Lightweight Underdrive pulley's

.Cortez

94' LS
So a great friend of myin has donated some AEM lightweight Pully's to me. (He's a very good friend haha) Now I was told their nice to have, and I know they look flashy, but I'm also told it can throw off my crank balance and blow my engine. So what do I do here? If this is true, I'm going to weight till I buy my rods, cams and camshaft and stuff for my turbo build, but if I can throw them in now I will.
Thanks, Learning!
 

Rich-PMS

New Member
I ran an underdrive pulley on my 390zx for 20k miles
I've go one waiting for me to install onto my dodge Dakota 5.2 :)

and I will eventually get one for the integra.
 

mirrorimg

Well-Known Member
Replacing the actual crank pulley for a lighter one isnt always the best. I have one in my garage that I decided not to use. The OEM pulley has a rubber insert in it acting as a harmonic balancer, dissipating any unwanted vibrations. It is also balanced, as the aftermarket ones may not be.

If you want to go aftermarket, there is Fluidampr, but thats going to run you a couple hundred dollars.

You could also do a PS/AC delete, and grind away the channels on the pulley, making it lighter, while retaining the harmonic dampening effect.
 


671GSR

New Member
i have full under drive pulleys crank too unorthodox pulleys never harmed me yet but am change out soon needs a new rubber damper
 

mirrorimg

Well-Known Member
If they look like this:

UNDERDRIVE PULLEY SET Ensures more miles from each gallon plus less stress on car's accessories Premium lightweight 6061-T6 billet aluminum computer machined to .001 tolerances Set includes alternator and power steering pulleys
Click to expand...
Then they are lighter pulleys for the P/S and alternator or A/C pumps, to replace their pulleys.

This is what a crank pulley looks like.

What a CTR crank pulley looks like

And what a Fluidampr pulley looks like
 

Adara

Banned
Do you now if they will fit also in the GA16DS engine? I presume they (DE and DS) use the same pulleys, not sure... And what about the other pulleys like from the alternator, will you have them too?
 

.Cortez

94' LS
Yes Mirror, and thank you! Thats exactly what they are. But is it true that by installing these I will mess up my crank balance? The man that has told me this has built b18b1 engines before, and just recently finished his latest twenty some psi b1 build, and I trust him, but I figured I'd like to know for certain.

If this is true, I'm just throwing them in the closet till I get my rods, cams, cranks, etc to finish the build then doing EVERYTHING at once.
 

mirrorimg

Well-Known Member
These will have no effect on how the crank rotates. It simply removes some of the weight of the old pulleys (and in theory) takes less effort to turn, freeing up some power. You will be safe to use them.
 
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