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serious power increase

If that little rice motor only weighs 300#, the back of the boat is going to sit higher out of the water than the front. I backed a 21 Pulsare with no motor in the water one time to switch trailers, guess what, the chines were 6" from even touching water! By the way, if these little motors were so great, my buddy wouldn't be spending $90,000 for 854Cu In big blocks to run ProMod, he'd just call WingTipshu and say send me over another pickup load rice burners!:rof:boatman
 
BigBlock

Maybe I should buy the block and all his old parts?Can always look for a Hull and outdrive later!!lol Whats it cost for a marine BB?
 
Wow, I was on page 4 before I realized this isn't a joke!

Realize it or not, the main reason that I/O boats use large engines with a low specific hp is for reliability reasons. High hp/ci leads directly to poor reliability. Yea yea they make 800 hp for 9 seconds at a time, relatively reliably, but when you make 800 hp for 9 minutes, it will turn into a pile of molten aluminum. 40 psi boost??? The heat load generated will not be easy to deal with. In fact, I would venture to say that the heat transfer area inside the engine isn't adequate to pull enough heat away from the cylinder/chamber to prevent the piston from melting.

A 454 will be WAY more reliable at that power level because it will get there at 10 psi boost, versus 40 psi.

As far as price goes, a capable engine management system will cost nearly $2500. A capable fuel system will be another grand.

I hope you have a good tow rope and fire extinguisher.

Edit: In case you're wondering, I've built a few turbo setups myself, including a 950 hp SBC airboat motor and a 320 hp 1.5 liter PWC engine.
 
I recommend using his old 4.250 crank and H-beam 6.385 rods with some SRP pistons 9.5:1,
Plasma moly ring set, I have a nice 454 4-bolt GenIV block,Machine it all up and balance it.
I can have a custom cam grind done.


Have your heads gone through assemble with Felpro Marine gaskets
you will have a 550 HP 496 that makes gobes of low end torque and great top end power.
It will jump up on plane and be gone with reliability.
 
Yeah--as far as engine management-especailly in a marine application it is crucial to be able to determine all parameters. I am on a university racing team "Formula SAE" and we use a high-tech management unit called a motec.. this unit alone is close to 4k. -Just something to reconsider. I dont think re-flashing a factory computer will get you good results, just not accurate enough.
 
Wow.....I am not on here for a few days and I miss all of this drama!:popcorn:

Ok......Engineer Mike is absolutely correct. There is no way that that block could dissapate that much heat quick enough even if you pumped 50 degree seawater through it. Why don't you just spray nitrous while your at it and gain another 250 hp. Im going to bet on the molten pile of aluminum side of things. Sure, those motors can make some impressive power....but for short bursts....Not running at WOT for 30 minutes straight in a poker run/ or even in a top end run......plus, when you spin a 21p prop at those kinds of rpm, cavitation increases and efficiency drops.

I won't even start into the torque issue....that is a given.

Twin milder 4cyl turbos with alphas might be cool and run good.....but not a single in this size of a boat. The center of gravity will be greatly effected. It won't plane, be able to keep bow lift and be squirly in the rear even if you get it on plane. It won't ride properly on the pad like that hull is designed.

It is good to think outside the box with things......but not so far outside you run off of the cliff.
 
Why not try installing a couple of cheapo turbo's on the 454 (if you wanna get your feet wet on a turbo setup)? I mean, it would make more power at less boost, be more reliable, and not require an entire custom engine and wiring harness to get it to work. That way you don't have to learn on 3 or 4 different fronts at the same time.
 
ok.. full engine tuning software will cost me 500 dollars. its called dsm links if you dont belive me research it.. i can tune every parameter and i will use the stock car harness/computer. the computer has a eprom chip which allows you to change parameters as you see fit.. fuel curves timing curves. ect ect.

as far as the fuel system. injectors are around 250 dollars for all .. and the fuel pump/regulator around 200

look you guys know big blocks and i trust your opinions but we know 4g63s. trust us making big power out of this particular engine isnt that expensive or hard. and it does it reliably :eyecrazy::lol: if you guys dont belive me please do some reasearch on the motor and see for yourselvs.. you just might be impressed.

anyways i will be building a big block putting it back in and selling the boat and getting back to my outboards.. :poke: cause i wanna go fast again :popcorn:
 
IMO, it'll be worth more in one piece if the boat is decent... guess it depends on how much you have into it initally.

