Why do I see a lot of tuned Z engines in Japan swapping out their chain tensioner for a toothed pulley instead - I know Kamerai makes just such a conversion, this is a different type I've also seen where it goes in through the front access cover on the head...

Are they that prone to failure???

here's another pic of what i'm talking about

hey thats a great idea i want one!!!

i couple of reasons i think. ease of adjustability and more importantly........

have you ever let the chain slip while adjusting the cam timing??? the tensioner stops the bloody chain from coming back up properly so you get the fun job of pulling off the balancer and timing cover to ge the chain back on. no tensioner?? no problems!!!

where do these come from??

well like i said kameari makes them and some other manufacturers...

i can find you the direct website link, maybe they have someone there that can answer english emails and do international purchases... lemme see here real quick...

Here's one link:

http://nkondo-web.hp.infoseek.co.jp/Kameari_L6_2.htm

Price is 50400yen = $481 at today's exchange rate

That's about right I think...

I thought I had seen them on another website but can't track them down right now...

-e

Ok the link I gave is the link to Shake Down Engineering - a shop that carries Kameari stuff... can't find the actual Kameari website right now... have it at home though.

-e

Eric, where are you at in Japan right now? How long will you be here?

Before everyone freaks & sends me emails about getting them some parts i am not in Japan at the moment - next time I go will be April for our much delayed honeymoon.

-e

Bring me parts!

Yea, I just put one on a freind's 240Z engine. The only advantage I can see is less resistance. Gears on bearings instead of a draging rubber tensioner. The Kameari unit I put in is anodized blue. So some of the appeal got to be visual. I don't like the fact that this setup is not self adjusting like the factory unit.

Talking about Kameari, does anyone use their Jet Block unit? I am experimenting with it and can't get it dialed it at the autocross. On the street it works fine, but at the track it seems to choke on itself.

Eric, I believe this type of chain tensioning is more positive and reliable for heavy use applications. This fixed (when adjusted and tightened in place) tensioner does not rely on a spring and in some cases oil pressure and a spring for tension. A stock tensioner works fine under acceloration because the tensioner is on the non-drive side of the timing chain, however under hard deceloration the tensioner may give to some degree. Not a good thing for a race engine with engine parts moving further, faster, and with tighter tolerances. So, under heavy use (racing) the fixed tensioner will maintain adjustment under hard acceloration and deceloration. Maybe someone can add to this as there is probably more to it that I do not know about.