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How many hours do you have on a BBC?

C

C Green

Member
How many hours are you guys putting on your BBC 454 and 502's? I put 60 hours on the first one and had the bearings go out, I had it rebuilt and got 35 hours and there is a bunch of metal in the oil pan. I was wondering if this was a bad rebuild or is it that the 454 is not a good airboat motor? Thanks
 
You hear a lot about valve train going in them. Sorry about your luck :( been there it sucks! There is alot to be said for having a airboat engine purpose built. If you are interested in a alternative to what you are running. Cadillac performance parts .com offers a bad boy crate motor that is purpose built dyno tuned for less money than what you have know and has over a 100 more ftp of torque! There are guys running his stuff on here that love it. If you have a smaller boat Water Thunder Performance ls2 engine plate form is hard to beat! Good luck with it. I'm sure you will get to the bottom of it and you will get some good advice from the motor builders on this thread.
 
YOU NEED TO CUSTOM BUILT FOR AIRBOATS ! SHOULD NEVER CALL THEM CAR MOTOR BOAT S! THEY TAKE A BEATING MORE THAN ANY OTHER MOTOR ! I AM A CAD GUY BUT WITH HARD PARTS ! :D I LOVE SMALL BLOCKS THUNDER FOR SMALL BLOCKS! POTTER FOR BIG ONES !
 
Even a stock crate motor is good for 100 hours. The 454 is more robust then the 502 for several reasons! It sounds like you are running too much timing or having detonation problems! Just as stated above if you have a good engine builder build you an airboat engine it will give you years of great service! You would be surprised how important it is to build a motor to a specific hull or gear ratio or even intended use!
 
I've got at least 500 hrs ona 330 sbc and it runs as good or better than the day I got it.
 
Allot of these BBC have it much harder then a small block because they are on huge heavy boats and are under a bigger work load!
 
I have it on a 18x8 foot boat, (Alaska). I cruise at 3500-3600 and max RPM is 4400. I thought that the motor should last longer than that. So I am trying to figure out what to do. I can not afford to buy a motor a year. So I am trying to find a motor that will last. Thanks
 
My 502 has OVER 1,400 hours on it.. Yes, 1,400 hours.. Either I'm really lucky, or I take really good care of my engine... :D Either way I'm knocking on a LOT of wood right now.... :wink: (I've probably just jinxed my engine now...)

Max RPM has never been over 5,000 and cruising has always been around 3,100.
Being on a 16' hull, it's never really worked hard for an extended pierod of time... But when it is called on to work hard, it is worked damn hard... Glowing exhaust, mufflers and all..
Gotta love a Big Block... 502 cubic inches of rompin' stompin' raw hell.... :D :D

Take care guys.....

Brian.
 
I have 700+ hours on my 454 from Diamondback, max rpm around 4600rpm with a 2.3 belt. I probably just jinked mine too!!
 
I had 120 hrs on my ZZ4 crate motor in my 14 ft Diamond back and no problems and I have about 80 hrs on my WaterThunder LS6 and both of them turned 5500+ and I cruse around 3500 to 4000 no problems you might want to look at a WaterThunder 600 hp LS motor guys have been replacing there BBC with these and they have all most exactly the same torque and are hundreds of pounds lighter
 
C Green how many RPM's are you turning it. Higher RPM's don't scare me it's when you load it down with a 2to1 and choke it at 4,500 or so this tends to cause detonation and burned up parts much worse then a few hundred more RPM's. Could you tell me what parts failed then we can find the root of your problem! Look at the top rod bearing what's it look like! This will tell you everything!
 
C Green":3uuzzft0 said:
How many hours are you guys putting on your BBC 454 and 502's? I put 60 hours on the first one and had the bearings go out, I had it rebuilt and got 35 hours and there is a bunch of metal in the oil pan. I was wondering if this was a bad rebuild or is it that the 454 is not a good airboat motor? Thanks
Click to expand...


