Go Back  Offshoreonly.com > Technical > General Q & A
Dyno BSFC question >

Dyno BSFC question

Notices

Dyno BSFC question

Thread Tools
 
Old 05-02-2008 | 06:41 PM
  #1  
Brad Zastrow's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jun 2001
Posts: 2,303
Likes: 109
From: McHenry, Illinois
Default Dyno BSFC question

Engine with quad rotor EFI that makes 1000 hp at 6000 rpm.
Brake specfic on the dyno was .603 at 4400 rpm and .650 at 5000 rpm and .701 at 6000 rpm at peak HP. Really fat engine. Question is can a very rich engine make power on the dyno yet be a real turd in a boat. The owner has been battling a boat that is slower than same hull setups. One engine builder told me horsepower is horsepower. I am wondering if the rich condition will not allow the engine get past the torque curve.
Brad Zastrow is offline  
Reply
Old 05-02-2008 | 08:38 PM
  #2  
Elite Marine's Avatar
Banned
 
Joined: Aug 2002
Posts: 5,658
Likes: 1
From: IL
Default

This is a more accurate picture
Attached Thumbnails Dyno BSFC question-2008-dyno-sheet1.jpg  
Elite Marine is offline  
Reply
Old 05-02-2008 | 09:45 PM
  #3  
ROB FREEMAN's Avatar
Registered
 
Joined: Sep 2006
Posts: 2,123
Likes: 2
From: Wis
Default

What did Bill think guys ? Isnt he a top notch builder you guys both know ? good luck , been reading the ongoing threads, good luck kirk
ROB FREEMAN is offline  
Reply
Old 05-03-2008 | 08:01 AM
  #4  
Banned
 
Joined: Feb 2005
Posts: 1,459
Likes: 1
From: Cleveland, Ohio
Default

Running that rich is hurting you. I would run the BSFC at .50-.55. . .500 at the low end of the pull and .550 at the top end. Your giving up a ton of horsepower and yes it will run like a turd in the boat. Hope the rings are still in it!
mrhorsepower1 is offline  
Reply
Old 05-03-2008 | 08:30 AM
  #5  
articfriends's Avatar
Platinum Member
20 Year Member
Platinum Member
 
Joined: Jun 2004
Posts: 7,317
Likes: 1,032
From: frankenmuth michigan
Default

Kirk this "motor" in question,it had high bsfc numbers before too but the afr's were correct?-was this the dyno sheet the owner got with it-
Smitty
Attached Thumbnails Dyno BSFC question-dyno%5B1%5D.gif  

Last edited by articfriends; 05-04-2008 at 04:12 AM.
articfriends is offline  
Reply
Old 05-03-2008 | 10:52 AM
  #6  
Elite Marine's Avatar
Banned
 
Joined: Aug 2002
Posts: 5,658
Likes: 1
From: IL
Default

Its not in question to me.

Yes its fat, but Gary Taylor has run this set up in his Howard Bullet for years with no issue. He builds the engine, rigs the boat and has done 130 MPH in a single. There is nobody on this board or industry that can claim that type of success in a single V. He built this engine and I trust him more than anyone. Is is the only engine he builds.

I might tune it in the boat, but it is not the reason why I am down 10 - 15 MPH. The torque and horsepower are there.

If I get ambitious and want to fine tune, its very easy and I have the program, laptop and cable. I have learned to modify the tables with a mutliper and have an O2 meter.
Piece of cake on an EFI.

I have bigger issues unfortunately. Drive? Hull??

I need Brads Skater with 6 drives. I can sell the 525's and buy another TPI engine! Problem solved.
Elite Marine is offline  
Reply
Old 05-03-2008 | 11:12 AM
  #7  
Brad Zastrow's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jun 2001
Posts: 2,303
Likes: 109
From: McHenry, Illinois
Default

Bill (Ateco) and I are both wondering if the rich engine would hold it back in real world application versus a dyno pull where an engine brake matches the power. The obvious fix is to lean it down and install it back in the boat. But we are trying to figure out why Kirks boat would not run faster after such a great dyno pull. I can not help but think the fat engine won't run in a boat under a heavy load even though it makes 1000+ hp on a dyno.

I am also thinking a stepped hull like a Gary's Howard would allow the boat to get past the rich setup. I think I also heard Gary does not run his personal engine this rich.

Last edited by Brad Zastrow; 05-03-2008 at 11:26 AM.
Brad Zastrow is offline  
Reply
Old 05-03-2008 | 02:16 PM
  #8  
Smitty's Avatar
VIP Member
20 Year Member
Super Moderators
 
Joined: Apr 2001
Posts: 4,213
Likes: 0
From: Chicago il
Default

IMO I have looked at the pictures Kirk has posted and I think the problem is with the hull/drive setup. I had a running rich problem when I put new motors in my boat and after it was dialed in running the boat, I saw no increase in top speed, just better running/idle and no more black transom.

I think that hull needs to go back to Florida and let the guys who built it take a look at it.
__________________
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
Smitty is offline  
Reply
Old 05-03-2008 | 07:04 PM
  #9  
Banned
 
Joined: Feb 2005
Posts: 1,459
Likes: 1
From: Cleveland, Ohio
Default

All my point is .......why leave power on the table. Yes, the power is very good , but can be better. And your EXTREMELY safe . It looks like a great combo!
mrhorsepower1 is offline  
Reply
Old 05-03-2008 | 07:42 PM
  #10  
Banned
 
Joined: Sep 2007
Posts: 12,849
Likes: 3
From: Frankfort,ill
Default

Originally Posted by mrhorsepower1
All my point is .......why leave power on the table. Yes, the power is very good , but can be better. And your EXTREMELY safe . It looks like a great combo!
.......why leave power on the table. ??? absolutely plus chance washin the cylinders down .....& losin the rings .... We were at .500 - .550 and made max hp and on the water plugs are coffee brown good luck KIRK call me need some 8 mm # 48 pulleys
RunninHotRacing163.1 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.