Best Chevy value?

[mud duck]

Okay, while boating Saturday afternoon I cracked my 454 block. At first I thought it was only the blower belt, but after closer inspection, oil is spattered around and there are cracks in front of the block. The cracks are up front near the crank shaft's pulley. So, my question to you bright people that know jet boats; Where can I pick up the best engine for a resonable price? I could prabably use my old blower, ignition, carb, oil pan, etc. However, I would most likely go with new heads for this next block. Will a B&M 250 blower bolt up to a 540 Chevy? Do I take this on now, or in the spring? Oh what an expensive day. The boat is a 1998 21' Ultra bow rider so I do want to get it running again properly. On the good side, we had an excellent day.
Don't let anyone tell you a stock Chevy 454 marine grade engine can handle 5 lbs of boost. It is not true, I am living proof. cry

[victorfb]

i guess it all depends on how much you want to spend and how much of a complete engine you need. a while back i was looking to build the 454 in the duelly. i talked to a few builders and alot of them said that the 502 crate from GM was the best bang for the buck. about the same if not cheaper than building the 454 the right way.
if you want to cheap, get a used motor from a wrecking yard and see how long that one lasts. just dont put that 5# of boost to it. :D

[flat broke]

If it were me, and in an odd way, I wish it were. I would opt for one of World's complete 509 packages. For a complete long block, they are a little cheaper than the zz502, the parts are arguably as good, and you get more out of the box HP. Now in regard to your blower. It's not that the 250 is a huge blower, but I think it moves enough air to start thinking about blower specific static Compression Ratios and cam profiles. That being said, a custom build might be the way to go. You can go custom with decent parts at a price that won't be all that bad. (that is a subjective term) The bottom line is that this is the point where you eitehr spend good money after bad, or wipe the slate clean, decide what you want out of your boat and build accordingly.
Good luck,
Chris

[mud duck]

The cam was swapped out when I added the blower last April/May. I thought this engine would last awhile with only 5 pounds of boost but I do have a theory on how it happened. I believe one of the valve cover vents fell forward and it got caught in the blower belt which then set off a chain reaction and something went horribly wrong inside. This only my theory, but I dropped it off this morning to get the real word on how bad the damage is. This might have to be a spring project. cry

[mud duck]

Well, the educated guess is the crank shaft snapped.
Are you suppose to have windows in your engine block?
http://www.***boat.com/image_center/data/521/452My_Picture0003-med.jpg
cry

[Duane HTP]

If the breather went through the blower belt, you can just about bet on a broken crankshaft. Sorry to hear about your trouble. Give me a call.
316-794-8616

[mud duck]

Another theory has surfaced; We got airborne a few times Saturday which is bad news for boats, especially jet boats. The engine did not noticeably get real high rpm, but it is hard to react fast enough and get your foot off the throttle. Who knows why it happened, but tomorrow I will get the ugly news which I believe will be that the crank shaft was snapped.
I have been browsing the internet and found complete marine 454 long blocks for $3,800, and I found blocks only for about $600. Cost is an issue, however this would be the best time to drop in a big beautiful 572. Decisions, decisions.
Duane I received your e-mail, thanks, I may be knocking on your door soon. :D
[ September 08, 2003, 08:49 PM: Message edited by: mud duck ]

[superdave013]

Do yourself a big favor this time. Spend the extra on some good parts. And spend that money with someone who know's how to put it all together.

[058]

Chevys have value? :D :D :D

[Jungle Boy]

superdave013:
Do yourself a big favor this time. Spend the extra on some good parts. And spend that money with someone who know's how to put it all together. Exactly my thoughts. I have suggested this to many of the backyard guys here that think they can assemble a boat engine with their cheapo torque wrenches and vise-grips and then listen to them moan about low oil pressure, knocking, ticking and other ailments that they have developed after a few hours of running. Do some research on a guy that understands "boat" engines. You may pay more now but in the long run, you'll be happy. Good luck, Duck.

[RandyH]

I feel your pain Mud Duck. You got all winter now. Have Duane build you a motor with good parts, send him your good stuff and come about Feb or March take your boat down, have him put it in, set it up, tune it and then go pick it up. You will be done for a long time. My 2 cents,
RandyH

[mud duck]

A few pics of the damage.
http://www.***boat.com/image_center/data/521/452My_Pictures0004-med.jpg
http://www.***boat.com/image_center/data/521/452My_Pictures0007-med.jpg
http://www.***boat.com/image_center/data/521/452My_Pictures0003-med.jpg
cry

[mud duck]

cry
http://www.***boat.com/image_center/data/521/452My_Pictures0009-med.jpg
http://www.***boat.com/image_center/data/521/452My_Pictures0002-med.jpg
cry

[mud duck]

Any suggestions on brands of forged pistons, rods or a crank shaft? Any suggestions on cubic inches? What gains do I get from a 540 over a 502?
Just looking for advice for my next engine. :confused: