Go Back  Offshoreonly.com > Technical > General Q & A
Cam and valvetrain longevity....??? low duration high lift... >

Cam and valvetrain longevity....??? low duration high lift...

Notices

Cam and valvetrain longevity....??? low duration high lift...

Thread Tools
 
Old 09-25-2016 | 04:44 PM
  #521  
Registered
 
Joined: Aug 2011
Posts: 2,733
Likes: 8
From: bel air, md
Default

Originally Posted by getrdunn
Have u tried that sv565 that you recommended to me for 565 builds?
I've used its bigger brother on tall deck motors with great results. I'm doing a pair of 555 budget motors as soon as the weather changes. I'll use the sv565 intakes and some top secret cams I designed on my own should make 725ish hp.
Black Baja is offline  
Old 09-25-2016 | 07:32 PM
  #522  
Registered
15 Year Member
 
Joined: Feb 2009
Posts: 8,356
Likes: 1,515
From: NW Michigan
Default

Originally Posted by Black Baja
I've used its bigger brother on tall deck motors with great results. I'm doing a pair of 555 budget motors as soon as the weather changes. I'll use the sv565 intakes and some top secret cams I designed on my own should make 725ish hp.
Well keep us posted how builds go. "Secret ninja cams". Cool....
getrdunn is offline  
Old 09-25-2016 | 09:25 PM
  #523  
Registered
15 Year Member
 
Joined: Feb 2009
Posts: 8,356
Likes: 1,515
From: NW Michigan
Default

Any trial on comps 4 pattern hyd rollers?
getrdunn is offline  
Old 09-26-2016 | 04:08 AM
  #524  
Registered
 
Joined: Aug 2011
Posts: 2,733
Likes: 8
From: bel air, md
Default

Originally Posted by getrdunn
Any trial on comps 4 pattern hyd rollers?
I've been told by our dyno operator that builds motors which every last hp counts to "save your money".
Black Baja is offline  
Old 09-26-2016 | 05:20 AM
  #525  
Full Force's Avatar
Thread Starter
Gold Member
20 Year Member
Gold Member
 
Joined: Oct 2005
Posts: 11,688
Likes: 216
From: Olmsted Falls,Ohio Marblehead,Oh
Default

Port engine should come out in the next couple days....at that point I will at least pull a valve cover and run a machinist edge across cylinders to see if exhaust seats are getting pounded into the head... from the things I am told the issues arise between 50-70 hours.. I am at 65 or 67, cannot remember
Full Force is offline  
Old 09-26-2016 | 06:27 AM
  #526  
Registered
 
Joined: Aug 2011
Posts: 2,733
Likes: 8
From: bel air, md
Default

Originally Posted by Full Force
Port engine should come out in the next couple days....at that point I will at least pull a valve cover and run a machinist edge across cylinders to see if exhaust seats are getting pounded into the head... from the things I am told the issues arise between 50-70 hours.. I am at 65 or 67, cannot remember
After a season on a new set of aluminum heads we have found it very beneficial to pull the heads and do a valve job. Even with very mild cams it seems as though things move around. After the first go round things seem to settle down and be good to go for awhile... If I was in your shoes I would just yank them and go through them. If you have mls gaskets don't hesitate to re-use.
Black Baja is offline  
Old 09-26-2016 | 06:31 AM
  #527  
Registered
20 Year Member
 
Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
Default

I think what we have learned here, is that

A ''custom high lift cammed" 540ci , with AFR 325 heads, is no better, than a 565ci, with good flowing chinese 320cc heads, and a low lift hyd roller cam. The boat lost acceleration by dropping 25 cubes, and a longer duration cam. It gained nothing for top speed either.

The old 4.375x4.530 combo , with a refresh, and a cam upgrade, probably would have been the best bet.

I'm really not surprised by any of this. The procomp 320 heads he had, were if I recall, knock off's of the old pro topline/RHS/Engine quest line of heads. In stock form, they dynoed around 600hp on tims 565. Then later, he had Gellner do a valve job and cleanup on them. That there probably helped them out a little, and had he redynoed, he probably would have been very close to his "630HP" he has from bobs combo, with a bit more torque down low from the added cubes and smaller cam. Those procomp heads castings were not very good quality, but like everything pro comp did, was take a good design, and copy it. They made some decent power, and probably flowed really close to the afr 325's after the tune up they had.

I don't think theres going to be any magic here, to get him the results he wants, whether it be from a spacer, intake swap, or even cam swap. I'd focus on the health of the engine, making sure all is well there, and keep on boating until you can strap a blower on the thing, and get the results you want.
MILD THUNDER is offline  
Old 09-26-2016 | 07:10 AM
  #528  
Full Force's Avatar
Thread Starter
Gold Member
20 Year Member
Gold Member
 
Joined: Oct 2005
Posts: 11,688
Likes: 216
From: Olmsted Falls,Ohio Marblehead,Oh
Default

Spot on... Gonna do some checking when engine is out and see what things look like ...
Originally Posted by MILD THUNDER
I think what we have learned here, is that

A ''custom high lift cammed" 540ci , with AFR 325 heads, is no better, than a 565ci, with good flowing chinese 320cc heads, and a low lift hyd roller cam. The boat lost acceleration by dropping 25 cubes, and a longer duration cam. It gained nothing for top speed either.

The old 4.375x4.530 combo , with a refresh, and a cam upgrade, probably would have been the best bet.

I'm really not surprised by any of this. The procomp 320 heads he had, were if I recall, knock off's of the old pro topline/RHS/Engine quest line of heads. In stock form, they dynoed around 600hp on tims 565. Then later, he had Gellner do a valve job and cleanup on them. That there probably helped them out a little, and had he redynoed, he probably would have been very close to his "630HP" he has from bobs combo, with a bit more torque down low from the added cubes and smaller cam. Those procomp heads castings were not very good quality, but like everything pro comp did, was take a good design, and copy it. They made some decent power, and probably flowed really close to the afr 325's after the tune up they had.

I don't think theres going to be any magic here, to get him the results he wants, whether it be from a spacer, intake swap, or even cam swap. I'd focus on the health of the engine, making sure all is well there, and keep on boating until you can strap a blower on the thing, and get the results you want.
Full Force is offline  
Old 09-26-2016 | 08:35 AM
  #529  
Registered
15 Year Member
 
Joined: Jun 2009
Posts: 9,967
Likes: 6,456
From: Chicago
Talking

Originally Posted by Black Baja
After a season on a new set of aluminum heads we have found it very beneficial to pull the heads and do a valve job. Even with very mild cams it seems as though things move around. After the first go round things seem to settle down and be good to go for awhile... If I was in your shoes I would just yank them and go through them. If you have mls gaskets don't hesitate to re-use.
Yeah cause Bobs valvetrain beats the **** out of the seats!! See you`re starting to figure it out!
ICDEDPPL is offline  
Old 09-26-2016 | 09:31 AM
  #530  
Full Force's Avatar
Thread Starter
Gold Member
20 Year Member
Gold Member
 
Joined: Oct 2005
Posts: 11,688
Likes: 216
From: Olmsted Falls,Ohio Marblehead,Oh
Default

I have never heard to fix aluminum heads after one season, ever.... I just don't see how that can be right
Full Force is offline  


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.