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engine problem 572

I think Jack Barta did on his newer boat right after he got it. I thought I saw your boat parked in the middle of the river on Sunday. Were you having trouble. I would have drove over if I had my boat back together. The Fremont Airboat Club was doing our bi-annual highway cleanup Sunday and I saw you giving a tour and it sounded ok when you went by.

Hope all is well.
sharon from stinger told me there were a couple of guys over on the SW coast going threw 572's on a REGULAR basis, maybe she can add some facts to my hear-say.
Did it blow or something else. Some of those guy's Sharon was talking about are alligator farmers and they are hard on parts!!They put blowers on them and whatever else. They are a Assembly line motor.
I have heard of guys dropping valves if they turn them to hard. I have heard the same thing about the 502 if you run them to high.
Well from the day I picked the boat up from Panther it has always ran warm, so the told me with the seat configuration it may not be getting enough airflow and asked me to put on a Large fan to cool the radiator. So I did that and it drop it a little bit but not much.

The oil has always been really hot.

But the boat has ran like a raped ape 10 people dry land. We went with this engine and set up for tour business because the Platte River sometime has no water in certain areas so we have to run dry for 15-20 feet. So the boat has ran great for the last 8 months.

Then Last year it was making a screaching noise in the water pump area, so we thought it just had a water pump going out or maybe a belt that needed to be replaced.

So this year we get the boat out around the first of April tighten the belts boat runs great, take it out on the river was running for about 20 minutes and all the sudden oil pressure drops to nothing. I shut boat off as fast I can.

Take the boat back to shop drop the oil pan metal shavings.

Know we got the engine apart and find out the three main caps are not registered to the block and the crank has been floating around the whole time. So this explains why the engine has ran warm and the oil has been extremly hot from Day one of owning the boat.

So I was wondering if anybody else out there has had this same problem.

I am also trying to get a answer from GM about if the 3 main caps were suspose to be registered to the block from the beggin. I would think they would have to be to have a true line block done.

Just looking for people with answers at this point in time.

And wondering if anybody else has had this same problem?
Have you contacted classic?If so what did they say? I can tell you your not the first with this problem.I personally won`t give classic a dime of my money,you only get taken,at least that's allways my experience.
Hey Nebraska, ya my driver calls me and says the engine just made a loud sound and shut it down in the middle of a tour.

We just got the engine together the week before.

Mind you this 572 only has 300 hours on it so when we put it together the heads looked great so we did not tear them down because there are only 300 hours on the engine.

So know the problem that just happen is a exhust vaulve blew apart and went into a piston but did not hurt the block.

After taking the heads apart we find out GM puts the softest vaulve money can buy into these 572 crate engines inturn they are just a assembly line engine so they try to cut cost so the novis street guy can put it there vehicle.

I believe if any airboat manufacture is going to put these engines on airboat expecially what I do with my airboat they should offer a upgrade on the engines.

For example the exughust temp coming out of airboat is much higher than what comes out a street car that gets taking out on Friday or Sat night.

I use this boat for a business it is under constant load at all time.

They need to put the best stainless steel vaulve, the best piston and hydrolic rollers and cam, and crank that money can buy. If you are spending 70k on airboat whats another 7k on the engine to ensure that its going to be able to handle the abuse that is put on it.

I abousulty love the Panther boat, every body that drives the boat wishes they had that counter rotator on there boat.

Know the engine, GM did some wrong from the beging like not having the 3 main caps registered to the block. And they are using cheap parts in the heads that may be good for a street application but not a airboat tour business applicaton.

