Do you use a timing light ?

[Ol' Ron]

The combustion cycle need more advance, when the engine is in cruise. That's why a modern ignition system has a vacuum advance. The load a matic works very well if it's in good operating condition. Same goes for the Vacuum brake on the old distributors. However the old engines ran on 60-70 Octane gas, with a lead additive in some cases. These ignition systems worked well, but as we know now, they weren't the most efficient.
Yes it works, but it can be made to work better.

[flatjack9]

I always run a little extra advance. I know this might not be best for max power, but how often do we run our engines in this mode? Almost all driving is done at relatively low loads. Here the extra advance will increase fuel economy. As Ron has pointed out, changing to a modern distributor with mechanical and vacuum advance is a good improvement.

[scooder]

I love the way we, me included, refer to an ignition with vacuum and centrifugal advance as modern, it makes me all happy inside, knowing that although we may not sing from the same hymn sheet, it is in the same book. And it's an old book.
With the chaps who like a tickle more advance in their ignition. I feel there is good reason for this.
The better gas we have now, higher octane, will stand a bit more advance early on. For max power the stock Ford figure still stands though.
So what's really needed is to get the advance in earlier. This would give you that "I like a bit of extra advance" seat of the pants feel. It would also have the extra advance in relatively low engine speed cruise. So this fits even with the cruise at 2000-2500 rpm gang. But keep the max timing stock.
A recurve of this nature can make the engine come alive, feels like a bunch more horses under the hood, even though the power is actually the same max, it just delivers it better. On a heavy car you have to be a bit more conservative with your all in rpm level.
This is why I like to fit the lightest springs from the recurve kits I can in a converted chevy ignition, I'd like them lighter, next one I will probably wind my own springs. Start changing other stuff and the ignition curve will want to be different again.
As I stated earlier, I set a stocker at stock timing and be done with it, this allows the car to be driven hard with no issues and operates as it should. If it's modified, it gets what it needs.
And if it's got one of those modern Mallory things hung off it, just getting it to run as good as a stock ignition is a ball ache. But they are recurveable, still wish they had lighter springs in the kit.
Sorry for waffle,
Martin.

[elwood]

Good read Martin,
In my opinion, your correct, and I do believe Jim uses lighter springs in his units..
I have his units in my 2 running 8ba,s and nether are stock, and they both are very zippy.
I always line the dot up with the pointer, and pop in the unit, and it gets just a slight advance from there..

[hardtimes]

Originally Posted by elwood

Good read Martin,
In my opinion, your correct, and I do believe Jim uses lighter springs in his units..
I have his units in my 2 running 8ba,s and nether are stock, and they both are very zippy.
I always line the dot up with the pointer, and pop in the unit, and it gets just a slight advance from there..

Hey elwood,
IMO, how can you go wrong by following Jims' input/instruction ? He may use different words than some to inform, but IMO he is right on ! And, how many thousands of units of all kinds (4/6/8s/antiques/classics) has he done for us and we love them all. I've always done as he says he has done timing.
BTW...doesn't the 'condition' of the engine (worn out vs new) account for a little variance in the timing process also ? A timing light will help in either case AND will tell you how worn things are ...if old engine.

[scooder]

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You can't use a timing light to see how worn out an engine is. A massively high mileage engine will still most likely run best when timing is set to stock. Of course run best is a ambiguous statement.
Compression test or leak down test or a vacuum gauge are single devices that will tell you the engine condition, a timing light won't.
Martin.

[Ol' Ron]

Modern engines have engine management systems that control the AF and ignition timing many times a second to give maximum performance and economy ALL the time. No reason why we can't do the same with a better carb and Ignition system on our engines. At least it's something to try anyway.

[Kahuna]

Martin
Mine is a Helmet distributor, converted to electronic trigger amd 12 volts
I know very little about ignition advance, but am aware that combustion chamber design dictates advance and how much a particular engine needs.
My engine has modified Canadian aluminum heads (modified only for valve lift and squish), is 290 CI, has a large cam (Potvin 425), and dual carbs.
The engine appears happiest using about 10-12 degrees initial and a max of about 24 degrees. I just wonder, short of another dyno test, if the engine could stand another few degrees, as I never can hear it ping. Just my ramblings
Jim

[Bored&Stroked]

Hey Jim: You can probably up your advance to 26 - 28 and see what happens. I've found that 26 seems to be a really good number for most of my performance engines (flatheads). We run this amount even on our blown race engines (of course we have race fuel, but we're also running a lot of dang boost). Given your engine specs, why not bump it 2 degrees and see if it still doesn't ping - chances are it will give you a bit better acceleration a bit earlier.

