?
I don't fancy my future block snapping a belt or smashing a pulley with the internal spec it'll have. I'm looking at aftermarket pistons and sending the head off for some proper work.

 

[whitz]

Is it worth getting a batch of pulleys made?? Maybe with the option of bolting on another pulley for a s/c.

Is this problem with the pulleys only a problem when a s/c is bolted on, or will a high revving engine going to cause problems?
I don't fancy my future block snapping a belt or smashing a pulley with the internal spec it'll have. I'm looking at aftermarket pistons and sending the head off for some proper work.

if it was just the crank pulley without the alternator pulley on it would be good for the 16v engines aswell

as know 16v would be more costly if the pulley went as its an inteferance

Ash

 

[rallycinq]

We possibly come back to the 1242 crank damper debate at this point.

Cheers

D

 

[Brooky]

Craig, does your mates trofeo cinq have a different bottom pulley?

Does the 16v have the same belt pitch, as I'm sure the mpi an spi dont

 

[craigb244]

I dont think the standard pulley will fail if the crank bolt is torqued up right.

I think the problem is when people but very high loads onto the face of it which is what the alternator pulley bolts on to (the 3 small bolts)

but even this can take pretty high loads when you consider that other fiats run it fine with a much higher output alternator AND a air conditioning pump and sometimes even an pas pump!

so yeah nothing for us to worry about

 

[Brooky]

We possibly come back to the 1242 crank damper debate at this point.

Cheers

D

What about the damper?