Idler / Tensioner

[Dale FZ1]

I’m looking for ideas / experiences with the idler / tensioner setup on the 30DET.

Having checked out the guide, I’ll be going with one high, one low. I do see clear value in moving the position of the bearings.

The question is whether there is any net benefit in using 2 x tensioners – other than saving a few $$ on the difference on the higher priced idler? It appears that either setup works quite ok, so is there any consensus on what is “best”? And does the use of two tensioners require a different spec timing belt.

Timing belt wise, I’ll be using either a Dayco 94407, or Bosch T866 which are both listed as 152 teeth x 25mm wide.

[Al]

Hey Dale,

On my setup i'm using one of each, don't know what benefits, etc there are, but that's how my mechanic wanted it. I am also using the Dayco belt. I recommend you move the lower tensioner position an extra 2mm to the right (from centre) to what is stated in the document, as even with the tensioner on the loose setting the belt was pretty tight, this was done on the second build of my engine.

[unique1]

Hey Dale,

On my setup i'm using one of each, don't know what benefits, etc there are, but that's how my mechanic wanted it. I am also using the Dayco belt. I recommend you move the lower tensioner position an extra 2mm to the right (from centre) to what is stated in the document, as even with the tensioner on the loose setting the belt was pretty tight, this was done on the second build of my engine.

my engine is exact same setup, one tensioner and one idler, the belt is also pretty damn tight to get on even with tensioner at the loose setting so i agree on the tensioner move to the right abit to give it a fraction of slack.

[Dale FZ1]

i agree on the tensioner move to the right abit to give it a fraction of slack.

Nearly caught myself out there with moving the tensioner mounting point. You're obviously referring to moving it further towards the right side of the car, or further left of centre as you look at the front of the block? ie the "other" right? Makes sense and an easy adjustment to make before drilling/tapping - thanks fellas.

Clearly the suggested use of two tensioners in the guide is another approach to address the issue of getting enough belt slack to make installation easier. So are there many people who've done this, and was sourcing a second spring for the additional tensioner difficult? It's all minor detail stuff, but interested to find out anyway.

[Adriano]

Its the top tensioner you want to move a fraction from the pdf, about 1-2,, to the left. Im using 2 tensioners, as it allows me to make the cam timing marks align exactly with the differences in deck height of a machined block/head, and thinner or thicker headgasket. ie if you tighten the bottom tensioner, and loosen the top, it advances the cam timing of both cams.

[Al]

Ooops, yeah it's the top tensioner you need to move to the left

Hence why i don't build my own motors

[Gts-t]

Im moving 1mm, i marked the spot the other day when i was getting the block ready to be machined, drilled for gtr headbolts and obviously the tensioner location. fwiw ill be running two tensioners, one high one low.

[Dale FZ1]

Its the top tensioner you want to move a fraction from the pdf, about 1-2,, to the left. Im using 2 tensioners, as it allows me to make the cam timing marks align exactly with the differences in deck height of a machined block/head, and thinner or thicker headgasket. ie if you tighten the bottom tensioner, and loosen the top, it advances the cam timing of both cams.

fwiw ill be running two tensioners, one high one low.

Good information, thanks both of you.

So what is the source/spec of the spring to use with the additional tensioner? Or are you going without?

[Adriano]

Without

[Gts-t]

^^ what he said

[xsv_32]

Ive relocated the tensioner as per the famous RB30 pdf. But im having trouble tapping the thread . Any tips? Bought a 8.6mm drill bit as advised to tap a 1.5x10mm hole but cant get the thread started! Any help would be great.

[Dale FZ1]

Start with a full taper tap, and put some grease in the flutes to lubricate your progress. Don't force things overly, and be prepared to back your tap out to make it easier. Remember you are cutting a thread, not just winding the tap in to an existing thread. Also keep an eye on things to make sure your tap is running in plumb.

Not that hard.

Edited October 22, 2008 by Dale FZ1

[leeroy_25]

I am about to be doing this to my RB30 block.. However I have a question. looking from the front of the engine the stock tensioner position on the RB30 is to the left of the engine/belt.. can I keep this position or do I need to move it to the right side? I was planning on putting the other tension above the water pump and on the right side. The reason I ask is the pics I have seen show the exact opposite set-up so I wondered if there was a particular reason for this?

If I have to move the lower tensioner over there is a hole for the stud.. but no flat area around it to lock it up against. wil I need to weld and machine the block back or something? also where do you put the small stud for the tensioner spring or do you do away with that?

Thanks

Lee