OK, I need some input from anyone that can help....I am seriously considering buying a boat with twin 598 cids / 1000hp blown engines with 10 hours since rebuild....I need to know from anyone that has had engines these big/powerful what to expect as far as reliability, maintenance, hours of service, etc., etc. They are operating at approx. 8 lbs boost. What would I have to do to de-tune them to about 800-850 hp? Thanks for any help in advance.

Dammmnn! Tell us more.

he,he,he, he....stay tuned for more

High horsepower=high mainteneance.
If you don't run them at WOT too long, and you maintain the valvetrain properly, you should get a decent amount of hours on them, if they were put together correctly intitially.
De-tuning should be fairly straightforward. Simply change blower pulleys to reduce boost and re-jet/tune the carbs. Timing might play a role as well.
I would not be afraid of 1000hp with this many cubes, especially if you reduce boost slightly.
Do they have intercoolers?

SO,

the engines have superchillers and running around 8 lbs boost....never had anything this big before so I'm a little gun shy about the engines....I do not plan on a lot of WOT, but wouyld like to be able to use the boat every weekend probably a lot of 3,500-4,000 rpm running....what do you think?

I'm certainly no expert, but I would not be afraid of them at all.
Just be SURE to change oil every 10 hours or less, drive oil at same interval, and check valve springs every other oil change.
If you aren't willing, or don't have the facility for this kind of maintenance, I would give it some more thought.

With 4-6lbs of boost you could still make good power, and have great life from the engines, I would think.

thanks, that's re-assuring.

Make sure the motors have that few of hours on them. Ask for dyno sheetsand talk to the builder. I bought a boat last summer with 1150's with 15 hours on them. They had more like 108 hours and only dynoed at 916hp. Would hate to see someone else get burnt like I did. ( $20k to get my motors to were they were suppose to be) Heath

These are 580's with 1000 HP SC'd, chilled Dry Sumped. 1000 is nothing for a set of 580's. Theya re pretty dependable if you keep the drives wet and don't over rev. If they are dry sumped it will definitely help keep oil in all the right places when the high R's hit.

Summer is giving you all the right info. Dependability is based on who wrenched them together and how that 10 hours of running time was spent and how you maintain and run them. Valve trains check MAXIMUM every 100 hrs.

You can also reset. the chips to lower the rev limiters and RPM's, Shorten up the throttle cables,

Good Luck!
I

thanks for the info 39, those are beautiful motors