Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
New Drivetrain: need help deciding on engine 950hp BBC vs 700sci >

New Drivetrain: need help deciding on engine 950hp BBC vs 700sci

Notices
General Boating Discussion

New Drivetrain: need help deciding on engine 950hp BBC vs 700sci

Thread Tools
 
Old 08-12-2016 | 03:07 PM
  #11  
BrettM's Avatar
Offshoreonly Advertiser
15 Year Member
Offshoreonly Advertiser
Commercial Members
 
Joined: Oct 2007
Posts: 801
Likes: 83
From: LOTO/Performance Boat Center
Default

As mentioned we have one brand new, never fired HP700sci in stock with exhaust. I am asking $39950, Merc retail is 60k plus. Will entertain offers. Its blue in color. Full Warranties.

[email protected]
BrettM is offline  
Reply
Old 08-12-2016 | 04:10 PM
  #12  
Registered
 
Joined: Jun 2005
Posts: 3,214
Likes: 6
From: west palm beach FL,
Default

single Arneson on a V bottom ? You mite what to look into this , I think Weisman has a surface drive with a duo prop for single engine applications .
mikebrls is offline  
Reply
Old 08-12-2016 | 04:33 PM
  #13  
Registered
20 Year Member
 
Joined: Jun 2003
Posts: 760
Likes: 6
From: Jacksonville, FL
Default

I'm eager to see how this setup works with the arneson. Are you going to run a cleaver or bravo style prop?

Contrary to my usual opinion, I'd say go with the 700sci. Easy to make into 900+ down the road. I'm usually all for aftermarket custom built motors (more so against merc racings prices) but a big NA motor with a solid roller cam presents its own issues. You'll be setting valve lash often which requires taking the headers off (unless you get 2 piece valve covers) so that's quite a job. Also, to make a big inch NA motor you can have water reversion issues from the cam, the pistons are weaker from the wrist pin being so high etc etc. those motors work well in cars where the load on them is significantly less, but a 30' heavy single engine boat is about the harshest environment you can put a motor in.
ToMorrow44 is offline  
Reply
Old 08-12-2016 | 04:58 PM
  #14  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,108
Likes: 3,694
From: On A Dirt Floor
Default

Originally Posted by TurboRaven
The 950hp 632 would be pump gas, good size cam, solid roller top end with isky and dry exhaust. Have not had an engine built by him before. Customers do have great feedback (even when something goes wrong).
Any feedback in I/O boats ? A Chevelle or etc is a whole 'nother boat...pun intended.
SB is offline  
Reply
Old 08-12-2016 | 06:25 PM
  #15  
Registered
 
Joined: Jul 2008
Posts: 2,801
Likes: 1
Default

Originally Posted by SB
Any feedback in I/O boats ? A Chevelle or etc is a whole 'nother boat...pun intended.
YUP.

Car guys rarely get marine stuff right the first time. Especially I/O's.

We're on pins and needles wondering what Bups new guy is going to deliver on that project.

I got unlucky a few times having car guys build boat engines for me. They were all smart good builders - with little to no marine experience.

VERY cool project Im eager to see it unfold - congratulations Turbo Raven!

UD

Last edited by Uncle Dave; 08-12-2016 at 06:28 PM.
Uncle Dave is offline  
Reply
Old 08-12-2016 | 06:37 PM
  #16  
Registered
10 Year Member
 
Joined: Jan 2014
Posts: 409
Likes: 88
From: W. Mich.
Default

Some random thoughts, worth exactly what you pay for them, and your mileage may vary.

I think the IDEA of dry (loud) exhaust is probably better than actually having dry exhaust, especially in a boat doing double duty as a family boat. Forget communication in the cockpit if the engine is running and I hope the area where you boat is a lot more lenient on noise than where we boat.

The Merc is undoubtedly going to be better for resale but I don't necessarily believe it's a given that it will be more reliable than some of the custom builders. I've lived on a lake all my life and have had my share of service headaches with stock power. Even wimpy stock power.

If you're going to do custom power, I'd stick with a "name" IE Boostpower, Teague, Pfaff, Carson, etc. Someone who specializes in marine applications, not the local drag race or toilet bowl racer hot rod shop.

We have a 600 CID / 900 HP BoostPower package and it's never so much a coughed wrong. It starts every time, idles, and pulls like a freight train. When I've had questions I can make a phone call and get Alexi on the phone. Try that with your Merc. It's also a much "cooler" package and if we're being honest, the cool factor is a huge part of performance boating. Nobody "needs" a performance boat. We want one. The custom engines are finished off so much nicer it isn't even funny.

Remember if you're dealing with a custom builder, it probably has to go back to them for service, and you can make a dyno show some really impressive numbers without it being realistic useable HP. See my comments about a reputable shop who specializes in marine power.

At the end of the day it's about what you want & can afford, and makes you and the family feel good at the lake. Or the show & shine. Or wherever.

Between the choices you've floated out there, I'd probably go with the Merc for all the convenience reasons.

Throw (for me) BoostPower into the mix and that would be my choice because I've dealt with them.

Good luck & whichever way you go post lots of pics and have fun.

