Power vs reliability
 

Lately Ive noticed alot of threads on how to make maximum power. Everything from head airflow numbers, port sizes, cam specs, compression ratios, boost levels, and so forth. Arguing the optimum textbook setups, and what not. Seems often, the reliability part of the engine combination, is put aside for dyno numbers.

I was talking to another oso member on the phone today, and this topic came up. We talked about a fun run we were on last year, and how awesome it was that everybody there, ran their $hit. 70mph boats, went 70mph, 80mph boats went 80mph, 90 went 90, 100+ went 100+. It was 30 miles to the stop, and 30 miles back on open water. The average boat in that run, probably spent a solid 45 minutes of wide open throttle time, or nearly wide open, in a 60 mile run. A type of run where if you were pushing the envelope on your setup, whether it be engine combo, timing setup, fuel tune, oil cooler sizing, engine cooling setup, and overall rigging, it was put to the test. For me, even though I've logged a couple hundred hours on my engines since I've owned them, this run was probably single handedly the hardest I've pushed them, and had a nice smile putting it back on the trailer with no carnage. What was a "fun run" turned into a alot of guys running their boats to the max. I remember getting off plane after, wiping my brow, and telling my co pilot, ''man, that escalated quickly" as my ears were ringing from the loud dry pipes screaming the whole run at high rpm. :cool-smiley-011:

I'm curious, as to what most guys on oso, feel comfortable running their engines wide open for, as far as miles or time go? I am more interested in a custom 900hp engine that sustains 60 miles of 6000RPM, than a dyno queen that makes 1000HP for 10 seconds during a dyno sweep, but fails after its first long wide open throttle run in the boat. Anyone have any real stories about how hard the pushed their custom built big power engines out on the water? Whether successful, or unsuccessful? Love hearing those stories, or watching videos of guys flogging the crap out of their stuff. :D

The harder I run my (properly set up) boats the happier they are!

From what I have noticed babying a boat, especially if its not set up for reliability, does not outlast a boat properly setup that is run hard, or fast like its designed to.

Machines break no matter what, might as well enjoy the hours we get out of them!

Great thread topic MT! I know there's a lot more to it and hopefully some good convo comes from this.

The engine that we're building now for my project is WAY over engineered. The idea is not to have a maximum effort, maximum power piece, but to have a solid combination that will stand the test of time.

Lots of Internet bravado about eeking the last few HP out of a combo when the most important aspect of endurance engine building is.....well, endurance.

Funny you started this thread as I was pondering the same thoughts while reading the posts about the CNC preparation of Tims AFR combustion chambers.

Sounds like my current build, over engineered to perfection:-)

I enjoy running fast for long periods instead of fast once in a while!

As much is it would be cool to brag about peak dyno numbers I'm more worried about a reliable tune that runs good throughout the entire rpm range.

Also, consider this........
The engine is only part of the equation as far as reliability goes. The "sub systems" play a crucial role in making the whole deal work.

Ignition timing, fuel delivery, cooling, oil fittings and lines, final tune etc.... are all part of it.

I race my boat with OPA in class 4 with a 548 making 750hp on pump gas naturally asperated. Once I finally got the combination right, it is reliable in race conditions. The engine needs top notch internals designed for endurance, quality shaft mounted rockers that are set up correctly with a valve train that is well designed, and a oiling system that keeps oil where it is supposed to be in rough conditions, that can keep oil temps in check no mater what.

I know a guy here in town that used to own a 33 outlaw with procharged 500efi's that ran the century mark. Imco drives and the whole ball of wax, I called BS when he told me the harder you run your boat the better it is on it until I started helping him maintain the drives on it! I have seen first hand its less stress on the motor/drive package. I then started running my (now sold) checkmate 251 hard and damn it the little pecker head was right:bananalove:http://i1004.photobucket.com/albums/...psiqfrsd0t.jpg
I now run my 32 sunny the same way he has ran his last few boats and love the outcome when it comes to maintaining our drives/engines! Great thread and I'm looking forward to hearing more opinions!

keep the wheel in the water boys

I use cams that are not as aggressive as some,,I give up some hp,,but they just run and run.learned that along time ago,ran the 1000 island PR at 5100-5300rpm for 125 miles and the last 25 we opened her up to 6000+rpm.sold those motors off and there still going.my present engines have been together for 9yrs this year and never apart.our big cruiser w/ 1200hp whipple and big stuff3 efi(sister engines to these are in the 44' liquid technology aluminum boat) have run for 3yrs and thats a 23k lb boat.again,cams are not overly aggressive.just good parts and some thought into longevity.

I have done some 18-35 mile each way fun and poker runs with my boat hunting 6000rpm of over. And at the end of the day I have a better chance of a header failing and screwing me than breaking an engine. Lost one engine on a poker run due to a bad tune drank a lot of beer on that idle home.

Although I wish I had a large expanse of water where the throttle (in my case) could stay pinned for miles that is not the case for me . I boat on a 35 mile long inland lake surrounded by mountains where long wfo runs would result in a hill climbing incident due to its snake like shape . I'm setting my 25' cat and engine up for short bursts of acceleration that would like to tear the seats off the floor . Should see trips real quick . :cool-smiley-011: Kinda pushing my stock Gen VI block to the edge with my power goal but the rest of the engine parts including valve train are rated for much more hp and rpm than it will see . So I guess the correct answer lies in the type of boat , its weight and where and how you intend to run it . Yep , I'm stuck on this little lake with my little cat but it should be akin to driving a sprint car on the water . :D