As far as water supply for run-in, whats required as far as volume and pressure from the hose for a 20 minute run-in????

I always run my motors, whether at initial break in or otherwise by pulling the hose off the transom where it attaches to the drive. Then I put the end of my garden hose into it. I have a shut off valve on my hose end, with about 18" of scrap hose to put into the intake hose of the motor. I then turn it on slow (I get water in my bilge, but oh well) and crank the motor till it starts then up the pressure until the motor takes all the water I have available. This is you max rpm. I have never had trouble with this method. Just remember to re-attach the hose to the transom before you launch.

I put a "FLUSH-PRO" in when I put it together.
For start-up, I pulled the intake hose off and used a 1" hose that was fed right off my water main.Temp never went above 130*.
Second run i tried the flush pro with the regular hose, idling was OK, but temp started to climb if i ran any faster.
Third time, i didn't want to put to much pressure to it so I did this(see pic). Worked great!!!!! Fed it with 2 hoses and didn't run out of water. Temp would run about 125* at idle, and drop to 110* at 1500-2000.

convincor,

I thought that was a trick photo at first glance. Looks like it would work well for extended runs such as breaking in a cam. Actually, I have been think of making something like that myself. I have a well and don't have enough water pressure/volume to keep the engine cool on the muffs when running much faster than idle. Next time I see a free barrel I might just have to bring it home. Just need a sharp blade for the sawsall and I'll be set. Thanks.

Or you could use a plastic barrel. This is a similar setup my marina uses to winerize the boats. They put the antifreeze in the barrel.

my barrel is plastic.

Great idea, I'll have to try that.