Cylinder Head option 1 or option 2 or save for 3?

Running a stock 460 with D3VE heads would the DOVE heads be a real benefit to get to 600 HP? my goal it to turn 6500 rpm.
Jet boat weights about 1500 lbs, has an aluminum A impeller. Currently turning 5000 at @ 60 MPH. I have tried to do some research and there is not to much information.
I have one guy telling me to go with the DOVE head and not to worry about going to SCJ heads. The SCJ head are about 2 grand a set and the DOVES are at 700 complete set (rockers, valves, springs).

A great deal of information is out there on doves/d3 heads. Neither head will hit 600hp without porting. The

dbaker wrote:Running a stock 460 with D3VE heads would the DOVE heads be a real benefit to get to 600 HP? my goal it to turn 6500 rpm.
Jet boat weights about 1500 lbs, has an aluminum A impeller. Currently turning 5000 at @ 60 MPH.  I have tried to do some research and there is not to much information.
I have one guy telling me to go with the DOVE head and not to worry about going to SCJ heads. The SCJ  head are about 2 grand a set and the DOVES are at 700 complete set (rockers, valves, springs).

IMO if both heads are ported with the same size valves and flow numbers are close to each other.The only gain in power with the DOVE heads will be from the smaller cc of the heads!!!

If you take the 700.00 off of the SCJ's does it change the equation, when it comes to porting every one is an expert on your dime. A poorly ported set of DOVE heads will surely be outperformed by a set of SCJ's out of the box, and a well ported set might be comparable and cost as much +75lbs and if you do not have a class requirement for the iron...well

Are you planning on changing your impeller?

A 460 can not make enough power NA to turn an A cut to 6,500 rpm.



S

What kind of HP do I need to make to get an A cut impeller to turn 6500 rpm?

dbaker wrote:What kind of HP do I need to make to get an A cut impeller to turn 6500 rpm?

Over 900 HP.

See this link and the extended HP chart at the bottom of the page.




http://www.jetboatperformance.biz/pages/FAQ.html



Hope this helps.

S

dbaker wrote:What kind of HP do I need to make to get an A cut impeller to turn 6500 rpm?

You'll need about 860-870 observed HP @ the impeller on whatever day in whatever weather. Just know that having that peak power @ 6500 won't necessarily get you there. Jet boats need a good wide power curve to stay ahead of the impeller.
That impeller chart JBP uses isn't very accurate. I've found the JAC SEA chart to be way more accurate.

Scott Foxwell wrote:

dbaker wrote:What kind of HP do I need to make to get an A cut impeller to turn 6500 rpm?

You'll need about 860-870 observed HP @ the impeller on whatever day in whatever weather. Just know that having that peak power @ 6500 won't necessarily get you there. Jet boats need a good wide power curve to stay ahead of the impeller.
That impeller chart JBP uses isn't very accurate. I've found the JAC SEA chart to be way more accurate.

Good to know Scott thank you.



S

Sometimes I can be helpful.

Scott Foxwell wrote:

dbaker wrote:What kind of HP do I need to make to get an A cut impeller to turn 6500 rpm?

You'll need about 860-870 observed HP @ the impeller on whatever day in whatever weather. Just know that having that peak power @ 6500 won't necessarily get you there. Jet boats need a good wide power curve to stay ahead of the impeller.
That impeller chart JBP uses isn't very accurate. I've found the JAC SEA chart to be way more accurate.

The nozzle and intake will make a little difference so, we should just leave it as, "a lot more power than a 460 will make NA using D0VE heads".

I'd stick with 2.

Mounting the third head is really hard.

Wow lots of information. Thanks for the insights. I did not realize the power robbing requirements of a squirt boat. According to the charts I should be pushing @450 HP. What would be the most cost effective way to get another 200 hp? Build wise without NO2. I am thinking of building up to a 532.

I am on a budget that the wife lets me have. I. Was just thinking of just stroking it and rods . Then later on a cam.

Basically start from the bottom up

dbaker wrote:Wow lots of information. Thanks for the insights. I did not realize the  power robbing requirements of a squirt boat. According to the charts I should be pushing @450 HP. What would be the most cost effective way to get another 200 hp? Build wise without NO2. I am thinking of building up to a 532.

Displacement. Cubic inches will be your friend in a jet boat but just remember; even with the BB Ford, the more stroke you use, the more windage issues you'll have to address. Make sure you have a good amount in your budget for a quality oil pan, especially in a marine app like a jet boat. Not a place to skimp. I would also get with Chris Straub on the cam. We've done a lot of jet boat combinations over the years and he has a real good handle on the needed power curve. Also make sure whoever is building the engine is familiar with marine-build requirements. Marine engines are "special needs" kids.

Scott Foxwell wrote:

dbaker wrote:Wow lots of information. Thanks for the insights. I did not realize the  power robbing requirements of a squirt boat. According to the charts I should be pushing @450 HP. What would be the most cost effective way to get another 200 hp? Build wise without NO2. I am thinking of building up to a 532.

Displacement. Cubic inches will be your friend in a jet boat but just remember; even with the BB Ford, the more stroke you use, the more windage issues you'll have to address. Make sure you have a good amount in your budget for a quality oil pan, especially in a marine app like a jet boat. Not a place to skimp. I would also get with Chris Straub on the cam. We've done a lot of jet boat combinations over the years and he has a real good handle on the needed power curve. Also make sure whoever is building the engine is familiar with marine-build requirements. Marine engines are "special needs" kids.

Another option is to run a slightly smaller impeller and use a little more rpm to make your HP. It doesn't cost much to have an impeller turned down.
JMO.

I am thinking of the lines of a b cut impeller. But that will be after the HP increase

dbaker wrote:Wow lots of information. Thanks for the insights. I did not realize the  power robbing requirements of a squirt boat. According to the charts I should be pushing @450 HP. What would be the most cost effective way to get another 200 hp? Build wise without NO2. I am thinking of building up to a 532.

The bigger engine with a better cylinder head... a 521 with SCJ heads from FRPP..

dbaker wrote:I am thinking of the lines of a b cut impeller. But that will be after the HP increase

Best thing to do is plan this all out before you start. There doesn't have to be any guessing involved. First thing I'd decide on is how much power you want to make. Then decide on the rpm range you want to make it in. That will dictate your engine build. Once you know that, cut your impeller accordingly. It will be very helpful to have the engine dyno'd, otherwise you will be guessing. Just make it a part of the engine build budget.

dbaker wrote:I am thinking of the lines of a b cut impeller. But that will be after the HP increase

Just beware that there will be a trade off in performance with the smaller cut impellers. A heavy boat with passengers will not plane off as nice with the smaller cut impellers.