equinox/ torrnet crank pully size question

[will_p]

is this pulley swapable with the grand am 3400 crank pulley? i was looking at getting the mrz underdrive pulley/ alternator set which is made for the grandam /alero 3400 for my torrent but was unsure if the pulley shaft and diameter were the same or not, i dont think that the torrent has the crank sensor cage in its pulley but other than that does anyone have any idea if the pulley will fit?

thanks

will

[geoffinbc]

Don't waste your money on junk like that. The pulleys do not have a damper like the stock ones do so they are only worth their weight in scrap.

[will_p]

thanks for your opinion but the stock 3400 pulleys do not have a dampener either i have ran a fast foward performance pulley on my wifes 3400 grand am for 50000 plus miles and just put the stock one back on so sell the car, and there is no dampener

i have also and still do run a custom car grills pulley on my 2.2 ecotec sunfire for 30-40000 miles and had no problems what so ever and noticed a definate performance increase on both vehicles

so back to my original question are the 3400 pulleys on the equinox/ torrent the same basic size as far as shaft depth and diameter as the grand am/ alero 3400 or not,

thanks

will

[bszopi]

To answer your question, to the best of my knowledge, yes.

To further clarify Betterthanyou's statement, and your arguement against it, he is correct. There isn't a dampener as you typically see on a SBC or the like, but instead the dampener is integrated with the pulley itself. Hence the reason why it weighs so much, and also has a rubber isolator sandwiched inside of it.

[will_p]

unless the rubber is completly encased in the metal of the pulley itself i could swear there is no rubber on it. it has a 24x sensor ring that is pressed inside it for timing purposes and nothing else i just cleaned it up completly with some sand paper because it was rusty from sitting for so long so i could press the ring back in it,there was no rubber isolator anywhere that i could see... the heavy weight may dampen vibrations, but from the reseach ive done the 3400s are internally balanced, so is this even necessary?

i noticed no vibrations what so ever from the light weight pulley when installed on the grand am

[bszopi]

If you look at the picture below, you will notice that there are 2 different pieces of metal: The inner piece that has the 4 arms, and the outer solid pulley. If you look between the 2, there is a piece of rubber sandwiched in there. Yes, the engines are internally balanced, but there is still other forces acting on the crank. We had a decent discussion on this awhile back, but I have a meeting in 2 minutes, so I can't look for it right now. I'll look later and post what I find.

[geoffinbc]

unless the rubber is completly encased in the metal of the pulley itself i could swear there is no rubber on it. it has a 24x sensor ring that is pressed inside it for timing purposes and nothing else i just cleaned it up completly with some sand paper because it was rusty from sitting for so long so i could press the ring back in it,there was no rubber isolator anywhere that i could see... the heavy weight may dampen vibrations, but from the reseach ive done the 3400s are internally balanced, so is this even necessary?

i noticed no vibrations what so ever from the light weight pulley when installed on the grand am

Every engine that has ever left and OEM factory has a damper. Every endurance racing engine is built the same way. A damper has nothing to do with the balance of the crank or lack there of. Several hundred dollars are spent on a seemingly useless item when the best engine builders in the country build a motor. They wont slap on an OEM damper. They need even more crank protection because they are using stroker cranks and winding them to very high RPM and making big horsepower.

Imagine a crank from the end not from the side. Every crank throw that the rods are attached to stick out about 1.75" or so. Now ever time a cylinder fires the crank throw is forced down and when that happens it winds up the crank like a spring. The crank then responds by un winding in the opposite direction and it can cycle several times with just one cylinder. Now multiply this by every piston attached to the crank. If you do nothing about these vibrations you will shorten the service life of everything attached to the crank. Rod bearings, pistion pin bores, timing chain, valvetrain and oil pump and so on.

You may have not seen any damage on your wifes car but if you did a tear down and close inspection you would find signs of damage and the engine will fail in less time than one equipped with a damper. Stock power levels may not test parts to their limit so you can get away without a damper for some time. But thats all it comes down to.

[CNCguy]

Well put BTY

[pocket-rocket]

[bob442]

Yes this could and would add some minor power. But that doesnt mean its good for it. If everyone here is saying there not good for the motor, i'd bet they know what there talking about. But hey, if you wanna go for it, thats great, i'm certianly not gonna jump through your computer screen and smack it outa your hands.
If you want some Real bolt on power with out sacrifising service life, get a CAI and a TCE TB

[1QUICKHATCH]

I had a torrent on the hoist on friday and it looks like they use the same crank pully as a 3500. So you should be able to use a stock 3400 pully as an underdrive pully! think the 3500 pully is around 7" and the stock 3400 (non torrent/equinox) is around 6".

if it was me I would get a tune on it, the equonix/torrents have some decent pep to them stock!

as for the TB they look to be the same as a 3500 DBW, so it is probly a 65mm if not its bigger than 60mm.

[geoffinbc]

Doubt this guy will come back to post. He will keep going to new forums until someone tells him that not using a damper is good for his motor.

[bob442]

he was 'active' yesterday, but yout probably right. lol

[will_p]

sorry to dissapoint i guess, i dont really have anything else to say i have heard your opinions and taken them into account, i keep checking back to see what other people have said in response, still havent decided what i am going to do but thanks for the information,

that being said i have been on GAGT and j-body.org for years and not heard of anyone having shortened engine life from using aluminum pulleys i talked to a guy on j-body who actually manufactures aluminum pulleys here is what he said

An aluminum pulley will have more stress on the main bearings. There is no way around it. Most people never see any ill effects from this, and I know of no one in the 4 cylinder or v6 60 degree to ever have a crank failure from an aluminum pulley. The ecotec is a slightly different animal as well. If you plan on revving higher than stock. Hardened oil pump gears are essential, and are required. The stock crank pulley and an aluminum one will expand across the flats and can take out the oil pump gears, under high RPM use, and with a two-step. The only two aluminum pulleys I would ever put on an ecotec would be one of mine or MRZ's. Both of ours are a VERY similar design, and hold up well. With an aluminum pulley the front rubber oil seal will wear a groove into the pulley snout and cause it to leak. Normally it takes 50,000-75,000 miles. It is just something that happens, and there is no way around it. I have repaired some RKSport ones, along with a few of my old ones from 2005ish.

-mike-

so i still havent decided what im going to do, honestly here is the first time i ever heard of aluminum pulleys being bad on main bearings, i had researched them tons of other places and not heard this debate so i AM taking this new information into account,

if i hadnt heard form you guys i would have already had the pulleys odrered for the torrent, now i am debating it, still not taking the pulley of my sunfire though

[geldartb]

it's not the engines life that is shortened it's the timing components. if there isn't anything to absorb some of the shock then it's going to get transferred into the chain and gears. now i'm sure there is other stuff that will be affected.

in the end it's your motor do what you want with it.