Dyna Ignition Coil Placement Small Blocks

[Psychopasta]

Hey peeps,

I'm thinking about where to place the new Dyna coils in my V50 Monza build. I'm thinking here:







Black cable ties are just for placement, mind. I'll use orange ties for the final job  The tank goes on nicely, and I won't need that space for the airbox. Any concerns or thoughts? Or examples of different/better placement?

- Pasta

[pat80flh]

Isn't the stock location bolted to those 2 straps of steel that span the frame tubes?

As I recall the dynas were a little too long to fit those brackets.


I ended up cutting off the forward bracket, moving it ahead and rewelding it to the frame on my V65

[Chuck in Indiana]

The Dyna coils *need* to be bolted to a heat sink. They'll fail if you just zip tie them. Trust me.
Edit:
Here are the brackets I made out of steel to mount the coils to the original small block mounts. I tell all about it in the Lario Rehab thread.

[Psychopasta]

Hey Chuck,

Their design isn't great for mounting onto a heatsink. Any suggestions on how to achieve it? The best I can see is to clamp them by one of their small, flat surfaces...but that won't give much heat flow.

- Pasta

[Chuck in Indiana]

Hey Chuck,

Their design isn't great for mounting onto a heatsink. Any suggestions on how to achieve it? The best I can see is to clamp them by one of their small, flat surfaces...but that won't give much heat flow.

- Pasta

I tell all on the Lario rehab thread, page 19 
http://wildguzzi.com/forum/index.php?topic=58695.540
Ignore the ballast resistor, that was a failed experiment. I've been running the green coils without issue for many thousands of miles, now.

[John A]

This is how I did it, the top is bolted to an aluminum heat sink , the bottom is attached with adel clamps. Pic doesn't  show it well but there is a substantial heatsink there. The installation is made to not modify the original structure of the motorcycle as is my habit

[Psychopasta]

Thanks guys!

So in both cases, the heatsinking is done by attaching brackets to the pole pieces, yes? The bodies themselves are radiating into free space, correct? I'm surprised there's much heat sinking, although some is better than none, I guess.

At the risk of  :Beating_A_Dead_Hors e_by_liviu do the Dynas suffer from thermal damage or vibration? I can see both of these solutions giving a much better mechanical coupling than thermal. Not arguing, just trying to understand 

- Pasta

[Chuck in Indiana]

My understand is that it is thermal. That iron core is where the heat is, and being solidly attached to something that can carry away the heat is what is required. 

[danomar]

The Dyna coils *need* to be bolted to a heat sink.

+1

Make brackets or at least mount one one to metal. For my former V50 III, I seem to recall that I used the front (headstock end) mounting point with perhaps spacers and then I made some form of rear bracket.

Consider staggering the coils, too. There is no need to have them side by side or even above the sparkplugs. Just keep the HT leads relatively short and away from rubbing parts.

HTH

[Psychopasta]

Hey guys,

Thanks a lot for this. 

I can see why you'd want to make brackets to bolt these things down, but I'm having trouble with the idea of those brackets acting as heatsinks. Heatsinks are usually large compared to the thing that is having its heat sunk, and they usually have a large surface area/volume ratio to get rid of the heat.

Looking at Chuck's photo, I can see that being a good solid mount, but it looks like way too small a contact area to provide much heatsinking. Also, since the coils are usually somewhere near to the engine, I would have expected heat to flow into the coils from the surrounding area, not away. Do the coilds really run hotter than the engine?

Not trying to be argumentative, although it is in my Scottish genes  But do coils really run that hot, can a little bracket like that like really act like a heatsink for something heavier, and does the engine heat not make it all a moot point?

You should see me when I am trying to be argumentative 

Cheers, Pasta