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

Page 1 of 2 1, 2  Next

View previous topic View next topic Go down

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

Post  dbaker on October 18th 2017, 7:18 pm

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).

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  jpierce55 on October 18th 2017, 8:13 pm

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

jpierce55

Posts : 66
Join date : 2009-08-23

View user profile

Back to top Go down

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

Post  Mark Miller on October 18th 2017, 11:24 pm

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!!!

Mark Miller

Posts : 1222
Join date : 2009-09-01

View user profile

Back to top Go down

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

Post  dfree383 on October 19th 2017, 6:51 pm

The chamber is a little bit better on Dove heads, because they are a little shallower. the D3 stuff benifits from a big deck mill.

Higher compression with the Doves too and you will need compression to reach your goal.

d3 heads generally have hardened seats if they haven been rebuilt to many times too
avatar
dfree383
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 13560
Join date : 2009-07-09
Location : Home Wif Da Wife.....

View user profile

Back to top Go down

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

Post  FalconEh on October 19th 2017, 11:10 pm

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
avatar
FalconEh

Posts : 1380
Join date : 2014-08-21
Location : on the blacktop or in the mountains ????

View user profile

Back to top Go down

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

Post  dfree383 on October 20th 2017, 7:12 am

FalconEh wrote: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

Imo the aluminum SCJs out of the box will equal a well rubbed on set of iron heads and are a whole butt load easier to improve on and port.

The aluminum heads are the way to go if you have the budget and if you don't have a clean set of iron to work with and the ability to do you own porting the money difference can be minimal if at all.
avatar
dfree383
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 13560
Join date : 2009-07-09
Location : Home Wif Da Wife.....

View user profile

Back to top Go down

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

Post  The Mad Porter on October 22nd 2017, 10:09 pm

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
avatar
The Mad Porter

Posts : 179
Join date : 2009-08-07
Age : 54
Location : Tacoma, Washington

View user profile http://www.reincarnation-automotive.com

Back to top Go down

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

Post  dbaker on October 23rd 2017, 8:39 am

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

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  The Mad Porter on October 23rd 2017, 12:47 pm

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
avatar
The Mad Porter

Posts : 179
Join date : 2009-08-07
Age : 54
Location : Tacoma, Washington

View user profile http://www.reincarnation-automotive.com

Back to top Go down

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

Post  Scott Foxwell on October 25th 2017, 5:03 pm

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

Posts : 390
Join date : 2011-06-23
Location : N/E Tennessee

View user profile http://www.straubtechnologies.com

Back to top Go down

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

Post  The Mad Porter on October 25th 2017, 6:20 pm

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
avatar
The Mad Porter

Posts : 179
Join date : 2009-08-07
Age : 54
Location : Tacoma, Washington

View user profile http://www.reincarnation-automotive.com

Back to top Go down

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

Post  Scott Foxwell on October 25th 2017, 8:09 pm

Sometimes I can be helpful. Very Happy

Scott Foxwell

Posts : 390
Join date : 2011-06-23
Location : N/E Tennessee

View user profile http://www.straubtechnologies.com

Back to top Go down

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

Post  rmcomprandy on October 25th 2017, 11:37 pm

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".

rmcomprandy

Posts : 4769
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

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

Post  dfree383 on October 26th 2017, 9:19 am

Scott Foxwell wrote:Sometimes I can be helpful. Very Happy

On the Chevy questions...... Razz Razz
avatar
dfree383
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 13560
Join date : 2009-07-09
Location : Home Wif Da Wife.....

View user profile

Back to top Go down

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

Post  Mark O'Neal on October 31st 2017, 2:12 am

I'd stick with 2.

Mounting the third head is really hard.

Mark O'Neal

Posts : 138
Join date : 2009-08-12

View user profile

Back to top Go down

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

Post  dbaker on October 31st 2017, 7:53 am

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.

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  dfree383 on October 31st 2017, 8:50 am

do you plan on reusing anything you have and about what is your budget? What are your fuel requirements?
avatar
dfree383
BBF CONTRIBUTOR
BBF CONTRIBUTOR

Posts : 13560
Join date : 2009-07-09
Location : Home Wif Da Wife.....

View user profile

Back to top Go down

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

Post  dbaker on October 31st 2017, 8:53 am

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.

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  dbaker on October 31st 2017, 9:01 am

Basically start from the bottom up

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  Scott Foxwell on October 31st 2017, 9:07 am

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. Wink

Scott Foxwell

Posts : 390
Join date : 2011-06-23
Location : N/E Tennessee

View user profile http://www.straubtechnologies.com

Back to top Go down

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

Post  Scott Foxwell on October 31st 2017, 9:10 am

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. Wink
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.

Scott Foxwell

Posts : 390
Join date : 2011-06-23
Location : N/E Tennessee

View user profile http://www.straubtechnologies.com

Back to top Go down

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

Post  dbaker on October 31st 2017, 9:15 am

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

dbaker

Posts : 13
Join date : 2017-10-18
Location : Dayton Texas

View user profile

Back to top Go down

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

Post  rmcomprandy on October 31st 2017, 9:52 am

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..

rmcomprandy

Posts : 4769
Join date : 2008-12-02
Location : Roseville, Michigan

View user profile http://www.rmcompetition.com

Back to top Go down

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

Post  Scott Foxwell on October 31st 2017, 11:07 am

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.

Scott Foxwell

Posts : 390
Join date : 2011-06-23
Location : N/E Tennessee

View user profile http://www.straubtechnologies.com

Back to top Go down

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

Post  Lem Evans on October 31st 2017, 11:50 am

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.

Lem Evans

Posts : 6906
Join date : 2008-12-03
Location : Livermore , Ky

View user profile http://bfevansraceparts.com

Back to top Go down

Page 1 of 2 1, 2  Next

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum