If it's not really about tuning or wiring. Then it belongs in here.
Hey all... Hopefully someone has some Experience with Nissan RB Timing belts...
I just did a 200,000km service on my R33 and changed the timing belt/Water pump. The workshop manual says to fit the tensioner which has a spring on it and to just use the tension of the spring to "decide" the tension on the belt. When I tried this the belt seemed way to loose so I used the Allen key slot and gave it a touch of tension till the belt felt firm... Got it all back together and the belt is making a decent whirring noise.
Now Ive heard plenty of times that a new belt can be noisy and will stretch a little and quieten down so I was not too worried...
But then I changed a leaky water pump gasket on my 32 GTR, Engine was rebuilt about 15,000km ago and the belt looked like new so I didnt change it... But same deal with only spring pressure on the tensioner it seemed loose and abit sloppy so gave it a touch of extra tension and locked it off... finished re-assembly and fired her up and is whirring just as much as the 33... Now since its the same belt I was not expecting any sound at all as it was silent beforehand...
So no im thinking both the 33 and 32 are too tight... So wondering how others go about setting the tension... Do you simply use spring pressure and the loose/slop is normal? Or am I doing it right and they usually whine after re-fitting and will go away.
If its too tight is it a real risk of it snapping? or is it just an annoying noise but wont harm anything.
If the belt kit didn't come with a new tensioner spring , its probably worth going and buying a new one and putting it on .
They do lose tension over time ( they are both going to be 20 years old after all )
If the belt is to tight, wear on everything the belt runs on will be accelerated and could cause premature failure .
Yeh the kit for the 33 didnt come with a Spring which I thought was strange as exactly as you say would be at least 100,000km old....
Small update, for the GTR. I tried getting to the Tensioner nut with just the upper cover off, and altho I could get to it with an open ended spanner I did it up way too tight do undo with the little spanner that would fit. So bit the bullet, drained the coolant again, rad out, balancer off and loosened the belt a little... This time I fired it up with just the balancer on to check before full assembly and its back to silent as before. :)
Generally just spring tensioner to me is to loose. I tend to give it a little more tension however its a fine line between a good tensioned belt and the whining noise.
As Lyndon said, if you go to tight you will accelerate wear on the tensioner/idler bearing and the back of the belt and teeth edges.