Flip and Fly

I am thinking of buying one off these engines. I was just wondering if the mechanical ignition is superior to the electronic ignition. What are the pros and cons of these two setups? Brison states that electronic ignitions operate as such,

"These units fix the timing ring at a specific setting, while changing the timing based on the engines current rpm. These units work very well, but are limited to a 24 degree advance or retard in the timing. Some of the Brison engines are optimized beyond the capabilities of the electronic timing for ease of starting and maximum power output. This is achieved via a mechanical connection to the timing ring".

So from a timing perspective the mechanical ignition is superior in that it has more range from advance to retarding of the timing. I am sure the advantage of electronic ignitions is simplicity, however are they less pron to causing radio interference, and just what are the advantages.

Any one have any knowledge in this regards! Thanks.

Geistware

My Feedback: (16)

I have one and find that they adjust the timing to maximixe the engine thrust in the low 7000rpm band. I will be putting my up for sale because I just ordered a bigger model with the mechanical advance. I get 7400rpm with an APC or Menz 20x8 and I get very strong vertical with a 16lb plane. I am getting a bigger engine because I need 7500rpm using a 22/8 propeller.

AJF--2

My Feedback: (119)

I have owned both and perfer the mechanical linkage. The transition is much smoother--- power is not even an issue. Call Gary and he will tell you that he will sell you either, but you get a better low idle and transition with the mech setup-- and aren't those the reasons we wanted electronic ignition in the first place?

Flip and Fly

Geistware,
thanks for the response. I went to your web-sight and I see that you have a lot of experience with this engine. I will be putting it in a 13 lbs Extra, the Midwest kit -- I went to great lengths to get it light -- and at 13lbs I don't need much more power than this. However I really would like to get a new one; also because I live in Canada shipping used equipment up here can get a little difficult if there should be lost shipments or major hassles. It does happen. Thanks all the same.

AJF--2,
I was thinking the same thing, why not go with the mechanical setup, it should be reliable and effective. A fellow flyer up here at one time had 2 Brison 4.2s with this setup and they were remarkably smooth and reliable! Also made good power and he seemed happy with his setup. However he left the hobby so I could not get his opinion on it. Thanks.

VinceL

I have owned a Brison 2.4 for a long time. Mine is one of the originals from Brison with mechanical advance. I want to be sure everyone understands that my engine was pretty early in the run and my particular problem may have been subsequently solved. I had lots of problems with the teflon ring on the front of the engine binding. I would think that everything was perfect and when it came time to start at the field the bind was back. I would take things apart and loosen and lube and sand for a little clearance, back to the field to have the same thing happen again. Finally the original ignition from Brison ( their box not what they currently use from C&H) failed. That was the last straw, I went with new at that time synchro spark and have never had another problem. FWIW I own several other Brison and a Fox with the same basic set up and never had any problems with binding from their mechanical advance systems.
I saw no signicant difference in how the motor runs with either advance system.

Flip and Fly

VinceL,
well if you have one of the first engines and it is still runing strong that's a good sign. I think the fully electronic ignition they offer is the CH. I have not heard anything bad about this system either. I believe Gary at Brison will sell the motor with either ignition for the same price. So it leaves me wondering which one to get.

Thanks for the imput, I have a ZDZ 80 and it has 100 flights on it and I wonder what the life span of these new lightweight motors will be! Brison motors are reliable for sure, and the 2.4 is light also.

Geistware

My Feedback: (16)

Thanks for the kind words. I have about 300 flights on my engine on two planes. I am now getting a 3.2 to get more thrust for my PW Extra.

Ed

Understand, that while the timing is advanced, and retarded mechanically, the spark is still produced electronically using an ignition module. Radio interference should be at a minimum with either system, with the mechanical system having the edge because of it's greater range.

> Jim

My Brison 3.2 pulls this 24 lb brute with authority !

Flip and Fly

GeeBeeJim,

I take it you like Gee Bees. Great looking plane, nice job. Is that thing hard to land or what! If I ever get 3D out of my blood I may just do the nostalgia air racer thing. What an era that was! The brison 3.2 is also a good motor I take it.

Thanks for the info, I was wondering if their was any more ignition noise with the mechanical setup. Thanks for shedding light on the matter. I think I am going to go with the mechanical setup. Seems a lot of people are convinced of their advantages.

As a side note, I have a scanner and was wondering how to down load pictures to this sight. Can't be that difficult, but how, any way I will keep digging.

Thanks all.

tkg

My Feedback: (1)

98% of the gas fliers can't tell the difference between the two systems. For most the disadvantage of the mechanical system is that over time the moving parts wear and you must replace then sooner or later. But thats way down the road, usually the engine needs work for other reasons first

Antique

My Feedback: (4)

Only difference I could ever see was when using electronic control the engine will not accelerate as fast if the low speed needle is set too rich..The electronics depend on the acceleration of the crank to control the spark, and if the transition is slow the timing will not advance as fast...The advance is so fast it takes a really rich low speed needle to even get it to happen...And, syncro spark is $$$ more than mechanical....The syncro spark we use is the best electronic control ever, with a timing light on the prop it looks STATIONARY at any rpm....
My mechanical advance is mounted on a ball bearing, it will outlast the rest of the engine....
Same bearing as the alternator in your car..Ever wear one out ?....
Electronic is way better on a twin or other engine where there is no easy way to make a link from the carb to the front of the engine without resorting to bell cranks...

Ed

Not too bad to land, it takes some concentration, ya need to hold some power on to deal with that big draggy cowl, but you get used to it.
Era ? The Golden Age of air racing of course. It was the first of the Granville brothers bulldog racers, and it first flew in August of 1931.

Thanks for your interest. > Jim