What are 'adjustable pulleys?' and do I want them?

[Guest chiefvinso]

So aftermarket are all adjustable?

[Steve W2]

So aftermarket are all adjustable?

 

Depends which ones you buy

[Guest chiefvinso]

So if they are not adjustable and lighter then this will help performance wise or are the teeth sifferent?

[Steve W2]

So if they are not adjustable and lighter then this will help performance wise or are the teeth sifferent?

 

They are (generally) lighter. And the the teeth are the same. They won't make your car go faster.

[Wez]

Doesn`t lightening any rotating part help with engine response?

 

Although not sure how much could be saved over the stock items as they weigh in at approx 0.96 lbs each.

 

[Steve W2]

Doesn`t lightening any rotating part help with engine response?

 

Although not sure how much could be saved over the stock items as they weigh in at approx 0.96 lbs each.

 

 

Yes, but I can't say I noticed any difference. You effectively decrease the inertia required to rotate the pulley's. In the same way as lightening the flywheel increases throttle response. That is definetly noticable.

[Guest chiefvinso]

I'm not saying faster, should have said what wez said. Surely the engine will rev more freely but not so much to notice unless you start lightening other parts I pressume.

[Chris Wilson]

Alloy cam wheels, even hard anodized ones, should be considered as a consumable. use steel in road car engines. Loss of inertia at 1/2 engine speed is trivial and probably unmeasurable. If you have skimmed the head or block you NEED them, if you want to ensure you can hit 100% accurate timing you MAY need them. 3 bolt or 5 bolt, once torqued up and Loctited are fine. 99% of the time you are buying pretty colours at a vast premium. In my experience HKS, Apexi, JUN and Tomei cams time up within 1, to at worse 2 degrees, to spot on on an unmachned engine on stock pulleys. money better spent elsewhere for most peole, to be frank.

[Steve W2]

Alloy cam wheels, even hard anodized ones, should be considered as a consumable. use steel in road car engines. Loss of inertia at 1/2 engine speed is trivial and probably unmeasurable. If you have skimmed the head or block you NEED them, if you want to ensure you can hit 100% accurate timing you MAY need them. 3 bolt or 5 bolt, once torqued up and Loctited are fine. 99% of the time you are buying pretty colours at a vast premium. In my experience HKS, Apexi, JUN and Tomei cams time up within 1, to at worse 2 degrees, to spot on on an unmachned engine on stock pulleys. money better spent elsewhere for most peole, to be frank.

 

What sort of mileage do you consider 'consumable' Chris? Are we taking 10- 20,000 miles?

 

to be frank

 

Who's Frank?

[Chris Wilson]

I have loads of race engines out there on alloy pulleys where they are changed annually at relatively low mileages, but they are turning 10,000 RPM plus in a hostile gritty environment with no belt guards. On a stock guarded MKIV engine you may see 20,000 plus miles OK, whereas stock steel ones are good for at least 300,000 from personal experience. Depends on alloy used, heat traet, hard anodised, blah blah.