Go Back  Offshoreonly.com > Technical > General Q & A
thinking about LS swap from twin 454??? >

thinking about LS swap from twin 454???

Notices

thinking about LS swap from twin 454???

Thread Tools
 
Old 10-27-2018, 01:01 PM
  #1  
Registered
Thread Starter
 
Join Date: Oct 2018
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default thinking about LS swap from twin 454???

Hey guys, i have a scarab panther 30' that i have the twin 454ci motors out of it, i was going to build them up NA to make about 680ish hp.
Im a LSX guy here and prepare many LS builds, head porting and specialize with the LSA's LS9's LS7's, LS3's and so on, big with the cts-v's and zr1's.
So im up in the air if i should just keep it simple and build up the original motors or swap out for the new tech....i can put together a pair of stock bottomend ls3's that make roughly the same in power, but just curious if others have done the swap and what have they seen different with their boat in performance and economy?
Im sure the ls motors would use half the fuel, but will the boat be a total dog and not have enough ass behind it to get it up and going.
Any insight would be great.
Thanks
Tony
XtremeCFM is offline  
Old 10-27-2018, 01:17 PM
  #2  
Registered
iTrader: (1)
 
Join Date: Oct 2013
Location: SF Bay Area
Posts: 2,886
Received 143 Likes on 95 Posts
Default

I have nothing of value to add but do think that would be a killer project that I’d love to see the results on.

On a side note since you deal with these small blocks in cars is can the stock LC9 handle any boost good for towing in my Z71?

Whats your plan for outdrives? Sounds like you’re aiming well above what a Bravo can handle but a beefier drive may need more torque than what the small blocks can give?
Baja Rooster is offline  
Old 10-27-2018, 01:45 PM
  #3  
Registered
Thread Starter
 
Join Date: Oct 2018
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

those little 5.3's love boost...are you thinking of using one of the lsa take offs and adapting to the cathedral heads? that combo is very common with trucks, those blowers make a ton of instant torque right off idle.
Keep the boost like 9 or 10lbs, good tune and it will make reliable power. Only issue really is the vvt and dod with those motors, also with the flex fuel setup your injectors should be good enough to cover the bump in power too.
here is some pics of a 81 camaro we are installing the lsa on a ls3 with truck accessories, we utilized this bracket by lsx innovations, very simple and great price.
oops, cant post pics till i have 10 posts

Tony
XtremeCFM is offline  
Old 10-27-2018, 02:15 PM
  #4  
Registered
iTrader: (1)
 
Join Date: Oct 2013
Location: SF Bay Area
Posts: 2,886
Received 143 Likes on 95 Posts
Default

I’ve never heard of using an Lsa take off (I’m just helping you get to ten post here) Is it fairly simple to adapt?
Baja Rooster is offline  
Old 10-27-2018, 05:46 PM
  #5  
Registered
iTrader: (1)
 
Join Date: Oct 2013
Location: SF Bay Area
Posts: 2,886
Received 143 Likes on 95 Posts
Default

A guy posted on that Facebook thing that he swapped his 454 for an LS and gained 5mph on a 21’ open bow. If you were talking 33’+ than I’d say that wouldn’t play out well but I’d think a 30’ would welcome the diet.
Baja Rooster is offline  
Old 10-27-2018, 05:58 PM
  #6  
Registered
iTrader: (7)
 
Join Date: Feb 2009
Location: NW Michigan
Posts: 8,302
Received 1,493 Likes on 807 Posts
Default

I'm just curious of the 454 CI 680 ish HP recipe?
getrdunn is offline  
Old 10-27-2018, 07:35 PM
  #7  
Registered
Thread Starter
 
Join Date: Oct 2018
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

combo would be basically 11:1, hyd roller cam (thinking something in the 234/242ish), aftermarket alum heads (ported), leaning towards dual plane intake with hp950 carb and dry exhaust should do it
XtremeCFM is offline  
Old 10-27-2018, 08:09 PM
  #8  
Registered
iTrader: (7)
 
Join Date: Feb 2009
Location: NW Michigan
Posts: 8,302
Received 1,493 Likes on 807 Posts
Default

You should just stick with your BBC's and stroke them 489-496 and with the right components and CR (so you don't detonate it to death) and aim for a little more realistic power. 600 + or -. Are your current engines 330's or 365 mags. (2 or 4 bolt mains). And lastly forget about fuel consumption.
getrdunn is offline  
Old 10-27-2018, 09:03 PM
  #9  
Registered
Thread Starter
 
Join Date: Oct 2018
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Default

yeah with the dual plane intake option i would say closer to mid 6's on them maybe alittle more,,,but yeah i'm not liking the fuel usage...with reworking the chambers i can make them detonation friendly.
i want to say these were 420's
XtremeCFM is offline  
Old 10-27-2018, 09:17 PM
  #10  
Registered
iTrader: (7)
 
Join Date: Feb 2009
Location: NW Michigan
Posts: 8,302
Received 1,493 Likes on 807 Posts
Default

Sucken gas and haulin azz!
getrdunn is offline  


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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.