On Mercury 700SCI:
80deg F ambient temp
85deg F inlet temp (inside hatch)
60deg F lake temp
55 second run @ WOT =
139deg F manifold air temp below IC
159deg F engine temp

To me, this was a below average temperature for boating. Where I live, it's constantly hotter than this, especially water temp. This was boarderline, with a 1" thicker IC core which removes another 25-30deg F.

Dyno testing typically does not show this, since swept test does not give the engine time to build more heat.

I got the intercooler handled, we brought the cupronickel to the high performance world, in fact, we introduced it to Mercury Racing. Problem with upgrading is $$, cupronickel pricing has gone off the charts with the ever increasing copper price.

Thanks,
Dustin

So when is Mercury going to wise up and run the 305/5.0 in stead of those measly Lysholms?

Not sure, but I'm working on a upgrade kit for some of the motors, since they're having some issues with SC longevity.

You mean like an induction swap out for an 850 or 1075?
With like more HP to boot?

What are the issues? and at how many hours?

We've seen alot of supercharger failures on the 1075 and 1200. This is related to blower speed and the duty cycle of the supercharger. Running larger SC's at slower speeds is far more reliable. So we have new 2.9 liter superchargers, 4.0 liter and 8.3 liter superchargers that were working on retrofitting kits so customers don't have to replace SC's as often. The 600 and 700 are extremely reliable, but it's a good idea to have the SC's rebuilt every 300 (700sci) (400 for 600sci) hours for customers that run there's hard. They'll certainly last longer, but it's good to replace bearings and seals before there is an issue.

We've been doing this for awhile.

Thanks,
Dustin

would the temp climb if run longer than 55 second run @ WOT ? Also would the 500efi 3.3 run longer also climb?



Dustin is the 8.3 liter a lot bigger looking than the 5.0? Picture?

55 seconds, constant boost, constant rpm, the screw compressor will hold temp steady. Doesn't matter what size screw, they will stabilize in approx. 30 seconds steady state.

The 8.3 is identical in dimensions, just driven off the large gear, vs. small gear. Meaning the rotors are mirrored. 2.3 and 3.3 are driven off the large gear, which drives the female rotor. The 5.0 liter drives off the small gear, male rotor. 8.3 is like the smaller scs, drives off the big gear, female rotor. There is a 66% difference in blower speed.