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/r319/jetboatperformance/impeller_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. :D

[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. :D
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

[AMANGO]

Thanks for the info! The horizontal portion of the loader sticks down below keel i will measure it tomorrow and more then likely be modifying it so its slightly in the hole. The droop did pick up speed when installed. So changing the carb out to a 1050 probably would not do much over the 850? i did spend a lot of time porting the intake side of the heads/ polish the ports i did not open up the exhaust side. But it sounds like i need to stick to seating up the pump and ride of the boat before i go any farther with the engine. My Friends that have boats that run 90 mph say my boat rides/lifts out of the water at high speeds nice. But there boats were belt by pros I'm more of a do it your self guy. Theres no fun in going out and buying a boat that you did not build. Thanks For the help so far

[roostwear]

I'm assuming the engine in your avatar is what we are talking about. The single carb TR, although they look cool, is holding you back. As Timinator mentioned, the a/f mixture in TR comes down out of the carb and hits the bottom of the plenum then has a pretty sharp bend to go down the runners. Air doesn't like to bend, that's why dual quads work better than a single (extra flow aside).... a straight shot down the runners.
To get the most from those heads you will need to work on the exhaust side. This is the weak point in 385 heads and where you'll find the most porting bang-for-the-buck.
You might also try wedges on your nozzle. Will they help? Maybe, maybe not. Every hull and setup is different. I'm just on the other side of the hill from you in Anaheim Hills, so if you need some local help, just holler.

[AMANGO]

I will defently try a 2 and 4 degree wege. that dosent coast to much. im running a 850 Demon vac secondary if i add one more 850 demon vac secondary do you think this is to much cfm? The engine is a 11.2.1 comp ratio. And i was planing on porting the exhaust side before next seasion but i do have Lake elsonor for testing. I would like to add a ride plate does any one have one for sale? and how much Thanks "That is my engine in the pic"

[roostwear]

Just adding CFM won't do much (other than use fuel). A good dual plane will more than likely outperform the TR setup you have now. Although they tend to use more fuel, I would consider going with a double pumper instead of a Vac secondary carb. Building and tuning an engine in a jet is different than in a car, so understanding the differences is crucial.

[AMANGO]

I had a Torker II single plane on it before the tunnel ram. Didnot notice much change at all. Mybe a Perf. RPM air Gap or a Victor JR? I will try to set up the pump first. Weges and modify the loader.

[AMANGO]

Just measured the horizontal portion of the loader and its below the keel line about 1" thats into the water.

[jetboatperformance]

Just measured the horizontal portion of the loader and its below the keel line about 1" thats into the water.
If thats a true measurement, its not only slowing you down its flat dangerous ,and can cause severe handling problems (decel "hook" etc) ,also if not already , it (the loader/intake ) should be overdrilled & "thru bolted" with C'sunk black oxide 5/16 course bolts and nuts & checked frequently . re the Carb (850) your probably fine at this point IMO and I dont belive the 1050 would benefit you. RE the "tire spin" the loader depth could have some effect on that and as Tim said you might benfit from a "inducer" be advised to try to make subtle and singular changes ,As hard as it might be to make multiple trips to the water trying things you'll benifit in the long haul Tom
**Thanks Tim ,just trying to help :D

[AMANGO]

Thats good to know and probably explaines why the boat when slowing down pulls back into the the water hard. Makes sence i will take a good picture of the loader before the mod and after and then its time to go to the lake for a test run, And i will post the results after the test run. Im also going to order the 2 and 4 degree weges to try as well. Thanks a lot you guys have been a lot of Help so far its all starting to make sence!!

[AMANGO]

Just modified the loader. Here are some pics i had to remove 3" of the horizontal portion of the loader to get it to sit in the hole an 1/8" below Keel. Sawsall worked good then reshape with a High speed die grinder.

