cam sprocket?

[zed]

Another newbie question - I've searched "cam sprocket", and read all the posts, but they don't seem to apply to my engine. (Sadly, Hainz vid is too big to download on dialup:()

So, please can someone explain why the bright/silver timing chain link is next to the "3" on the sprocket? My manual says it should be on "1".

It's a standard L18 engine, which has never been worked on... done about 250k miles, so the timing chain should be stretched right? I'm collecting parts and information for a rebuild here...

many thanks guys

[datsunaholic]

The bright link is on "3" but where is the other bright link? If it's lined up with the mark on the sprocket AND the cam sprocket pin is in #3 then someone set it there. If the engine has been run the bright link will land anywhere- it won't hit the number every revolution.

 

When I did the head on my L20B the bright link was nowhere to be found, BUT someone had set the static timing on #1. No wonder it backfired all the time.

[bonvo]

i never understood this there are 3 cam timing locations?

[banzai510(hainz)]

yes there is 3

its on my vid,http://www.guba.com/general/search?query=hainz&set=5&x=0&y=0

it advances the chain for chain stretch or cam advance

 

L20s came from factory set in #2 position for emmissions

[bonvo]

got it so ill have to watch the video :P

[datsunaholic]

L20B wasn't set at #2 for emissions, it's because the chain is longer and has more static "endplay" due to having more links.

[banzai510(hainz)]

Doug you sure????

2 links longer is going to need 4 deg advance just for that porpose?

 

Doesnt really matter. if you got it set on 1 2 or 3 and its a new chain it will run!!!! if a Performance cam then one needs to dial it in with a degree wheel.( I dont know how to do that).

General rule of thumb is if cam is advance the power comes on sooner

[datsunaholic]

I've built both L20Bs and L16s and the cam timing on an L16 at #1 is not the same timing as #1 on an L20B... combination of longer chain and the increased distance from sprocket to sprocket. Of course each engine varies... a milled head causes cam lag, all else equal. It's amazing what just a few thousandths does.

 

I do know what happens when you set an otherwise stock L20B on #1... a bit of backfiring out the intake when trying to start it, at least cold. Same effect as a worn chain, the cam ends up lagging the crank and dist timing. When it heats up the block/head grows more than the chain so it tightens back up a little bit.

[zed]

thanks everyone for the info