Excessive Transom Soot
01-28-2002 | 02:09 PM
#21
Thread Starter
Platinum Member
Joined: Jun 2001
Posts: 21,346
Likes: 10
Thanks Adivanman!
That makes perfect sense as you can definately distinguish an audible difference when the temp comes up to normal operating range. I'm not familiar with the MEFI3 ECU unit that you mentioned, but I imagine the PCM-555 unit in my motor operates in much the same way.
That makes perfect sense as you can definately distinguish an audible difference when the temp comes up to normal operating range. I'm not familiar with the MEFI3 ECU unit that you mentioned, but I imagine the PCM-555 unit in my motor operates in much the same way.
01-28-2002 | 09:18 PM
#22
Guest
Posts: n/a
There is one more issue that I will mention that I discoved while working through the install into the Camaro...
To dummy the story down - fuel needs spark to burn. Too much fuel and not all will burn and what does burn will tend to burn "dirty". Long story short, the coil amplifies (battery) energy to very high voltage which travels through the spark plug wires to the plugs where it arcs across the plug gap and ignites the fuel. I think we can all agree on that.
What I found on the HP500 EFI is that the Mercury Racing (Mercruiser) plug wire were VERY resistive - to the tune of 4000 ohms per foot plus. Compare that to MSD completition wires at 40 ohms per foot (give or take).
More resistance means less spark energy in the combustion chamber regardless as to your opinion regarding OEM or aftermarket ignition.
Now, I DO NOT SUGGEST THAT YOU CHANGE PLUG WIRES IN YOUR BOAT. However, the car is a different story. As best as I / we can figure, the high resistance decreases the likelyhood of leakage through the wire or at the plug boot, which in turn decreases the likelyhood of blowing your boat to kingdom come when you start it without running the blower.
Perhaps this is a Mercury or CG sacrifice of performance for safety. What this does suggest, however, is that the maintenance of the ignition system (plugs, cap, rotor) is very important, as they are handicapped out of the box.
I'll let you know how the MSD's work in the car.
To dummy the story down - fuel needs spark to burn. Too much fuel and not all will burn and what does burn will tend to burn "dirty". Long story short, the coil amplifies (battery) energy to very high voltage which travels through the spark plug wires to the plugs where it arcs across the plug gap and ignites the fuel. I think we can all agree on that.
What I found on the HP500 EFI is that the Mercury Racing (Mercruiser) plug wire were VERY resistive - to the tune of 4000 ohms per foot plus. Compare that to MSD completition wires at 40 ohms per foot (give or take).
More resistance means less spark energy in the combustion chamber regardless as to your opinion regarding OEM or aftermarket ignition.
Now, I DO NOT SUGGEST THAT YOU CHANGE PLUG WIRES IN YOUR BOAT. However, the car is a different story. As best as I / we can figure, the high resistance decreases the likelyhood of leakage through the wire or at the plug boot, which in turn decreases the likelyhood of blowing your boat to kingdom come when you start it without running the blower.
Perhaps this is a Mercury or CG sacrifice of performance for safety. What this does suggest, however, is that the maintenance of the ignition system (plugs, cap, rotor) is very important, as they are handicapped out of the box.
I'll let you know how the MSD's work in the car.
01-29-2002 | 08:26 AM
#23
Thread Starter
Platinum Member
Joined: Jun 2001
Posts: 21,346
Likes: 10
That's great info, J.
I appreciate all the insight...Handicapped is very appropriate for the situation. I just checked the plugs not too long ago and looked fine. Perhaps something more recently(winter fuel, cold rich starts, etc) fouled them.
L8R!
Looking forward to hearing about the project completion!
-Nick
I appreciate all the insight...Handicapped is very appropriate for the situation. I just checked the plugs not too long ago and looked fine. Perhaps something more recently(winter fuel, cold rich starts, etc) fouled them.
L8R!
Looking forward to hearing about the project completion!
-Nick
02-01-2002 | 01:06 PM
#24
Registered
Joined: May 2001
Posts: 589
Likes: 0
From: Tampa,Fl
I just put 496HO'S in my 38 Special and had a tremendous amount of soot during the first five hours. It went away for a while but think it might be fuel related. I also live in Tampa and question the fuel I purchased on the last run(Imperial)because the soot really increased after a run last weekend down to Fish Tales in St. Pete.
