I was running 15*initial and 21* mech = 36total ,all in by 4000rpm with the stock MSD springs. I played around with the timing today and bumped up the timing to 20* and have no problems with hard starting. I changed the springs to come all in by 3500rpm. My total is now around 42*. I don't hear any pinging or anything. I could change the bushing to a 18* and have a total of 38, would that be better? or leave it alone? I could spin the tires a little from the start now, so it does feel a little peppy. I also have no hesitation off the start. Is this ok? ?sound normal?

This is a loaded question because you didn't provide any details on the motor.

If it's a near stock motor with low(er) compression, 42* isn't bad. I run lots of initial (for a good size cam), but I keep the total around 34* for max power. Your motor may run just fine at 42*, but it probably isn't making the best power on that much. Only the dragstrip can tell.

Can you give us some specs on the motor? Hopefully we can figure out a good timing curve.

I set mine for the best MPH at the track. Came out at 40* total at 2800-3000.
Int.just happened to be 20*.

No hard starting or engine run on, and no overheating.

Sorry. It's a pretty much stock 210hp holley carb 327, stock stall turbo 350, stock rear. The prev owner prob put a "small" cam in it.

You think I should change my mech bushing? I believe the one that it comes with is 22*. If I change it to the larger one It will bring it down to 18* that would be a 38*total. Question ...Does bringing in total faster produce more power faster? Also the stock spring brought in my total all in at around 4000rpm. I changed one spring to a light blue and now brings it all in around 3500. Should I shoot for 3000?

Another.. the new motor I'm putting in later requires a 2400 stall with the comp 280H cam. Would I be able to leave my all in at 3000 for this combo also or around 3500? Also what do higher compression motors require compaired to stock?

Less total?
less initial?
Less all in?

Sorry for all the questions, but thats how you learn. ASK QUESTIONS!
Thanks.......

Don't confuse total timing advance with the advance curve (how fast the advance comes in)

I think you should run 36* total advance -- your engine should make max HP right in that area. 42* sounds like a bit much to me, over the years I have found that SBCs with factory heads (except Vortecs) and flat top of dished pistons almost all make best power with between 34 and 38*

On the advance curve, there are two things to work with.

1st. I think you want to change the bushing (the larger black one works for me) so you have LESS mechanical advance. Less mechanical advance gives you MORE initial advance with the same total timing setting. For example: 36* total - 26* mechanical advance = 10* initial. 36* total - 18* mechanical advance = 18* initial.

2nd. Select springs that allow the mechanical advance to come on quickly. This will improve your low speed throttle response. Use a timing light, a tach, and a friend to help you determine what RPM the advance curve starts and stops. You want a curve that starts just above idle speed and ends up around 2600-2800 RPM. You can mix springs to get the curve you need.

Also, If you have an MSD distributor the directions will help you pick the right bushing and springs to match the curve I mentioned above.

Hope that helps.

Sounds like alot of timing for that motor .Maybe outer balancer ring has slipped?

Don't confuse total timing advance with the advance curve (how fast the advance comes in)

I think you should run 36* total advance -- your engine should make max HP right in that area. 42* sounds like a bit much to me, over the years I have found that SBCs with factory heads (except Vortecs) and flat top of dished pistons almost all make best power with between 34 and 38*

On the advance curve, there are two things to work with.

1st. I think you want to change the bushing (the larger black one works for me) so you have LESS mechanical advance. Less mechanical advance gives you MORE initial advance with the same total timing setting. For example: 36* total - 26* mechanical advance = 10* initial. 36* total - 18* mechanical advance = 18* initial.

2nd. Select springs that allow the mechanical advance to come on quickly. This will improve your low speed throttle response. Use a timing light, a tach, and a friend to help you determine what RPM the advance curve starts and stops. You want a curve that starts just above idle speed and ends up around 2600-2800 RPM. You can mix springs to get the curve you need.

Also, If you have an MSD distributor the directions will help you pick the right bushing and springs to match the curve I mentioned above.

Hope that helps.
I have a dial back light with RPM. I'll change my bushing tonight from the 22 mech to the 18 and put the timing back to around 18 initial. I have the chart that came with the dist, so I'll try some different springs too. I'll let you know how it turned out.

Cool just remember total is way more important than initial. I set my timing for the correct total advance and let the initial fall where it may.

Cool just remember total is way more important than initial.
Yes on a race car
No on a street car..
Its the curve getting up to total and the advance above that thats more important.
A stock to mild street will have 6 to 8 intial at 500 to 650 rpm
Correct Curving up to around 30 to 36 between 2900 to 3300 rpm
With advance going to 40 to 48 at cruise start coming in about 1800 to 2200 rpm.
If u cant get within these, u have the wrong dizzy, vac leaks, wrong carb, or defective/mismatched components.

I agree with Eric, to a point.
As for our kiwi friend, I don't think LP gas likes a lot of initial.

