2.76 Upper Pulley

[Sergg]

Alright so I'm getting close to switching out the wagon wheel and going with an 2.76 upper, I noticed I cant install it if i keep the idlers stock.... So here's my question, Im completely stock and my car is a daily driver, Is an idler kit or other pulleys necessary if Im just changing the upper to a 2.76 and keeping the lower stock and if so which would ya'll recommend.

 

[BlksvtCobra01]

Do a search look at Cobra Bob's site. Yes replace the idlers the factory stamped ones are crap and will grenade.

 

[01yellercobra]

How does the upper cause the stock idlers to grenade? If he's keeping the stock crank pulley the only thing spinning faster is the blower.

FWIW, a friend of mine has been running a 2.76 upper with a 4lb lower and stock idlers for about 3 years now.

 

[Rich'sTRsvt]

It is harder to spin a smaller upper pulley and puts more stress on the idlers. There are people who have kept the stock idlers without problem and others who had them self destruct. It's just preventative maintenance so you don't get stranded later.

 

[cj428mach]

It's probably "harder" on the idlers because people run a much tighter belt to prevent slip on the smaller pulleys.

 

[Oiljunkie]

It's probably "harder" on the idlers because people run a much tighter belt to prevent slip on the smaller pulleys.

belt size doesn't change the amount of tension that the tensioner will load the belt with?

 

[gksingh]

There's no set period, could be now could be later.
With my 2.8/100mm idler and 74.5" belt. One of my Oem idlers blew at 70,000 miles. Others were actually fine But just for peace of mind I changed them all to Dayco Heavy Duty ones and they aren't stamped. Around 20 bucks a piece and they are solid.

If your not gonna change em right away, periodically check them. You can actually see the stamped part starting to lift a bit. I say just change them.

 

[01yellercobra]

belt size doesn't change the amount of tension that the tensioner will load the belt with?

If they run a belt that keeps the tensioner in the middle it shouldn't. But a lot of people like to max out the tensioner and use a belt that requires pry bar to get on. I did that with an old set and killed the front main bearing.