Give us more information so we can give you the best answer. Do you run a gear drive, if so are you sure it is not pushing or pulling on the crank. In other words do you have it shimmed right? If not it will take out your thrust bearing in no time. What size oil pan do you run on your big block? If you run a standard pan they should have at least polished the inside of your block so the oil can drain down faster. I run a Potter Cadillac because everyone I know with big block Chevys ends up with a box of parts. Unless you have the BB Chevy built by a guy who knows airboats you will have troubles.
 
I just need to know what your rod bearings look like this will tell me the most info! Small block and Big block Chevy's rarely have thrust bearing problems because that is what all of the gearbox's are designed to fit! However a belt drive has a clamp collar that could be adjusted wrong or you may have an old gearbox which some of them had problems! My guess is you will see the bottom half of your rod bearings look OK and the top half are worn!
 
C Green,

Like everybody else above, don't want to jinx myself but... I have about 140 hours on my 454 turning 5100 at wide open throttle. She's been good so far.

How about oiling? What weight oil? Engine heater for your extreme cold up there? Whats your oil pressure running?

Basketcase
 
I JUST FINISHED BUILDING MY 454 AFTER BLOWING IT LAST HUNTING SEASON, WE WENT BACK AND FOUND THE HISTORY OF THE BLOWN ENGINE AND FOUND OUT IT WENT THROUGH 2 OTHER AIRBOATS BEFORE BEING PUT ON MINE, THE ENGINE WAS 15+ YEARS OLD AT THE TIME IT BLEW
 
this got my attention!!
I have 96 hours on my 502, I always pull the oil drain plug and make sure there is not any
water in the oil after sitting a while, I use 15w40 rotella.. and change it after a couple
of runs.. sometimes it is a while between runs.

I go to a GMC dealer and buy the big 1 quart AC oil filters only 3.50 each in Covington,ga.

before mufflers the engine would turn 5300 rpm.. now with the supertrapps it is 4900rpm

I let the engine idle before shutdown after a run.. change antifreeze and distilled water
every two years, change gear lube amzoil every year.

retorque intake bolts, carb, manifold bolt, check for cracks every couple of runs.

big block chevys don't like high revs.. the old 396 especially the solid lifter engine
would break valve springs

I am too old to ride below 70 degrees!! and above this 100 degrees we are having!!

I know this is probably an overkill but it makes me feel good.

a sure way for your boat to get blown up or turned into a submarine is to loan it to
a "good friend".

my engine is a marine 502 so I do not know if there is anything internally different
other than you can not put a mechanical fuel pump on it

would like water thunder's thoughts on any difference..
also any big differences between the 348/409 and the 454/502
supposedly the 502 has "canted" valves.. not sure what that means and if that is
better against valve float... the older I get the more I find out that I don' t know
what's going on????!!

emmitt
 
I got what is supposed to be a 454-425HP crate motor.
it had 403 hours on the hourmeter when I bought it used in 2000, (I can't say for sure all those were on this motor). Since then I have put another 420 hours on it. I had to redo the heads about 50 hours ago (1cracked ex.valve and several loose ex.seats). I change the oil every 30 or so hours with 20w50.
usually cruise about 3200.
5000 RPM MAX.
 
Sorry guys, it is hunting season up here and I have been gone. The season is 40 days long to hunt everything so it is busy time of year. Wish I had an airboat that worked. The motor was a marine 454 built by S & S engine in Washington.

THUNDER- I have not had time to touch the motor. I can tell you that there is two holes through my oil pan in the middle, on each side of it. When I pulled the oil pan off on the river there were large metal chunks. I put it back on and pushed for 2 1/2 days to get it down to the closest road. I will pull it soon and find out.

Crow- I run a belt drive with approx 3 hours on it. I had just bought it.

Case- Oil pressure is 50. I run 5W-30

Thanks Chad
 
In my opinion the best cold weather Big Block engine you could be running is the
Marine Levitator 496 Cubic Inches Fuel Injected and designed to run on 87 Octane.
12 month Warranty (have not had one come back)

If you want a small block then Waterthunder is your man!

If you want more info on the 496 let me know I will e-mai it to you.
 
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