L20b Camshaft timing

[tecktinkershop]

Howdy gentleman. Been a while since i been on here, broke some rings in my l20b a few years ago and i'm now finally getting around to putting an engine back together for my pick up. 

   So, getting ready to put the timing chain on and I'm having trouble finding the specs on how to set the cam timing. I've done this before as the spring loaded tensioner flew apart once before so i put a wholoe new timing chain set up in it, sprockets and all. But, now I can't seem to find the resource I used before or even were i wrote it all down. 

   With the engine at top dead, which hole ( 1,2 or 3) does the camshaft dowel pin need to be in on the cam spocket and how many links need to go between the tooth marked respectively on the cam sprocket and the marked tooth on the crank spocket? Thanks in advance for any help

[tecktinkershop]

Oh, and i might add that the aftermarket cam sprocket does not have the v notch on the backside which is supposed to line up with the mark on the camshaft retainer plate.

[captain720]

Hainz has a vid on u tube

[racerx]

I think its datsun L series

[datzenmike]

44

[john510]

L-20b goes on hole #2 and watch the Hainz video.

[distributorguy]

Many of the aftermarket timing chain setups are not made the same as original, so if you just chose "position2" because that's the way it was originally set up, you might find its nowhere near correct when you try to start the engine.  I overlapped 3 different brand sets here in the shop and none of them line up with each other.  

[banzai510(hainz)]

the Melling or Cloyes sprocket might not even have the see thru holes in the right spot.

I woud buy the Jap sprocket or a OSK sprocket.  Tsubaki kits are the oneto get if you can find them

[racerx]

Tsubaki is good quality

Bought mine at Winchester auto from San Jose, ca.

[Stoffregen Motorsports]

Many of the aftermarket timing chain setups are not made the same as original, so if you just chose "position2" because that's the way it was originally set up, you might find its nowhere near correct when you try to start the engine.  I overlapped 3 different brand sets here in the shop and none of them line up with each other.  

This is exactly the reason I don't just use a hole number. Jeff is right. None of them are ever the same. If anyone is serious about getting their cam timing right, buy a $60 brake runout gauge and learn how to check split overlap. It is so much simpler than using a degree wheel.

 

Here's a gauge on Amazon - https://www.amazon.com/dp/B000R6VTZC/ref=asc_df_B000R6VTZC5494326/?tag=hyprod-20&creative=394997&creativeASIN=B000R6VTZC&linkCode=df0&hvadid=167143431342&hvpos=1o3&hvnetw=g&hvrand=4476747009404703859&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032734&hvtargid=pla-312848023657

[datzenmike]

There are only 3 choices of holes and it will run in all three. Number two is probably going to be 'close enough'. Far and away most L series engines are not heavily modified and you probably won't be able to tell the difference but if you think you do, just pick the one that gives the best power or economy.

[Stoffregen Motorsports]

On a stock L20B, the difference between the three is marginal, but still measurable. For those who want to cross all their t's and dot all their i's, I don't see taking an actual measurement as being overly cautious. This is, after all, an enthusiast hobby.

 

In the case of the OP, who said there wasn't even a notch on the back of the gear, checking it with a dial indicator may be the only way he knows for sure if it's right.

[don51o]

I've always used #1 BUT never done "real" timing check. Two adjustments for stretch. Always used factory parts.

[datzenmike]

L16/18 come from the factory on #1, the L20B is set to #2. When the chain stretches the cam timing advances relative to the crank position. This would open exhaust later and close the intake later benefiting higher RPM cylinder filling and disadvantaging lower speed torque.

[seattle smitty]

My project is an '81 720 with a well-worn Z-22, and I'm seeing some numbers on the cam sprocket.  As I recall it from my 510 days long ago, you could reset cam timing from one to two to three to compensate for increased wear and chain-stretch as your engine aged.  But there could be another factor nowdays.  Since about the mid-Seventies some manufacturers have been retarding the cam timing for emissions reasons.  For example, when I did a top-end rebuild on a Ford 460 in my dad's pickup, I was told that the cam timing had been retarded 8 degrees from early years of this engine, and that I could get back some engine efficiency by restoring the engine to "straight-up" timing.  Aftermarket gearsets with the "right" timing could be had, but I was cheap, and filed a new keyway (came out quite close, too!!).  

So the question is, was "smog-timing," i.e. somewhat retarded, a feature of Datsun engines in these years?

As a related question, I just loosened all the headbolts on the Z-22, but don't want to pull the head until I can find the curvy wooden shim I made per the 510 book of the time that holds the chain and it's tensioner in place.  Am I right in guessing that 510 shim will work on the Z-22, or do I have to make a shim to another pattern? (Of course, if I were going to change the cam timing I'd have to pull the cover anyway, but haven't time for that now).

 

[distributorguy]

Actually, smog timing was typically advanced in imports.  This helped make up for the poor drivability caused by retarded engine timing (which can be corrected by recurving the distributor.  I'd set the cam timing around 106-108 Intake centerline (peak lift at #1 intake lobe) for best drivability.  108 gives you a larger torque plateau, 106 will give more hp and a more "peaky" torque number with less overall power "under the curve."

[seattle smitty]

Wait, now we're talking two kinds of timing, where I was using the words "smog-timing" to refer just to the camshaft.  However,  you gave me actual specs to shoot for,  thanks much!!

A distributor guy, oh, excellant, because I have a question for you (besides whether your friends refer to you as Dizzy).  Should I PM you, or put it in another sub-forum?

[Stoffregen Motorsports]

1 hour ago, seattle smitty said:

A distributor guy, oh, excellant, because I have a question for you (besides whether your friends refer to you as Dizzy). 

I hate that word...dizzy.

[Stoffregen Motorsports]

Just like I hate the term JDM...

[distributorguy]

19 hours ago, seattle smitty said:

Wait, now we're talking two kinds of timing, where I was using the words "smog-timing" to refer just to the camshaft.  However,  you gave me actual specs to shoot for,  thanks much!!

A distributor guy, oh, excellant, because I have a question for you (besides whether your friends refer to you as Dizzy).  Should I PM you, or put it in another sub-forum?

 

You can email me direct at jeff@advanceddistributors.com with business related questions, unless its forum-appropriate.  

[seattle smitty]

I think the Brits or Aussies came up with "dizzy" as shorthand for distributor,  something I was exposed to when I had a Ford Fiesta with an English engine, and which I occasionally use as an on-line, what, space-saver?  Like "JDM" maybe (can't figure that one out)?  But if you don't like it, I won't use it.

 

[Stoffregen Motorsports]

Don't let me dictate what words you use. I have a problem with lazy language in general. To this day I have yet to use the term "LOL". Call me a grumpy bastard if you like, but i prefer the more technical terms over the slang, when speaking about cars and such.

 

And you're probably right. Those brits have a way with language. Spotted dick? What the $#%^*?

[seattle smitty]

 Spotted Dick, isn't that a social disease? But what is "JDM"?

[Crashtd420]

16 minutes ago, seattle smitty said:

 Spotted Dick, isn't that a social disease? But what is "JDM"?

I'm actually surprised at the answer....

"Japanese domestic market"... I always  thought it was something else till I looked it up

[Stoffregen Motorsports]

JDM is supposed to refer to vehicles sold only in Japan, but it has been misused and redefined (inappropriately) as meaning a certain style or era of Japanese car.

 

Spotted dick is actually a kind of pudding, which is another word the brits screwed up as it's not so much a pudding as it is a cake.