Cheers
Slippery is offline  
Reply
Old 08-12-2016 | 08:07 PM
  #17  
Thread Starter
Registered
5 Year Member
 
Joined: Feb 2016
Posts: 18
Likes: 0
Default

email sent
TurboRaven is offline  
Reply
Old 08-12-2016 | 11:14 PM
  #18  
Thread Starter
Registered
5 Year Member
 
Joined: Feb 2016
Posts: 18
Likes: 0
Default

Originally Posted by BrettM
As mentioned we have one brand new, never fired HP700sci in stock with exhaust. I am asking $39950, Merc retail is 60k plus. Will entertain offers. Its blue in color. Full Warranties.

[email protected]
Thanks Brett! Email sent.

Originally Posted by mikebrls
single Arneson on a V bottom ? You mite what to look into this , I think Weisman has a surface drive with a duo prop for single engine applications .
Have done quite a bit of research as well as talked with owners and Rik. Should be a clean, fast and most importantly-indestructible setup.

Originally Posted by ToMorrow44
I'm eager to see how this setup works with the arneson. Are you going to run a cleaver or bravo style prop?

Contrary to my usual opinion, I'd say go with the 700sci. Easy to make into 900+ down the road. I'm usually all for aftermarket custom built motors (more so against merc racings prices) but a big NA motor with a solid roller cam presents its own issues. You'll be setting valve lash often which requires taking the headers off (unless you get 2 piece valve covers) so that's quite a job. Also, to make a big inch NA motor you can have water reversion issues from the cam, the pistons are weaker from the wrist pin being so high etc etc. those motors work well in cars where the load on them is significantly less, but a 30' heavy single engine boat is about the harshest environment you can put a motor in.
Will be an offshore cleaver or hering prop. I'm no stranger to setting valve lash as I have a 950hp n/a LSX (solid roller) in my street rod currently. I hear ya though, def more maintenance required.

Originally Posted by Uncle Dave
YUP.

Car guys rarely get marine stuff right the first time. Especially I/O's.

We're on pins and needles wondering what Bups new guy is going to deliver on that project.

I got unlucky a few times having car guys build boat engines for me. They were all smart good builders - with little to no marine experience.

VERY cool project Im eager to see it unfold - congratulations Turbo Raven!

UD
Thanks for the input. Yeah, I fully agree: good auto engine builder X= good marine engine builder.

Originally Posted by Slippery
Some random thoughts, worth exactly what you pay for them, and your mileage may vary.

I think the IDEA of dry (loud) exhaust is probably better than actually having dry exhaust, especially in a boat doing double duty as a family boat. Forget communication in the cockpit if the engine is running and I hope the area where you boat is a lot more lenient on noise than where we boat.

The Merc is undoubtedly going to be better for resale but I don't necessarily believe it's a given that it will be more reliable than some of the custom builders. I've lived on a lake all my life and have had my share of service headaches with stock power. Even wimpy stock power.

If you're going to do custom power, I'd stick with a "name" IE Boostpower, Teague, Pfaff, Carson, etc. Someone who specializes in marine applications, not the local drag race or toilet bowl racer hot rod shop.

We have a 600 CID / 900 HP BoostPower package and it's never so much a coughed wrong. It starts every time, idles, and pulls like a freight train. When I've had questions I can make a phone call and get Alexi on the phone. Try that with your Merc. It's also a much "cooler" package and if we're being honest, the cool factor is a huge part of performance boating. Nobody "needs" a performance boat. We want one. The custom engines are finished off so much nicer it isn't even funny.

Remember if you're dealing with a custom builder, it probably has to go back to them for service, and you can make a dyno show some really impressive numbers without it being realistic useable HP. See my comments about a reputable shop who specializes in marine power.

At the end of the day it's about what you want & can afford, and makes you and the family feel good at the lake. Or the show & shine. Or wherever.

Between the choices you've floated out there, I'd probably go with the Merc for all the convenience reasons.

Throw (for me) BoostPower into the mix and that would be my choice because I've dealt with them.

Good luck & whichever way you go post lots of pics and have fun.

Cheers
Thanks for the input! Yeah, no noise complaints to worry about here in Hawaii. Glad you have had good luck with your NA BBC and I agree with you: all depends on the builder and their marine experience. I'll give Boostpower a ring to review options. I'm also that guy who always likes to have something a little different that everybody else. However being in Hawaii, I don't want to be shipping a custom engine back and forth across the pond..that adds up quick and too much downtime..
TurboRaven is offline  
Reply
Old 08-13-2016 | 08:53 AM
  #19  
Registered
20 Year Member
 
Joined: Jun 2003
Posts: 760
Likes: 6
From: Jacksonville, FL
Default

If you're in Hawaii and using it in saltwater all the time is another plus for the 700 with closed cooling. still needs to be flushed good after each use but you won't have to worry about the heads rotting away.
ToMorrow44 is offline  
Reply
Old 08-13-2016 | 10:20 AM
  #20  
Registered
 
Joined: Nov 2003
Posts: 1,277
Likes: 5
From: Stockholm, Svea Rike
Default

Originally Posted by mikebrls
single Arneson on a V bottom ? You mite what to look into this , I think Weisman has a surface drive with a duo prop for single engine applications .
Dito. A friend of mine rigged his Batboat 28 with ASD - did not work well. Went to SSM6. Turbo Raven - take A look att SCX insted.
Mange is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.