Go Back  Offshoreonly.com > Technical > General Q & A
Help with cam choice >

Help with cam choice

Notices

Help with cam choice

Thread Tools
 
Old 01-27-2008, 03:09 PM
  #1  
Registered
Thread Starter
 
Join Date: May 2007
Posts: 64
Likes: 0
Received 0 Likes on 0 Posts
Default Help with cam choice

Hi I was wondering if I could get some advice on a good hydraulic roller profile... I'm currently building a pair of 540
engines with a 9.5 cr.... will be using a dual plane air gap/ 850
and EMI manifolds and pipes. have been considering Comp cams
Dur @ .50 Lift lsa
299 319 243 257 .570 .554 107°

Thanks in advance Ed
inxs01 is offline  
Old 01-27-2008, 04:30 PM
  #2  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,558
Received 1,821 Likes on 907 Posts
Default

I would say no way on the cam you posted. Too much duration, not enough lift and 107 lsa will need dry exhaust.

Crane #168741 or similar would most likely be a good choice.
Griff is offline  
Old 01-27-2008, 09:47 PM
  #3  
Registered
 
Join Date: Jul 2007
Location: NY-NC
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Default

We have a nice Ultra-Dyne hyd rollers ground up for our 540/650hp's .600 lift, 236 @ .050 and 112 centerline. We sell them for $295-Mark
OLSKOOL72 is offline  
Old 01-27-2008, 11:35 PM
  #4  
Registered
iTrader: (1)
 
KAAMA's Avatar
 
Join Date: Oct 2000
Location: Western Michigan
Posts: 4,464
Received 78 Likes on 47 Posts
Default

Originally Posted by inxs01
Hi I was wondering if I could get some advice on a good hydraulic roller profile... I'm currently building a pair of 540
engines with a 9.5 cr.... will be using a dual plane air gap/ 850
and EMI manifolds and pipes. Ed
243*/257* on a 107* lobes sounds like you might be headed for some grief....sounds kinda big. For about the same price you would pay for an off-the-shelf cam you can Call or pm "RMBuilder"/Bob Madara of Marine Kinetics in N.Y. He is an expert at taking all your engine specs and producing a custom cam profile specifically for your application. Bob specializes in marine offshore hi-perf cam applications and has does them all the time for guys with our kind of boats for several years.

Bob's number is...(585) 654-8583

Also, what kind of boat do you have? You might get away with running with a single/open plane intake manifold on a 540cid engine vs the Air-Gap dual plane intakes you plan on using.

Last edited by KAAMA; 01-27-2008 at 11:40 PM.
KAAMA is offline  
Old 01-28-2008, 06:46 AM
  #5  
Registered
Thread Starter
 
Join Date: May 2007
Posts: 64
Likes: 0
Received 0 Likes on 0 Posts
Default

I've got a 34 Scarab Ninja.... The reason I was choosing a Dual Plane manifold was in an effort to keep the torque up
however I appreciate all of your feedback and am open to any suggestions..... Ed
inxs01 is offline  
Old 01-28-2008, 09:02 AM
  #6  
Registered
iTrader: (1)
 
KAAMA's Avatar
 
Join Date: Oct 2000
Location: Western Michigan
Posts: 4,464
Received 78 Likes on 47 Posts
Default

Originally Posted by inxs01
I've got a 34 Scarab Ninja.... The reason I was choosing a Dual Plane manifold was in an effort to keep the torque up
however I appreciate all of your feedback and am open to any suggestions..... Ed
I would think that with a pair of 540cid engines in a 34' boat you should notice a big difference in torque just in cubic inches alone vs a 454 or 502cid engine....so, you should be fine with a single/open plane intake manifold such as a Dart.

The extra 1/4" of stroke of a 540 will give your boat a real kick in the pants.
KAAMA is offline  
Old 01-28-2008, 07:23 PM
  #7  
Registered
Thread Starter
 
Join Date: May 2007
Posts: 64
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks for the info.... the boat currently has a pair of 454 / 420's and I was looking for a little more
inxs01 is offline  
Old 01-28-2008, 07:38 PM
  #8  
Registered
iTrader: (1)
 
Join Date: Nov 2005
Location: Grand Rapids MI
Posts: 1,028
Received 2 Likes on 2 Posts
Default

Originally Posted by inxs01
Thanks for the info.... the boat currently has a pair of 454 / 420's and I was looking for a little more
I too am building a copy of a 420 but wanted a little more. i went with 230/238 @.050 .544/.544 witha 114. We shall see what it brings on the dyno.
Car Biz is offline  
Old 01-28-2008, 09:33 PM
  #9  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,558
Received 1,821 Likes on 907 Posts
Default

Originally Posted by Car Biz
I too am building a copy of a 420 but wanted a little more. i went with 230/238 @.050 .544/.544 witha 114. We shall see what it brings on the dyno.
I doubt you'll see much change with that cam.
Griff is offline  
Old 01-28-2008, 11:09 PM
  #10  
Registered
 
Join Date: Jan 2004
Location: Tylertown, MS
Posts: 406
Likes: 0
Received 0 Likes on 0 Posts
Default

Cannot go wrong with RM builder. He helped me with a cam set up that was based on what I was doing with boat. Pleasure to work with. Rebuilt 454 mk 4's with roller setup that dynoed 469 hp at 5200 rpm. Think I'm right on rpm. Used dual plane and eldebrock 750.
team Tickfaw is offline  


Quick Reply: Help with cam choice


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.