Hot MSD Box

ox_ford_guy · #1 (**permalink**) 06-25-2007, 04:36 PM

Guys...My MSD 6AL box in my Backdraft gets very hot after about 45 minutes of normal driving.
I can only put my hand on it for a few seconds as it is so hot to the touch.

Is this normal? The box cover sort of looks like a heat sink so maybe it is met to get really hot?

If this is in fact a malfuntion any ideas what might cause it?
I tried out another 6AL ignition box temporaraly with the same result so I know it is not the box....I have also checked/cleaned the grounding from the battery to the frame at the rear of the car and frame to the engine in the front.
All is clean with good contact.

.Thanks for any help anyone can provide...ox_ford_guy

jwd · #2 (**permalink**) 06-25-2007, 05:28 PM

That's normal for them to get hot. MSD says to mount them in the engine compartment where there is good air flow. Not under the dash.

DAVID GAGNARD · #3 (**permalink**) 06-25-2007, 07:25 PM

Same here; on my 65 fastback the MSD box is under the hood and gets about the same temperature you have described,been running the same box close to 10 years now, so far, so good.....

On my 65 Mustang road race car, the MSD box is mounted on the inside of the passenger footwell, directly under the cool air vent, so it gets fresh outside air blown on it constantly,yet is still gets as hot as the one mounted on my street car, that box has been in the race car for 2 years now, so far, so good..........

I guess they just run hot!!!!!!!!!!!!!

David

rblong · #4 (**permalink**) 06-25-2007, 08:15 PM

Dito here - I have two cars with MSD in engine bay - no prob.

strictlypersonl · #5 (**permalink**) 06-26-2007, 05:32 AM

In a roadster that rarely runs with a top, the passenger compartment installation is probably cooler than in the engine compartment with the heat-generating side-pipes. Lots of air circulation, even under the dash, I suspect.

Pete Munroe · #6 (**permalink**) 06-27-2007, 08:52 PM

My MSD is under the dash on the passengers side, the box is bolted on the cowl crossframe and has air flow under and over.

Seems if it was in the glove box where there will be no significant air flow...maybe not ideal...but, generally, in my car it is a lot warmer under the hood than in the passenger compartment.

I would vote for the passenger compartment, or maybe up in the front of the car forward of the radiator bulkhead...( not great in the rain, just don't mount it upside down.)

Pete

Ant · #7 (**permalink**) 06-27-2007, 09:16 PM

Interesting post, I have had MSD 6AL on the passengers firewall in a previous Cobra with no problems, with this more purpose built race car, I was contemplating (common occurence) fitting the box behind my SC Dash where the glove box normally goes, I also have a dry sump tank mounted behind a glass wall at the end of the footwell, considering having a slide vent to allow heat to keep the wife happy on a cold winters day, as my car wont have a top!

I did run on my first car the original style cool air vents, they used to be plentifull here as a lot of old cars ran one on each side of the heater unit, no more, but my point was there is a lot of nice warm air on top of the footwells and if you leave the tubes off they act as a very good heater vent........but having said all that most of you live in a warmer climate than us here in NZ!

ox_ford_guy · #8 (**permalink**) 06-28-2007, 01:09 PM

Guys..Thanks for all the replies, I guess the box getting hot is OK and normal. Mine is mounted up under the cowl inside on the pasanger side. It is upside down with the power chip facing out. I guess this is OK, right?
I believe the newer Backdraft cars have it this way.
Thanks..ox_ford_guy

DAVID GAGNARD · #9 (**permalink**) 06-28-2007, 01:22 PM

Both of my boxes are mounted the same on a side panel, but I've seen them mounted in just about every position you can imagine.......since the box is a sealed unit and consists mainly of circuits/boards (no moving parts), I would think you could mount it in any postion......

David

jwd · #10 (**permalink**) 06-28-2007, 01:27 PM

Quote:

Originally Posted by DAVID GAGNARD

Both of my boxes are mounted the same on a side panel, but I've seen them mounted in just about every position you can imagine.......since the box is a sealed unit and consists mainly of circuits/boards (no moving parts), I would think you could mount it in any postion......

David

Actually the box is not sealed (the circuitry inside is though) and MSD recommends not to mount upside if there is any chance water will get to it as it won't be able to drain out.