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The saga continues

S

stan

Well-known member
This subject has been covered before by thunder and others ,considering the circumstances I thought it worth mentioning again.Here at work the operators use one of two boats to get back and forth to there machines in the salt marsh.The old diamond back went through a motor after 300 hours the replacement lasted 97 hours and it,s replacement lasted a whopping 37 hours all the engines were 330 hp gm engines purchased from three different air boat manufactures ,the boats were always operated on water never stuck .The final conclusion for the failures are running out of oil at high rpm.It never fails ,tring to save a dime will cost you dollar .The plan now is to outfit the next engine with the proper AIR BOAT oiling system.Do not assume that an air boat manufacture will sell you an engine that will stand up to air-boat use. My opinion used to be that the average air boat car motor would last about 200 hours until I met a gentlemen recently that had maybe 1800 hours an his big block .So I know for a fact engines can be made to last with some minor modifications .Which I'll admit to the fact that my Knowledge is more that a little week on that subject.So what say y'all other than dry sumps what are some good easy solutions to this problem ?
 
How about a 10 or 12 quart oil pan, that should be enough. Or maybe adding one of those pressurised resovoirs with the electric solenoid and low oil pressure switch.
 
Has any one asked the crew just to back off on the gas pedal pressure!!! :D :D :D

You may have to weld a bolt on the bootom of that gas pedal. :o

Just have the boss man buy one of waterthunder 450 hp motor. It will have all the mods done for you. Then report how many hours the crew can put on it before it blows.
That would be a test of all test for longevity and abuse.

Drive it like you stoled it or dive it like it it's not mine it belongs to the bossman :D
 
I don't have an hour meter but I do have a GPS system that tells me miles traveled. It told me that I put almost 400 miles on my Cadillac during the 3 months of duck season. These are extreme use miles as the weather is bad and the loads I carry are big. I have an 8qt pan on my motor and I run Delo 15-40.
 
heck if 'n it was me I would just fire the next guy I saw get in the boat without checking the oil no questions asked. I had the same problems with my excavators and dozier operators and that solve my problem quick
 
When I was working seismic, we had HD oil systems and large oil pans in our BB engines. We also had a twice daily check for oil level, water level, oil pressure, and temperatures. Once a day checks on the belt drive and prop.

If we got caught skipping any checks we was fired on the spot.

We also had a limit of 10 seconds at WOT no exceptions. Period.

When your running another mans boat, you do it his way or go home.

Scotty
 
I agree with yah Scotty. Back then, before i got caught in the an airboat's web, i was accustomed to the 10 second rule.

10 seconds on the starter and 10 seconds on WOT .

...another rule.... speed and load are inversely proportional to engine life!

in an airboat, well if it's a beneficial info, i would like to make mention that the automotive engines we are using are not the same derrated engines like the AC ones. those AC engines can take up to 85 to 90% of max (WOT) rpm continous running and live up to the TBO time, provided with adequate cooling and lubrication.

the auto engines on the other hand, especially when stock ( treat those custom built differently) are rated to peak rpm, way beyond the rpm of max. torque. these may produce hundreds of horses for lesser CID but you get them at a higher rpm! just treat it this way, the wear at 4000 nrpm is twice as much as that at 2000 rpm... in other words, you'll only get half the engine life at 4000 that at 2000 rpm EVEN WITH ADEQUATE LUBRICATION AND COOLING!

oil treatments and lower temps may or may not have significant effects.

so, be easy with the pedal and rub less on the metal! and do a pre-start check....
 
I'm not totally up to speed about Stan's new job - Is it still for a branch of the Volusia county gov't? If so, firing someone for not checking oil is probably not going to happen. It may work in the private sector, but it's not so easy to fire someone from a gov't job.

(not that I disagree that is by far the best solution!) ;)

If you have to write them up three times or some other crap then replace a motor just to fire them- maybe the racing oil pan is the most simple solution.

It still wont make it idiot proof though. But it's a start.
 
Stan,

Good topic! Don't know if it will help but here goes...

Got a brother, (really) my other brother Darell.
Runs rock crawlers up in the hills,(kinda near sniper).

Bad to the bone rig he has, I drove it up a hill there called The Widowmaker! I swear a billygoat would have a hard time with that hill!
It utilizes a "low oil sender" to activate both an idiot light and a bright blinking visible alarm. More importantly...it uses a oil accumalator system similar to what we used on the submarines. Here's a few at Summit..
. http://store.summitracing.com/egnsearch ... =%2D115995

I sure wish I could afford one :cry: But wait..maybe if I tell her it's this or a new motor :thumbup:

Basketcase
 
I was told by a reputable machine shop that after market or replacement oil pumps have high pressure springs in them. So when we use those oil pumps in our airboat engines, and rev them up high for extended periods, all the oil goes to the top of the engine starving the main bearings etc.

This machine shop guy said he sees plenty of burned up engines caused by this and we should put the stock spring in the oil pump that comes in the oil pump box. I've run oil pumps with both the high pressure spring and low pressure spring. The high pressure spring will put my pressure right off the scale when the engine is cold and runs about 60 pounds when the engine is warm. The stock pressure spring runs about 60 cold, 40 warm, and about 20 pound idleing which I believe is more than enough pressure.

