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

I like to run my boat hard, I have had good success with my BAja engines after learning BBC, may latest engine went boom after being ran hard for 6 miles at 5600, leads me to now....

on my current builds as you know I am going for reliable and good parts, not top of the line but good, guys say I am gonna regret going 650-700 hp because that's going to be unreliable, I disagree, I think I am making good choices to be rock solid reliable engines, I am not chasing every last single hp, and they make whatever they do, but I am trying to maximize what I do have.

guys say blowers are not reliable, not true either, it's all about quality and maintanence

The biggest issue I see is guys trying to save a buck, or meet a timeframe goal, I tried that in the past at both and failed. This time I set in my mind it's done when it's done....

Sorry to break it to you Tim, but we are talking boats...it aint EVER done. Thats just the way it is.

that is very true, I don't mind pouring money into it to get good results, the days of cutting corners are over, too many times myself and others lose that battle...!!

Everything on a boat has to be VERY precisely built and up to the task you are asking it to do. There aren't many people that take that time

attention to detail is a must when assembling a endurance marine engine!

and the rigging.the pounding our boats take,,everything needs to be secure.

Sometimes, its nice to put the opinions aside for a moment, and hear what is working for others. Keep the stories/setups coming. Even if it was a failure, its worth talking about.

My general setup.
468ci mark iv engines 8.9:1 compression
vintage Dart 308 Race series alum heads, bowls blended and valves unshrouded, 165 seat/450ish over the nose isky springs. MLS head gaskets/arp head studs
crower 236/245 .630 lift 114lsa cams
morel lifters 4603
crane rockers
.135 pushrods
JE pistons, manley rods, chevy steel cranks,
B&M 420 blowers with twin 850's, 6lbs boost holley mechanical fuel pumps
stellings headers with dry tails
dynoed 804HP @ 6200 and 735ftlbs
msd distributors with crane ign boxes
No water stats, oil stats with bellhousing coolers
air fuel ratio low 11's wot, timing locked at 34* (although changing to daytona sensors with custom 3d maps this year)

100 hours on this current setup with lots of wot time in a old 38 non stepped fountain with huber trannys and #4 drives. Prior to rebuild engines had lots of time on them, but with smaller blowers and less power. either way, So far so good on this combo.

Intercooled? That's some good power.

LAck of detail is for sure ending in failure.... that's what I had happen to me.... but lack of any ability lol

No intercoolers. Blower is 7% underdriven. Have considered adding them, but going to check temps in the intake manifold this summer via an IAT gauge. Just some budget motors, nothing fancy. Someday I'd like to build something cool!

Cmon guys, I know there's alot of bad azz setups out there being ran hard......

I run my boat as hard as I safely can but I have never run 30 miles pinned. The speeds are too extreme to run that long into cruiser wakes or channels with other boats or wave runners.

You just need to find a bigger lake....

I have a new theory, as long as everything is set up correctly and good parts are used 1.7hp/CI is the limit to a reliable roots blown set up. Above that you better have all your ducks in a row.
Everything I`ve changed so far was for reliability not more power.
4% underdriven and 6psi right now. I could easily turn up the boost and make a close to 1000hp but I`d rather boat all summer and going 10 mph slower on the top end is fine with me.

My best boating day is getting on the trailer knowing that I don't have to wrench on the boat before I can go back out. I totally agree, tune it to live!

My buddys 353 (Lake Effect on OSO)

509CI GM Forged 502 cranks, Manley H beam, JE pistons
MErc 525 cams
GM Performance Edelbrock aluminum heads
HP500 intakes I think 850 blow through carbs
7 PSI M-1 Pro chargers

he never dynoed but boat runs 105 and a best of 107, so must be about 800 or so, used every single weekend and ran pretty hard.... it seems to live, good building and MONITORING is everything to keep engines alive.

NOT missing part or all of the season is priceless....

What's the old saying. Fast, reliable, cheap. Pick 2!!

I once rowed a boat half way across my lake. My back gave out. You just cant win.

