Boat Engine 383 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-18-2013, 10:33 PM
done learning, done living
 
Last photo:
Join Date: Feb 2009
Location: Middle of the Mitten
Age: 29
Posts: 1,718
Wiki Edits: 0

Thanks: 161
Thanked 92 Times in 83 Posts
Boat Engine 383

Working on getting a boat engine together. I have the rotating assembly for a 383. Scat 9000 crank, 5.7 rods, kb dished pistons with a d shaped cup 18cc. I have a set of L31 Vortecs sitting on the shelf but have been looking at the Gmpp small port bowtie heads. Chevrolet Performance Vortec Small Port Bowtie Cylinder Heads 25534421 - SummitRacing.com I am also looking at Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts 24502586 - SummitRacing.com for a cam that is suggested from a Marine Performance book that I have been reading. Not really sure what would have to be done to the stock vortecs to run that cam but if someone could throw me a link to a book or some good info. Another thought on a cam is Chevrolet Performance Hydraulic Roller Camshafts 14097395 - SummitRacing.com which I should be able to run with the stock vortecs. I'm don't have a target hp/tq number in mind I just want the boat to be fun! Great acceleration and good top speed. The boat is about 20 ft and weighs app 3,500 without passengers (typically four adults).

I'm not sure where the point of saying "it's pointless to go that much on a cam or heads because you still have the wet log manifolds which are staying.

I am also looking at an efi system from Marine: Affordable Fuel Injection these guys live about fifty miles from me so it will be nice for tuning and such. Just not sure if I want to go tbi or mpfi. I've heard tbi makes more torque? But mpfi burns more efficiently and will allow the engine to run smoother and last longer?

I know this isn't a boating forum but it's my favorite forum

thanks

    Advertisement

Last edited by crussell85; 02-18-2013 at 10:35 PM. Reason: spell check
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-18-2013, 11:53 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,688
Wiki Edits: 0

Thanks: 367
Thanked 866 Times in 828 Posts
what type of exhaust manifolds are you using.some cams do not work well with wet manifolds. What rpm are you planning to run the engine at most frequently. How much horse power do you need to get the speed you require. or what RPM is your prop most efficient at? are you concerned about fuel burn or power ? I will likely try to talk you out of the vortec heads.
building a good/reliable boat engine costs more than a car engine
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-19-2013, 05:41 AM
done learning, done living
 
Last photo:
Join Date: Feb 2009
Location: Middle of the Mitten
Age: 29
Posts: 1,718
Wiki Edits: 0

Thanks: 161
Thanked 92 Times in 83 Posts
Running the stock manifolds. The vortecs came stock on the 350 engine. Max rpm is 5000
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-19-2013, 10:43 AM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,688
Wiki Edits: 0

Thanks: 367
Thanked 866 Times in 828 Posts
wet or dry? power required?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-19-2013, 11:18 AM
done learning, done living
 
Last photo:
Join Date: Feb 2009
Location: Middle of the Mitten
Age: 29
Posts: 1,718
Wiki Edits: 0

Thanks: 161
Thanked 92 Times in 83 Posts
Its a 2001 Volvo penta with the sx out drive.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-19-2013, 11:24 AM
done learning, done living
 
Last photo:
Join Date: Feb 2009
Location: Middle of the Mitten
Age: 29
Posts: 1,718
Wiki Edits: 0

Thanks: 161
Thanked 92 Times in 83 Posts
Is this a bad out drive?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-19-2013, 01:03 PM
Registered User
 
Last photo:
Join Date: Feb 2011
Location: hawaii
Posts: 96
Wiki Edits: 0

Thanks: 2
Thanked 1 Time in 1 Post
There are many calculators on the Internet to figure your hull speed and the hp required to go a given speed in knots I would google for a hull speed calculator. I've found on my 16 ton 42" dive boat the first 7 knots ill need 60 odd hp but if I would want to go a additional 4 knots at 10 kt ill need a additional 400 hp. My leingth at the waterline and tonnage Re holding me back. For your little 20 ft'er you can really get going with little hp but you'll find a point whare it takes more than 100 extra hp to just gain a knot or 2. Basically what I'm saying is you can build a 350 hp engine and get a max speed of 8.5 knots or a 900 engine and go 12 knots in my case. What would be the better bang for the buck? Easy choice for me was a cat 3208 as opposed to a MAN with triple he hp and only going marginally faster
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-19-2013, 02:10 PM
done learning, done living
 
Last photo:
Join Date: Feb 2009
Location: Middle of the Mitten
Age: 29
Posts: 1,718
Wiki Edits: 0

Thanks: 161
Thanked 92 Times in 83 Posts
So... ... maybe just look into the 7395 cam and the stock vortec heads?
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-19-2013, 06:14 PM
Richiehd's Avatar
JS-70
 
Last photo:
Join Date: Jun 2011
Location: Jupiter FL
Posts: 917
Wiki Edits: 0

Thanks: 234
Thanked 66 Times in 58 Posts
Quote:
Originally Posted by crussell85 View Post
So... ... maybe just look into the 7395 cam and the stock vortec heads?
In my opinion that 7395 has too much duration for wet exhaust. You may end up with water reversion, and a no start in the water.you need to pick a marine performance cam or speak to someone that knows marine camshaft design. (Mike Jones Cam design, Denver NC)
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-21-2013, 12:44 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 991
Wiki Edits: 0

Thanks: 2
Thanked 90 Times in 82 Posts
Here is the Ramjet intake for Vortec heads.


