pulleys

[northwestsupra]

ok so i know there is alot about lightweight pulleys, some people like them and others dont, well to keep this simple, i like them, now i know there main problem with the rotational weight of the crank pulley that people have a problem with. well i'm thinking of doing some CAD drawings of the pulleys and make some CNC aluminum pulleys. but i would also like to make a good crank pulley that is has a A/C removal. now my question to you would be, has anyone else made pulleys before, and if so does anyone have the dimensions of the pulleys to make my life easy :sarcasm: i was also looking at making some other things like valve covers and lower and possibly upper timing covers. tell me what you think on these ideas, cause i might just make a couple of one offs to sell.

 

[IwantMKIII]

ok so i know there is alot about lightweight pulleys, some people like them and others dont, well to keep this simple, i like them, now i know there main problem with the rotational weight of the crank pulley that people have a problem with. well i'm thinking of doing some CAD drawings of the pulleys and make some CNC aluminum pulleys. but i would also like to make a good crank pulley that is has a A/C removal. now my question to you would be, has anyone else made pulleys before, and if so does anyone have the dimensions of the pulleys to make my life easy :sarcasm: i was also looking at making some other things like valve covers and lower and possibly upper timing covers. tell me what you think on these ideas, cause i might just make a couple of one offs to sell.

yes


do some research, you can't just fuck with a harmonic balancer and expect it to work properly without some good engineering know-how :nono:

 

[Piratetip]

This would be a good place to start learning.
http://www.supramania.com/forums/showthread.php?t=63213&highlight=anodized
http://www.supramania.com/forums/showthread.php?t=44732&highlight=anodized

 

[Dan_Gyoba]

I suppose that if you are going to live with the consequences of it being just a pulley, and NOT a harmonic balancer, then just the diameter is going to be enough.

You say that you like the lightweight pulleys, which tells me that you're willing to suffer the consequences of removing the harmonic balancer in favor of the lower rotating mass. I guess you can put both me and IwantMKIII in the same camp of disliking the idea. As such, you can also put me in the column of not wanting one.

Valve covers? Sure. I'd like some nice shiney aluminium valve covers. Upper timing cover? Sure, sounds good. I'll leave my harmonic balancer alone though, thank you.

 

[northwestsupra]

yup and thats what i had a feeling of, and thats why id almost rather make just a alternator pulley and water pump, and maby forget the idea of the crank, but as for the crank yes, getting the harmonic balance just right would be a pain in the ass, but its been done, i mean im pretty sure upgraded supra has done this and gotten away with it.. and as for the upper and lower covers the upper cover i would have about 2 inches taken off the top for the visibility of ADJ. Cam gears. and as for the lower it wouldnt have the little groves in it. the valve covers i would probably make them look sharp edged but race like

 

[selfinfliction]

the valve covers i would probably make them look sharp edged but race like

these look pretty good, (except they are shinier now than in the pic) they're stock, polished with the grooves ground off of them. don't think i would go through the trouble of fabbing up custom valve covers when the stock ones can look this good with some work.

 

[bgrieger]

You could just wait for a set of unorthodox pulleys to come up on ebay. Match with an ATI crank pulley and you get the light weight, the bling, and a proper balancer...of course, you may have to wait a while for the accessory pullies to come up in the color you want.

 

[suprawalt]

I suppose that if you are going to live with the consequences of it being just a pulley, and NOT a harmonic balancer, then just the diameter is going to be enough.

You say that you like the lightweight pulleys, which tells me that you're willing to suffer the consequences of removing the harmonic balancer in favor of the lower rotating mass. I guess you can put both me and IwantMKIII in the same camp of disliking the idea. As such, you can also put me in the column of not wanting one.

Valve covers? Sure. I'd like some nice shiney aluminium valve covers. Upper timing cover? Sure, sounds good. I'll leave my harmonic balancer alone though, thank you.

why dont people like aluminum pulleys?because i just got one because i thought it was a good idea but maybe not.

 

[supraslo]

the guy that use to make all of my pulleys done them the old fashioned way and wittled them out of a hunk of aluminum on a laythe. I may be able to see if he still has the dimensions wrote down somewhere but i doubt it

 

[northwestsupra]

ok so i have done 2 cad drawings so far of just the P/S pulley, they are the stock 150mm, but again CNC aluminum. so they will be lighter, just seeing what style would be liked

 

[northwestsupra]

now this one i thought looked pretty cool, but as for strength wise not sure how it would do. but as for weight it would be the best

 

[IwantMKIII]

^it would work depending on material and how its cast or if its machined, how the original material is made.

material properties is everything if you have a targeted design set

 

[Dan_Gyoba]

Hmmm...

Of those two, I like the lower (4 hole) better. But maybe something in between? 6 hole I think might look better.

@suprawalt: I don't have anything against Al pulleys for the accessories, in fact I like that idea. It's the harmonic balancer that I'm leery of replacing. It is the size and mass that it is for a reason, and I'll take the long-term reliability over a small gain in power any day. That's my choice. If I were racing where a couple of HP could make the difference between winning and losing, and I could afford to tear down my engine at least once a year, that'd be one thing. But that's not the case. I want my car to be reliable, and hopefully less expensive to maintain.

 

[Dutch7m]

so just to say it short:

a ballanced undampened lightweight crank pully (like the unorthodox one),
is that a do or a don't?

 

[Poodles]

don't

NWSupra: that last pic is nice, but you'll induce stress at the points unless you curve them. Cracks = bad

 

[northwestsupra]

wow guys thanks for all the advice and ideas. i just started working on the draw up of the 115mm Water pump pulley, simple, almost exactly like stock but with some cut out sections just for that like .2 less grams :evil2: but i also think i may have made it to big, i have to remeasure once again

 

[IwantMKIII]

don't

NWSupra: that last pic is nice, but you'll induce stress at the points unless you curve them. Cracks = bad

completely lost at what you're getting at here....like i said, if you have a design the rest of it is on material properties

 

[kaz87supra]

why make them the stock size?

make the accessory pullies oversized to underdrive, that way you dont have to run a smaller crank pully. thats where a real gains would come from.

 

[northwestsupra]

i guess i dont understand the differnce or point of a underdrive pulley, and what it does. i understand the meterials used and the point of them being lighter. i do understand that if it is smaller that it will spin faster meaning you can get a little more out of what ever pulley it is, but if it bigger the pulley will take longer to make a full rotation meaning that you will loose efficiency out of whatever it is that your making the pulley for. but how does making it smaller give more power?

 

[kaz87supra]

you underdrive the acessories on the engine to free up horsepower.

like you said a larger pully will spin, the alternator for example, slower. the larger pully also gives the crankshaft more leverage to turn the alternator, so it has more tq availible, meaning it needs less hp from the crank to turn it, plus it turns it slower... and it requires less hp to turn something slow than it does fast because of the friction in the bearings and the energy required to spin a givin mass at a givin speed.

think of it kinda like this, a free running engine with no load. closed throttle and running on the idle circuit is using very little engergy(air/fuel) and to raise the rpm of that engine you must give the engine more energy(air/fuel) to spin faster. so spinning slower is less energy and hp being used to spin that alternator.


now the draw back of spinning it slower is at idle you will notice your headlights dim because the voltage will drop off, or you will notice the steering will be slightly stiffer driving around parking lots, and I wouldnt underdrive the waterpump, just bc i like to let the engine have all chances of staying cool.
the only ill effects you will notice are at idle, once you ar revved say above 2000rpm everything will fuction normal. and as an added plus, all ur accessroies will last longer bc you are not spinning them as fast.

its 2am im off to bed

Adam