How much air does an MSD box need

jwinkler · #1 (**permalink**) 05-12-2005, 08:40 PM

I have just finished installing a 6AL in the passenger compartment on the firewall.

In order to keep the car somewhat civilized, I left the interior carpet in place, which means that even with its isolator mounts, the bottom of the box is against the carpet, so my question is how important is it to have a gap under the box? Since it's inside the passenger compartment, it won't see the same temps it would in the engine bay, but will it give off enough heat to hurt itself?

I'm a little overly sensitive to this, since the MSD is going in in place of a Mallory that got cooked (as best I can tell) by being too close to the heater hoses in the engine bay.

Thanks,

JLW

PS - I asked this before, but before I start the motor, I'm going to pull the distributor and turn the oil pump. If I mark where the distributor rotor is in relation to the body, can I pull it out and put it back in without having to move the motor to TDC?

jwinkler · #2 (**permalink**) 05-12-2005, 08:44 PM

Here's a pic of the MSD mounted against the firewall:

rblong · #3 (**permalink**) 05-12-2005, 08:57 PM

I can't answer the MSD question. Mine is in the engine bay on the fire wall and I have had no problems. At least on a chevy you can remove and reinstall distributor as long as you take care and get it back in the same location. I assume the Fords are the same way. Have not had to pulll mine on my first Ford to own!

Rick Parker · #4 (**permalink**) 05-12-2005, 09:16 PM

The MSD unit will be fine. The "Potting" that protects the intrenals of the MSD box helps disipate the heat through the aluminum box itself. I can't imagine too much heat being conducted by the mounts.
Regarding the distributor removal. Note where the rotor is pointing, if easier rotate the engine until the rotor is pointing directly to the front, side, rear etc. While removing it slowly twist it back and forth to prevent from pulling the pump drive out of the pump. After spining the pump with a drill reinsert the distributor so the rotor ultimately ends up pointing in the same direction as when removed. You may have to turn the pump drive a small amount before the distributor will slip back in easliy. Once you get the hang of it and see what has to "line up" it becomes easier. I do this each time I change the oil.

Rick

Rick

Zoom This · #5 (**permalink**) 05-13-2005, 10:00 AM

I also have my MSD box installed under the dash, passenger side. The box does get hot while it is working. If I touch mine after the car has been on the road for a while, it is surprisingly hot to the touch. Not mildly warm but somewhere around 100-120 degrees.

Jack21 · #6 (**permalink**) 05-13-2005, 02:16 PM

I always mount the box in the engine compartment, but away from exhaust manifolds or headers.

CR Cobra has a little "shelf" in the engine compartment that's perfect for CD box.

Ceramic coated headers put out far less heat to the engine compartment components also.

Tommy · #7 (**permalink**) 05-13-2005, 02:19 PM

Rick -

Have you ever added oil via the distributor hole? I have no oil filler hole in my valve covers, so adding oil via the distributor hole would be easier if it doesn't cause a problem.

Rick Parker · #8 (**permalink**) 05-14-2005, 08:30 PM

Tommy:
I can't say that I have ever added oil that way but it certainly would be ok. If you are running a stroked 410 Windsor without breathers you may want to reconsider. You may begin to have problems with seals and gaskets leaking, caused by the increased crankcase pressure created by the increased displacement. The engine has to be able to breathe.

Rick

Tommy · #9 (**permalink**) 05-15-2005, 05:49 AM

Rick -
Thanks for the answer. My engine breathes trough a vented catch can that is connected to each valve cover with AN 10 hoses and fittings. I can add oil by disconnecting a hose and pouring oil through a fitting, but it takes a long time.

cobralee · #10 (**permalink**) 05-15-2005, 11:51 PM

I have my MSD box mounted under the dash, facing downward, so not attached to the firewall. It works fine, no heating problems.

Russ Dickey · #11 (**permalink**) 05-16-2005, 08:36 AM

My 6AL is mounted on the firewall, pretty much centered behind the left valve cover. Everyone has always warned me about the engine heat in that location, and advised me to put it in the passenger foot well, but thus far I have 7600 trouble free miles on it.

RICK LAKE · #12 (**permalink**) 05-21-2005, 04:23 AM

jwinkler J I have my Fast computor and MSD 6AL mounted to the bottom of the ERA glove box hanging over it. Both are rubber mounted and have the R/S boot box air tube blowing on them that is for the foot well. 7 seven years in the car rcaing and no problem. Had to send the MSD back for a bad schunt in it. They replaced it for FREE. Have raced for 20 minutes and you can touch either box. Had a bad ground wire when the schunt blew. They are out of the way and stay dry if it rains. Rick Lake