Like Tree4Likes

525SC Weiand 177 On A 454 MAG in Formula 242LS

Reply
Old 03-25-2011, 05:29 PM
  #11
Registered
 
blue thunder's Avatar
 
Join Date: Nov 2001
Location: Pennsylvania
My Boats: 330 Carver 30' Scarab Panther 17' ProV Lund
Posts: 3,359
Default

Summit or jegs carry the kit to change out the blower input shaft to keyed. Thats what I did. Then you can run any pulley made. If you want smaller splined pulleys though I have some I could measure and see if they'd work for you. I think the were 2.75" OD. Also on the ignition module you may be able to get away with the 24* tbolt but your idle in and out of gear around dock will suck (stalling) and my opinion is your all in advance will be too much and may cause detonation. 525scs had a much lower comp ratio than you have. The 14* v6 module allows you to run 30* all in (safe) and a healthy 16* idling. Works good that way.
blue thunder is offline  
Reply With Quote
Old 03-25-2011, 09:39 PM
  #12
Registered
 
Join Date: Jul 2007
Location: Shorewood, Ill
My Boats: Malibu Sunsetter for surfin and wake action
Posts: 173
Default

Blue Thunder, not to take away from Century Ultra, but if you've got a matched pair of pulley's at 2.75" for splined shafts I'd be interested. Maybe send me a PM with your number and we can talk about it. Unless Century Ultra takes them first.
paulb32 is offline  
Reply With Quote
Old 03-26-2011, 02:40 AM
  #13
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boats: .......32............. ...............Active Thunder....
Posts: 15,738
Default

Quote:
Originally Posted by blue thunder View Post
Summit or jegs carry the kit to change out the blower input shaft to keyed. Thats what I did. Then you can run any pulley made. If you want smaller splined pulleys though I have some I could measure and see if they'd work for you. I think the were 2.75" OD. Also on the ignition module you may be able to get away with the 24* tbolt but your idle in and out of gear around dock will suck (stalling) and my opinion is your all in advance will be too much and may cause detonation. 525scs had a much lower comp ratio than you have. The 14* v6 module allows you to run 30* all in (safe) and a healthy 16* idling. Works good that way.
He really shouldn't have an idle problem with the stock 454mag cam. The V6-14 module gives 14* advance on a V6 engine, but only about 10* on a V8 engine and all the advanc eis in by 2000rpms. A V8-HP module would be near perfect with 20* advance. He could run 10-12* at idle and full advance is at 3000rpms.
I was suggesting to run a smaller lower pulley to reduce boost slightly. Since the 525SC is 7.5:1 and has 5.5# of boost and his engine is 8.75:1, a 1# boost reduction would reduce his overall effective compression ratio and get it close to the same effective comp ratio as the 525SC.
Griff is offline  
Reply With Quote
Old 03-26-2011, 02:41 AM
  #14
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boats: .......32............. ...............Active Thunder....
Posts: 15,738
Default

Quote:
Originally Posted by paulb32 View Post
Blue Thunder, not to take away from Century Ultra, but if you've got a matched pair of pulley's at 2.75" for splined shafts I'd be interested. Maybe send me a PM with your number and we can talk about it. Unless Century Ultra takes them first.
No way Century Ultra can run those pulleys. Those are 8# pulleys and he really should reduce his boost slightly, not increase it.
Griff is offline  
Reply With Quote
Old 03-26-2011, 07:27 AM
  #15
Registered
 
blue thunder's Avatar
 
Join Date: Nov 2001
Location: Pennsylvania
My Boats: 330 Carver 30' Scarab Panther 17' ProV Lund
Posts: 3,359
Default

I measured the pulleys and they are actually 3" pulleys. PM me if you would like them. I also have the splined shafts that go with them.

You can surely start with the V-8 modules century and switch to v-6 modules as I did to improve manners if necessary. You really shouldn't go over 30* all in timing with your higher comp and iron heads. Plus you would gain zilch in performance between 30 and 32*. So you'll need to set the base at 6*. One other thing you should do is buy a new balancer. Older balancers can slip giving you a false timing setting. Too much timing will melt your pistons fast on a high compression blower engine. btdt.
blue thunder is offline  
Reply With Quote
Old 03-26-2011, 07:12 PM
  #16
Registered
Thread Starter
 
Join Date: Feb 2008
Posts: 140
Default

Thanks everyone very helpful! I just checked and the blower I have already has been converted to the keyed shaft. I didn't know the difference when I bought it that the factory merc blowers had a splined shaft. I also measured the pulley I got with it. The blower currently has a 10 groove 3" pulley on it. The guy also gave me a 6 groove 2.75" blower pulley and a 6 groove 7" crank pulley. Looks like I need a pulley or two to reduce boost. Do I need a 10 groove or doesn't it matter if its 6 or 10? The tensioner pulley is obviously 10 groove. If anyone has a pulley(s) they want to sell please let me know. Thanks again!
CenturyUltra is offline  
Reply With Quote
Old 03-26-2011, 07:15 PM
  #17
Registered
Thread Starter
 
Join Date: Feb 2008
Posts: 140
Default

Also should I get a 1050 dominator or smaller? Any guesses on hp/torque with the stock mag/blower/1050 and stainless marine exhaust? Thanks.
CenturyUltra is offline  
Reply With Quote
Old 03-26-2011, 08:11 PM
  #18
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boats: .......32............. ...............Active Thunder....
Posts: 15,738
Default

Use the 10 groove. The belt will grab better and not slip.
IMO, the pulleys you have will make too much boost for you. The 3.0" upper and 7" lower is 2.33:1 overdriven and will make about 7# of boost.

You ideally want about a 3.5 upper and 6.5 lower which should make a little less than 5# of boost. It will create less heat by spinning the blower slower and will also reduce the chance of detonation.

If its a 525SC blower, then you need to use a Dominator Carb to fit it. A 1050 is bigger than you really need and biger than the 525SC needed, but it will work fine.

I would guess you will be about 475hp or so.
Griff is offline  
Reply With Quote
Old 03-28-2011, 10:08 PM
  #19
Registered
Thread Starter
 
Join Date: Feb 2008
Posts: 140
Default

Do I need an upgraded fuel pump or the stock one should be sufficient? Are there heads I should keep my eyes open for that would work good to lower compression? Thanks.
CenturyUltra is offline  
Reply With Quote
Old 03-29-2011, 02:05 AM
  #20
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha
My Boats: .......32............. ...............Active Thunder....
Posts: 15,738
Default

The fuel pump will be fine for the power you are going to make. Unless you want to start spending a ton more money, I wouldn't worry about getting different heads. You could get some mild porting done on you stock heads and have the combustion chambers enlarged to about 120cc. That bring the CR down to about 8.5.
Griff 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 11:14 PM.


Copyright 2011 OffShoreOnly. All rights reserved.