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View Full Version : Two Newbie Questions? MSD?


Tap
06-26-2007, 01:42 PM
1. Has anyone had any success with a Multiple Spark Discharge (MSD) between the Distributor and Plugs on the engine. It usually helps a little on race cars for a cleaner burn. Instead of one spark per compression cycle you get 3-4?

2. After flushing my engine on the trailer, I get about a gallon of water that drips back through the raw water impeller and into a tub under the trailer. THis usually happens overnight, Is this normal? [engine is MCX predator]

Thanks in advance,
tap

chevy08bud
06-26-2007, 01:53 PM
I would seriously doubt that it would help. I've run MSD on cars with big engines, but not on anything that is newer. If you feel like tinkering with your boat all the time, then give it a try. I used to mess with this kind of stuff all of the time, but have gotten to the point where my motto is "if it's not broke, don't fix it". The gain would be marginal at best. If your boat is starting OK and firing OK, then I'd leave it alone. You only get multiple sparks in the lower RPM range and not where you would really like for it to be, which is in the upper RPM range. There just isn't enough time for multiple sparks above a certain RPM. Not sure what that number is, but MSD has it documented. Just my 2 cents.

Tap
06-26-2007, 02:23 PM
I agree with the lower RPM improvement. Just a thought that came up over lunch with a few gear heads.

Anyone with thoughts on the impleller drips?

rcnjson
06-26-2007, 03:52 PM
MSD does have a marine igintion system which I guess would be the same as a 6al for the street. The biggest difference is high RPM's and it is because the MSD is a capacitive discharge -vs- an inductive discharge. The MSD can dump a full charge and recover faster than the inductive system so at high R's you still get a powerful (full strength) spark. The multi spark is done at 3k so there may be some advantage to that especially as you accelerate to pull a skier up but at skiing speed you would probably be out of the range of multi spark. Your biggest bang for the buck would be standard tune up stuff. New coil, cap, rotor, wires, plugs would bring a lot of life back to an old engine.

The leak... I'm not so sure I understand the problem. Is water leaking back out of the pickup on the bottom of the boat? If that is the case, if there isn't a check valve in line, any water lower than the pump, ie anything in the hose to the tranny cooler, the tranny cooler, the hose from the tranny cooler to the raw water pump... is going to leak back out. There isn't a check valve on my boat, so I would guess the same thing would happen if I flushed my boat. Maybe I don't understand the problem though?
k

TMCNo1
06-26-2007, 04:17 PM
Usually after a boat is run in the driveway or taken out of the water, some water will come out of the raw water intake due to the expansion of the water from heat soak in the engine compartment between the raw water pump and the pickup. No problem what so ever.

Tap
06-26-2007, 05:43 PM
TMCNo1: Thanks again for the peace of mind.
rcnjson: I see your point on the high end, I suppose if I start sking in the 10-15mph range I would see some improvement. I will just need to find skis that 3' wide and 8ft long. Thanks again for the insight.

tap