I set my total timing at 36 where it no longer advances by reving the engine. The problem is it puts me at approx. 21 or 22 degrees initial and it creates hot start problems for me. It's a GM HEI that was rebuilt and it's only got about 15 mechanical in it plus it's got a 10 degree vac can on it. I tried the lightest springs but that didn't seem to change anything except eratic timing at idle. The weights have the # 41 stamped into them if that means anything. They are dark grey in color. Someone mentioned elongating some slots on it but I don't know how to do that. My battery is a NAPA Legend 7524 with 675 cranking amps and I've got good connections at my cables with the - cable being a 2 gauge wire and the + cable being a 4 gauge wire. I was not able to get my alternator tested yet but will as some guys suggested that here in another post.
A guy at NAPA told me I run the risk of burning a hole in a piston with too much initial but doesn't he mean too much total timing? My questions are: 1. Is he right? 2. How can I get more mechanical out of my distributor? 3. Am I ok with the 10 degree vac can?

Any other suggestions are appreciated. I want to get the best performance out of the car but not at the risk of ruining the engine and I understand this is a fine line. I definately want to stay conservative. Maybe I should just set the initial back to 16 where I didn't have hot start problems but then my total will only be like 31 and I understand from what I've heard and read here that I'm missing out on some horsepower.

Thanks

I'm taking my battery and alternator to Autozone for them to check tonight. If it is the alternator, anyone recommend a good one or just get a stock replacement while I'm there?

Well, you know since you're looking at replacing it anyway there's a lot of previous info here somewhere on the best alternator to get - converting away from a one wire.

Found it!:
http://www.chevelles.com/techref/ftecref14.html

Scott, The trick is to grind on the weights and center cam (mainly the center cam) to get the weights to sling out a little farther. Be careful though not to go too far or they'll sling out far enough to bind and sstay in that position. Take a reference measurement at a marked point to measure "sling out" before you start.

Xtreme,
Been reading up a lot on that conversion using the search function but not sure if I'm ready to tackle it yet. Thanks for the link. What is it with you and links (end links) anyway?!! Thanks again for sending them to me. My front suspension turned out great.

Von,
Where exactly would I start grinding on that center cam or weights?

Scott, when they rebuilt it they may have put a bushing over the pin that rides in the elongated slot that limits mechanical advance.
Take the dist. out and remove the cap, rotor, weights, etc. Hold it upside down. You'll see that one of the weight pivot pins extends thru the weight cam plate and fits into the slot.
The length of the slot controls the amount of mechanical advance.
To get good access, remove the dist. gear and slide out the shaft. You'll be able to get at the slot for grinding or use silver solder and files in the slot to shorten the curve. You may just be able to remove the bushing but it may give too much mechanical advance. You'll just have to play with it or find someone that can put your distributor in a distributor machine and set up the curve out of the motor.

Say "hi" to your family from Eileen and I.

Randy

ToyzRMe, On all the HEI's I've seen, the amount of advance on them isn't limited by the pin/bushing and slot like it is on a points type dist. It's limited by the shape of the weights and center cam and sometimes by the springs if they're very stiff. My experience with HEI's is that you have to grind on the weights and center cam to increase the amount of mech advance. Removing the bushing or grinding the slot won't change a thing. Aftermarket weights don't fit and are worthless but you need the lighter springs that come with them.

"What is it with you and links (end links) anyway?!!"

I about fell over laughing with that one!! Glad they helped. I've been looking into that alt conversion too, but haven't needed to do it yet. Good luck!

Try flipping over the center cam.

If that doesn't do it, grind the weights a little at a time.

As Von said, the aftermarket weights are junk but you do need the light springs from the kit.

Tom

MY BAD. I re-read Scott's post. For some reason I thought he was using a converted points dist on his '70 Chevelle. Sorry.

Randy

From Ignitionman on the V8buick board:

"The HEI uses limiting of mechanical advantage of the center plate curvature as it is interfaced with the weights. In other words, the center flattens out in its curvature and then stops the ability of the weights to move it further, making the mechanical advance curve stop at that point, no definate stop "pin" is involved.

The only way to do a large cap HEI correctly is to select the correct weights and center. As one of the best starting points for stock to moderate street engines, use parts from late 70's to early 80's 350 Chevy Suburban, center 375, weights 41. These parts are NOT available new as individual parts, but are in a shaft assembly, but you would want to do the wrecking yard thing far before that.

If a person would obtain a 375 center plate, it would be easy to make a two pin jig out of it to modify other centers that had enough meat on them to grind/sand off to make a 375 from it. 41 weights are fairly common. This 375/41 combo is common also to new Chevy Performance crate ZZ series engine HEI's, non-EFI, 350/383/454/502/572, in ZZZ, ZZ3, ZZ4, ZZ430, ZZ383, ZZ454, ZZ502/502 and ZZ527.

BTW, between all the different center/weight combinations for large cap HEI, there are over 455 different curves/limits. Have fun finding just that right one for YOU!"