brand new 460 12je pump and new 'A' impeller something wrong???

[navyman]

I have a 78 glastron cv-23 brand new 460, 12je pump, and new 'A' impeller and the top speed of the boat is 48 mph at 5400 rpm and it takes a bit to get to that speed! So what would the problem be? Maybe wear ring??? I dont have a clue but I see on tons of posts that this boat should do 60 mph + with a stock 460. Well My 460 is not stock it has an Edelbrock 750, Weiand stealth intake, flat top pistons and a pretty radical cam, with a little bit of head work. 48mph is it. Something has to be wrong! It shoots out of the water with the nose up and it takes a sec but when it starts levelen out 48mph is the top! I wounder if a place diverter will help that much if so that will be the next purchase.
Thanks Mike

[Duane HTP]

pretty radical cam,
This could be part of your problem. Give us your cam specs. The cam may be radical enough that the engine is not making it to it's power range.
Yes, a diverter usually always helps.
As easy as those pumps are to check clearances on, I'd pull the bowl and impeller and make sure on the wear ring. That's a lot of rpm for no more speed than you are getting.
Also, do you have the boat weighted down too much with a bunch of extra gear in it? Coolers, anchor,etc.

[Amm]

Have a hook? Take a straight edge and put it underneath the hull. One edge should be flush with the transom. Hopefully the most aft section of your hull is completely straight.
If your boat has it, I am pretty sure this hook slows you down considerably.

[malcolm]

That's really a 23 footer? Might be the whole problem right there. How heavy is it?

[ap67et10]

you said its a new setup...or at least fresh. is this i boat you recently got and redid everything or have you had this boat for a while and just decided to redo everything...maybe you bought it with this all done to it. anyways my point is do you know what the boat ran before the new rebuilds? did you gain anything? does the boat run slower? if you have a baseline of some sort then you should be able to figure this out a little easier. just cause weight and hull design may be your limiting factor.

[Riverbass]

Are you checking your speed off your speedo or GPS dont trust the speedo.

[TIMINATOR]

Log exhausts are quite restrictive, especially with stock exhaust ports. Stock 460 smog heads exhaust ports only flow about what a stock 350 chevy do, way too small for a 460. The cam shouldn't be bigger than 230-235 at .050. Also, did the shop that built it use a stock or street legal roller timing set? In a 460 application, the cam timing is retarded 8 to 12 degrees from split overlap. This was done to keep the oxides of nitrogen down in a car application, but it will kill the power in a boat deal. If the cam was properly degreed when installed, this shoulden't be an issue. Stealth intake is way too big for your application, a Performer rpm airgap is the weapon of choice. The stealth will be down by 50-70 ft-lbs of torque at 4500 rpm. Make sure your distributor is advancing total 12 dist degrees(thats 24 crank degrees)at 3000 rpm, use 10-12 deg. initial advance.Many non-performance shops use the deep dish pistons in all 460 rebuilds, with your smog heads, the compression ratio would be about 7.3 to 1. Way too low, especially with the too large cam. Do all of this stuff and repost. TIMINATOR

[sleekcrafter]

A healthy Ford 460, will usually pull 4900rpms thru logs, seems your way past that rpm, check your tach verify that it's reading correctly. If you just installed the impeller, and did not install a match wear ring, this could account for some poor performance, and some excessive rpm's. Check these two items, they will cost you nothing, and report back.;)

[Willis]

This could be part of your problem. Give us your cam specs. The cam may be radical enough that the engine is not making it to it's power range.
Yes, a diverter usually always helps.
As easy as those pumps are to check clearances on, I'd pull the bowl and impeller and make sure on the wear ring. That's a lot of rpm for no more speed than you are getting.
Also, do you have the boat weighted down too much with a bunch of extra gear in it? Coolers, anchor,etc.
Duane,
I need a little info on that inducer made by DPS.
What is it rated at as far as how much CF does it pump in relation to a A impeller

[flat broke]

As Tim said, you need to know what your motor is really made of, but since you're not complaining about not pulling the RPM you suspected, that's just one piece of information in your current puzzle.
How have you determined you have an "A" impeller? Have you physically verified it's size against the manufacturers specifications? Next, as already recommended, verify your front and side clearances between the wear ring and the wear ring surface of the impeller.
Without any detailed information on your motor build, most would say that you are pulling more RPM with that "A" impeller that what most folks achieve. To give you an idea, my motor could only pull a properly clearanced detailed "A" impeller to 5600RPM... My motor made 751hp on the dyno at that RPM. My heavy Spectra 20 was going a good 30mph faster at 5600 than you are at 5400. Sufice it to say that something is amiss.
If your clearances check out, you need to check to make sure that there isn't debris stuck in your impeller. Since its a JE pump we can rule out a leak at the suction/intake gasket. If your clearances check out, the last thing I'd look at is your rock grate/loader. If you are running a factory rock grate, it could be inducing some cavitation compared to running a loader grate. This could account for some of the excessive RPM you are seeing on your tach.
Now for some bad news. You have a pretty big boat for what is more than likely a fairly docile motor. That combination with a jet won't yield the best results. To give you an idea, I was just out doing testing in a 23' open bow with a new AT312 pump. With full tanks, safety gear, an empty cooler, and two big heavy guys we were getting just over 60mph. Stock for stock, the pump in that boat is more efficient than your JE. Couple that with the fact that the motor makes more HP, and your numbers don't seem far off.
What you have is a nice family cruiser. Go through the other suggestions posted in this thread and nail down as many of the variables as possible. That will tell you where you may be able to grab a little more effiency. But honestly, asside from your excessive RPM, you may well be close to what would be "normal" for a boat of your weight/size/power. If you like the boat, definitely invest in a diverter, as even if it doesn't add any speed, the ability to trim the boat for different water conditions is usefull. Depending upon what you find when you nail down all the variables on the motor build, you may find out that going to a larger impeller, while turning less RPM, will make your boat more enjoyable to use.
Sorry none of us can give you a "magic bullet" answer. Post back with answers to as many of the questions as you can, and you'll more than likely get further direction that may help you out.
Out of curiosity, what are your expectations for the top speed of this boat?
Chris

