Timing chain tension retaining tool dimensions

N

nospark

Well-Known Forum User
I need to make a hardwood tool thingy to retain the timing chain. After doing a good search the only dimension diagram that give me confidence was from "www.californiaparts.net" (the source website is no longer accessible).

This is the diagram
www.bluehandsinc.com/l-series-timing-chain-tension-retainer.html

Are these dimensions correct ?

They state on the diagram that its for a L20 engine. Is it good for an L6 engine (240z) ?

What would be the recommended thickness of the wedge ?

Thanks in advance for any info
 
ben240z

ben240z

Club Member
I have always used the wooden handle from a wire brush. It still sits in my toolbox and is used on numerous occasions.

You can make or buy a proper one if you choose that route
 
Albrecht

Albrecht

Well-Known Forum User
The original Bill Fisher/Bob Waar 'How To Modify..." book, published in 1973, contained a 'life size' pattern for the chain wedge.

'Life Size' isn't going to work digitally, but here's a scan of the page. Total length is 175mm. width at widest point is 26mm and it is 34mm thick. That 34mm thickness is a bit much in my experience, and you can get away with less as long as you don't let the wedge twist in situ.

The recommendation to make it out of hardwood is because a soft wood may be more susceptible to damage by the chain, dropping wood dust/chips into the lower part of the timing cover and the sump.

A better material would be something like the typical Polyethylene/HDPE kitchen cutting board or a hard nylon. I've got a 'pro' version I bought in Japan which is made from some sort of hard plastic, and it has long cuts in it to give it some 'spring', which is helpful. Chain Wedge.jpg
 
Farmer42

Farmer42

Club Member
The important thing I found when I made my own was to remember to drill a hole in the top as the diagram shows to make sure you can get it back out. I forgot and had a job getting it out as there is nothing to hook it and you do need to wedge it pretty tightly to stop the chain from moving.
 
N

nospark

Well-Known Forum User
Thanks for the info. I am being overcautious on this because getting it wrong and having to take the front cover off would be very bad news for me. I guess the key measurement is at the chain tensioner itself, which my diagram suggests is 25.3 mm (say 26mm).

A lash pad popped out a couple of years ago. I just prised it back in and carried on driving it as the car only does 600 miles a year. Albrecht, at the time you advised that I should take a peek as there might be something else going on inside. Now started to get on with it. The header/manifold studs came out without snapping (yippee) and I can see that my inlet valve seats are probably "brass". So its likely to go off to the local engine machine shop when this virus situation settles down.
 
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