30* Timing?

Well I finally got my little 383 together and in the car. I have had it out for 2 test and tunes and it seems to like 30* of timing. The first test and tune I had it on 34* and it MPH around 120, good but I was expecting better. I had to pull the distributor to re-prime the oil after the check valve failed (external oiling), and didn’t check the timing before heading out to the 2nd test and tune. Once at the track, it picked up 3 mph, now provided it was a near perfect day 60 degrees 35% humidity, and I had jetted it up from the first session. After the 3rd pass I decided to pull some more timing because the plugs seem to indicate it still had too much, set it at 28* it slowed down. Went back to 30* for the last pass and it was back to 10.85 at 123ish. I know the Edelbrock head is a much better head than my 906 but I was not expecting 10* difference as my 906’s liked right at 40*.

I was also curious if a different octane gas would be a factor . I normally run 90 pure gas but the station I get it from changed hands and now it is only 87. I am only at 9.5 static compression, 7.95 dynamic , since I am having to run a .066 gasket because of the being .007 out of the hole and aluminum rods.

What brand and heat range plugs?
Most of the B/RB motors I've play with like from 34 to 36 degrees total timing with good near optimum tune
Did you verify the TDC on the balancer and the timing cover?
If not do that next

Currently I am using the NGK 6987, which is a 6 heat range. I started with the Autolite 3924, but I went through my stash testing carburetors and starting using the NGK's I had on hand.

I was having some issues with the timing gear that came with the engine because it appeared the engine has been line bored, so when I went to the short chain, I checked TDC again. However, now that I think about it I did not go back and check my cam timing.

If you are saying that total timing, all in at say 3K, and it runs best at 30 degrees. That probably isn't correct and your damper or something isn't right.

my quickest times were 38* started at 32*, (locked out) (93 octane with booster) 383 stock compression steel shim head gasket .484 purple shaft T/Q carb, stock cast iron intake






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Timing needs for an engine are dependant on a lot of factors.
A flat top piston with a quench to the combustion chamber can need less than a dome with an open chamber.

I had a 512 CID flat top piston, Indy 440-1 heads, 0.039" head gasket (quench), 13 CR that liked 32 degrees. 34 was no different, and 36 slowed the car slightly, but measurable and repeatable.

My 11.75-1, 388” smallblock with hand ported Brodix B1BA ended up with 30. We made several pulls and it made no more power above 30.

I hear this 30-32 timing thing all the time on the internet, but that is NOT what happens at the track.

Next time at the track, walk around and ask what guys are running. I've never heard anybody running that low of timing. I actually think that some are convinced that if you run more than 34 degrees you can disrupt the time/space continuum and destroy the entire universe as we know it. That's a worse case scenario of course, the damage may be merely limited to our galaxy. Good luck what ever happens, but don't believe everything you hear (including this)

A couple of thoughts. The dampner and pointer may not be set to true TDC. 87 octane may not be enough. So the engine is in detonation with more than 30 total. maybe thats all it likes. My 580" with Indt -1's barely changes ET between 30-36. Less than .05
Doug

For your fuel, compression, cam and quench situation, the motor responded bestTO AN OBSERVED 30 degrees. So trust the time slip. But if you change fuel, or timing light, or cam timing, then you will need to retest the timing it wants. The next time you have it apart, recheck tdc marks and cam timing. That way you can be certain of the observed timing

I’ll be at Grove Creek May 25-26. Stop at my trailer, I’ll hand you the timing light. (The Holy Grail Sears 2134).

, that is the holy grail of time lights, same as mine. Sorry, I'll be in Eddyville. I'll see if I can't bump into to you somewhere this summer. Good luck.

By all means, run it where it likes it. The timeslip doesn't lie. I'm very surprised if that motor didn't want 36-40 degrees. Like said, something may be off giving you an inaccurate reading.

Like has been said run it where its happy. Could be alot of things but who cares if the plugs look good and its faster let it eat

Back in 80s we ran a 426 Hemi 12.1 pistons roller cam and cross ram intake, it likes 36-37* fast forward to 2012 a Barton all aluminum 528 ran 30*, what Barton told him to set it at.? We moved it up to 35* once but didn’t help. The only thing I thought was it being aluminum, the 426 all iron.

I’m planning on making Cedar Falls, Grove Creek and maybe Rock Falls. Good luck to you as well.

the thing with electronic ign is some they advance & some retard as the rpm goes up, you check the total @ 3k & its 30deg, but @ 6k it could be 34 degrees

I was able to locate some 90 octane pure gas, so I am going to run that tonight. I think I am going to jet it down some, as when I cut the plugs it looks like it is rich now and it is suppose to be 15 degrees warmer today than last weekend. I am also thinking about going ahead and adding two degrees of timing. I am curious if the 87 octane is part of my problem, as when I went to shut if off last weekend it wanted to run on for just a second. I do have the timing locked out, my box will pull 20* when I start it. It will idle right around 1,200-1,300, so the run on may be a high idle and 87 octane. The engine itself by water temp was very cool, it was hard to get it to over 180* last weekend, so I want to say it is not running hot. When I have had run on in the past with the iron heads I was convinced it was hot because it was lean (water temp 200).

This is 32*

i like to see the timing mark on the ground strap in the middle of the curve, not down low next to the spark plug body
Other than that that plug looks good to me

so looking at that ground strap colorization, which way does the timing need to go ? more or less ?

I'm not sure so I would put one new plug with the same # and install it in #7 and advance it 4 degrees and go drive it at light throttle cruise and check it to see where that line ends up
Please let me know what it likes

U are correct...
I have found different mopar ECUs will vary the timing, sometimes advance and/or retard up to +/- 4 degrees..
Thats why when changing an ECU, one needs to recheck the timing both initial and total...

Just my $0.02...