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Old 12-16-2017, 12:52 AM
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Default BBC valve train

I know a lot of other forms of performance engines you see people talk about valve train and valve train life but not much in boating other then ( hey that cams to big it won't last or its to rough on valve train) any body have any experience on here with putting their stuff on a spintron ? Thanks.
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Old 12-16-2017, 07:20 AM
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Let me get my popcorn for where this will go...
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Old 12-16-2017, 09:14 AM
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If you've been in the high performance world long enough you see what works. Our engines are endurance engines. Use things like Inconel exhaust valves. Lighter valvetrain components are always better for valve train stability. Shaft mounted rocker arms are better than stud mounted ones. Roller cams are better than flat tappet (generally) But a lot of this depends on usage and HP levels. You dont put severe duty pro flo valves, full roller valve train on a 260 Mercruiser sbc.
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Old 12-16-2017, 11:57 AM
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I understand it very well. There is a lot of hp in the valve train. You just do see much of the super throw down stuff in boat engines and it's not like they are cheap builds.
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Old 12-16-2017, 01:06 PM
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Originally Posted by phughes69
You dont put severe duty pro flo valves, full roller valve train on a 260 Mercruiser sbc.
Why not ? Assuming replacing cam too ?
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Old 12-16-2017, 06:42 PM
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Originally Posted by Single cat
I know a lot of other forms of performance engines you see people talk about valve train and valve train life but not much in boating other then ( hey that cams to big it won't last or its to rough on valve train) any body have any experience on here with putting their stuff on a spintron ? Thanks.
As you probably know, Spinton testing is extensively used in NASCAR. For marine, would need a BBC mule block that was set up the same as what you plan to use in the boat and is machined specifically for Spintron testing. If all this is in place, you then need to find a shop that has the Spintron equipment to test with and will let you to test. This process is not inexpensive, but can provide long term durability and valve train stability at 7000 RPM for marine based BBC engines.

Last edited by BenPerfected; 12-16-2017 at 06:45 PM.
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Old 12-16-2017, 07:49 PM
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Originally Posted by BenPerfected
As you probably know, Spinton testing is extensively used in NASCAR. For marine, would need a BBC mule block that was set up the same as what you plan to use in the boat and is machined specifically for Spintron testing. If all this is in place, you then need to find a shop that has the Spintron equipment to test with and will let you to test. This process is not inexpensive, but can provide long term durability and valve train stability at 7000 RPM for marine based BBC engines.
Agreed, very expensive for an engine that is usually for a "pleasure" craft... if you're a competitive racer with a big budget, maybe and even then, not usually commonly done...
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Old 12-17-2017, 06:51 PM
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Originally Posted by Single cat
I understand it very well. There is a lot of hp in the valve train. You just do see much of the super throw down stuff in boat engines and it's not like they are cheap builds.
depends where you look.

There are some guys in the marine world, doing things like 55/60mm cam cores, big lifters, and so on. The main issue with marine engines vs car/drag race engines, is the enviroment they need to operate. A guy can build a 8000RPM big block for his drag car, and what happens below 5k rpm doesnt matter to him. SO, hes got the big heads, big valves, and necessary components to go 8000rpm. The boat guy, needs his engine to operate off idle. An 8000rpm max engine, isnt going to be very friendly around the docks, or low speeds. He may limit his max rpm to only 6000. He doesnt really need the titanium retainers, hollow stem valves, and so on. Power goals are typically met in marine with either cubic inch, or forced induction, not RPM.
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Old 12-17-2017, 06:59 PM
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I feel a lot of it depends on what boat it's going in and how the boat is run. We can get away with a lot more in our boat because the way it's set up.
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Old 12-17-2017, 07:29 PM
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What is it you're looking to do ?
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