Put the black bushing in. Leave the springs the way they are. Put the vac can on full manifold vacaum.

Don't run it (hard) with 42 total, it's too much. you probably can't hear the high rpm ping, but I bet the plugs will show it.

I agree with Eric, to a point.
As for our kiwi friend, I don't think LP gas likes a lot of initial.

Put the black bushing in. Leave the springs the way they are. Put the vac can on full manifold vacaum.

Don't run it (hard) with 42 total, it's too much. you probably can't hear the high rpm ping, but I bet the plugs will show it.

Thanks, I will try this. My total is around 3500... leave that?

LP gas likes a lot of initial.
LPG is diff yes.
Street engine
intial is same as petrol
Real fast curve about 28 to 30 deg all in at 2200 to 2400 rpm max.
Curve steep up to around 1400 to 1800 rpm at 16 to 18 deg then flatten out to all in.
Vac Advance same except total about 32 to 38 deg. tending to the lower end.
needs a good spark (36000 v), plugs about 2 steps colder and about 32 to 36/1000 gap
Also vac advance same as pertol off manifold vac

I would leave it.
That's exactly how mine is.

There may be some small power gains bringing it in earlier, but it would be very minor. Important to Eric as he searches for consistent 10's, for sure. To me who wants a reliable street car, nope.

My thinking is to reduce the chance of high gear ping accellerating from a highway cruise. With 18 initial, 18 vacaum, @ 18 in mech in at 2500, that's a LOT of timing at cruise. Delaying mechanical to 3500 will reduce the advance by 10 at 2500, and make it less likely to ping on a heavy load at low rpm.

Might not be an issue with an automatic, but I tend not to downshift unless I have to, and I most often don't have to.

What in the heck size wrench is that nut!!!! I have every size except 9mm. Thats the one I need right? Anyway I brought my initial down to 18* and my total is now 39* all in at 3500. Can't believe I can't find that wrench....Well when I change it I should be at 36* total. I pulled a plug and they look good.

Yes on a race car
No on a street car..
Its the curve getting up to total and the advance above that thats more important.
A stock to mild street will have 6 to 8 intial at 500 to 650 rpm
Correct Curving up to around 30 to 36 between 2900 to 3300 rpm
With advance going to 40 to 48 at cruise start coming in about 1800 to 2200 rpm.
If u cant get within these, u have the wrong dizzy, vac leaks, wrong carb, or defective/mismatched components.

Sorry, I think you need to do a little more research before you start correcting me . . . :rolleyes:

Total timing is what you get at WOT, too much and you get detonation and hurt your motor! I don't see how you can believe timing at idle is more important on any car, mild or hot. Street cars get detonation and blow up just like race cars.

Too much or too little timing at idle doesn't mean squat other than the engine's idle quality may suffer a little if its too far off. Stock engines had 4 - 6* at idle and a slow advance curve because of emissions! Not because that is how the engine ran best!

When an engine is throttled and cruising with a vac advance can of course adds alot of extra timing to help burn lean and diluted cruise mixtures. When I say total, I am talking about total mechanical advance with the vac can disconnected.

Set your total (no vac advance included) for 36* and play with your bushings to get initial down around where the engine is happiest. The bigger the cam, the happier the engine will be with more advance at idle.

Got to be careful with a lot of timing in your vacuum advance. The can brings the timing way up at cruise. Stock engine should be fine, but I have to cut my can way down or I will rattle at cruise.

Eric..The question I was answering was in a previous post,,And has since been edited ,not answering yours cause u never asked a question.
U will also see from my post I place limitations on parameters of total, similar to yours...Also if u go back over some of my posts I also suggest that set to whats up top, and the intial means squat...thu if someone uses an after market adjustable dizzy the total can be adjusted...or are able to machine and mod Stock dizzies they can also be made adjustable...mine are, a std pionts and a HEI.
Bit of a miss understanding I think..

"Set your total (no vac advance included) for 36* and play with your bushings to get initial down around where the engine is happiest. The bigger the cam, the happier the engine will be with more advance at idle"

This confused me a little?? If I set my total at say 36 THEN try to get the initial where I want, that would screw up the total.. The initial is adjusted by turning the dizzy and when that done the total moves up too. The total would be adjusted by the bushings.

"Set your total (no vac advance included) for 36* and play with your bushings to get initial down around where the engine is happiest. The bigger the cam, the happier the engine will be with more advance at idle"

This confused me a little?? If I set my total at say 36 THEN try to get the initial where I want, that would screw up the total.. The initial is adjusted by turning the dizzy and when that done the total moves up too. The total would be adjusted by the bushings.

IMO, the only way to do it is find the initial the motor likes (for starting and idling), then recurve the distributor for the proper total timing. After that, set up the slope of the curve (with springs and such) for best street driving.

But you're right, if you set the total then play with initial, you'll mess it all up.