Hope to see you on the river some time.
thanks for the facts dan- its a shame when anybody has engine problems, like ya said though - its more of a production line piece- but GM sells it as a hand-built unit. if im not mistaken one person assembles the complete engine. hopefully there isnt anything seriously wrong with bryson's motor, ,im sure he will let everybody know what the outcome is, so others know what the achilles heel is in this application.
No engine is perfect, thunder put alot of time and effort into his engines- he knows the application and the demand on the parts- but he is not selling a factory GM LS.
there is a difference and it shows.
dan what kind of blowers are they bolten on them things anyway ? sounds like it would make for a interesting ride ! 8)
EDIT: wow im a slow typer, sounds like tim found the problems ! major ones. ouch sorry to hear that man....... :(
I was not making up stuff when I said the 502 and the 572 have a a problem dropping valves. You have to go through the heads and replace the factory parts if you plan on working those motors.
this is the only big block chevy I have ever owned.. 502 iron heads.
had a few friends with big block chevys ('68 chevelle 396/375 horse, a terror on the
street...however, the people that know that engine always say the same thing.
do not overrev .. I did see a few broken valve springs..the valves were bent and
the guides were cracked..
so from the beginning my prop was pitched so it would only turn 5200 rpm.. and after
I installed 3" supertrapps that cut it down to 4900 rpm..
and I am very satisfied with the boat and a little piece of mind goes a long way
5500 max rpm back then on the 396..so I use that as a guide for my 502.
emmitt kelly
For what it's worth from my perspective/experience with GM crate engines. The 572 actually has a very nice shortblock. The components are good aftermarket Callies stuff and as I recall JE or CP pistons. My personal preference I won't even consider using any Mark V or VI blocks. In the case of the 572 at least it's a "Bowtie" block. The 502s are very weak and just don't hold up to the stuff I build. But in your case the problem was oil temp. One drawback of the 572/Mark VI blocks is crappy oilpans with nowhere near enough volume to keep oil temps down, so you pretty much HAVE to run an oil cooler. The registers are shot in the block because it was walking the mains and I'm actually surprised they didn't spin. I really wouldn't recomend using that block again if it's going to be in heavy duty use. Airboats put engines under a constant load and they build a lot of heat. That's why they HAVE to be kept cool both in H20 and oil temps. This is also why I use inconel exhaust valves, because the EGT's get so high. There are quite a few mods/upgrades to consider when making a lot of power and running hard. As for the top-ends in GMs....Yeah, it's pretty basic stuff. Don't get me wrong...It's perfect for their intended use in an auto application, and 7 out of ten times work well in an airboat. But if she get's run really hard for long periods of time, I suggest some upgrades. JMO

I will let you all know what the end result is.

We are still checking with GM to find out why the three main caps were not registered to the block from the factory to begin?

I will follow up with you all on this issue.

I have learned alot about this 572 and what I use it for in the last month. They are not made to last for the application we are using it for.
Sorry to hear your'e having motor troubles tim. be sure to stay in contact with felber and waterthunder these are 2 guys who know how to make chevy engines work in airboats. And this brings up a good point crate engines look like a good deal but were never meant to be run on airboats some people have good luck some don't but i think in the long run a waterthunder engine would run better and longer than a crate engine
I break alot of parts and it sucks.You do learn alot and school is expensive! I feel your pain :( Get that thing running and get it back to work! T-rex i don't know what they are putting on them. I just heard they run the mess out of them :) I was spraying a stock rod 383 today. It won't be long. I can't help it!
hello Joe,

Classic, Panther has been great to deal with. They have stood behind everything they have built on a boat that has went bad even when it was not there fault but the Dealers fault I bought the boat through that is no longer in business.

I learned along time ago to just let it go if you have a problem with a airboat manufacure. The first boat I ever spent 35k love the way it look, but it did not do what the manufacture said it would do so I sold it to a guy and told him why I was selling it and lost my ass on the boat. So he put more time and money into it and found out what was wrong, come to find out the Manufacture put a different gear ratio in it than what I ordered. The manufacture even sent him the parts know the boat runs great. You think I would love to tell the world who it was. They tried to make it right by sending me different blades, and then when all that didn't work they just kept telling me I had them build the boat to heavy.

They kept telling me I built the boat to heavy, no they just put the wrong gear ratio in the reduction unit. I have more respect for a manufacture when they say they are wrong rather than them putting the blame on somebody else.

In this case GM is to blame here.

I will buy another boat from Panther in the near future,but I will put my own engine on the boat for my tour business so when it breaks I can only blame myself. Not GM.

Crate engines are not designed for what I do with a Airboat.

Tim Bryson
Tim thats a big bummer, A good friend just had a 502 come apart after 25 hours of real easy running on his airboat and was 12 months and a few weeks old ( the guy bought it to play with on his ranch and just doesent use it much) he loves the boat but is dissapointed to say the least that the motor cratered at such low hours and is not warrantied. A custom built motor by a guy like thunder is a wise investment. Now heres the question would my buddy be better of buying another 502 or just a 454 he really just rides around the marsh no ground pounding. (18 by 8 air ranger) and there is a $3500 difference in the two motors.. or get a custom motor from a a guy like thunder?
My opinion is if you can somehow make it work (money wise) you will 100% of the time be better off buying someting that is built for the application you will be using it for. If you get an engine from an airboat guy who specializes in builing airboat engines they will be better to answer questions when they come up as well as recommending combos. Plus they MAY warranty the engine for use on airboats.

Just my opinion but this applies to everything in life.
loco it sounds like you answered your own question ! and if you do a search - both dave and felber made statements on which GM blocks they would recommend and why, felber yesterday in the 572 posts, but daves was a year or two ago, and he is in the keys right now i believe, so im not sure if he can be contacted now or not.
there are some good strong BBC's out there but a crate motor looks to be a waste....someone needs to build it for the application.