I come here when I need straight scoop without drama...

I need a reminder tutorial about cam timing marks.
There are 3 on an L28.
My cam is currently on the #3 position which advances the cam timing?
Going to #1 would retard the cam timing?

This effectively reduces low and mid response in favor of higher rpm?
Will the idle quality suffer at all (lumpier would be fine with me).

Am I close on this?

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD

Love your opening comment tj....

I'm sure the 240Z guys will chime in with their answers for you in a bit!

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Phil
1981 280zxt - Now in the care my son!
2014 370Z Sports Touring Roadster

My engine guru is coming by my house tomorrow to do this cam reposition to retard with me. I was going to just man-up and do it myself but I can wait a day and get the expert to lend a hand.

Midrange was real strong and top end was done by 6500.
Will be interesting to see how the cam timing changes that.

Tj

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD

The three positions are meant to be used to compensate for chain wear and stretch. If your engine is on the third mark that indicates it's a very high-mileage motor or that the previous owner was trying to mess with it. If the po set it to the third position with a new chain then he has advanced the timing, which generally speaking hurts top end performance but adds torque, but if you have a stock cam, the stock timing should be used.

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71 on a rotisserie, two more in pieces in my shed...and a 69 1600 waiting for me to get to it

I built the engine myself 2 months ago. Set the cam to 3 because I was worried about lack of midrange power. Wrong. Smoked 2 sets of tires and diffy is howling now.

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD

So this is a rebuild, but no new chain? between the chain stretching, and the wear on the guides, that's why they have 3 positions like Marc said. Of course, from what it sounds like, it runs good, so why fix it.

New engine for me. I rebuilt it myself for the experience.
Same chain. This is a car that drives 500 miles a year (maybe).
The motor was a relatively recent rebuild from some factory.

Midrange is more than I need, I want more top end.
So going from 4 advanced to 4 retarded should shift the curve some from what they say.

Plus I think the retarded setting will help with cylinder pressure which is a bit high for pump gas. According to some websites the later intake closing will benefit me. I currently run 50/50 Avgas and Premium pump gas.

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD

My error. It was on position #2.
We reset to Position #1 so I can try the retarded position.
Bolt wasn't as tight as it was supposed to be so that was good to find.

Let my friend drive it whose machine shop I used to build the engine (for no cost). He hammered the throttle stop and screwed up the linkage on the triples. I thought the stop was set to damage-proof but I was wrong.

More to do.
Tj

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD

You know that kameari makes an adjustable camshaft sprocket that lets you adjust cam timing any increment you want, without removing the sprocket, right?

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71 on a rotisserie, two more in pieces in my shed...and a 69 1600 waiting for me to get to it

I believe MSA has those. zcarparts.com

Those are pretty neat. About $300 bucks.
I can't imagine I will ever touch it again (unless and until I blow the motor sky high...).

Some people must change it fairly regularly?

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240z DCOE40 / F54 / N42 / L490 Isky
Thank you Total Seal!
Not a DD