MILD THUNDER

iTrader: (3)

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MILD THUNDER

iTrader: (3)

I asked this question to Billy Godbold at comp cams this morning. It appears I may have been a bit off base here , and that there may be some exceptions to the rule, as far as running the hydraulic lobe with a solid roller lifter . I will report back later .

fbc25el

A while back I was thinking about going to solid roller lifters on my Cam Motion cam so I gave them a call. They said no problem but I should change the springs to 170 on the seat with a rate of around 470 and no more lash than .010. hot . Just some info.

MILD THUNDER

iTrader: (3)

Went back and forth with Billy today at Comp (manager of valvetrain engineering) as I has some other questions regarding a cam for a friends builds. I follow Billy on facebook and some of the testing and development they are doing these days with valvetrains is simply awesome. Anyhow, He didnt get into specifics, as far as the comparison of a hydraulic cam with a solid vs a hydraulic lifter, or a solid cam with a hydraulic vs a solid lifter. But, He did say, that a good marine hydraulic profile, may be one that was intended to be a tight lash solid profile. And on the contrary, the HUC/HLO series of hydraulics, would have been well suited to running as a tight lash solid setup if lash is kept under .012.

He recommended discussing my needs with David McGarver, who specilizes in endurance applications. The new HUC lobes are used in 90% of the marine hyd roller applications he said. They have a nice selection of lobes in that family, and if you like a big hydraulic, they have it. (714 lift hydraulic lobe). I attached those profiles in pdf

Rookie

iTrader: (4)

Just curious, where, how long and what lifter? I have many Johnson and Morel "short travel" and "high RPM" lifters at the shop that the inside are broken and making noise after 1/2 a season trying to spin 5800+.

Those are some nice lobes.

MILD THUNDER

iTrader: (3)

Myself and icdedppl have been turning the morels to 6000 with no issues. All 4 sets are from 2012. On dyno we have pulled them to 6500 routinely without a hint of valve float or instability. We are running just over 200 seat and 500 open. He has a crane 651 hydraulic, I have a Crower hydraulic.

I have been running hydraulics in my engines since 2008, and prior to that they had a decent amount of time on them. Never had a broken lifter , broken guide plate, broken rocker stud, or any valvetrain failures. Other than 1 cracked trunnion from a 1985 crane gold rocker that failed after being 30 years old.

as for the 7000rpm , I was generalizing , but there are guys who are doing it. Alot have 55mm cam cores, 903 lifters with 810 wheels . That would be a morel lifter , because Johnson or anyone else doesn' make a hydraulic in that size that I am aware of . I have seen Mike tkach wind his 588ci to 7000rpm on the dyno , at 1200hp with a morel hydraulic , and no signs of lifter pumping up or issues. I believe he spun those and his blown 540s in his cat with hydraulic lifters to 6500rpm and 130mph .

I know you know valakos motors well. Isn't He running a 1.8 rocker on his setup? How long hours wise does he usually go before going into it for maintenance ?

I would think if a guys busting Johnson's and or morels in half a season trying to turn only 5800rpm, something is grossly wrong in the rest of the valvetrain setup. What spring pressures were they running ? What pushrods ?

5050

im a little confused on what u are saying. Yes a hydraulic roller is more aggressive open to close with total duration but ramp speeds are slower but I’m comparing something like a solid .420 .714 lobe with 258 266 @.050 with adv duration 290 298 vs say a large marine hydraulic roller .647 254 262 @.050 309 317 adv duration 114LS on both. Hydraulic does have more total duration because it’s actually less aggressive and opens more gently and sooner and requires less spring pressure because it’s less aggressive. Solid roller opens later because of lash ramps and it’s aggressiveness and will have more open time when valve is fully opened position. If hydraulic cams were so aggressive every drag racer in world would be using them. Solid roller are performance and better valvetrain stability period, where they have issues is longevity in high lift high spring pressure but will make more power due to higher lifts and longer peak open times. a solid roller will live a very long time on a hydraulic profile due to less spring and be better control of valvetrain vs hyd lifter. U can’t run hydraulic on a solid due to aggressiveness because it will collapse lifter. U will loose a little bit of cam spec putting a solid roller on hydraulic cam but u won’t have to worry about eating a hydraulic cam up if it was made to aggressive that a hydraulic lifter couldn’t handle it and ate up lobes. I’ve seen some threads like Tim P. Cam grinder cams ate lobes from being to aggressive for hydraulic lifter. U can also look at ramp speeds by subtracting .050 duration from total duration. The lower the number more aggressive it is. Another good thing to know on cam specs is valve overlap which u can know by adding duration.050 Int + ex divide by 4 and subtract lobe sep # then multiply by 2.

endeavour32

iTrader: (4)

I've ran Morels on three engines, all of them turned over 6000 rpms and I've never had an issue with a lifter. If I knew I could make the same power with the new engines converting them to Hydraulic, I would. I'm not scared of Morel hydraulics at all, however; I'm sure I would give up some power, and that I don't want to do.

MILD THUNDER

iTrader: (3)

the problem is comparing advertised or total durations. A cam like a crane hydraulic , is measured at .004. A comp cam hydraulic, is measured at .006. The crane will show more advertised duration, and a longer split from .004 to .050. On paper. So comparing to a comp, one could be let to believe the comp is a more aggessive lobe because of that. A solid, is measured at .020 . Advertised Duration becomes even shorter on paper. Again, making the solid look even more aggessive.

One could look at crane and comps master lobe catalog , and get the duration measureents at .200 , and compare. One thing that will always show a higher number at .200, is when a lobe has more lift. A 245* lobe with 680 net lift, will have a higher .200 number than a 245 lobe with 630 lift . This is why lift and lobe intensity are relative. A lower lift lobe with equal .050 duration, will just about always be easier on parts than a higher lift version. You only have so much real estate to work with, and when the lobe is made larger , the hill the lifter has to climb can only get steeper.

comparing a 714 net lift solid, to a .647 lift hydraulic , is not really apples to apples. Comparing a solid lobe design with say a .370 lobe lift , and a hydraulic with .370 lobe lift, of similar .050 duration, the comparison gets a little more fair .

overall , I think when your going for max performance , and or rpm levels that exceed a hydraulic lifters capability, the solid is a no brainer. However ,if the little extra power isn't gonna matter , or the rpm levels aren't excessive, the hydraulic roller lifter on a hydraulic roller cam, works , and has worked for a long time in marine engines. When a guy is making well over 1000hp with forced induction, and still not collapsing a hydraulic when opening the exhaust valve under extreme pressure, I see no reason why a guy with a NA engine making 600 or 700hp in the 6000rpm neighborhood, needs a solid lifter to survive

5050

I agree with u. The only thing I see different is if someone getting a custom grind HR cam bigger than .650 lift on 1.7 ratio and abnormally aggressive ramp a solid roller on the hr cam is a better idea as hr lifter and an overly aggressive hr cam will have issues. .