[Boomer]

I had a cv-23 with a stock 460 Pac a jet. it would run about 51-52 mph at 4900 rpm. checked with a GPS. Always thought it would run 55 with a fresh engine and pump. I also had a place diverter

['78 gt boat]

I have almost the same set up but my boat is an 18ft. Spectra 460 BBF, 780 cfm holley and a JE pump. The pump is currently being rebuilt but it GPS'd at 58.7mph @ 5000rpm. It also has a place diverter which I'm sure helps out.:)

[navyman]

well I just checked the cam card and its 216 int and 220 exh at .050 and I know its an 'A' impeller because I bought it brand new from cp performance and the heads are dove c 429 heads with bigger valves and some exhaust grinding. I know for a fact that it has flat top keith black pistons because I bought them and had the machine shop press them to my rods. I run atleast 91 and then add some 100 octane fuel or it pings like crazy!! the cam has been degreed and it has a double roller timing set. I have not checked the clearences of the wear ring....I know...I should of!! LOL! the wear ring did not look to hot but the shaft was like brand new. I am going to buy a thrust bearing and I am going to order a new wear ring and have my machine shop match the impeller to the wear ring. No there isn't any thing in the impeller or the intake, I know this because I had a rock in the impeller and it would barely move the boat so I ended up buying a new one before finding this out....I learn the hard way....LOL..I personelly think its the jet drive! I will try to rebuild it myself and hopefully it gets me to atleast 60+ mph!! Oh ya it does have the stock berkeley waterlogs on it but all ground down and pollished to a chrome like finish...That should give me like 10 mph...right? LOL Oh ya the speed was taken with gps and my tach ...well all my gauges are brand new vdo blue line but I did check it and it matches my digital timing light rpm to the exact. I dont have to high hopes of 75, 80...mph but 60s would be fine and if I cant get to 60's I have a 671 blower with intake just waiten for the 460 in the boat, I had plans for it but like the wife says plans always change...LOL I hope this helps and I will check the clearences after the new wear ring and thrust bearing gets here. Until then I will be going 48 mph. I guess, thinken about it... if I lighten it up a bit I should go a little bit faster I had the nose packed down pretty good with all the camping gear, tent, chairs, coolers ect, me at 155 pounds, my bro at 220+ pounds and a full tank of gas 30 gallons needless to say the water was a little choppy do to some winds!
This weekend its supposed to be 90's at the lake so I will go out empty by myself and a little gas and see what happens and repost. I wish I knew what it did before I bought the boat with a blowen engine. Thanks Mike

[flat broke]

Don't bother taking it out on the water again until you've checked the wear ring/impeller clearances. As far as rebuilding the pump, there isn't much to it. If the bearing is in good shape, there's no reason to really futz with things much. Check your clearances and report back.
As far as taking everything out of the boat, what does that really accomplish? If that stuff would be in the boat when you "normally" use the boat, you might as well leave it in there. You can try moving it around in the boat, but if it's stuff that will typically be there, you're only fooling yourself by testing the speed of the boat with the stuff removed.
While your checking your wear ring clearances, do yourself a favor and measure the impeller just to be sure. You'll have the bowl off, so you might as well double check. Just because the box says it's an "A" doesn't mean someone couldn't have misplaced something. Probably not the case, but it never hurts to nail down every variable you can.
IMHO, expecting 60 out of that setup (even with the pump tight) is unrealistic considering the documented performance of other heavy boats with jets and similar power. The low 50s speed posted by the other CV23 owner is more in line with what boats of this size/power would do with a jet. Like I said earlier, if you like the boat, buy the diverter, figure out your cavitation problem and enjoy a 50-55mph family cruiser.
EDIT: I just re-read your post and found a couple other issues. First of all, you don't need to have your shop machine the wear ring or impeller. If the clearances are off, you can measure the o.d. of the wear ring surface on the impeller. You then buy your replacement wear ring with an o.d. that gives you acceptable clearance. They make undersized wear rings specifically for this reason.
The other thing is with regard to that blower. If you are already seeing detonation with your static CR and 91 octane fuel, what are you going to do when you add boost? You'd have to lower your static CR to allow the blower to make any boost and have the pistons survive. Not to mention I'm betting the KB pistons aren't forged which means they should be replaced if you're going to use a blower anyhow.
Chris

[Legal Chemistry]

Although I diffent boat... mine is still 24-25' spins an A to ~4900 in the low 50's with 30 gallons of gas, stereo, coolers, and 4 peeps. It sounds like your pump isn't as tight as it could be, but the speed is about right.

[sanger rat]

If I am reading it right he installed a new impeller and used the old wear ring. I'm guessing thats the problem right there.