Full force that combo is basically what I .putting together right now. But in us the blower

Could you guys add if the motor was home built, local performance shop built, or (brand name, ie teague, mercury, sterling, zul, chief, etc) built? I have allways been curious about this. I have come to the conclusion that either you go mild, or go to a big name shop for performance for reliability. This is why I went with outboards. This thread is changing my mind a bit though.

I like to idle mine over to the sand bar and drink and listen to music. I think the stock Suzukis should last like that for more seasons than I will :D

Built them myself made my own piston oilers flywheels all the brackets and dry sumped the upper wet sump #6s and a lot more. But I also bought some machines so I could do my hobbies myself. If you want to do something bad enough you can.

97mph+ 2001 Baja 33' Outlaw poker run 750-830hp (previous boat)

Cruise 80-100mph, 4500-5800rpm for 30+ mile spurts every time out, up to 150miles in one day.

Rigged from day one with

500EFI's (factory sealed)
M3SC Prochargers at 8psi
IMCO Extreme SC Drives
Stellings boxes
Upgraded fuel system
etc.

240 trouble free engine hours and counting

Multiple drive rebuilds

I drive fast, hard, however you want to describe it. But there's a difference between Hard and Abusive. Abusing your equipment WILL result in premature failure. Driving a performance machine like its made to be driven is OK in my book. Especially when you properly maintain it. I do try to drive.....smooth though, if that makes any sense.

Looking forward to running Unleashed the same way with the new custom built engines! Attempting to make 1000+ reliable HP. Plan on sharing positive results after running her for a few years.

I don't actually know how much power can be reliable, or what it takes exactly at each level. But enjoy learning every day.

Most would say supercharging stock Mercury engines is NOT reliable. Maybe I was just "Lucky"

Most also say that "if you drive like a grandma" XR drives will live behind power. I was NOT "Lucky" there. My IMCO's had every upgrade possible, amsoil changed every 15hours, and I followed every piece of advice on this site. They still broke/wore out prematurely. The drives lasted longer driving faster, freeing up the hull, getting on plane normal instead of taking 5 times as long to "nurse" it up on plane, etc.

Pretty much seems that everything fast breaks. The larger it is, the faster it goes, and the older it is, the more they break. But they all break and wear out. Might as well enjoy the drive on your way to that next failure! Hopefully the "secret to reliable speed" is revealed in this thread, gold chains and all!

My advice to all friends is buy a less expensive boat then you can afford, at a price below what its worth, so there's room to rebuild and upgrade as needed.

Great thread. I was playing with the idea of doing a 496 stroker with a 250 blower trying to get to the 650-700 hp range. I'm now thinking about scrapping the blower motor idea and going with

http://m.ebay.com/itm/351056794293?nav=SEARCH#

Any advice or opinions?

well here my thing low hp you can run any parts. but when i went to big hp i try to get info on all the parts that last. now i have 582 dart with 355dart pro 1 heads 675lift cam,crower shaft rockers.dyno 744hp 718tq at 5700rpm . i have bravo one drive 136 gears .so my crusing rpm is 600rpm lower then when i had 150 gears. i run50mph all day long and i am not in the 4barrels. nice speed and easy on the gas.

What kind of carb. Are you running?

Nothing unreliable about a supercharged engine. Unless of course its poorly thought out, poorly tuned, etc. But that also goes for any engine as well.

I agree with you 100%. My thoughts were going to a 572 ci over the blower motor is that the cost is in the same ball park, the 572 wouldn't have to be pushed as hard to produce 650-700hp and would be more forgiven on a fuel issue such as bad fuel or low octane. But I do really like the noise a blower makes. :whistle:

i have a 1050dom i got from aed. . i wish i got the 572 when i frist started to do my motor. there a guy put a crate572 in a checkmate and his boat ran great. my motor started out as a 540 dart block. i had it made to a 582 and i love it .the boat is really a lot of fun to drive now .you can tell the power from 540 to 582 it made my boat move a lot faster

What size boat do you have it in?