BBC powered boats can and do go fast.. just depends on what your budget is to make them do so. If you have a boat in great shape, then I really think it'd be worth putting some money into building a bbc to drop in it and comfortably run 70+.
 
so you take a little harassment online and your giving up what was so wrong with your old motor i know you had some scoring on the cylinder walls why not just bore it out and rebuild it and have some fun with it if nothing else is really wrong you could rebuild it much cheaper than you could put a new motor in for
 
theres an old saying there is no replacement for displacement apples to apples a big block chevy is always gonna make more hp than the 4 banger if you were to build a bbc and boost it with 30 lbs it would make a lot more hp than the numbers you were talking about
 
stclairriverblaster said:
ok.. full engine tuning software will cost me 500 dollars. its called dsm links if you dont belive me research it.. i can tune every parameter and i will use the stock car harness/computer. the computer has a eprom chip which allows you to change parameters as you see fit.. fuel curves timing curves. ect ect.
Click to expand...

Yea yea, been there, done that. I converted a MAF 1 bar LTx ecu into an open-loop, SD 2 bar closed-loop setup. Never worked as good as even a Holley Commander (or a carburetor, for that matter), let alone something good like Motec or BS3.

stclairriverblaster said:
as far as the fuel system. injectors are around 250 dollars for all .. and the fuel pump/regulator around 200
Click to expand...

Where are you going to get a reliable fuel pump and regulator that will support 800 hp at 80 psi, and do it for hours rather than seconds, for $200?

stclairriverblaster said:
look you guys know big blocks and i trust your opinions but we know 4g63s. trust us making big power out of this particular engine isnt that expensive or hard. and it does it reliably :eyecrazy::lol: if you guys dont belive me please do some reasearch on the motor and see for yourselvs.. you just might be impressed.
Click to expand...

Nobody is doubting that they make the power. Everyone is saying it won't do it cheaply or reliably in a boat. There is a very good reason that Mercury Marine increases the cubes and head flow (4v now) to the max and uses modest boost levels.

stclairriverblaster said:
anyways i will be building a big block putting it back in and selling the boat and getting back to my outboards.. :poke: cause i wanna go fast again :popcorn:
Click to expand...

Awww... To be honest, I'm a little disappointed you won't be trying this. It would turn out to be good entertainment for all of us.
 
im not giving up. im moving to tn. and the lake i will be living by will have NO rough water. its always glass its in a valley. and in a boat this big its really boring. there is no sense of speed. at least doing 70 in three foot chop gets my buthole puckering lol!!

the hull is in really good shape.. but it needs interior really bad.. the upholstery is really bad.

edit: its called twin walbro 255s and a apr fpr and i wont be making that power for hours considering i put the boat in. go for a quick blast and go back home. i dont need it to make that power for hours.

and i WISH i had the spare change to try this on the side. i would love to prove you guys wrong. lol
 
I'm really disappointed your not following thru. I was looking forward to a good winter read!! I think its a crazy idea but i like it.......for someone else to do lol. I do have to wonder how much crap someone more respected here would catch for the idea though. Your idea is off the wall but I kinda feel your integrity and age was a large part of the greif you caught. You don't always come off as someone who could pull off a build of this degree and I beleive that hurt you here. I do wish you could pull this together but the liklyness is probaly not good. So all that being said how about going the other way. Big motor {your 4cy 800hp} in small boat {pwc shell} probaly just as much work, alot more bad azz to it and the chance of it working alot higher!! Would be just perfect for your in and out speed runs on a flat lake.

Good luck, keep dreaming and don't let the man get you down!
 
mkhammer said:
I recommend using his old 4.250 crank and H-beam 6.385 rods with some SRP pistons 9.5:1,
Plasma moly ring set, I have a nice 454 4-bolt GenIV block,Machine it all up and balance it.
I can have a custom cam grind done.


Have your heads gone through assemble with Felpro Marine gaskets
you will have a 550 HP 496 that makes gobes of low end torque and great top end power.
It will jump up on plane and be gone with reliability.
Click to expand...


How much? sounds like a nice freshing up my big pig could use.
 
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