[frosted tips]

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. :DOr try a sterndrive :confused:
cause now your at bass boat speeds. have fun at 80 :jawdrop:

[Aluminum Squirt]

If you really want to get scientific, put a pressure gauge on the intake side. It will let you know when you are in the ballpark with your loader. I'm not smart enough to tell you what it should be at (I think I remember around 25 PSI, but that may be way off). This will let you know when you are getting close. I'm guessing when you were way below the bottom, you intake pressures were rediculously high, very dangerous on shut down. Glad you are getting it sorted out before you get into some really good numbers. You've got so many things you could work on. It's always dissapointing to build a nice mill and see it not get the number you were expecting. There's a lot of speed and safety in the pump and hull, I'd get that all set up first, then start messing with the motor. Get that hull straight, your loader set up right, a good tight pump, right size nozzle (if using an adjustable), and a place divereter, then you can start screwing around with the HP. You'll be going real deal fast in no time-Aluminum Squirt

[AMANGO]

Going to test and tune on Saturday. I had a question? just received my 2 and 4 degree wedges and i noticed that they are ribbed around them so do i have to use gaskets or just torque them down to get a good seal? I will post the results after my trip.

[bp]

Going to test and tune on Saturday. I had a question? just received my 2 and 4 degree wedges and i noticed that they are ribbed around them so do i have to use gaskets or just torque them down to get a good seal? I will post the results after my trip.
no gaskets needed.

[AMANGO]

Nice. Thank You.

[AMANGO]

Well I made it to the lake and here's the results:
-1st Run modified loader only. 76.8 MPH 5400 RPM a little lower then normal on the RPM, jetavator all the way up was the best position.
-2nd run 2 degree up wedge best speed 71 MPH jetavator position did not make a difference.
-3rd Run 4 degree up wedge same results.
But here is the catch. My fuel pump was acting up, I believe my carb was running dry on the 2nd and 3rd run. After a high speed pass the engine would run out of fuel then shut off. the only way to get the pump to pull the fuel was to pressurize the tank. That was 1 problem and i discovered a vacuum leak at the manifold where the 2 part tunnel ram comes together. One last thing after talking to my dad (Tech support)I realized I'm running a pcv valve which I'm going to remove because i had it set up wrong causing a bigger vacuum leak. basically i was running a tall breather on one side and on the other a pcv valve going to the carb when it should have been closed off on the side were i was running a breather. I will fix these problems and then try agine! I will be selling my 850 cfm speed demon vacuum secondary carb. Ran for one season. If anyone is intrested 300 dollars OBO.

[496jet]

I also have a delta bottom we run our loader 1/4'' below keel and hang shoe 1/4'' below as well .this works well on our set up. also we run a 3 1/16 FTN
how heavy is your hull ? pic of it running top end would help!

[AMANGO]

also we run a 3 1/16 FTN
On the fine tune nozzle did you get an increase in RPM and how much? I have a standard nozzle and was thinking of getting it machined for the inserts if possible? I will try to get some pics of the boat on top end next time out. It might be a little before i can post them. going to fix a few things. And its Dirt bike time. Thanks

[496jet]

also we run a 3 1/16 FTN
On the fine tune nozzle did you get an increase in RPM and how much? I have a standard nozzle and was thinking of getting it machined for the inserts if possible? I will try to get some pics of the boat on top end next time out. It might be a little before i can post them. going to fix a few things. And its Dirt bike time. Thanks
Unfortunately, I installed the FTN at the same time as the new impeller so I don't know RPM differences. I really doubt it would have changed. My diverter is a place and the stock size was very close to 3 1/16. In my opinion, if I was you, I would not spend the money on it, just yet. When you cut your loader, did it make a big difference on the way the boat shut down? 1" below keel was way too much, but remember, the Delta bottom is a lot different than a radius bottom and the set ups are not the same.

