Hey Guys,

What should a valve job on a pair of Merc 600SCI's cost assuming all valves are replaced, along with springs, keepers, etc. Is it necessary to replace rocker arms and push rods too?. Motors hve 375 hours now and run perfectly. Staggered setup so motors can stay in the boat for the work.

Thanks, Mark

I would do it for $5000.00 and you shouldn't need new ret or rocker arms unless they are bad.

Pesky Varmint

my question,are you running in salt water? if so and it has heen flushed everytime i would say around 4800.00..now my question is why do you want to replace the valves? do you want more performance? then i would spend a little more money and just replace the heads with afr's,cam upgrade and reprograhm the pcm should get you a extra 100+ hp

600sci motors are close cooled, and therefore only have antifreeze running through the motor and heads. These mercury heads are proprietary, and have cooling ports on the front of the heads... therefore you can not replace them with aftermarket heads while retaining the stock closed cooling system.

Whipple makes an excellent upgrade path for these motors.

Stage I = PCM upgrade = 675hp +/-
Stage II = above + smaller pulley = 730hp +/-
Stage III = above + cam = 815hp +/-
Stage IV = above + 4.0 whipple = 850+ horsepower

Chris

P.S. a basic rebuild should consist of replacing springs, and doing a valve job if necessary. Anything else is extranious.

Thats why they make drills and pipe taps

You should not need to replace the valves, rockers, or push rods. I would probably replace the roller lifters. Just get a good valve grind job, springs and seals. Probably looking at $1000 per engine for valve jobs, springs, seals and gaskets. Add another $500 per engine for lifters. The rest would be labor, and probably $600-1000 per engine.

I'm very curious why you are inquiring about a valve job at 375 hours.

Is this a schedule in the manual?
Are you looking at leak down tests and figuring "its time"?

I defer to CB on all merc 600 matters - whats your take?
I would think the 600 is so mild as is they'd last a lot longer than that.

Uncle Dave

I believe that Merc recommends a "going thru" for the top end every 400 hours on a 600sci. Springs, seals, and a valve job. They also recommend changing the oil in the supercharger about this time.

If it were me... I would do both a compression test, and a leak down test, and if that was all good..I would just replace the valve springs and do a tune up, and call it good for another 100 hours.. then check it again after that.

Chris

Are you pulling the heads off?
Alum heads; new guides, installed and honed to size 20.00 each. times 16
Valve seats; I would replace with alloy;seats 25.00 each plus labor.
3 angle valve job; 200.00 per set.
Surface heads to cc chambers 40.00 each.
As far as replacing the valves I would inspect them for pits and stem wear, then decide on replacing or not.
Valve springs for sure start at 180.00 per set up to about 240.00 for better quality.
I would replace lifters for sure. Rocker arms, I would leave unless you have bearing wear or you just want to up grade to some jesel sportsman series. If you change the rockers to shaft mounted you WILL have to change the length of the pushrods.
Hope this helps Mark @ M.E.R. Performance Marine