Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   Cam and valvetrain longevity....??? low duration high lift... (https://www.offshoreonly.com/forums/general-q/341258-cam-valvetrain-longevity-low-duration-high-lift.html)

Black Baja 09-25-2016 04:44 PM


Originally Posted by getrdunn (Post 4484971)
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.

getrdunn 09-25-2016 07:32 PM


Originally Posted by Black Baja (Post 4484980)
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 09-25-2016 09:25 PM

Any trial on comps 4 pattern hyd rollers?

Black Baja 09-26-2016 04:08 AM


Originally Posted by getrdunn (Post 4485037)
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".

Full Force 09-26-2016 05:20 AM

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

Black Baja 09-26-2016 06:27 AM


Originally Posted by Full Force (Post 4485058)
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.

MILD THUNDER 09-26-2016 06:31 AM

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 09-26-2016 07:10 AM

Spot on... Gonna do some checking when engine is out and see what things look like ...

Originally Posted by MILD THUNDER (Post 4485071)
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.


ICDEDPPL 09-26-2016 08:35 AM


Originally Posted by Black Baja (Post 4485069)
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!

Full Force 09-26-2016 09:31 AM

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


All times are GMT -5. The time now is 07:33 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.