How many hours on bigger power stuff?
 

What kind of hours are guys getting out of their bigger power engines? Like say between 750-1100HP.

I currently have around 80-90 hours on my current engines, that made 800hp. Being a engine nerd, I don't exactly 'cruise" them much. Lots of extended periods of the throttles buried to the dash, or hard acceleration from 3k to wot when playing around. Boat is old, heavy, and slow, so they often get run hard, trying to keep up with the modern more efficient boats. I just pulled them out, and going to be changing some rigging and adding intercoolers this winter. I plan to leak them down, and do compression tests this weekend, but they've been good, no issues, no oil consumption, smoking, etc. I am curious to see how they leak down.

Nothing fancy here. mostly old school stuff.
468ci
GM steel cranks
Manley Rods
JE blower pistons
speed pro rings
ARP main stud kits
ARP head stud kits
MLS head gaskets
Dart heads
Isky Tool Room springs
Crower 236/245 .630 lift cams
Trend .135 pushrods
Morel lifters
Crane Gold rockers
B&M 420 blowers 6lbs boost
twin 850 holley carbs
stellings headers
9:1 static compression
34* total timing

Wondering what other guys are getting between rebuilds on these types of engines? Big NA, supercharged, etc,

We are in the same # hour range as you. How many hours our engines will go before a failure is mostly a guess as we have too many variables compared to the cookie cutter factory tested Mercury HP engines. It gets down to how much risk you want to take when you know the answer isn't likely much more than.....???

friend of mine has 200 plus hours on N/A 735's and they still run like a clock, nothing done except oil changes...
but for how long more... ???

183 hours on the short blocks, new springs on one engine this spring, due to breaking drive gears twice on the same engine at 6k and over reving the piss out of it. but I do cyl head maintenance normally every 3-4 seasons = averages 70 hours. but I;m not afraid to take it over 6200 for extended runs.

I am going to be replacing my springs as well this winter. I like your program !

I have an 1100 I refreshed after a timing incident a customer had. Replaced his own lifters, timing light decided to be afu, anyway, besides the corner of the piston melted it was mint at 155 hours iirc. Bearings were perfect rings, skirts, cylinder walls, etc all looked great. In fact if it was just an inspection on a used engine mid summer I'd say run it.
Valves and guides good
Springs acceptable but were replaced
Je pistons
Carillo rods
Coated bearings .0022-.0024 rods and mains, I found this tight but can't argue with success.
Only issue we had was it had random low oil pressure. Found it had an anti cav oil pump.

Low oil pressure and tight clearances were before it was refreshed *

Did he lose a lifter at 155 hours, or was it just preventative maint? 155 hours is nice, for an 1100HP build. I like that.

I got 175 hours out of my twin turbo 572 tall deck making over 1500 HP. Solid roller cam with .710 lift. Dart 360 heads with Isky tool room springs running 265 on the seat.

That engine was a work of art! :drink:

Preventative maintenance, had copies of merc 900 cams. Kick in the nuts to do some extensive pm and have all hell break loose!

LOL +1

I was thinking what you said!

What happened at 176 hr?...just refreshed engines or damage?

This tread is going to be all about the driver if the throttles are to the dash you will never get big hours out of a big HP engine.

How fast does the 43 go with over 1500s?

The 1500hp engine was in a 30 checkmate with a #6 drive.

That's what I was figuring but wanted to here speed. Is it stepped bottom?

The blue boat?

My first marine blower motor I built was a 502 with merlin heads, a procharger, felpro head gaskets, arp head studs, stock 502 cam and factory lifters,got rid of the metric ringed je pistons, wasted my money on comp cam roller tip rocker arms. I ran that motor 175 hours, when boat wasn't idling it was pinned quite often. Towards the end it burned oil, leaked oil from every gasket, had high leakdown and bad blow by. When I pulled it out and tore it down rings were so soft you could roll them off the pistons like wire, the comp roller tips were blue and melted at the fulcrum balls, one of the rocker balls was split in half but miraculously hadn't let the rocker arm and pushrod eat itself! That was 13/14 years ago, I have learned alot since then and use better parts. My last few builds on my own blower motor (1100 hp 540) I used t/d shaft rockers, coated je blower pistons, 14 qt oil pan, Dart big M block, quaility american 4340 crank and rods, Isky tool room springs, .680 lift cam. I run it out to 6200/6300 and have held it for 10 minutes at full boost, BUT it was in a Baja 272 so I could never run it at wot for 45 minutes though like a true "offshore " boat but what I did was everytime I built the motor I did a leakdown test as soon as we were done dynoing it for future record. The leakdown was always in the 3 to 6/7 % range after the dyno, IF it was high then I would have went right back into the motor. Oil change intervals at a max of 30 hours (fuel dilution), sometimes change the filter and cut it open after 12-15 hours, especially if It got ran at alot of wot . Every fall when I went to put boat away I would do a compression test then leakdown test on the lowest compression cylinders. Somewhere around 80-120 hours, usually around a hundred the leakdown results would start getting into the 20% plus range and I would pull motor out and tear it down, EVERY SINGLE TIME I DID I FOUND SOMETHING ON THE VERGE OF TOTAL FAILURE!! Once I found a melling heat treated oil pump drive that had broke off one of the drive tangs that turn the pump, wasnt long for this world before that would hav ended badly, once I found a head gasket pushing away from cylinder to water passage (felpros on merlin block with afrs at 950 hp, no extra valley hold down bolts), it had not blown yet but there was no fire ring left intact so it was imminent. I also found at one point that a cloyes hex adjust comes with a POS chain that should immediately go in the trash, there were several rollers at 118 hours that were crumbling at the seam that I didnt realize they had! I still use a cloyes hex adjust but buy a different brand seamless roller chain (the hex adjust has "true" roller pins but has seams in the rollers). BUT, I continuously hear about other blower motors going 200, 300 hpurs which simply amazes me. So personally at 14 psi boost and 1100 hp I tear into mine every 100 hours or so, in 14 years of running various blown combinations have never blown one up and had to pull motor in middle of the season . My opinion is IF you run your boat like a race boat and its blown you better be changing valve springs, lifters, rings, rods, bearings, oil pumps, timing chains, etc at a set interval, mine is 100 hours!

What rods and crank you running? And valve springs cam lifters Thanks.

I run a older version of this for a crank: http://www.competitionproducts.com/H...products/1231/
Back when I bought it they adverstised it as a "howards 4340 american made crank", was supposed to be virgin alloys, forged and machined in USA, large radiuses, and "permatoughed" .080 deep on the rod and main journals (the new ones no longer claim this). I also run the Hpwards ultimate duty billet rods, forged and machined in the US , Comp products no longer has the full line of howards stuff, my rods are 6.385 version of these with upgaraded rod bolts:
http://www.competitionproducts.com/H...products/1793/
Isky tool room valve springs and a .680 lift hyd roller cam with about 260 @50 duration specc'd by Bob Madera, I was running the Morel high rev lifters until the last rebuild cycle which I converted to Isky red zone solids, never put motor back in the boat when I finished it this year, ended up buying a twin engine 33 Sacarab AVS with HP 500's, Smitty

IMO.. It will all depend on the tune. Back, way back in the day (80's) My first blower motors were either to fat or to lean. I made plenty of ashtrays out of pistons. The blower motors I got to live, I had fat, & after around 80 hours the ring gaps measured .090 to sometimes .130... Blow by was bad LOL New rings bearings ...etc and away I went again for another 80 hours. Now with good AFR meters I think its possible to get 300 plus hours on the bottom ends. For those of you old enough to remember having cars in the 70's before fuel injection, motors were puffing oil, and pretty much junk after 80,000 miles. Now with fuel injection cars don't even need tune ups till over 100,000 miles. In all reality a blower motor .vs a naturally aspirated motor of the same power should last longer. You don't have to put as much cam,spring, compression etc etc.

oh & before you all think I am an old fart.. I got my first boat at the age of 14 & bought my first car at 15. So no wise cracks LOL

Did a leak down and had one cylinder at 25% so did a refresh. The block, heads and crank have over 750 hours. That engine has always been over 1200 HP.

The 30 was all white and was a straight bottom. It went 120. There was more speed in the package but it would have required more setup changes and I decided 120 was good enough.

