Like Tree1Likes

496 HO - Remove Turbulator and Lost Speed?

Reply
Old 08-19-2009, 03:49 PM
  #1
Registered
Thread Starter
 
Join Date: May 2007
Location: Woodinville, WA
My Boats: 08' 28 Daytona
Posts: 231
Default 496 HO - Remove Turbulator and Lost Speed?

Has anyone removed the turbulators on their late model 496HOs and lost some speed?
CheckedOut is offline  
Reply With Quote
Old 08-19-2009, 04:01 PM
  #2
SeaRay Sundancer
Gold Member
 
tblrklakemo's Avatar
 
Join Date: Nov 2005
Location: SW Missouri
My Boats: In the Slow Lane
Posts: 2,914
Default

I did it in my fountain and noticed no change up or down.
tblrklakemo is offline  
Reply With Quote
Old 08-19-2009, 04:51 PM
  #3
Registered
 
Join Date: May 2004
Location: Okanagan Falls BC. Canada
My Boats: 1990 Mirage 257 , twin 6.2 MX
Posts: 595
Arrow

Don't have 496's , but experimented on my 6.2's [ 377cu]
removing the turbulators on the port engine first. Didn't make any difference , rpm's [ speed] stayed the same. Same result for the starboard engine. The exh ports at the riser joints are small for both 496 and 377 , so the turbulator really doesn't make a diff in or out. Putting mufflers on or slip ins at the tips would affect rpm's at WOT , dropping as much as up to 200, hence loosing speed. The turbulators get red hot at high rpm's and burn up water droplets [ condensation ] while going down to idle while the engine cooling down. It's a Merc warranty issue .
An aftermarket exhaust manifold/riser and slightly more cam would be your best bet for some performance gains.

Last edited by spectras only; 08-19-2009 at 04:54 PM.
spectras only is offline  
Reply With Quote
Old 08-19-2009, 05:17 PM
  #4
Registered
Thread Starter
 
Join Date: May 2007
Location: Woodinville, WA
My Boats: 08' 28 Daytona
Posts: 231
Default

Spectras, Thanks for the advice. Unfortunately, Considering that I would have to take the motors out anyway to install the headers, it would be a tough call to spend 10k on a set of headers when for roughly the same price I could drop in a set of 525s with around the same amount of hours. With a 525 I would pick up over twice the power gains and also leave room for improvement ala a Whipple kit which would last much longer on the better stock bottom end than on a 496. If i can get a better deal, I may think a little hard about it but given that the 496 needs ALOT of parts to really get where i want to be It will be cheaper in the long run to get another set of motors.

Last edited by CheckedOut; 08-19-2009 at 05:23 PM.
CheckedOut is offline  
Reply With Quote
Old 08-19-2009, 05:20 PM
  #5
Gold Member
Gold Member
 
Join Date: Jul 2008
Location: Delray Beach, FL
My Boats: Baja 342 Raylar HO 600's
Posts: 2,715
Default

$10K that is a stretch for Blue power... In this market you couldnt get more that $3000 a piece for used 496 HO's...

You can buy new 496 Mag HO's from IMCO for $5000!

Checked out - If you take the manifolds off and have them ported, you might pick up 100 RPM. A few people on OSO have been successful porting them. Even when I installed Stainless Marine Manifolds and reprogrammed the ECU I only picked up 150-200RPM.

Last edited by Keith Atlanta; 08-19-2009 at 05:25 PM.
Keith Atlanta is offline  
Reply With Quote
Old 08-19-2009, 05:31 PM
  #6
Registered
Thread Starter
 
Join Date: May 2007
Location: Woodinville, WA
My Boats: 08' 28 Daytona
Posts: 231
Default

Quote:
Originally Posted by Keith Atlanta View Post
$10K that is a stretch for Blue power... In this market you couldnt get more that $3000 a piece for used 496 HO's...

You can buy new 496 Mag HO's from IMCO for $5000!

Wow that is rough........Considering that dealer cost is 14k. I would believe that when I see it. They probably dont have a warantee and were out of a repo or sunk boat.

Last edited by CheckedOut; 08-19-2009 at 05:43 PM.
CheckedOut is offline  
Reply With Quote
Old 08-19-2009, 05:46 PM
  #7
Registered
 
Join Date: May 2004
Location: Okanagan Falls BC. Canada
My Boats: 1990 Mirage 257 , twin 6.2 MX
Posts: 595
Question

Checkedout, did you attend our Harrison Lake Poker run ?
spectras only is offline  
Reply With Quote
Old 08-19-2009, 05:51 PM
  #8
Registered
Thread Starter
 
Join Date: May 2007
Location: Woodinville, WA
My Boats: 08' 28 Daytona
Posts: 231
Default

Quote:
Originally Posted by spectras only View Post
Checkedout, did you attend our Harrison Lake Poker run ?

No. Unfortunately. Maybe next year.
CheckedOut is offline  
Reply With Quote
Old 08-19-2009, 06:24 PM
  #9
Platinum Member
Platinum Member
 
BrettM's Avatar
 
Join Date: Oct 2007
Location: LOTO/Performance Boat Center
My Boats: Cigarette,Sunsation, Skater, Wright Performance
Posts: 732
Default

Quote:
Originally Posted by CheckedOut View Post
Wow that is rough........Considering that dealer cost is 14k. I would believe that when I see it. They probably dont have a warantee and were out of a repo or sunk boat.
http://imcomarine.com/ca_store/index...roducts_id=835

Truck motor with some marine parts.

I just shopped all over for 496 HO's with warranty and paid more than I would have liked.

525's are higher in price then metioned as well from what I found.
BrettM is offline  
Reply With Quote
Old 08-19-2009, 06:33 PM
  #10
Registered
 
jordy's Avatar
 
Join Date: Aug 2004
Location: Phoenix, AZ
My Boats: Big beatdown pontoon boat. Bring your own fenders.
Posts: 828
Default

Quote:
Originally Posted by CheckedOut View Post
Spectras, Thanks for the advice. Unfortunately, Considering that I would have to take the motors out anyway to install the headers, it would be a tough call to spend 10k on a set of headers when for roughly the same price I could drop in a set of 525s with around the same amount of hours. With a 525 I would pick up over twice the power gains and also leave room for improvement ala a Whipple kit which would last much longer on the better stock bottom end than on a 496. If i can get a better deal, I may think a little hard about it but given that the 496 needs ALOT of parts to really get where i want to be It will be cheaper in the long run to get another set of motors.
You answered your own question. For the few mph gains you'd get by changing exhaust, etc. with the 496's you'd be better off to save your pennies and hundies and go with some blue power. The 496 is a great engine if you leave it alone and let it run like it was designed to run. I know it's tempting to start tweaking on them in the never ending quest for more speed and power, but then reliability starts being sacrificed... which is more important?
jordy is offline  
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not 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



All times are GMT -5. The time now is 08:19 AM.


Copyright 2011 OffShoreOnly. All rights reserved.