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Old 03-09-2013, 08:57 AM
Hogg Hogg is offline
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Originally Posted by sprayed99 View Post
Okay I get it... but bottom line if we all followed GM's information none of us would be running these engines past 1000hp. We wouldn't even see them running Heads and cam swaps and making north of 400rwhp. So If the 500hp statement needs to be made it also needs to be followed with the source as we all know its just GM doing the good ole CYA.
To imply that 1000hp using a stock 6.0 block esp. in a marine environment will be be durable is risky.

GM marine engines have to pass the 300 hours "dock test". And engine is in a boat that is tied to a dock. The engine is held at WOT for 55 minutes at a time, and let idle for 5 minutes, then returned to WOT for another 55 minutes for 300 hours straight. BTW 300hrs is 12.5 days. A 18,000 minute test length with 1500 minutes at idle and 16,500 minutes at WOT.

Other GM engines have to pass the 200 hour test, the engine on a dyno is cycled from the rpms at which peak hp and peak tq occur at WOT for 200 hours.

Your 1000hp scenario would be for 10 seconds at a time MAYBE. Hold that 1000hp for a minute of 2 and see what happens. Maybe it will take it, but for how long is anyones guess. Without proper engine validation it is simply conjecture.

My point here is that even though GM is obviously conservatively rating some of their performance parts, simply taking performance parts and having them stay together for short periods of time doesnt meake the factory ratings invalid, just conservative. just because an engine block has survived 1000hp, doenstmean it shoudl be rated ta 1000hp. A perfect example of this is the LSX iron block, GM rated at 1500hp sustained, and over 2000hp short term(less than 10 seconds ina drag race scenario).

With a 500hp factory rating and claims of 1000hp short term surviveability, in a marine environment, sustained durability would be somewhere in between, but again this is again conjecture on my part.

The GEN 3/4 engines are great powerplants and will survive dozens or dyno pulls at WOT over 1000hp. Simply amazing engines with many many examples of NA daily drivers running 500-600 hp at the crank and forced induction running even more.

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