Dartht33bagger

I received my l31-R crate motor today. No big surprises except for one: there are no timing numbers on the timing cover. Just one little notch. Looking online, it looks like the way to set the timing on these motors in the trucks is to through a SCAN tool on the OBD2 computer. Apparently the single notch on the timing cover means 0*.

How can I go about setting the base timing on my TPI based L31-R without the marks? Is there a 1 to 1 transfer over from my old 305 engine, or do I need to adjust the computer to expect a 0* base timing and adjust all of the spark tables up 6*?

sofakingdom

iTrader: (1)

"Setting" "timing" isEEEEEEZZIE.

Doesn't matter about "L31", "numbers", "cover", or ANY of that.

Your distributor currently is ... somewhere. Your car runs. Can't be ALL that bad.

Mark where it is now.

Adjust it.

Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.

OK, how about now?
Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.

OK, how about now?
Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more..

OK, how about now?
Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.

OK, how about now?
Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.

OK, how about now?
Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.
OK, how about now?

Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.
OK, how about now?

Better/worse?
Better: adjust it some more the same way.
Worse: adjust it back, plus a little bit more.

Is this "hard"? Are we talking rocket surgery here? I'm thinking, ,,, .... hmm, ,,... ... ,, . ...... NOT.

Allow me to paraphrase one if The Great Ones in a COMPLETELY unrelated field, but whose wisdom is a blindingly obvious light to eliminate the confusion of those who just can't seem to grasp the obvious:

"If it RUNS good, it IS good."

(did I mention "obvious"? if not, ... ,, ... sorry)

Don't outsmart yourself, although I can easily tell you're MUCH smarter than me, over the obvious.

"If it RUNS good, it IS good."

Adjust. If it gets better, you're doing the right thing. If it gets worse, .... you do the math. Keep adjusting until it's as good as it can get. At that point,

Can I make it any more simple for you?

armybyrd

iTrader: (4)

Just did this myself a week ago on my L31r-after stabbing the distributor in correctly the timing was already pretty close and the engine ran well.

Dartht33bagger

I suppose the trial and error method would work. I'm usually pretty **** about being as precise as possible about torque specs and stuff, so I'd still like to figure out a way to know FOR SURE what the timing is. If it isn't possible then I'll just make it run good enough

Lurbie

iTrader: (3)

Sofakingdom did you write this under the influence of exhaust fumes?? You are normally very matter of fact about doing things right, and you entertain me with how direct you are in telling people how to do it right. When I read this I thought " oh no, another idiot joined the board," but I looked and saw it was one of the few people who I have a lot of respect for.
What happens if he advances it so much he melts a piston? Why not buy a piece of timing tape and do it right?
Don't take my comments wrong, I still respect you, I just don't agree with this one.

Queball

if i recall your timing marker should be sitting on the 2oclock position on timing cover
to time it with a gun correctly..

http://www.crankshaftcoalition.com/w..._TDC_lines_SBC

sofakingdom

iTrader: (1)

To "time" correctly, the HUMAN involved needs to disabuse itself of the laughable and erroneous fiction that IT knows better than THE ENGINE does, what the "timing" needs to be. An intelligent HUMAN would instead LISTEN to the ENGINE... no, actually, would ASK the ENGINE what it wants the "timing" to be.

I've known lots of engines in my day. Some were pretty weird, some were strictly ordinary. But I can assure you: NOT ONE has ever whupped out a "light" and looked at a "mark" and a "tab", then looked up a "spec" in a "book", and decided on that basis how it was going to run.

So, for people like Lurbie who seem to think somehow that "tuning" was not possible in the days before wideband O2 sensors and stuff like that, there's no real hope. As long as they think they know MORE about what their engine should like than THE ENGINE does, they'll be hopeless.

Best spark "timing" for any engine is where that engine runs the beet it ccn, in its user's opinion. That involves some combination of max power, crisp throttle response, freedom from detonation, gas mileage, running temp, and maybe some other things too.

LISTEN to your engine.

"If it RUNS good, it IS good."