dmaxx3500

just finished up 3 588's for my 42' cig,going to go to the dyno monday morning,dyno guy wants to use his msd distrubuter and box,i'd like him to use my [merc]thundervolt ing and dist,but he says it won't work,ive got 2 extra modules and the short wiring harness's,,my q is has anybody else used factory ing's on a dyno?,,also while their running the engines what should i be watching for and what should they be doing,,they said they'd dial in the timing, carbs, adj the valves,retorque heads,ck for leaks,run in the motors to seat the rings,and do a couple of pulls for power,,anything else i need to see?

chromecat

looks like everything I did... I had the same issue I wanted to use my ignition stuff, but couldn't...

oh yeah... good luck.

Don

tunertech

hmmmmmmm,

mrhorsepower1

I dyno with Mercury ignition or MSD all the time. What ever is going to be used and run in the boat is what gets put on the dyno. I use everything including marine exhaust.

Mbam

What Dean said. That's the whole reason for the test, to qualify the engine as it is going to be run in the boat.

J-Bonz

iTrader: (3)

billet marine

Dynos are usually set up with MSD ignitions and their own fuel systems to make for quick/easy set ups (Ignition wise) and for easy plumbing (Fuel wise) Any good dyno will have a "fuel counter" plumbed inline to read fuel consumption. This along with sensors to monitor air usage (CFM) will calculate "brake specific fuel consumption" figures. VERY IMORTANT... Torque and horsepower are nice to know but for reliablity, your air fuel ratios and other important criteria are most important. You should dyno your engine with every component possible from your boat. (Fuel system, ignition system, oil cooler/filter and lines and even exhaust if possible.) Shops that work with marine engines will usually have a merc plug pre wired, just like your boat.

I have seen many issues from swaping components from the dyno to the boat. MSD cable longer, changing base timing. MSD harness wired backwards, reverse polarity on pick up. Bad fuel pumps or regulators, found after hours of running on the water. Problems with oil lines, coolers and thermostats, found after hours of diagnosis.

If you cannot run your fuel, oil and ignition systems on the dyno for all of the testing/tuning, at least put them all on for the last pull of the day. (Hot wired, fuel line sticking in a gas can, oil lines setting on milk crates, etc) This way you can see if any of the boat components change the oil pressure, fuel pressure, torque, HP and RPMs recorded. If there is a noticeable difference, you will most likely have "issues" later on the water.
Good luck, Curtis @ Billet Marine

dmaxx3500

thanks,curtis,,i'm not looking for high end hp/torque numbers,just to make sure its done right,,does anybody know how to wire up the merc dist/box?

mrhorsepower1

The purple wire in your Merc harness is "switced or key" power, it needs to be wired into the ignition switched power of the dyno. Curtis brought up many good points as well. There are many details that need to be addressed when on the dyno. I take extra time before the engine is even fired to lean down the carbs/fuel injection during the break in period. You do not want to run excessive fuel through a new engine. On marine engines we run them about 30-45 minutes just during the break in time. Getting the proper fuel curve / air fuel ratio and horsepower depend on the ability of the tuner/ operator. After all tuning is performed the cylinder heads are re-torqued the following day, compression and leak down test performed, valves re-lashed if mechanical style camshaft, new oil and filter installed, and final installation of additional rigging .( motor plates and such) Make sure you get your money worth when going to the dyno and not 1 or 2 pulls and " here ya go" pitch. When it is all said and done from break in to dyno testing our engines have about 3 hours of actual run time before they are shipped.

RunninHotRacing163.1

DDmax , Gellner says it all right there we had the last set done in Joliet they did'nt want to be bothered with using our msd /ign, but they decided if we spent our time and hooked it all up they'd do it .. who's dyno ing those bad boyz