Snyder 5.5 Changes Things

[crminal]

Interesting reading here. So here comes the question....
I am using a FS electronic ignition which is self advancing up to 28 degrees (right way to put it?)
When I set up my ignition, I made a pointer which lined up with my pulley and marked it a TDC. Would you ever rotate the dizzy to advance or retard timing? What would be gained if anything?

[Art Bjornestad]

I think an impulse mag has a spring that lets the mag spin very fast after is is wound in the first few seconds of the engine start procedure. This allows the mag to get enough revs to produce a stronger spark. Art

[BRENT in 10-uh-C]

Originally Posted by crminal

Interesting reading here. So here comes the question....
I am using a FS electronic ignition which is self advancing up to 28 degrees (right way to put it?)
When I set up my ignition, I made a pointer which lined up with my pulley and marked it a TDC. Would you ever rotate the dizzy to advance or retard timing? What would be gained if anything?

Lets start by asking you how do you know that 28° is the optimum timing for your engine?

If you were to say your engine makes peak horsepower at 27°, then theoretically you could retard the initial timing of the distributor by 1° to accomplish 27° of full advance.

[columbiA]

I am running Champion C16C,s gapped at .035" in my "B" with a 5.9 head for 14,000 miles with no problems.

[Patrick L.]

I'm kinda of the opinion that less is more, at times.. And this is one of those times.. Regardless of which cylinder head these little engines have,, why would they ever need 40º of advance.. I don't think they do.. I don't think any 2000 rpm engine needs 40º of ignition advance.. i doubt there are very many of us that even run our engines that fast.. My left lever is usually at 9:00-9:30 and thats its 'sweet spot'..

[Brobrian]

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Originally Posted by Patrick L.

I'm kinda of the opinion that less is more, at times.. And this is one of those times.. Regardless of which cylinder head these little engines have,, why would they ever need 40º of advance.. I don't think they do.. I don't think any 2000 rpm engine needs 40º of ignition advance.. i doubt there are very many of us that even run our engines that fast.. My left lever is usually at 9:00-9:30 and thats its 'sweet spot'..

I suppose we can only compare spark advance from car to car if we agree to set the points to just open at TDC (using the pin) and as long as all the linkage on the advance lever is straight.

With those things in mind, my cars both ran best in the full advance position. Now, since installing the HC head, the coupe runs best at 9 o'clock or so.

BTW I still don't prefer the new running characteristics. Just doesn't feel right, and I can't relax for listening for engine knock.

[Keith True]

I have one truck with a Brumfield head that I can only run very little advance on.Start it up,pull the lever down 2 or 3 clicks,and that is it.Any more and it actually pounds and bucks.I'm just not used to that.All my cars have always been sensitive to the spark and GAV settings.Start at full retard,a couple clicks down for idle,about halfway down around town,and all the way down for flat out.Each one has a little variation,but that was always in the ballpark.The truck with the Brumfield head has a B cam,and is either .060 or .125 overbored.I did a couple of engines over years ago and I can't remember which car got the big drilling.The main thing is,it doesn't bother in the least.Three clicks down and it runs like a bear all day long.Another thing with it,is if I do advance it too much,I never hear a ping,it just goes right to detonation,or hammering.It is combustion,not bearing noise.

[BRENT in 10-uh-C]

Originally Posted by Brobrian

BTW I still don't prefer the new running characteristics. Just doesn't feel right, and I can't relax for listening for engine knock.

You can if you 'up' the octane rating of the fuel you are using. A higher octane rating will compensate for detonation (within reason!!).

.

[crminal]

Originally Posted by BRENT in 10-uh-C

Lets start by asking you how do you know that 28° is the optimum timing for your engine?

If you were to say your engine makes peak horsepower at 27°, then theoretically you could retard the initial timing of the distributor by 1° to accomplish 27° of full advance.

Thanks for the response. I think I know where you are going here.

So, if I wanted to do some "trial and error" timing by rotating the dizzy a degree or two, it would be okay. Then I could optimize my timing.

[Duffy1]

So how can you tell if you are running it too retarded are to advanced . Too retarded causes carbon build up.Too advanced causes rattling and is hard on the engine.

[Purdy Swoft]

I feel that driveing to slowly in an attempt to be easy on the engine causes most of the problems. When some speed and momentum is not maintained when approaching hills you will end up lugging the engine. Timing knocks occur when the engine is lugged and that is when the spark needs to be retarded to cushion the knock. A lot of people read the owners manual and try and use the spark as was necessary over eighty years ago. In the day that the manual was printed, the roads were mostly trails, fuel octane was very low. driving speed was slow and more use of the spark was necessary because of the conditions of the time. Its not safe to drive at the creepy speeds that they were driven eighty years ago on todays highways. To be perfectly honest, most just don't understand or know how to drive a model A. A lot of people are either lugging the engine to the point of timing knock or running so retarded that the manifold runs red hot, neither is good for the engine.

If you are driving on trails like I like to do or driving slow on back roads. more spark retard is needed. If you hear knocks, retard until they go away. If speed and momentum is maintained , run full advance, or you will lose power and run hot. On the highways or main roads, I put it up on 50 mph and let er go. With my 5.9 head and other mods, mine runs about like modern cars. I can accelerate up the hills if I need and I never lug the engine. I run 3.78 gears and believe that is the best all arround ratio. With any manual transmission vehicle, you will do more damage to the whole driveline by lugging in high gear!!!

[Tom Wesenberg]

Originally Posted by Duffy1

So how can you tell if you are running it too retarded are to advanced . Too retarded causes carbon build up.Too advanced causes rattling and is hard on the engine.

Too retarded causes loss of power and overheating. Too advanced causes hammered out babbit and knocking.

[spdway1]

I NEVER move my spark lever, not even to start it, am I doing something wrong? Its starts fine, runs fine up and down hills, back roads and highway.

[steve s]

Originally Posted by spdway1

I NEVER move my spark lever, not even to start it, am I doing something wrong? Its starts fine, runs fine up and down hills, back roads and highway.

Depending on exactly where your universal setting is, it could run even better and with less risk of busting or jamming your starter mechanism.

Steve

[modelAtony]

I have 5.9 brum , 3.27 gears in my inserted engine . don't know about sniders 5.5 but basically same as brum. DONT run your spark more than 1/2 . REALLY more like 1/4 at 50 mph. DONT CARE WHAT PEOPLE TELL YOU . 1/2 IS TO MUCH. HAVE FUN MODELaTONY LAFAYETTE,LA

[marc hildebrant]

spdway,

Why would you NOT adjust your spark ? Surely the fact that the spark has an adjustment for the driver means that it was normally moved during operation ?

Marc

[spdway1]

Originally Posted by spdway1

Its starts fine, runs fine up and down hills, back roads and highway.

I don't see/feel/hear a difference. So why would I?

[duke36]

just to confirm, what should be the spark plug gap be for a Brumfield 5.8:1 hi compression head?

[ronn]

I don't see/feel/hear a difference. So why would I?

are you sure it isnt disconnected......................?

[colin1928]

Originally Posted by rip94611

just to confirm, what should be the spark plug gap be for a Brumfield 5.8:1 hi compression head?

That would depend on the strength of the ignition system (voltage out of the coil) and spark plug design
Generally go with what the spark plug manufacture recommended
Maybe start at around 0.032" and adjust as needed