[bp]

also we run a 3 1/16 FTN
On the fine tune nozzle did you get an increase in RPM and how much? I have a standard nozzle and was thinking of getting it machined for the inserts if possible? I will try to get some pics of the boat on top end next time out. It might be a little before i can post them. going to fix a few things. And its Dirt bike time. Thanks
nozzle inserts won't affect engine rpm; they affect the characteristics of the pump. in a lot of cases, standard nozzles aren't perfectly round. boring the nozzle for inserts corrects that.
to keep it simple, a boat moves due to force, and the force is a result of mass times velocity. changing an insert can alter the velocity and mass values, but the sum remains the same (i.e., the same amount of hp is aborbed by the pump, but the characteristic is altered).
with a larger insert, or no insert, more mass at less velocity. smaller insert, greater velocity less mass. you can get extreme with this to where the boat will hardly plane, or it accelerates like a demon to about 40, then quits. FTN stands for "fine tune nozzle", and small changes can have dramatic effects...

[AMANGO]

Unfortunately, I installed the FTN at the same time as the new impeller so I don't know RPM differences. I really doubt it would have changed. My diverter is a place and the stock size was very close to 3 1/16. In my opinion, if I was you, I would not spend the money on it, just yet. When you cut your loader, did it make a big difference on the way the boat shut down? 1" below keel was way too much, but remember, the Delta bottom is a lot different than a radius bottom and the set ups are not the same.
On the shut down it did make a difference. Know its very controllable before when it was one inch below keel the boat shut down hard. I'm looking into a ride plate and shoe from ARS. The one that doesn't require machining to install? Thanks for the info!

[AMANGO]

I also have a delta bottom we run our loader 1/4'' below keel and hang shoe 1/4'' below as well .this works well on our set up. also we run a 3 1/16 FTN
how heavy is your hull ? pic of it running top end would help!
On your set up do you run a droop? Or wedges + or _ degree on the wedges? being a delta bottom just wondering. Thanks

[496jet]

Yes i run a droop with no wedge. when i put the droop on i went 2 mph
faster.

[AMANGO]

Has anyone tried the ARS marine Adapt a shoe and ride plate kit that does not require machining Will this case to much drag? from my understanding all shoes stick down below Keel.What kind of top end MPH gain?

[DonziGT230]

About your PCV; it read as tho you're going to keep the PCV and block off the breather?--DON"T!! At light throttle you'll probably have a lot of vacuum in the block and under load may pressurize it. You can safely eliminate the PCV and replace it with another breather tho. I can't say much for the pump & hull stuff, but I know engines.

[AMANGO]

Thinking of going to a roller cam as well. Here are a few cam grinds I'm looking at?
Schneider Roller Cams
429/460 Ford
Grind # 306-14R, Rocker Ratio 1.73, Lobe 110, Degree intake lobe to 108.
Lift .657-666 @ 306x314 Duration Now at 50 Lift 380x385 @ 50 272x284 This is a very good Nitrous Cam
OR
429/460 Ford
Grind # 296-R, Rocker Ratio 1.73, Lobe 108, Degree intake lobe to 106.
Lift .631 @ 296 Duration Now at 50 Lift 365 @ 50 268 This is a very good Nitrous Cam.
What kind of HP gains and RPM? currently running 5600 RPM
I'm also working on the heads. Porting the exhaust side and intake to SCJ port size as close as i can get! the exhaust side has been improved a lot a little to much i grinded a hole in one of the exh ports, but weld and re grind.

[simple_mindedness]

this may not be exactly what you may be looking for but have you considered a snoot instead of a droop? just a thought i know that this really helped squirtcha
http://hi-techperformance.com/images/Cast_Snoot_Web.jpg

[AMANGO]

I might have to try a Straight snoot. I'm going to add a shoe and ride plate First Fix a few other little things and be back in the water next summer. I was still experimenting with a 2 and 4 degree wedge when i ran into a fuel pump problem it wasn't keeping up with the fuel demand it was running dry on top end. Straight Snoot looks good Thanks