Pulleys interchangeable?

[Swing]

Are crankshaft pulley's interchangeable between all Yaris engines? I'm guessing that they use the same bolt and spacing to go onto the crankshaft, whether you have the 1.0 or even the 1.5.

For the 1.5 there are nice lightweight versions, which could be interesting but I don't have a 1.5 engine. If they are interchangeable they could be used.
I would like to have a lightweight pulley that also does underdrive, I think 10% is acceptable. I found something about NST underdrive pulleys but they are no longer supplied?

So, can I use pulleys from all Yaris engines (also newer models), and perhaps more Toyota engines?
For older and newer Toyota performance engines (from 4A-GE to 2ZZ) you can find all kinds of lightweight pulley sets. Do they all use the same bolt to bolt onto the crankshaft? Then it is only the size and belt width that is left, to compare.

Same questions go for the alternator and waterpump, they are probably very similar amongst all vvti engines?

[cali yaris]

Most of those pulleys you mention will not fit the Yaris.
Any two-belt pulley (1st gen Yaris/Echo, xB, xA) will not work either.

Our lightweight 1NZ pulley is lighter than an underdrive but keeps the original size. Best of both worlds and always in stock. I believe it will fit your 1.0 but I'm not 100% sure.

[Swing]

I would assume it fits, but that's the answer I'm looking for.

But I'm also looking for the underdrive to be honest. Lightweight is always good at the crank, but I'm looking for underdrive to save more power. As you might have guessed by now, I want to change a Yaris to be more fuel efficient. I have several plans, but I think a pulley that does underdrive and is lightweight would be the best. You say best of both worlds because you want to keep original cooling capacity I guess? That makes sense. I use my MR2 on the track and I wouldn't want underdrive. But seeing a stock Toyota always perform well on the track with original cooling, I know a 10% or more underdrive can be save on a Yaris that never visits the track and never goes to the desert.

Do you know if the pulleys for the waterpump and alternator are the same?

I could also fit bigger pulleys on the alternator and waterpump, to underdrive the waterpump at least.

Right now I have the 1.0, but might hop over to the 1.3 version later. The 1.3 is probably more suitable for a small hypermiling project.

[CTScott]

The European EPC shows different part numbers for the crank pulley for the 1NZ versus the 1SZ and 2SZ (which share the same part number).

[cali yaris]

But I'm also looking for the underdrive to be honest. Lightweight is always good at the crank, but I'm looking for underdrive to save more power.

The only reason to use an underdrive is to save weight. My pulley is lighter than NST's underdrive, but stock size. :smile:
Also, read up on here about NST pulleys breaking and their lack of customer service following such failures.

[cali yaris]

http://www.yarisworld.com/forums/showthread.php

and this famous one of course:

http://farm5.staticflickr.com/4131/5002413491_09afa34551_z.jpg

[Swing]

I think the above link is not complete?

The European EPC shows different part numbers for the crank pulley for the 1NZ versus the 1SZ and 2SZ (which share the same part number).

Yes I would expect different part numbers, I guess al that is important if the bolt is the same, and of course the belt width and number of groves.

The only reason to use an underdrive is to save weight. My pulley is lighter than NST's underdrive, but stock size. :smile:
Also, read up on here about NST pulleys breaking and their lack of customer service following such failures.

Why is that the only reason? 10% underdrive means (at least for the water pump) 10% less power needed. (and of course, also 10% less cooling power).
I read about the NST and poor customer service etc.

You are right from the weight point of view, but I also want it to use less power. So lightweight + underdrive is better it seems to me.

[WeeYari]

10% underdrive means (at least for the water pump) 10% less power needed. (and of course, also 10% less cooling power).


If only that were true.

It is not really a matter of consuming less power. The light weight achieves that. Going 10% underdrive was a way of making the pulley lighter still, while still providing enough rotation to drive a/c, alt, and water pump.

[CTScott]

I think the above link is not complete?



Yes I would expect different part numbers, I guess al that is important if the bolt is the same, and of course the belt width and number of groves.



Why is that the only reason? 10% underdrive means (at least for the water pump) 10% less power needed. (and of course, also 10% less cooling power).
I read about the NST and poor customer service etc.

You are right from the weight point of view, but I also want it to use less power. So lightweight + underdrive is better it seems to me.



The bolts have different part numbers as well.

[Swing]

Ok thanks. Could be because of simply different width of the pulley and length of the bolts,.

If only that were true.

It is not really a matter of consuming less power. The light weight achieves that. Going 10% underdrive was a way of making the pulley lighter still, while still providing enough rotation to drive a/c, alt, and water pump.

But if it's 10% smaller then it's like a 10% smaller gear. It means that for every revolution of the engine, the waterpump will drive 10% less, costing 10% less energy. The alternator is a different story, I guess the same for a/c if you have it. The alternator will have a certain load to generate a certain amount of current, so that will always be the same amount of resistance.

So why wouldn't underdriving work? Of course I could also put a bigger pulley on the waterpump (might be easier to find) to have the same effect.

Of course, the lightweight idea is straightforward and clear.

[CTScott]

Ok thanks. Could be because of simply different width of the pulley and length of the bolts,.




It could be that or it could be that they are different diameter bolts. Unfortunately I don't have enough detail on them to be able to tell. You could go you your local parts department and have them pull the three different MK1 Yaris crank pulley bolts to see the difference. Over here we just get the 1NZ, so we don't have access to the others.

[echo-francis]

I think its just a question of accessory driven by the belt because on my 2005 toyota echo I use a Lightweight Crank Pulley for the yaris because I have removed my power steering. maybe it is different for the 1.0 or the 1.3 I dont know?

[DJYojimbo]

micromimageoline light weight oem pulley is the best! I've had mine on for more than a year now and still working great as ever!

[Swing]

Thanks again for the input.

I guess that if I will step over from my 1.0 to a 1.3 engine, it will be easier. Since the 1.3 in the EU seems to be the 2NZ-FE, just a smaller version of the 1.5 1NZ-FE everybody has in his Yaris TS. Difference should only be the stroke. Of course, all extra parts on and around the engine might be different, but I'm guessing it will be possible to just fit the lightweight pulley.

Edit: hmm, maybe the European Yaris 1.3 has 2SZ-FE instead of 2NZ-FE.

[cali yaris]

It means that for every revolution of the engine, the waterpump will drive 10% less, costing 10% less energy.

I'm sorry to correct you, but that is just not the math of how an engine works.

10% smaller crank pulley diameter does not equal 10% less "energy" usage. It's an insignificant change (really!) to the overall function of the motor, in terms of what the water pump draws from the system.

[Swing]

Can you be more specific? Perhaps I was not clear. I meant that the waterpump will then draw 10% less power since its driving 10% slower. I'm not expecting a 10% profit overall, since powering the waterpump is only a very small portion of energy, compared to driving the car forward.
So I just meaning 10% less energy uses by the waterpump, not in total.

But I agree that it's probably not worth it when you can buy a normal size pulley that is lightweight. I'm expecting that the weight loss of that pulley makes a much larger difference on mpg, than the underdriving.

[cali yaris]

I meant that the waterpump will then draw 10% less power since its driving 10% slower.

I'm not sure what you mean but "draw less power". In any case, I really doubt that it's a 1:1 ratio as you suggest.

The power requirement that is reduced is only the parasitic drag on the pulley from the pumping of water. I doubt it's even measurable with any tools we might have. It certainly will not make a difference in horsepower or mileage.