Hi all.

New member here so hi, and apologies if I posted in the wrong area.
I’ve built / building an st170 turbo but I didn’t forge it. I used a decompression plate of 2my and 2 x 0.6 head valets. I’m a bit stuck on the timing belt as I’m not sure how tight to do the tensioner. I think in the stock position it would be way to tight. Had anyone got any ideas on where it should be please ? Thank you

 

St170, focus rs Mk1 turbo, gsxr thottle bodies in to a custom plenum. Hks dump valve, mishimoto Intercooler, 2.5 inch pipe work and water methanol injection

95% finished...

 

looks a awesome bit of kit

 

MeV rocket, nice.. I love that intake.

How are you controlling the vvt ?

Mine is the St bottom end and Bt top end with the 1.8mm gasket and there is plenty of available slack.

The tensioner should be automatic if your using the ford one. What makes you think it’s to tight ?

 

If it helps I run a spacer plate on my silver top and all I did was make sure the cam belt could be twisted through 90degress on its longest side. No more or less just 90 . It survived a set up session on the rollers. I was always told that 90 degrees was right along with two full turns of the crank by hand and you will fine

car looks very well btw

cheers

Adder

 

That looks really nice

 

Thanks dude, I’m having a link g4 monsoon ecu installed next week which will control the VVT.
So when i has it running a couple weeks back under load there was a awful sound like a screech coming from the cambelt. I think I’ve ver tightened the tensioner.

 

Thanks adders !
Ermm I’m not sure what u mean by the whole 90 degrees thing..
im using a spacer plate as well so I’ve increased tree engine hight. So I have a 2mm spacer and 2x 0.6mm head gaskets. I’m not sure what the standard head gasket is.. I’m guessing 1.2mm? Just say it is, I’ve made my head 2mm higher. So I’ve made the cambelt stretch 4mm longer than it would need to on a stock st170. 2mm up and 2mm down. I’m not sure how much this would take the tension out.. il post a pic of my tensioner up now.. maybe I have the wrong one but it’s just a normal one that u use a 10mm sock and a Allen key to adjust and lock off.

So I might be having a Monday morning dumb moment but what do u mean by twist the belt ? Lol 😆 🤦🏻*♂️

 

Coupe pics of the tensioner..

 

The pointer should be in that little window. It will swing both ways as the engine rotates but on average it should sit in that window. ( The square hole in the other pointer ).

And as a manual check you should be able to twist the belt 90deg with your finger and thumb on the longest part of the belt.