Re: Roller lifters input
 

Open the 2nd ring up around 30% more then the top ring.

Chris

Re: Roller lifters input
 

JDCB,
How many hrs did your buddy get and how nasty was the cam? From my experience with solid rollers the life expectancy is pretty good if the net lift is kept .700 or less and if the duration @ .200" is 200 degrees or less. Spring selection has to be an endurance type spring that will maintain adequate pressure as they cycle out. If the lobe design is too aggressive, i.e. a drag race cam, life will be pretty short in an endurance motor. I wouldn't recommend running a solid roller lifter more than about 100 hrs even with a mild lobe design. Just my .02! Let us know what you decide to go with!

Craig

Re: Roller lifters input
 

GPM,
My cam specs are as follows. Intake, adverstised = 292*; at .050" =263*
Exhaust, advertised = 300*; at .050" = 268*. .686" valve lift on both I/E.
So what does this tell you? How agressive the ramps are? I lost one Isky lifter on this cam and had it reground, before Ultradyne sold out.

cstraub,
I take it you dont run Gapless rings? My buddy is looking to buy some rings for his motor and is wondering if it is worth the extra to use the gapless. He has run C&A's second ring gapless, and I am running Total Seal top gapless rings. Any pro's or cons for either or is simple better?
Next, where do I see a pic of the Brodix push rod liners? And where can I get them and does the hole have to be round or can it be oblonged? I have used bronze tubes in the past to seal up leaks in the intake ports from opening up the push rod tubes. Not the easiest thing to install..

Thanks
Dick

Re: Roller lifters input
 

Dick, do to political reasons I can't post the info you have asked. If you want to PM me that is fine or call: 423 854 0007. The Brodix pushrod liners are in their catalog. You can also use 6061 aluminum tubing. We did this with some wild 5" bore center stuff from EPD years ago. Your correct, it is not fun but if it saves you from a catastrophic failure then it is worth it.

Nothing wrong with Trends pushrods either. Bob makes a nice part as does Terry at Manton and Dennis at Smith Bros.

Chris

Re: Roller lifters input
 

Mr.G, I used to be a firm believer in the Ultradyne cams also. Until I asked Harold to design a special cam for my boat. Best I can recall that was 6 years ago. I waited a full year for that cam and then gave up. I moved on to the Comp cams. I haven't broke a spring, a lifter or lost a lobe since. I run bigger cams with more lift and duration at way higher rpms with no problems. The ramps are just one step slower,they make great power, and I stay running. I have to wonder if your cam is part of your push rod problem.

Re: Roller lifters input
 

Who would think that rolling a wheel up and down a hill could be so difficult. :evilb:

The root of the problem is the weight of the valvetrain, right? You have to have the nasty cam profiles to make the power, everything else is a tradeoff between strength and weight, and good parts aren't cheap.

So at what point is titanium going to make sense in a max effort marine engine?

Re: Roller lifters input
 

Tomcat,
Have you price titanium motors.. lately?? Nothing I can afford.. well until I blow up everything else..!! :D :D :D

Re: Roller lifters input
 

Not exactly. Heavy is not that bad if it is used in the right places. Key is to design parts that can handle the pressure per square inch where it is critcal. It's like that lifter that has 2 axles. Distribute the load and the part will last...and win Championships.

Chris

Re: Roller lifters input
 

From the Del West site:

"The lower mass of the titanium valves combined with the matching Del West keepers (locks, cotters) and spring retainers allow for the use of higher RPM and more aggressive cam profiles without the loss of valve control. This results in the development of broader torque curves with increased horsepower and higher RPM and power numbers."

Where it says higher RPM and more aggressive cam profiles I see more endurance at the same RPM and profile. How much more for a set compared to good steel valves? No prices on the site.

Re: Roller lifters input
 

Are Titanium valves worth the money?What is the main reason to use them over SS? Longivety or performance?