Yea thats what I thought. I set the initial at 18* lastnight and now have a total of 39* with the 21* bushing. I'm going to replace it with the 18* bushing so it gives me a total of 36*, Once I find the freakin wrench!!. My total comes in at 3500. I'm still not sure where to end this at. I might just leave it like Jim said or maybe try 3000, I 'm not sure. Thanks

steptoe, OK -- were cool. :beers: Thought you were telling me I was full of it ;)

Yea thats what I thought. I set the initial at 18* lastnight and now have a total of 39* with the 21* bushing. I'm going to replace it with the 18* bushing so it gives me a total of 36*, Once I find the freakin wrench!!. My total comes in at 3500. I'm still not sure where to end this at. I might just leave it like Jim said or maybe try 3000, I 'm not sure. Thanks

What wrench? you said 9mm b4? ain't no 9mm bolt on a firstgen camaro, ain't no any kind of **mm bolt? If yer real careful, you can get the eclip off the bushing with a lil "hook" tool, like dentists use, might find one at radio shack, can do it without pulling the "dizy" if you're lucky. Not lucky, it goes "boing" and ends up who knows where.

Awe common Jim . . . I have all kinds of bolts with 14mm capscrew heads on my Camaro :eek:

steptoe, OK -- were cool. Thought you were telling me I was full of it
Nah m8..thuuu. welllll...being a Yank...sort of like this...When the british where top, then going back a few yrs, the Romans....now the US...its sort of the thing to do to tell the guys/or boss at the top they are full of it lol.
Its not fair really...its not your guys fault u where born there....
(tounge in cheek...Kiwi humour)

9mm bolt on a firstgen camaro
There is no equivent or anything close to a 9mm
8mm fits some ok
13 close to 1/2 " but not good practice, thu 12mm on a worn 1/2" works well
14mm close to 9/16" again not a good idea
For the hold down plate to loosen the dizzy is a 9/16" and if 1/3 way up the shaft of the ring spanner put a bend in it makes a good custom tool.
Another is the starter motor, a 9/16" with a bit taken out with grinder on each side of the shaft at diff pionts.
Bottom line DONT MIX...right tool for the right job.
Witworth for old English veclies
Imperial for US
And metric for jappa (imports)

I use all 3 regularly...each in its own tool box.
Adjustable spanners...Dont have one...hate them...a m8 got one out of his tool box in my workshop to do something, asked to look at it...ended up way over in a neigbours place....true.

Kiwi humor Eh . . . Hmmmm . . . well, if you guys would all quit having relations with sheep down there and focus on world domination like we do in the US (LOL, yeah right) you might get somewhere :D

LOL your funny..... The nut holding the bushing on the distributer is a 9mm nut I believe. 10mm is too big, 8mm is too small, 7/16th is too big and 3/8th is too small. You tell me??? Your saying the nut slides off like the ones you hammer on kids toys? You know the ones you can never get off without destroying!! It says LOCKNUT....

http://www.msdignition.com/pdf/8361_85551_frm23794.pdf

I see what your saying. How did you get it off again?

LMAO..
Kiwi humor Eh . . . Hmmmm . . . well, if you guys would all quit having relations with sheep down there and focus on world domination like we do in the US (LOL, yeah right) you might get somewhere
We produce the best export lamb in the world...Gess wfich ones get exported lol

mnm99,

Do you mean the nut on the hold down clamp? If so, 9/16".

-Chad

hmmmm..... my msd rtr 8360 uses an e-clip to hold the advance bushing on, I think? Was a year ago...

hmmmm..... my msd rtr 8360 uses an e-clip to hold the advance bushing on, I think? Was a year ago...

http://www.msdignition.com/pdf/8361_85551_frm23794.pdf

Jim, take a look where it says " Changing the advance stop bushing " Now remember the dist is still in the car so I can only see the top of the nut. Your saying this just prys off instead of unscrewing?

Your saying this just prys off instead of unscrewing?
It seems my memory is faultly.... find that wrench!

Bit of misunderstanding as to what nut u meant..

You need a set of "points spanners' Im not sure what u would call then in the States
maybe hobby spanners,,,something like that
They are small. open enders, come in sizes as factions /32 and /64th of an inch. Cost a couple bucks...Sometimes they come with a set of fine files. Again we call these piomts files, but model hobists also use them.
Usually come in a small roll up plastic pouch.

Bit of misunderstanding as to what nut u meant..

You need a set of "points spanners' Im not sure what u would call then in the States
maybe hobby spanners,,,something like that
They are small. open enders, come in sizes as factions /32 and /64th of an inch. Cost a couple bucks...Sometimes they come with a set of fine files. Again we call these piomts files, but model hobists also use them.
Usually come in a small roll up plastic pouch.

In the states, we call it a wrench... Look at page 4 on the install for changing the "advance stop bushing" look for " 2. Remove locknut and washer on the bottom of the advance assembly (figure 6). http://www.msdignition.com/pdf/8361_85551_frm23794.pdf

Thanks