600SCI Upgrades
 

Hey Guys,

I am considering doing some upgrades to my stock Mercury Racing 600 SCI motors. I have looked into the whipple kits and I am not very comfortable with spinning the rpm's that high for the horsepower gains. What other modifications are available to this package without having to tear the engines apart? Cam changes, etc.

Any input would be appreciated.

The only differences between the 600 and 700 are the cam, blower pulley size and ecm tune. You can change those 3 things and make it a 700. Or, you could change those 3 things and do Whipple's cal and get over 800. You dont have to spin it to the moon to make good power. You can prop it for 5600 and still make around 800. Let me know if I can help in any way.
Eddie

I had Whipple set my rev limiters at 5800 instead of 6000. Just ask him when you order and they will set the limiters wherever you want.

Why are you afraid to spin them higher?

Spinning faster means more heat and more wear on all components.

We can have the limiter set for you anywhere you want. You will give up some power, but if that's ok with you, then just go that route. You can spin them 5600 with no issues what so ever. You do want to change the springs, retainers and locks though. The stock springs are a little light on the seat at around 120 pounds They also have a very short install height at around 1.820-1.825. We have found that by ditching the stock 7* retainers and locks and using the 10* retainers and locks that we do, we can pick up about .100 in install height. If you keep the short 1.820 install height, you pretty much have to go back with the PAC springs that they come with. I haven't been able to find a spring that will install that short, handle the lift, and give the proper seat and open pressures. By changing to the better and stronger 10* like we do, that opens up valve spring choices. Once those parts are changed, 5600-5800 is no problem.
Let me know if we can help.
Eddie

I have the stage 2 whipple upgrades, ecm change, pulley change, air filter, water reroute with larger fittings.. It really woke up the beast! Over 200 hours since the upgrade and still runs perfect! I will only run it up to 5800 and for not too long. I would highly recommend it.

I have done the same as relaxalot and have 90 hours since the upgrade with no problems, I am proped to run 5600 rpms and the boat gained 10 mph with the upgrade.