Timing belt pulley upgrade

[avguy]

... I know that the plastic pulleys fail way under the 100k km, ....

Wow, thanks I wasn't aware of that. So we must be driving around in 2 time bombs ready to explode. I'm going out right now and replace both of the plastic pulleys I installed in our Aveos with those metal ones that the OP of this thread said never fail!

[Prozack]

I've been kicking around an idea for awhile to make pulleys from aluminum. I'm a machinist and have access to cnc lathes. I've been thinking about turning some out and using my car as a ginea pig. I feel aluminum would work much better than steel, with it being much lighter and better heat dissipation properties. Right now it's just an idea tho. I have my old plastic pulleys in the shop to use for measurements.

[EyeintheSky]

What kind of cost would it be for one I would definitely be interested in one maybe even 2 since already looking into buying another Aveo.

[Prozack]

Not sure I haven't calculated the total cost. Right now it's just on the drawing board.

[06T200]

I've been kicking around an idea for awhile to make pulleys from aluminum. I'm a machinist and have access to cnc lathes. I've been thinking about turning some out and using my car as a ginea pig. I feel aluminum would work much better than steel, with it being much lighter and better heat dissipation properties. Right now it's just an idea tho. I have my old plastic pulleys in the shop to use for measurements.

Hey, I like your innovative thinking. Maybe Teflon treat the rolling surface to wear on the belt a bit better? On some race application's I have seen timing belt idlers that I would swear were just a skateboard wheel machined down to fit. Good quality aluminum should wear on these belts fine IMO. I know the Opel engines in Europe these engines are copies of do have metal idlers in production, not sure why Korea went with the plastic stuff, other than to shave cost.

[zchandran]

I don't understand why you want to keep the pulleys. You have to remove the pulleys anyway to get to the water pump, so why not just change them while you're in there? I'd rather bet on a brand new plastic pulley with fresh bearings, than a steel pulley with tens of thousands of miles of known bearing wear.

I'm getting ready to change my timing belt again. I put in a ContiTech kit at 50K miles, and I'm now at 130K, so I'll just get the same thing again.

[avguy]

I don't understand why you want to keep the pulleys. You have to remove the pulleys anyway to get to the water pump, so why not just change them while you're in there? I'd rather bet on a brand new plastic pulley with fresh bearings, than a steel pulley with tens of thousands of miles of known bearing wear.

I'm getting ready to change my timing belt again. I put in a ContiTech kit at 50K miles, and I'm now at 130K, so I'll just get the same thing again.

I think that you and I are the only ones around here who aren't caught up in the metal pulley mania, and feel ok about the plastic pulleys. I suspect the others in this thread would say that getting 80K out of your replacement plastic pulleys is nothing short of a miracle, and that going with plastic again will result in certain disaster. Well, I've used plastic pulleys 3 times in the past, would always do so again, and have never lost a minuter of sleep over that choice. But for the rest of you who believe all of this stuff about metal versus plastic pulleys, carry on!

And just an unrelated comment for you Z, that MANY of us have used your timing belt DIY, which was one of the first, and probably the best of the bunch.
So on behalf of everyone who benefited from your helpful work, THANK YOU

[Prozack]

I don't understand why you want to keep the pulleys. You have to remove the pulleys anyway to get to the water pump, so why not just change them while you're in there? I'd rather bet on a brand new plastic pulley with fresh bearings, than a steel pulley with tens of thousands of miles of known bearing wear.I'm getting ready to change my timing belt again. I put in a ContiTech kit at 50K miles, and I'm now at 130K, so I'll just get the same thing again.

The reason I would like to replace he plastic pulleys is because I have seen multiple stories of aveo owners losing an engine because the plastic pulleys failed. Not the belt itself. Plastic is just not a good choice for this application. With all of the intense heat and stress from the belt tension, I'm suprised they don't fail sooner.

[thankful_ragamuffin]

We just did a warranty replacement timing belt on an '06 Aveo. Car came in with a driveabilty issue and my tech found a defective cam sensor. While he had the cover off he found an idler with less than 10,000 km on it with a bad bearing. Luckily, it was only growling badly and had not seized yet. Yes, it was a plastic idler. No, the plastic had not failed - the bearing did. The same bearing in a metal pulley would have had the same results. We had used a quality belt and w/p kit in the original install and the manufacturer warranted the part, but any manufacturer can have a bad bearing slip through. The point? The quality of the bearings not the material the pulley is made from is more important. A failed bearing will also destroy a plastic pulley making it look like the plastic, not the bearing failed.

[northguest47]

the first mod i did was the drive pulley (80% lighter,perfect balance) and it made such a noticeable difference, someone should make a pulley set, i have the older aveo unfortunately without air-conditioning, so thats a toughie set but a lightweight pulley set for all Aveos would be nice and lightweight rims.. big difference from stock for sure on the rotating mass.