Go Back  Offshoreonly.com > Technical > General Q & A
Hawk 525SC Upgrade >

Hawk 525SC Upgrade

Like Tree2Likes

Hawk 525SC Upgrade

Reply

Old 09-09-2018, 12:53 AM
  #1
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default Hawk 525SC Upgrade

I have Twin Hawk 525SC's with 850 carbs and about 20 hours. Both run great with no issues so of course I can't leave well enough alone. I'm thinking upgrades, Super Chillers or the Like Dominator's, etc. Looking for some suggestions to pick up 100 HP or more per side. I would rather not remove the motors but hey if I need to.
RBeyer is offline  
Reply With Quote
Old 09-09-2018, 02:10 AM
  #2
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boat: .......32............. ............Active Thunder....
Posts: 16,977
Default

Were the cams upgraded?? or still stock???

I think the only way you'll gain 100hp per side without getting into the engines is by going to at least 671 blowers and 871's would be better.
mike tkach likes this.
Griff is offline  
Reply With Quote
Old 09-09-2018, 09:59 AM
  #3
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default

Originally Posted by Griff View Post
Were the cams upgraded?? or still stock???

I think the only way you'll gain 100hp per side without getting into the engines is by going to at least 671 blowers and 871's would be better.
It has a Crane 132561 Cam 174 Wieand with 5lbs boost
RBeyer is offline  
Reply With Quote
Old 09-09-2018, 01:07 PM
  #4
Registered
iTrader: (1)
 
Join Date: Oct 2013
Location: SF Bay Area
My Boat: 1997 Baja Islander 272
Posts: 2,547
Default

Adding 8-71s would probably drop the intake temps as much as adding a chiller to the 174 even at the same boost level.
Baja Rooster is offline  
Reply With Quote
Old 09-09-2018, 01:09 PM
  #5
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boat: .......32............. ............Active Thunder....
Posts: 16,977
Default

That's the stock 420/525SC cam. Increasing boost and adding a chiller will probably only get you another 30hp. Keep in mind the Hawk 525sc has 8.75 static compression, where the Merc 525sc had 7.5, so the Hawk can't take as much of a boost increase using the small blower.
A bigger blower is your best option to gain 100hp and a roller cam swap would also help.
Griff is offline  
Reply With Quote
Old 09-09-2018, 11:11 PM
  #6
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default

Originally Posted by Griff View Post
That's the stock 420/525SC cam. Increasing boost and adding a chiller will probably only get you another 30hp. Keep in mind the Hawk 525sc has 8.75 static compression, where the Merc 525sc had 7.5, so the Hawk can't take as much of a boost increase using the small blower.
A bigger blower is your best option to gain 100hp and a roller cam swap would also help.
Tough call, if I'm gonna jump in I think pull them go full roller and the blower. I'm not doing that if I cant tune them on a dyno though.

Anyone looking for two 174 Blower setups with about 20 hours on them? Might even consider selling both motors complete. I know of two 1100's, brand new builds looking for a home.
RBeyer is offline  
Reply With Quote
Old 09-10-2018, 10:59 PM
  #7
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default

Originally Posted by Griff View Post
That's the stock 420/525SC cam. Increasing boost and adding a chiller will probably only get you another 30hp. Keep in mind the Hawk 525sc has 8.75 static compression, where the Merc 525sc had 7.5, so the Hawk can't take as much of a boost increase using the small blower.
A bigger blower is your best option to gain 100hp and a roller cam swap would also help.
Ok let's go back to the blower upgrade thought. Is the 420/525SC Cam adequate for the increase blower volume? I'm guessing along with a 6.71 or probably if I'm going to do this a 8.71 going to a Dominator Carb is also correct.
This all sounds pretty simple and basic, is this all that will be required with the current build? Again it's very fresh maybe 20 hours since the build, I bought it this way or I would have done more in the first place.
RBeyer is offline  
Reply With Quote
Old 09-17-2018, 12:25 PM
  #8
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default

Originally Posted by RBeyer View Post
Ok let's go back to the blower upgrade thought. Is the 420/525SC Cam adequate for the increase blower volume? I'm guessing along with a 6.71 or probably if I'm going to do this a 8.71 going to a Dominator Carb is also correct.
This all sounds pretty simple and basic, is this all that will be required with the current build? Again it's very fresh maybe 20 hours since the build, I bought it this way or I would have done more in the first place.
Not looking to minimize what goes into an upgrade, I have certainly done some bigger projects. Roots style blowers and this conversion is new to me.
RBeyer is offline  
Reply With Quote
Old 08-20-2019, 09:12 PM
  #9
Platinum Member
Platinum Member
Thread Starter
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
My Boat: 1995 Saber Cyclone 28
Posts: 648
Default

Originally Posted by Griff View Post
That's the stock 420/525SC cam. Increasing boost and adding a chiller will probably only get you another 30hp. Keep in mind the Hawk 525sc has 8.75 static compression, where the Merc 525sc had 7.5, so the Hawk can't take as much of a boost increase using the small blower.
A bigger blower is your best option to gain 100hp and a roller cam swap would also help.
So this now looking to be a winter rebuild project. I am expecting to go full roller cam, new heads, and go through the bottom replacing and upgrading whatever is needed. The question is do I go to larger blowers or go naturally aspirated and build bigger motors, can I accomplish my goal with the 174's and a chiller with the rest of the work suggested. Looking to get 600 to 650 HP.

Griff you seem have a lot of experience with this. Please looking for all suggestions.
RBeyer is offline  
Reply With Quote
Old 08-21-2019, 12:43 AM
  #10
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boat: .......32............. ............Active Thunder....
Posts: 16,977
Default

Originally Posted by RBeyer View Post
So this now looking to be a winter rebuild project. I am expecting to go full roller cam, new heads, and go through the bottom replacing and upgrading whatever is needed. The question is do I go to larger blowers or go naturally aspirated and build bigger motors, can I accomplish my goal with the 174's and a chiller with the rest of the work suggested. Looking to get 600 to 650 HP.

Griff you seem have a lot of experience with this. Please looking for all suggestions.
If you're doing new heads and full roller cams, you should be able to make 600hp+ with the 174's.
I would build the engines internally to be able to handle 700+hp.
Then I would use your 174's and see what they do. I wouldn't do chillers as I think you'd be better off go to just go with bigger blowers if you want more power.
You will probably need more carb. I would send yours out and have them made to 950-1000cfms.

If the 174's don't make enough hp for you, then upgrade to big blowers later.
Griff is offline  
Reply With Quote

OSO Sponsor
OSO Advertiser
OSO Advertiser
OSO Advertiser