relaxalot

I have a 600sci single with a Bravo xr. The motor has 300 hours and runs great. I am curious about the life of this motor. I have 100 hours on my XR and it has a heat exchanger drive cooler set up on it. How long before the supercharger should be rebuilt? How long before a valve job? How much should I expect to pay for valve job and whipple refresh? If it still is running strong and not burning oil should I not mess with it? Or is it better to be on the cautious side? I have a 28 foot Howard deck boat, I think it weighs around 5000 lbs. I just changed drive oil and it was clean and no sign of metal anywhere. Motor uses a very slight amount of oil maybe 1/2 quart a season (50 hours). I was thinking about doing a leak down test this winter. Appreciate the feedback!

tnc110

600sci in a deckboat...pics please...sleeper!!!!

relaxalot

I don't know how to attach photos for this website. I would be happy to post up some pics. It is a sleeper. I had Whipple upgrade the motor with a stage 2. I have nothing but good things to say about that choice. It will run in the mid 90's with it's current setup. http://www.howardboats.com/boat_spec...port_deck.html

relaxalot

I don't know why but either I can't figure out how to attach photos or I am not allowed to post them.

Kelly O

Your concern would be with the valvetrain, particularly if you have run above stock rev limit due to upgrades. I was in same situation as you last winter with my 600sci's- Stage 2 upgrades that had been flawless and running perfect. Leakdowns and compression perfect as well.
Decided to do top ends- new valves, springs, lifters, pushrods, and upgrade cam to find some more power. Dustin has a tune using the 525efi cam that will get you another 130hp from where you are now but you know what that will do to your drive life.
Had talked to too many with valvetrain failures, especially running Whipple tune at higher rpm's, to ignore the top ends. There are some better parts to install that will be more reliable in the upper rpm range as well.
Bottom ends should be of no concern until 500hrs., as long as you don't drop a valve into it !
Blowers are usually fine but I was on a boat that did same top end refresh as me and we seized a blower on one of the first test runs. Again, we are spinning these blowers faster than stock so there is some risk but most have been ok.
I would scan you motor and see how long you have run at upper rpm ranges to help decide whether to do top ends. That and the leakdown should guide your decision.

92nsx

How to upload photos:
1: Open a photobucket.com account
2: Up loaded photos to photobucket from your computer
3: Copy and paste IMG code from photo on forums

In the end it looks like this

wellcrafted

Kelly O , is right on with what he said, if you upgrade your 600 sci for more power get the xr off there ASAP as mine only lasted 6 hours before it came apart in pieces.

relaxalot

Hey Kelly O, Thanks for the info. Can you tell me approximately how much $$ it was to completely redo the top ends? I rarely exceed the stock redline which is at 5450 I believe. That being said, of course I have given in to the temptation. I did the stage 2 at 128 hours. I have 300 hours on the motor and 100 hours on the drive. A tooth came off in my last drive at 198 hours. Prior to that at 126 hours I had a drive rebuild. So I have had drive problems.... At the last drive rebuild I had the guys at Max Machine Worx in Lake Havasu add on a heat exchanger that picked up lake water and directly cooled the gear oil. This greatly reduced the temperature of the drive oil and I believe has helped longevity. I just had the gear oil changed and it was very clean. I am running Allisyn oil. I am easy on the throttle both on and off. With the cooler the oil stays a honey color much longer than without. I also have an external cooler like most drives. I am glad I did the Whipple upgrade and would do it again in a second. That being said if I blow another drive soon I will buy the SCX IMCO and maybe put that cam in for another HP boost and not worry about it. I will post some pics soon of the boat and cooler set up. I am also running 5 blade Hydromotive P5X props. I was running Maximus props and I think that they are so sticky that hurt the drive life. The Hydromotive slips more getting on plane and then seems to still have the top end. Wellcrafted, what did you do after your drive issue? SCX or back to Bravo? If you are running a XR maybe consider the cooler idea?

sport

Have you guys with the 600sci's had any other problems such as sensors, injectors, boost valve, fuel pumps or headers? I have had my stage 2 upgrade for about 90 hours now with no issues but I worry about the drive, I change the oil about every 15 hours and have had no metal on the magnets but I still worry about the drive, I run a 15.25 x 30p maximus most of the time that has my slip at about 15% and a p5x that is slightly higher on slip. the boat is a 28 Nordic heat and try not to go to hard on the throttle coming on plane but you never now when something is going to break.
John

relaxalot

Sport, When I first had my boat there were some problems with low water pressure and intake temp to high. These were fixed by the stage 2! I did the water reroute and that fixed all my problems. No other problems at all. Well.. engine is hard to start when it is extremely hot out. I have found if you simply turn the key to the "on" position several times and back to 'off' prior to actually engaging the starter it will fire right up. I have only had this problem when it is like 115 degrees out. Just a typical Havasu day! I would change oil every 25 hours on drive using a full synthetic. I run Allisyn but everyone has their favorite oil. I believe the Maximus to be pretty hard on drives. The only other preventative measure on the drives would be to add a heat exchanger to cool the drive oil. I will try to get some pics up of mine. How do you like your Nordic? Max Machine in Havasu did my cooler.