After reading some posts on hear and having had a couple BB olds motors I thought I would revisit my engines timing.
I didn’t build it and have no specs for what’s in it…bangs head…

when I bought the car last year it ran ok but I thought the timing was a little to much advanced. It was around 22-24 before mechanical input. I brought it back to 15 for an all in of around 30.
it ran better so I left it there for the season.

I tried advancing it to 22 again and it definitely killed some power..all in was around 36-37
i went half way back to 18 with all in around 33 and runs great, off line power is right there.
amazing what a couple degrees does over or under…

 

Engines like what they like...

 

Curiosity clarification questions here, not arguing points:
22-24° with the vac advance canister connected to full intake vacuum right?
What is the base timing with the advance can disconnected and the vac nipple capped off?
What is your curb idle RPM setting?
At what RPM is the full curve "all in"?

Have you tried simultaneously setting the timing and A/F mixture with just a vacuum gauge, (no timing light)?

 

All base timings were with vac disconnected at 750 rpm then ran to 3k to get all in with mech advance.

after all set, reconnect vac and ran to 1800 rpm for vac advance test.

I still will need to check the vac setting and adjust again. Lol I haven’t even pulled all the plugs for gap yet..hehe
im only to third base with this motor.. 🤪

 

You're not going to get to your total timing at 3k RPM. You need to check it to the RPM that the distributor stops advancing.

 

I’ll check it again but it seemed to be done at that point. It appears that the mech advance on the HEI was set to max at 15 degrees. Haven’t been into the distributor to see if it’s at a stop or super heavy springs.
I did run it to 4k once and no changes and thought that was high enough for checking timing.
should I go higher yet…hard for me to hold it as it’s screaming in my ear…hehe.

 

It does run good where it’s at..no ping

 

From the pictures in your intake thread, the distributor looks like Pertronix Flamethrower. Which HEI are you using, PN? Heavy springs bring the timing in later.

 

I honestly have not made it that far…it has a flamethrower modular on top but may be a stock HEI.
this motor was built late 90s but only accumulated 5k..now 6k since then.

copy on springs…it comes in fast so must not be heavy ones.

 

I’m still talking nice to it getting it to trust me…
and 7k as of Saturday…🤭
and some tire rotations..hehe

 

Do you think it’s worth lowering initial and giving it more mechanical?

it launches hard currently or as hard as a one wheel wonder will….

just picked up a posi from Mr Nick to install to help that issue..

 

It looks like you have a D1100 distributor, it is supposed to have 23* of mechanical advance. So your 15 initial + 23 mechanical puts your total at 38. The 3 sets of springs are copper, silver and natural. Depending on which springs used would bring your total in sooner or later.
0017-004400.qxd (summitracing.com)

 

That’s what I was reading too.
I think they put a limiter/ stop in it. I’ll have to get motivated to see what’s under the cap.
it is defiantly set at 18 idle@750rpm and 33max after mech at high rpm.

I had my HO set to lower initial and with mech kicked in to 38 total. It was on the edge of ping if bad gas was used.

this engine does not seem to like more than 18 initial with the way the mechanical is currently coming in.
If it is being restricted to 15 mechanical, do you think it’s worth trying to increase it to get total higher but maybe heavier springs so it comes in later?

I guess I am going to have to pull the cap and see what has been done under there.

 

I really wish I had all the specs on what went into this motor.

 

If it's running well where you have it, I'd leave it alone.

 

Eric I did find the part number on the dist and it is deed a D1100.