[VR-VS] How to fit Clarko's 20% underdriven pulleys onto a ecotec engine

[VS FTW]

Good write up mate, how hard is it for the gain you get to do the rest of the pulleys?

 

[Immortality]

As I see it the only mistake you made was step 16 should come after every second step

I don't think I would have completed the install, let alone this write up If I had

Good write up mate, how hard is it for the gain you get to do the rest of the pulleys?

Sorry mate, I don't follow??? There are no other pulleys to replace other then the idler pulleys but there is no gain to be had there. I haven't really seen any nice alloy pulleys either so not much point. I would however recommend upgrading the harmonic balancer. The factory item is a POS. Powerbond do a good race balancer which works real well. I have one on my VN and it got rid of a vibration the engine had from the day I bought the car

 

[SweetWagon]

The water pump doesnt fit the L67 too well, not enough clearance to the idler (belt passes through twice)

I think dropping down a size on the idler pulley should gain enough clearance

 

[Immortality]

Seems a bit odd, unless the L67 uses a different idler pulley?

 

[SweetWagon]

I think the idler is physically closer to the water pump on the L67, look at this pic compared to ecotec in first post.

 

[Immortality]

Yep, definitely a different idler pulley. Not sure how that would work with the 5% OD harmonic balancer you have, as the serpentine belt for the blower will be running at a different speed to the serpentine belt for the engine accessories.

 

[SweetWagon]

Yep, definitely a different idler pulley. Not sure how that would work with the 5% OD harmonic balancer you have, as the serpentine belt for the blower will be running at a different speed to the serpentine belt for the engine accessories.

Hi Bart,

They are 2 separate pulleys stacked ontop of each other, so belt speed is no issue, i will post my progess back here for any other L67 owner's once i work it out.

Cheers.

 

[Immortality]

Hi Bart,

They are 2 separate pulleys stacked ontop of each other, so belt speed is no issue, i will post my progess back here for any other L67 owner's once i work it out.

Cheers.

LOl, i didn't think about that till after i replied. Considering they are 2 separate pulleys, maybe someone has fitted the wrong diameter pulley at some stage as there is definitely clearance. Other wise you may need to get the standard ecotec pulley at the back.

edit. just looking at your pic again, the L67's have a smaller idler pulley at the top to clear the tensioner assembly for the m90 serpentine belt. If Holden wanted to use the same belt length they would have increased a pulley size else where to compensate. It looks like they possibly made the lower idler a bigger diameter for this reason????

 

[SweetWagon]

LOl, i didn't think about that till after i replied. Considering they are 2 separate pulleys, maybe someone has fitted the wrong diameter pulley at some stage as there is definitely clearance. Other wise you may need to get the standard ecotec pulley at the back.

edit. just looking at your pic again, the L67's have a smaller idler pulley at the top to clear the tensioner assembly for the m90 serpentine belt. If Holden wanted to use the same belt length they would have increased a pulley size else where to compensate. It looks like they possibly made the lower idler a bigger diameter for this reason????

My theory is a little different, from comparing the 2 pictures, i believe both the double stacked and smaller ribbed idler pulley have been mounted physically closer to the center of the engine, aswell as closer together vertically.

I think they have done this for a few reasons due to the supercharger belt tensioner assembly.

The smaller ribbed idler pulley at the top is not to clear the tensioner assembly, but to clear the water pump and double idlers as mounting location has changed.

I will just drop down a size on the rear idler pulley, should solve the issue at hand

 

[SweetWagon]

Just an update, had some success with getting the water pump pulley fitted today, wasnt quite as simple as dropping to a smaller rear idler pulley, I also had to grind down the pulley mount bracket to clear the smaller idler. But once that was done, it was smooth sailing. Belt used: 6PK2830.