MSD 6AL on a Cleveland

[rdorman]

I was always intending to put a soft touch rev limiter on my Cleveland. Then in one of the Cleveland forums, I read a couple of guys that talked about how the MSD really 'woke up' their Cleveland below 3000. Sure, I spend very little time below 3000 but what the heck! So on Saturday, I installed it. It was suprisingly easy to mount and wire. The car fired right up and with the 3000 RPM chip in there to test, worked great. The motor hit 3000 and stayed there. Sounds like a nasty miss when it hits the limiter.

In with the chip I am starting out with and off for a little test drive. It is true, it does make the motor happier in the lower RPMs. Enough to notice. It definiatly pulled smoother and I swear the gas mileage picked up but I have not been able to check this yet.

I think it was a good addition. If there was only a good place to hide that big box, perfect.

One word on the installation. The kit includes no ring connectors. So if I had not had some for the power, ground, coil and tach connections, I would have to go get some.

Rick

[What'saCobra?]

MSD 6AL is a great piece. The reason why it 'wakes up' engines under 3000 rpm is because it fires the plug multiple times under that rpm. That is why it is called a Multiple Spark Discharge (MSD) system.

Above 3000 rpm there isn't enough time to fire more than once, sort of, so only one big spark is fired off.

Several precautions are suggested, however. Be careful not to attach your nice new tach to either of the coil terminals when the new 6AL output is attached to them, as will be the case. ONLY attach the tach to the 6AL tach output, a dedicated blade plug on the end of the 6AL. Otherwise, say perhaps goodbye to your tach, particularly if it is an older electric tach and a real Cobra type and size. (Don't ask me how i know!)

Also, be prepared to use an isolater/amplifier tach driver in the system if you use an MSD magnetic trigger (for instance, using the billet MSD distributor, a fine piece also), rather than the points as the imput to the 6AL, (which MSD is the only way to go for great maintainability and input switch control.) Even using the 6AL's tach output, some tachs will show nothing, without the $50 adapter for your tach. SW tachs are OK, usually, but some AutoMeters will not be OK and will show nothing w/o the adapter.

Download the MSD and tach diagrams and determine if the tach adapter is necessary.

But, don't let this little tach technical thingy dissuade you. The MSD works absolutely great on an engine that is struggling with a DuraSpark or regular points system...

And you thought you had a carb problem!

By the way, when it misfires at the chipped rev limit, it rotates the cylinder chosen for the miss from the entire eight, rather than just one, which reduces plug fouling and reduces backfires.

[rdorman]

Good builds!

I have mine wired to a Mallory Uni-light (sp). I have also heard that they don't like a lot of heat or vibration. I was going to mount it inside the foot box but that did not work well. As it turns out it is on the top of the firewall directly downwind from the hood scoop.

I have heard of a few problems with some fo the units. But there are thousands of these things out there. For the price, I like it!

Just to add to what was just said, my SW tach works fine. Although as I recall the manual did recomend a tach adaptor for SW, $27.99 from Jegs.

Also, it fires for 20 degrees of crank rotation. With the lazy old open chamber Cleveland head I can see why that would be beneficial.

Rick

[What'saCobra?]

Yep, there are actually two adapters, but the one for the magnetic triggers (8920) is a bit more expensive than the white wire trigger (8910).

Anyway, i mounted it upsidedown in the vented driver foot-well on a plate, with SHORT RUBBER isolator standoffs between the glass footwell and the mounting plate for vibration protection. The unit must be vibration isolated as this has been a serious source of some troubles in the past for all electronic systems in cars, including the MSD.

Make sure water cannot drop on it in the upside down configuration. Although it is a potted system, there is no sense in testing the water-proofing.

[Dennis Kelley]

Best money I ever spent. I broke a drive shaft at full throttle and I was very happy to have the rev limiter. It saved my engine it would have been ugly without it.

later dennis

[RallySnake]

Rick,

I added a MSD 6AL recently, too. I have been running an MSD6 for many years but wanted the rev limiter. So, I found the right deal on eBay. I mounted it in the engine compartment for a short term test. It worked OK for about a week, then failed and wouldn't start the car. I reconnected the old MSD-6 and sent the AL off to MSD for repair. They replaced an internal fuse and sent it back.

I decided I wanted to mount both devices in the car so I would always have a backup. With all my computer equipment, it was hard to find a place to put them, though. I had an aluminum footrest next to the clutch pedal and decided to take that out and make the MSD box my new footrest. I spray painted both units flat black and mounted them onto an aluminum sheet. Then, I mounted the assembly against the left side on the driver's footbox so the 6AL is in the same position that my old dead pedal was. The 6 is right behind it and I can easily swap the connectors around if one should quit.

Works great!
Paul

[lovehamr]

I use an older billet Accel dual point with one set of points backed off and unconnected. When connected like this the points only carry a few milliamps to trigger the box, so they'll last for ever. If something happens to the MSD box two small jumpers can be used on the coil to bypass the MSD and run the engine on the point setup. Instant no problem. Think of it as a "limp home" mode. MSD even includes the jumper wires in the set. I love my MSDs and would never go back.
Steve

[rdorman]

I do have the back up stuff just in case! I can road side jump just about any thing!

Rick

[trularin]

So, Rick, what did this animal cost you and do you think it would be an "over-all" good choice for a Cleveland?

Where did you get it at?

I have eight things to fix on my car ( now that I broke it more than it was ). I had tried a box back when I was first getting everything to work and it didn't work for me at the time. I gave it back to the guy who let me borrow it. Anyway, I'd like to improve the lower end without a CAM change. We have about the same engines, that's why I am asking.

Thanks.

[rdorman]

I would say yes. We are not talking huge differences here, but definiatly noticable. I find it pulls smoother, if not stronger at lower RPMs, seems to start easier, and throttle response has improved. I don't remember what it cost (it has been setting on the shelf for so long it is out of warrenty!). Either 179 or 249, something like that. I purchased it from Jegs.

Even without the performance difference, I would spend that much for the peace of mind with the rev limiter. Although just a rev limiter alone is less expensive. The directions that come with it show how to wire a switch in the circuit that can be used as a theft deterrent as it disables the ignition. As nice little bonus.

Rick

[trularin]

Thanks!!!

[westcott cobra]

Rick,

we did more or less the same to our Clevelands.

During the winter I installed a MSD Digital 6 with rev limiter and 20 degrees start retard because of my high CR.

The advantage of the Digital 6 are the dials for the rev limiter, no pills are needed and you can choose between low and high CR setup generally.

The box is installed along with a Holley/MSD Magnetic Pro-Billet Distributor and a Holley coil but I will change to MSD Blaster HVC coil.

It sits upside down under the co drivers footwell.

Till now everything is fine. The same results as You described for the 6AL.


Clevelands rock, Greetings from Europe,

Uwe

[clayfoushee]

Rick, most of the Unique cars I've seen, including mine, have the MSD mounted to the frame-member just behind the dash on the far right side. It's totally invisible, yet easy to get to.