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Swamplizard

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Discussion starter · #1 ·
Some of you have followed the Harley project boat saga .. at this point I fear I will be lucky to get a year out of these motors since my luck has been all bad with motor builders (Bill's Marine Davie FL) so I might as well prep the wife for the bad news of big expense next year for new power.

If you mechanically savvy folks were me - what would you power it with and ballpark the costs for the new motors for me.

Reminder of the boat size/stats:
43 footer, 10'6" beam, 22-degree deep vee, arneson surface dirves, 15-18,000 pounds of glass, foam, and kevlar

Thanks folks - I'll need time to save the $$$$
 
#2 ·
You need good reliable torque to move that monster.

Your 502's can be stroked to 4.25 to give you 540 cid's.

Use good heads, small cam, good parts, and of course good engine builder.


What's happening with your engines now?
 
Discussion starter · #3 ·
got an independant guy named Frank who is trying to fix the builders shoddy work. We are still doing things like compression checks, timing, he's put mechanical guages on it to see why oil preasure seems off for port motor and starboard was overheating and then the impeller went completely. So tomorrow- replace impeller, change oil in port motor, double check that the right thermostats are in and seatrial again and do some more testing. We are getting there but at this point my faith in these motors is near zero.

I find in S Florida that you almost have to do everything yourself cause the caliber and quality of work (on average....dont everyone get insulted now...is just not there. Simple things like oil changes and tire balancing get hosed up so imagine dealing with high performance engines???? ect) so I think I need to take a bigblock marine motor class and just dive in and learn what I have to learn. I want this beast to be reliable so the wife and I (now that we are empty nesters) can start cruising big time and hit the bahamas and Keys regularly. Hope Frnak can get them stable enough to build some trust in them.
 
Discussion starter · #6 ·
are 500s enough HP? I've got guys telling me they would go diesel with this thing to get twin 600 hp and make it run. Diesel is really not an option for $$$ reasons, plumbing reasons, engine height, and transmission reasons.
 
#7 ·
Torque is what you need to push this thing.

So if money is no object, I agree with them. Diesel would be best.

However, because of the mammoth cost of diesels (hold on to your seat when you see the prices) your next best would be to build gasoline engines with a ton of torque. The only way to do this reliably is with big cid's.

Because of the load you need to build them with low compression and proper squish (piston to head) clearances. Anything to stave off detonation will be worth it's weight in gold.
 
Discussion starter · #8 ·
now hat is best description of what is needed that I have heard to date - thanks/makes sense. I had hoped the 502 with a pencil thin cam, carbs, and gills would do just that but since the motor builders wont tell me what's in the things ... the rest is guess work on my part. again - thanks!
 
Discussion starter · #10 ·
Kevin - nice! can you post the numbers when you get them? Be safe up there dude - Ivan's still at 140 mph.

ALSO - so I can educate myself - what is THE book to read on marine motor build outs so I know what I'm getting next time?
 
#11 ·
Never found a book on marine engines, School of hard knocks, the only way I have ever learned. Definately a difference in car (ie)racing than marine applications. I have personally found a common thread between mud bogging engines & marine. We are well versed in that, being from north Fla. (swamp country). I will post the # from the 604's. KR. Being I never read the post on your engines I dont know all the details...
 
#12 ·
There have been marine conversions around for some time for the Cummins diesel engines. This website does not have a cost but in the past, they have been around $4000. I have heard that low mileage engines can be picked up for around $2500. $1500 to $2000 for a transmission. Not sure if they will fit it your engine compartment. A reliable 550 lbft of torque at up to about 3600 rpm might push your boat to fair speeds with great mileage and reliability.

There are also kits for the power stroke Fords, closer to BBC size, but more expensive kits as two exhaust manifolds are required.

Sell your existing motors to defray part of the cost.

http://www.hsmarine.com/
 
#13 ·
Swamplizard said:
Kevin - nice! can you post the numbers when you get them? Be safe up there dude - Ivan's still at 140 mph.

ALSO - so I can educate myself - what is THE book to read on marine motor build outs so I know what I'm getting next time?
Click to expand...
dennis moore has a book out on marine big blocks (big block chevy marine performance) by hp books hpbooks-1297
 
#14 ·
Dennis Moore's book is THE book that everyone on this board suggests... and most of the advice that you get on this board is right on line with what he says... find his big block book and read it about 4 times.. then you will digest it all
 
#15 ·
I agree. D. Moore's book is great and can be a big help. But WOW, look at the size/weight of Swamp's boat! I think he has to go beyond what Moore's book has to offer. I can't be of any help to him 'cause I really don't know chitt. But I do know he's going to need two big tq monsters in the engine room to make his Harley go. Diesel might be the best thing to look into but the $ amount will be up there.
 
#16 ·
Yes, he really needs bigger motors than suggested in D. Moore's book.

These motors are for your normal boats and Swamplizard's is larger than the norm.

Torque, torque, torque.

BTW: Dennis's books are very good. If you have no other info or trusted source to go by than this is a decent source to follow.
 
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