So I wonder if those high pressure oil pumps are what's killing these engines.
 
its volume not neccesarily the oil pressure that starves the engine, thats why reputable engine builders will put oil restrictors at certain points in blocks (not that i know where or on what blocks but there are plenty of others here that could answer that) , and like whats been said, you still need a large oil capacity pan, to be prepared for that demand. so stock pan and a bigger pump= no oil in pan real quick. and im not a engine builder, but this is real easy to understand. extended time in upper rpm ranges are hard (or fatal) on a engine that wasnt designed for it.
 
T RITE CANT FIND THE POST ! OIL PAN 8 TO 12 QT ! MINIMAL ! KEEP THE MAIN S HAPPY! YOU ARE HAPPY ! MY CREEPER WILL HOLD THREE QTS ! LONG STORY !
 
Not to throw cold water on this thread, but new engines shouldnt be burning any oil....checking the oil shouldnt really matter, although I always check mine. Havent added oil in 3 years on my Cadillac with the 13 quart pan. It sounds like its either a) the wrong oil for the load carried, b) the wrong engine for too much load, c) the engine not set up right for the load,d) no proper oil cooler, or a combination of the above. I have personally seen Cadillacs on tour boats that got 2000 hours, albeit at direct drive, on a regular basis. I agree that rpm kills engines faster than anything. But something isnt right with this boat and it needs to be gone through by someone damn knowledgable. Does the engine /boat vibrate a lot? I have seen a bad propeller eat an engine quickly through harmonics.

Maddog
 
my response had nothing to do with the engine being ' low' on oil. but a engine being run at upper rpm's the oil pump will push all the oil to the top of a engine before gravity can do its thing and let the oil drain back to the oil pan to get cycled again.
this doesnt seem to be a problem that gets talked about with caddy's alot, not sure if its because they dont get usually put to the 5,000 rpm and up catagory or the oiling system is just different from the usual small and big block gm stuff, or what. maybe part of it is that with the caddy's we dont even have a selection of HIGH VOLUME oil pumps to choose from, our problem is even the 'stock' replacements take a shit on us, brand new out the box.
charles youve got a higher capacity oil pan by almost double regular gm crap, this is exactly whats needed to keep a hard working engine alive for any length of time.
goodnite everybody, im beat.
 
T-rex---I agree with you too....wasnt dissing you in the least. But 30 something hours from a new engine, when not many people are making the upper end mods on a regular basis and still getting many more hours, tells me there is more to this story. Just my 2 cents.
 
I agree with what was said in one of the first posts get a WaterThunder engine they are well thought out and have had all the modifications you need they are built from the ground up to be an Airboat motor and the are time tested and proven to be reliable
but I also very much agree that checking the oil level is a must on any engine his motors just seem to take more abuse than any others I know of
 
Yea it's really hard for me to figure.All the engines had the proper amount of oil .(The last engine took out #3 rod journal the rest of the rod bearings and mains were jam up like new. Kinda funny though the oil was checked that morning heck I watch the operator ckeck it ,when the rod went to knocking ,he brought the boat in and the mechanic checked it it was dead on full ,took the boat to the manufacture that sold us the engine and they called back saying the engine was 2 .5 quarts low on oil and to come get the boat ,we got the boat back and drained the pan and filter and came up with 5 quarts ) timing was dead on ,all suffered from rod bearing failure .I like the idea on the 10 second rule as well as the other recommendations.
 
You should never use a high volume pump unless you have at least a 7 qt pan and plenty of return on any SB or BBC. 99% of the time a high volume pump isn't needed anyway. Proper clearances and fit are, along with heavy duty reciprocating parts. On our air boat engines, we like to run a 10 or 12 qt. full sump pan whenever applicable since there are no cross members underneath. Even a 7 or 8 qt. pan should do fine with proper drainback, windage and baffles. Heat is also a killer on bearings and more oil means less heat and better longevity as a rule. Oil coolers come into play and also add more room for more oil because of lines and coolers holding extra oil. As long as the crank doesn't run through the oil, you can't have too much. A good windage tray helps on boats to help keep it in the sump .
 
stan":2aux5akp said:
Yea it's really hard for me to figure.All the engines had the proper amount of oil .(The last engine took out #3 rod journal the rest of the rod bearings and mains were jam up like new. Kinda funny though the oil was checked that morning heck I watch the operator ckeck it ,when the rod went to knocking ,he brought the boat in and the mechanic checked it it was dead on full ,took the boat to the manufacture that sold us the engine and they called back saying the engine was 2 .5 quarts low on oil and to come get the boat ,we got the boat back and drained the pan and filter and came up with 5 quarts ) timing was dead on ,all suffered from rod bearing failure .I like the idea on the 10 second rule as well as the other recommendations.
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Usually the furthest journal from the pump suffers first, which leads me to believe heat or improper clearances or fatigue of somekind may be to blame. Keep in mind also that the GM crate engines are about like Jasper engines done on an assembly line with little regard to checking anything. Rod sizes and journal sizes are all over the place. They use engine assemblers , not engine builders. There is a difference. Get a rod on the low side and a journal on the high side and you have a disaster waiting to happen. It may not show up for years in a passenger car, but marine engines typically are run harder, longer with much more neglect and with less warm up before going WOT. They really need to be purpose built IMO. Brass freezeplugs and epoxy paint do not a marine grade engine make. I think they need extra attention and better parts.
 
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