Dale

[Kahuna]

Thanks Dale
I forgot to add that I'm working with a fellow on his distributor machine to set up the 12 initial/ 24/26 max on the helmet. Really, just trying to limit the amount

[scooder]

Jim, you got 10-12 initial and 24 max already built, as Dale said by all meens try bumping you dizzy a couple of degrees see what happens. Even though you got your Canadian heads (slightly higher compression) it's quite an open chamber, plus with tight quench cooling the charge it can in theory stand a bit more advance before ping or knock sets in.
Your 10-12 initial and 24 max is about where I would start with your engine combination. Have you tried allowing the advance to come in earlier? Backing off the vacuum brake would allow this.
Martin.

[scooder]

Forgot to add, if raising the max timing makes no change to the power up top, go back to what you have now. It's worth having a play backing the max timing off and see what that does, you may find more power, may. Just remember we're playing with the max timing only here. If advancing it gives you a bunch down the bottom, it shows that you want more initial or all in timing earlier.
Have fun.
Martin.

[GEOFFNZ]

As far as the ping test which we used 40/50 years ago goes, the improved fuels we now have here make it almost impossible to get pinging in a low compression stock engine in our experience.The timing light is so much more accurate.Geoff

[BUBBAS IGNITION]

I think the orginal posters question was very well answered in regards to the timing light question.
The discussion has turned to timing and heres some reading from our
www.gasolinealleyshops.org site in regards to our dyno testing results.
You can wander around the site or read one dyno day here http://www.lindertech.com/gas/8-21-07.htm

We still run this truck , nowdays at the ECTA event in Willimington Ohio and hopefully this year we will get our big stroker ( 304 ci) motor in the truck and go after the new record ( 110 mph). Bonneiville has gotten too expensive to travel fuel, room board etc so we love the 150 mile ride to Willmington.

All in all we have approx 5 days on the dyno and have found that anything over 28 degrees drops of the hp quite a bit...

Enjoy........

[Kahuna]

Bubba
Is 24 degrees a typo?
That dyno info says 28???
Thanks
Jim

[BUBBAS IGNITION]

Originally Posted by Kahuna

Bubba
Is 24 degrees a typo?
That dyno info says 28???
Thanks
Jim

Yep i fixed it , thanks......

[hardtimes]

Originally Posted by scooder

You can't use a timing light to see how worn out an engine is. A massively high mileage engine will still most likely run best when timing is set to stock. Of course run best is a ambiguous statement.
Compression test or leak down test or a vacuum gauge are single devices that will tell you the engine condition, a timing light won't.
Martin.

Hey Martin,
Thanks for your input !
Well, considering your comments, I wonder , when I put the timing light on an old engine, say V8 flathead, why the timing light shows the timing jumping/floating around a few degrees back/forth
I've always thought/found that worn stuff, i.e.-time gears, cam gear, dist shaft gear/tang , timing related stuff were worn maybe even badly. Engine in such condition could/ would still run. Hm, have to rethink that,eh.

[jake197000]

what bubba said. sun used to have a saying,test dont guess.

[scooder]

Originally Posted by hardtimes

Hey Martin,
Thanks for your input !
Well, considering your comments, I wonder , when I put the timing light on an old engine, say V8 flathead, why the timing light shows the timing jumping/floating around a few degrees back/forth
I've always thought/found that worn stuff, i.e.-time gears, cam gear, dist shaft gear/tang , timing related stuff were worn maybe even badly. Engine in such condition could/ would still run. Hm, have to rethink that,eh.

Solid copped leads like those normally fitted to old stuff, if the timing light is a clip over the lead type (most modern ones) they pickup HT "noise" from other plug leads, this makes it look like the timing is flicking around. You'll find though if you watch it, it will flash more times on the correct point. Can take a bit of patients, try it.
Martin.

[josh1331]

Bubba, when I assembled your helmet distributor,, was I suppose to retard/ advance distributor until I heard ping then back off. I'm a newbe at this. Thanks john