having an issue on a 69 small block.just installed a rebuilt stock distributor with a crane module, a new high performance shaft and new distributor cam.i can only seem to get 30 degress total timing.using the mr gasket spring kit with medium spring.advance is all coming in by 3000 rpm but cant get more than 30.any suggestions?thanks

 

Check into a member here Lars He has some wonderful Info on Timing and how to set it up . Old "sticky" and I think even a website .
Anyhow contact Lars he can set you right up and It works great .

 

What's your base/idle timing amount (ie: what's the delta between that and 30*)?

 

about 11 degrees initial timing

 

What exactly is limiting how far you twist the distributor?

 

had the initial set at about 14 and still couldn't get the 36

 

The amount of advance between initial and total is determined by a bushing thhat limits the travel. If you want more, you use a smaller bushing.
I would suggest setting it getting your total advance set and dont worry about initial unless you have issues or need to pass emmisions.

 

ok the kit came with a brass bushing as oppsed to the plastic one that was on the shaft.i'll have to check the diameter on that

 

Just rotate the distributor so you get the 36 total. Is there a reason it won't rotate any further? If it's hitting the manifold, pull it up, rotate one tooth, and then set timing to 36 total. If you can set the timing to 11 initial with 30 total, then the timing can be set to 17 initial and 36 total - perfect numbers.

Lars

 

no i was just being cautious not wanting to set initial that high.brand new engine and i dont want to lean it out and break somthing.

 

Optimal timing is not going to burn up your engine.

 

That's correct. Unless your timing is so far over-advanced, or your centrifugal curve is so agressive, that you're actually getting into detonation under high rpm/high load, a correctly-set timing curve won't do any damage to your engine. In fact, an over-retarded timing setup is likely to do more damage, since retarded timing will raise combustion tempertaures and cause you to run hot. So crank some timing into that puppy and set it up right - 17 initial with 36 total would be a great setup, assuming you get the total to come in around 2500-3000 rpm.

 

i set my race boat motors to 40 one time and bent valves in both they were bbc 10-1 roller cams

 

try to get to 36 as suggested above then go drive it or better take it to the track if you have that option.....read the plugs then back it down to 34 and see how it does. All engines are different....my engine actually runs a little better with less timming......my uncles big block likes timming he is running 40 degrees with a bottle

I usually bounce between 32-36 and see what it likes and also how it starts then lock it in

 

In my 35 years of NHRA racing and building race & street engines, I've never heard of ignition timing bending valves. I've seen detonation from over-advanced timing break pistons and rings, and I've seen lean mixtures and retarded timing burn valves and seats, but I've never heard of timing having the ability to bend a valve. I imagine anything is possible, and I'm sure there are failures that I have never heard of or seen, but that sounds awfully funny, and I would tend to think that there was something other than ignition timing that caused the valves to bend.

Either way, the engine you have now will run just great with the 17 initial and 36 total - this setup will give you a very nice idle, and top-end power will be great. Unless you have extreme compression or exceptionally bad gas, you won't get detonation with those specs, and you'll be very happy with the way the engine runs.

Lars

 

That's generally a good range. On the dyno, we see that small-block Chevys and Fords with smaller diameter bores and good heads want total timing in the 32-34 range. The same engine with a stock head and a less efficient combustion chamber will take 34-38 total. Large bore engines with inefficient factory heads (big Pontiacs with factory heads, for example) will take 38-41 total, while the same engine with a good aftermarket head will take 36-38. So the "mean" spec tends to be 36, which is a pretty safe "best performance" spec for almost all performance engines if you don't actually have a dyno or a drag strip to check the performance.

A few years ago, I did an article with Hot Rod Magazine with then-Editor Matt King. We ran a small block Ford on the Westech dyno, with noted dyno operator Steve Brule. Once the engine fired up, Matt asked, "Hey, Lars, check the timing on that thing before the pull, will ya?" Nobody mentioned any specs or numbers, and I ran in the test cell with the engine running, grabbed the timing light, had Steve run the rpm up until the timing pegged out, and I set it to 36. When I got back in the control room, and said, "You did want timing at 36, didn't you?" Brule looked at me like I was stupid, and said, "What else would you set it to?"

Me (green shirt), Matt King (behind Steve), and Steve Brule (in black) discussing setup prior to a dyno run:


King (left) and Brule looking over the run numbers after I set up the timing: "What else would you set it to?"



Lars

 

Lars...no doubt your knowledge far surpasses mine.....I have read articles from Brule on carb tuning ...good stuff. Your dead on with your description of what type of engine can take specific degrees of timming. My small block is only 355ci @ roughly 12:1 compression and good flowing heads. I found the car to run better at the track with less timming and has much better street manners.

As far as the op is concerned you are right 36 is the way to go

 

Hi Everyone ,
I had a good feeling when I suggested Smyth1 get a hold of Lars that it would bring a good discussion on Timing ..... I have a '74 Coupe L82 350 set up with Lars methods and it runs and performs great here at 4275 ft. elevation . His set-up for 36 timing total with an adjustment on springs gives me about 19 degrees at idle and it purrs just fine.
Thanks Lars and everyone else . This Forum is great !!