75 MPH 600 +HP? Looking to go 80+

[AMANGO]

Hello I'm new to this Threading, but I'm looking for a little help. I just rebuilt my big block ford 460 engine bored .030 over. a few tech info 11.2.1 comp. 585int 588 exh comp cam extreme marine duration @.050 254 int. exh 264 lobe separation 112.0 cam rpm range 2500 to 6600. Cylinder heads Pro comp I port matched the heads to the intake an offenhhauser Tunnel Ram with single carb setup 850 CFM looking to go to a 1050 CFM. Est. Hp 600 +. Boat info 76 Eliminator bubble deck 18.5 ft Rebuilt Berkeley pump well Berekely intake and American turbine Bowl Gen. 5 Droop snoop and jetavator and B cut impeller and a extreme loader. The engine currently turns 5400 to 5600 RPM depending on conditions I was hopping to turn 6000 to 6400 RPM and my speed is GPS at 75 MPH I'm trying to Breach 80 + and thought that would be possible with my build. The boat when accelerated hard will caveatted and hit the rev. limiter? I was thinking of going with a different nozzle with changeable inserts? maybe 3 1/4" its a standard nozzle know 3" and adding a ride plate and shoe? When the wife lets me spend a little more $ If you guys have any info that will help It will be highly appreciated. Thanks

[jetboatperformance]

Welcome to the forums ,Several things come to mind , my cam and "power band" choice would likely have been different but that said , under the correct conditions true 600 hp will turn a standard "B" cut Impeller right at 5800 rpms (+ or-). The Jet drive ,if working properly will literally "limit" your motor back to its actual power . Knowing more (and seeing pics ) about the actual boat and set up would be helpful to make suggestions to you Tom
(chart is courtesy of Hitech)
http://i147.photobucket.com/albums/r...ler_Chart1.jpg

[TIMINATOR]

A performerRPM or a Strip dominator will give you better mixture distribution, and should make more power in the rpm range that you are into. Jetboats also prefer tighter lobe centers on the cam. Mke sure that you or somebody you know how to correctly "read" sparkplugs so you can get the tuning close. The cavitation under acceleration can be a loader grate that is not optimum for your setup and Horsepower, or it may need an inducer(pre-impeller). at your HP, you probably need the inducer. Your pump will need to be dissembled and the shaft needs to be machined and keywayed for the inducer, we charge $85.00 for the machinework and we do it in-house. The pump r&r parts, if on the bench runs about $100.00+ any gaskets. We sell inducers for $395.00. Shipping by Greyhound bus is cheap! Call for further info. TIMINATOR 623-877-8553

[AMANGO]

Thanks for the info so far. Im also running a malery unlite distrebutor with the led triger. about 35 deg. of timing and summitracing CD ignition box with rev limiter. I will get some pics of the boat. Will the droop snoop make the RPM drop a little? When i rebuilt the pump i also put a liped ware ring in it. If the engine is not making 600HP mybe the loader is a little on the big side loading to much water in to the pump at higher speeds. Thanks

[jetboatperformance]

The Droop will should have virtually no effect on rpms , the loader may however , curios to see what loader you actually have and how it relates to your keel Also is your boat a round keel or delta bottom (i suspect rounded by the year) Tom

[AMANGO]

620-103115
Loader Scoops
Hardin Marine
"XS" Xtreme Loader Scoop for 12JC, 12JG, 12JI Pumps
The "XS" Xtreme Series Jet Loader Scoop is just that - Xtreme. It is designed for all out competition in boats that produce 500+ horsepower. By using an open center loader style design this loader will jam pack the impeller virtually pre-loading the pump.
Note: Engines that don't make 500+ horsepower that attempt to use this unit may actually experience an overloaded jet creating a "bog" type sensation.
This is the loader I'm running and the bottom is a delta if thats the one that is flat before the loader about a foot or so. Its defiantly not round be for the loader, i will try to get pics and upload haven't figured that out yet. What kind of top speed gains do you think if i add a ride plate and shoe?

[AMANGO]

JUST ADDED A FEW PICS.620-103115
Loader Scoops
Hardin Marine
"XS" Xtreme Loader Scoop for 12JC, 12JG, 12JI Pumps
The "XS" Xtreme Series Jet Loader Scoop is just that - Xtreme. It is designed for all out competition in boats that produce 500+ horsepower. By using an open center loader style design this loader will jam pack the impeller virtually pre-loading the pump.
Note: Engines that don't make 500+ horsepower that attempt to use this unit may actually experience an overloaded jet creating a "bog" type sensation.
This is the loader I'm running and the bottom is a delta if thats the one that is flat before the loader about a foot or so. Its defiantly not round be for the loader, i will try to get pics and upload haven't figured that out yet. What kind of top speed gains do you think if i add a ride plate and shoe?

[roostwear]

Although it's hard to tell from the pics, it looks like your loader has too much bite (below keel) and may be overloading your intake. From the sound of your build I would guess your HP may be 500 or so. The Procomp heads are, at best, equivalent to D0VE heads, and throwing a TR at them won't make them flow better even with a stout cam. You are at the point many of us are at at one time or another. Bolt-ons won't do much good at this point... you need to get your setup straightened out before you build it more. Your hull may not even LIKE a droop and may slow you down. Or it likes a droop with a 2* wedge (or 4*). All this is part of getting speed from maximizing your setup. I'm at 75 with a .040 over 460 with a Comp 282H cam, Stealth dual plane, 8.5:1 motor in an open bow with an E pump. Keep in mind each change you make in hardware affects your setup and the process starts over. Welcome to the jetboat zone... test, change, test, change, repeat.

[jetboatperformance]

Keep in mind each change you make in hardware affects your setup and the process starts over. Welcome to the jetboat zone... test, change, test, change, repeat.
Well said Roost.... Amango put a 4 foot straight edge on the bottom (keel) ahead of and into the "loader area and check the debpth of the horizontal blades ,for your boat I would be at or 1/8 "up" from the top of the straight edge . You can use a sawzall or ?? to trim them and then grind to reshape the leading edges please call if you need help or more info Tom

[TIMINATOR]

TOM: didn't notice he is closer to you, fix him! I'm still here for answers though. TIMINATOR