Merc marine intake for Vortec head use. Used on 305/350/383 marine engines, I run this in my 1997 Vortec 350 reg cab shortbox 2wd truck, runs much better than teh stock truck intake, and allows me to run any sized injector I wish(unlike teh stock truck intake)


Same marine intake next to Vortec truck intake manifold


Same intake in Mercruiser red



different angle


Here is the same marine intake with the upperplenum removed. You can see how the runner eopenings are across from the cylinder head intake port it feeeds. the cross ram runners are about 10" long from the opening inside teh plenum to the intake gasket flange.


Inside of Vortec 305/350 truck intake. Lots of injection debris impeding flow.


Scorpion 400 intake, it uses the same tunnel ram lower that is mentioned elsewhere in this thread.



peace
PAuly

Last edited by Hogg; 02-21-2013 at 12:50 PM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-21-2013, 04:15 PM
BadBehavior's Avatar
Registered User
 
Last photo:
Join Date: Nov 2012
Posts: 42
Wiki Edits: 0

Thanks: 11
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by F-BIRD'88 View Post
If you wnt to go fast and have fun on the water find a good used Hydrostream.
Google it.
Been reading this Post. I agree with F-Bird on all, Except this, to each his own of course, GO fast, Get one of these, put 6 cyl in present boat, sell it put funds into safer boat than the above "chine walker" I know, I owned 2 before I wised up! Sorry had to say it
Larry
Attached Thumbnails
Click image for larger version

Name:	YELblueTrlr.JPG
Views:	86
Size:	72.5 KB
ID:	71587  
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 02-22-2013, 08:40 AM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 64
Posts: 1,059
Wiki Edits: 0

Thanks: 1
Thanked 21 Times in 18 Posts
Hey BadBehavior, That boat is sexy like a good women.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 02-22-2013, 06:43 PM
Registered User
 
Join Date: Jan 2010
Location: Chapin,S.C.
Age: 59
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
We still build that 5.7 engine w/ the same intake as the mercruiser in which is a Bosch injection set-up.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 02-23-2013, 10:05 AM
bondo's Avatar
Member
 
Last photo:
Join Date: Nov 2002
Location: Chaumont Bay N.Y.
Posts: 960
Wiki Edits: 0

Thanks: 7
Thanked 15 Times in 15 Posts
Quote:
Originally Posted by F-BIRD'88 View Post
Quote:
Originally Posted by crussell85
Is this a bad out drive?
I'm not real up on this Penta drives. I am of the opinion they are light duty.
This hi perf 383 motor build recipe I laid out is no wimp.

Hot rodding a boat is not the same as hot rodding a car.
It is never cheap.

A Mercruiser Alpha drive (V8 {1.5:1 ratio} in good condition is the minimum.
Mercruiser will tell you you need a Bravo Drive for this engine.

Any all V6 engine drives will not work.
The stock default thru the drive exhaust routing will not work.
Ayuh,.... I believe you'll find that the SX drives are cone-clutch drives, which are miles ahead of the Merc Alpha drives, more like the Bravos, but not quite as heavy duty...

It's a dependable drive up to 300 hp, 'n still dependable over that, if the operator has self-control over his righthand...
in other words, skip the WOT jackrabbit starts, 'n yank back on the throttle if by chance ya clear the water, 'n catch air on a wave...

'n,... The thru-prop ain't so much the problem, but the open plenum exhaust manifods are the choke point in the exhaust flows...
The vortex created by the prop, actually helps pull the gases out...

Quote:
Originally Posted by F-BIRD'88 View Post
If the SX drive on your boat is not in excellent condition do not hot rod the engine.
A worn drive will not last behind a powerfull engine. A 4 cyl V6 drive or drive for a 305 is light duty and usually the wrong internal ratio.

If this is a light duty drive just enjoy your boat for what it is.
Or it will soon become a lawn/driveway ornament.
Only the Ratio changes, each drive is as strong as it's sisters....

'n, of course, a Worn out drive isn't dependable, regardless the amount of power applied...

There's No reason the OP shouldn't move forward with his Plan,...
383s are stuffed into boats, quite regularly...

If crussel would like a more Marine rated conversation 'bout this,...
Feel free to stop by iboats boatin' forums,...
There's many conversations there, 'bout this exact thing...
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
boat engine for truck. s-10again! Engine 18 11-11-2012 04:38 PM
Boat engine help handymann3 Engine 6 07-05-2010 03:07 PM
Street Engine w/ Boat Cam BG383 Engine 4 08-05-2009 10:52 PM
Corvette engine in boat KennyNova Engine 7 08-14-2007 07:11 PM
cool 100 ++ MPH boat blown boat video Infomaniac Engine 12 11-24-2003 09:08 AM


All times are GMT -6. The time now is 04:32 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.