Thunderbolt IV ignition

S

Speakrdude

Ensign
Joined
Feb 25, 2004
Messages
942
I am replacing my Mallory ignition system, (was points, then Mallory w/ weights) with a used Thunderbolt IV ignition system. Actually recommended by someone that frequents this forum.

The powerpak looks like it was made to bolt to the manifold. My question is, can I simply moiunt this to the transom? It has some standoff looking washers like it may generate heat.

Jim
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Thunderbolt IV ignition

Sure you can bolt it to the transom, just make sure the ground wire makes a good ground on the engine.
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Thunderbolt IV ignition

I can just see it a few years from now after you sell that boat, some guy comes to the forum and says. "I have a problem with my Thunderbolt ignition that's on my Volvo 350 Chevy engine" everyone is going to say, Volvo don't have TB ignition, that's Mercruiser :)
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Thunderbolt IV ignition

They used the Prestolite BID distributor for years in the V8 and V6 engine, the 3.0L went to the EST and eventually so did the V8's and V6 engines. The Prestolite distributor also had mechanical advance (Springs and weights) the EST is all electronic and doesn't have the external module like the Thunderbolt, it's all under the cap, but it also requires a special coil and connectors and a special way of setting the timeing. Unlike the Thunderbolt IV.
There is nothing wrong with the TBIV system, just record everything so you (and the next owner) knows what is going on and all should be fine.
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,513
Re: Thunderbolt IV ignition

There is nothing wrong with the TBIV system, just record everything so you (and the next owner) knows what is going on and all should be fine.
Click to expand...

Ayuh,........

Just enter it in the Ship's Log...................d:)

I usually cover it with the word "Custom" in the For Sale listings,.....
And,......
"As Is" in the Bill of Sale................ :love:
 
P

paulie0735

Chief Petty Officer
Joined
Dec 6, 2005
Messages
463
Re: Thunderbolt IV ignition

I would mount it to a solid piece of aluminum plate, look around a scrap yard for something about 6" square by around 1/4" thick, than mount the alloy plate to the transom. The alloy acts as a heat sink (soaks the heat out of the module) and the stand off washers help isolate the module from the alloy when it gets hot. Just make sure it can't get wet by any transom wave that may come over the back when you back off! (if you have that problem). Good luck.
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,476
Re: Thunderbolt IV ignition

If you mount the module on standoffs away from the aluminum plate, aren't you defeating the purpose of using the aluminum plate as a heat sink?
 
P

paulie0735

Chief Petty Officer
Joined
Dec 6, 2005
Messages
463
Re: Thunderbolt IV ignition

no, the heat will travel through the mounting bolts to the alloy. If you mount it without the stand off bolts the heat will simply be shared evenly between the alloy and the module rather than the alloy dispersing the heat.... basic physics tells us that hot always goes to cold and alloy is a very efficient disperser of heat. It 'will' work without the standoff bolts but it works better with them.
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,476
Re: Thunderbolt IV ignition

That's not how heat sinks work but it is probably not critical in this application since the module itself more than likely has a heat sink on it.
 
You must log in or register to reply here.
Top