Hey check was that you I saw pulled over on 465 in Indianapolis right at interstate 70? Shoot out weekend.

It was. A semi hit something and threw it into our back window shattering it. It was pretty exciting for a moment or two.

You built this engine probably what, around 10 years ago? I think its pretty awesome, to make that kind of power, and go 50 hours, let alone 150 hours. The low end torque that engine made was insane. :coolcowboy:

IMO The tune makes a huge difference followed by how hard its driven.

Good read on what goes on in a NA engine, vs forced induction cylinder pressure wise when pressure transducers were installed.

http://rehermorrison.com/tech-talk-9...essure-spikes/

Automatically everyone assumes a forced induction setup, is harder on things, than a NA engine. It is very common, that the high compression N/A engine, will see higher peak cylinder pressures, than a blown setup, and overall, a harder load on the internal parts. Kind of why you can run say 8:1, with 10psi of boost on 93 gas and not detonate, where a 12:1 N/A engine, might need race fuel. This is not new info, and probably why today, we are seeing so many OEM production engines, using forced induction now. Whether it be a little 4 cyl turbo, 6 cyl turbo, etc . These engines are just as if not more powerful than the larger n/a engines they replaced, and more economical, and longer lasting.

Its like diesel tow rigs. Everyone acts like its the whole "diesel" fuel thing that makes the power/torque. Take away the turbo, and they are slugs, and will get smacked by a N/A big block. Give them diesels 25lbs of boost, and that changes the game. I've driven 12 liter, and 15 liter diesel trucks, that lost the turbos, or blew the turbo hoses. They wouldn't get out of their own way without the turbos.

That dyno session was when we were playing around with a hydraulic roller. It was even better with the solid.:)

Piston top designs vary greatly between high compression and 'boosted' lower compression motors, especially an engine that has a large combustion chamber. Think BBC and even worse Hemi.

You are lighting the fire before a piston comes up to tdc, and the closer the piston top comes to the top, these big domes can create some bad issues including, creating partial and then multiple combustion areas, places for fuel to hide, and etc, etc. Dome designs today are far better for making power by addressing these concerns, but will still have flame propagation and combustion issues compared to a flat top or dish.

Oh, one last other issue with N/A especially domes/large domes is during tdc in overlap, it can block the exhaust valve from the intake, cutting down on the time and quality of 'pull' your exhaust can help the intake.

So again, less dome/lack of dome/etc helps alleviate many issues for many different motor designs. However, you need compression for power.

nice pics,,I like how theres nothing coming out of the breathers,,good to see someone can plumb a dry sump oiling system.

Who doesnt? Are you saying no dry sump setups have valve cover breathing ?

nope,they can

Could you give us a complete run down of what you have currently? If I remember correctly you are not running chillers, did you ever record what IAT is on your current setup?

:hijack::offtopic::throw:

Compression test done on port engine today.

#1=150psi #2=155psi
#3=147psi #4=152psi
#5=145psi #6=150psi
#7=155psi #8=152psi

Did leakdown test. Particular leakdown tester showed 15-20% leakage on all cylinders. Not sure on the accuracy of this particular Napa tester. First gauge on leakdown tester, was set/regulated to 100psi. When hooked to cylinder, leakage would show 20%. But gauge would drop from 100, to 90psi. My old leakdown tester had two psi gauges. If you set it to 100psi on first gauge, and second gauge read 90psi, you had 10% leakdown, if second gauge read 80psi, you had 20% leakdown. I may get a new tester, and retest.

However, no leakage at all at the valves. Any leakage was past rings. Looking into cylinders with borescope, crosshatch pattern on cylinder walls, looks like the day they were honed.

PS, Matt, Dan/icdedppl's Intake air temps, are like 150ish WOT full boost if I recall.

I knew you would bite :angry-smiley-038:

Sorry, I won't derail your thread anymore.

Your engine is fine, its your leakdown tester that needs an overhaul! :cartman:

And you better not be playing with my beaker while I am gone.

wow no feedback
 

Nobody`s ever built a 555 or 565 or 572 here I guess , ok. Too bad Bob doesn`t build short blocks I`d have 7 pages of replies... wait wait no I don`t want that either.