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540 freshin up "I hope"

so far every thing looks great . was running rich . To small carb with to much jet. walls looks nice a quick hone job and done. crank comes out next.
time for a beer break.;)
540build021.jpg
 
Gimme Fuel said:
This will be a good project. Sounds like your cam is mismatched for that size engine. I would get all of your specs together and call Bob Madera at Marine Kinetics for a custom cam. It is not as expensive as you would think. He is the man, period, for marine cams.

What other components are in your engine? Head type is a huge factor on how much power you can make. If you list your components (heads, intake, pistons, CR, etc.), that will greatly steer good recommendations your way.
Click to expand...

Here is a list of components : we will start at the top:
carb will be a custom 930 cfm (because I have one in stock)
dart open intake
heads are gm open chamber 113 cc Pn 14096188
roller rockers 13759 crane gold 1.65 ratio
hydraulic roller cam ( don't know yet)
valve springs
piston's are PN# 257942 4.5 bore 20.cc dish forged JE one valve relief.
comp distance 1.270
cometic head gasket .018
rods are 6.385 4340 h beam Manley
crank is Lunati. 60442502 4340
power flow manifolds
the piston is down in the block .010
 
fast94persuader said:
It looks awesome!
That bad boy needs some dart heads!


Hey by the way what the heck kind of prop gave you 9 mph?
Click to expand...
A freind with a big bad ass boat with twins had it and let me have it for free
I think it cost allot.
It did not jump out of the hole like the lazer but feels like a 2 stroke after 3000 rpm .BIG BITE :bigthumb:
 
slingblade said:
A freind with a big bad ass boat with twins had it and let me have it for free
I think it cost allot.
It did not jump out of the hole like the lazer but feels like a 2 stroke after 3000 rpm .BIG BITE :bigthumb:
Click to expand...

The prop looks like a Hydromotive Quad IV to me
 
slingblade said:
Here is a list of components : we will start at the top:
carb will be a custom 930 cfm (because I have one in stock)
dart open intake
heads are gm open chamber 113 cc Pn 14096188
roller rockers 13759 crane gold 1.65 ratio
hydraulic roller cam ( don't know yet)
valve springs
piston's are PN# 257942 4.5 bore 20.cc dish forged JE one valve relief.
comp distance 1.270
cometic head gasket .018
rods are 6.385 4340 h beam Manley
crank is Lunati. 60442502 4340
power flow manifolds
the piston is down in the block .010
Click to expand...

I get a CR of 8.895 with that info. Not bad, would work with a few pounds of boost even.

Looking up those head specks they say 118cc chamber...have yours been cut? That yields a 8.623 CR.

Those are decent heads, but like the 088 Gen 5/6 equivalents, they have a poorly designed short side radius in the runners. With some porting in that area, they really begin to flow nicely and match closely with aftermarket head flow numbers. They have a 325cc runner stock.

Glad to see that you are running a full roller setup and you have a very nice rotating assembly that can handle some serious power. Are you looking to make power with boost or N/A this time. Cam will depend greatly on that.

On your exhaust risers, are they the long ones that introduce the water at the very end? If so, you can run a more open header cam yielding some more power if going N/A.

I think you could be around 550-575 hp very easily naturally aspirated with that semi-low compression ratio. I will be around a 10.5 CR on mine with aluminum AFR heads shooting for around 700hp.
 
I am up in the air right now .I would love to boost it . If i can make a deal with the guy with 2 off of a 525sc.
if no boost I might do a set of heads . would like to make 10:1 comp
 
great tip "GIMME FUEL" Bob sounds like he is the man.
He is working something up for my motor.
looks like I can square the block up and cut a little off heads and get around 9.2 comp. That would be just fine with me.
We will be doing some port work on the short side and some relief work around the valves. I am sure he will coming up with around 112 center line.
will need to build cyl pressure . open intake a little late .I just hope I don't run into exhaust reverb problems . I would hate to suck water in.
 
Yea, reversion sucks. Bob knows best though. I have either a 110 or 112 centerline on mine with no reversion problems (just builder stupidity...yes thats me) running the long EMI manifolds. I think I am going to have my tails lengthened through the transom and full dry to avoid any possibility of reversion. Clamp on my Gaffrig switchable mufflers and be happy.

A good friend of mine just had his Crockett 454 rebuilt due to reversion problems with running silent choice. That was pricey.
 
Do you think that the shotgun exhaust should help this ? I know one thing when slowing down the exhaust goes under water. You can see them above Joe's ugly melon
540build001.jpg
 
No, it will not improve anything. All it does is create more back pressure (possibly). It is something that hinders the free movement of exhaust/water from the pipe. Ive never used them but I know a lot do. Chances are it is minimal HP losses/back pressure created. They should be far enough down stream where they wouldn't add to reversion. The reversion will occur at the point water first mixes in (way back up in the tail pipe). I would measure what length of dry pipe there is until the water ports in the tails.....that would help Bob calculate what length of exhaust "pulse" can be his maximum. Bob and I went back and forth for a week with my exhaust and cam profiles.
 
here is the pipe .There is some water ports at the end about 1 inch back. The rubber hose between the shotgun is 8 inch then the shotgun is 9 inch.
The flaps are adjustable on the shotguns they are set way loose at idle they flap around but as soon as you give it any gas they open up. The rest of the pipe is the 90
540build029.jpg
 
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