You are certainly correct Mark in that generally something else is going on to cause a lifter to spit the needles out. However, it happens. Guys neglect to lash the valves, run them for longer intervals than they should, let springs get weak, improper geometry, etc. It can happen as well with a hyd roller, but I would say that it is more likely to happen (or should I say that it's easier to occur since the valvetrain is more "extreme") with a solid. The springs are stiffer, therefore, have more weight to lose. A 10% decrease in weight in an 800# spring is twice as much as a 10% drop in a 400# spring. A solid generally turns more rpm, the cams are generally more aggresive, etc. It's not neccessarily the fault of the lifters, it's just that things can go wrong with a solid a little faster and/or easier.

Not trying to argue with you. Just clarifying why I posted what I did earlier (3 yrs ago) in this thread.

Hope you are doing well. Haven't heard from you in a while. Need to catch up sometime.
Eddie

You are right about leaving some power on the table. The issue is that most guys don't have the ability, tools, desire or know how to lash valves. Very few of my engines stay local. The majority of them go over 8 hours away. So, it's not really feasible for them to come back to me to have the lash done. They may or may not have someone near them that they trust or want to work on their stuff.

I talk about it with several of my customers, I would say that 99.9% of them do not want the hassle of a solid. They would rather sacrifice a small amount of power for reduced maintenance and the longevity. Obviously, there are some instances where you have to go to a solid. Since we only build marine engines, and pretty much all of those are pleasure boats, we have very little calling for solids. However, we do build a few. We currently have a few hyd rollers that we are turning close to 7000 rpm. So far, no issues with that rpm.

Hope you are doing well and staying busy.
Eddie

I agree hydraulics are a low maintenance alternative, but a good shaft rocker system all but eliminates having to set lash once it's done the first time. RPM isn't an issue if you have light enough valves, retainers, locks. But when controlling a heavy BBC marine valvetrain, the spring pressure required, combined with an aggressive cam, can certainly wreak havoc on the plungers. Based on my own personal testing, I have found the limit of the hydraulics to be more related to HP then RPM, also lobe profile plays a large factor. There are so many variables, it would take forever to type all the scenarios and factors at play, but in brief; as the lifter is coming up to open the exhaust valve at blowdown on a boosted engine, that particular part of the lobe is trying to snap the valve open very quickly against significant cylinder pressure, and valve spring pressure. This can cause the plunger to drop down in the lifter, destabilizing the valve and pushrod, and moving your exhaust opening point to where it shouldn't be. Best case scenario it acts like a rev limiter, and you have an engine that just won't pull to where peak HP should be, boost usually increases, the engine becomes more timing sensitive, and egt's go up. Worse case you break the plunger (I almost always break the freakin plunger). This phenomena, I was surprised to find out, doesn't just occur at high rpm. When upgrading to the high RPM Morel's in one engine, I found a 30hp gain as low as 3500rpm on a 1000hp 557. If you're going to run a hydraulic, run the best lifter you can get. Other benefits of a solid are, a lighter lifter, and because you don't need room for the plunger, you can get the pushrod right down close to the wheel, this of course greatly reduces side loading on the lifter, and you can run whatever spring pressure you need to control the valves. Hydraulics certainly have there place, but don't think the engineers at Merc were putting solids in just for the hell of it..

while i agree that more power could be found with solids,in my application the gain is not worth the hassle of removing the center headers to gain access to the valve covers.you can barely slide a sheet of paper in there.

Good info, thanks guys.

If your valve train is stable, to begin with it; will not require constant adjustment. I have customers that run all season long, without adjustment, we usually check valve lash at the end of the season along with spring pressures and a visual. After the first; adjustment after break-in on the dyno and double checking after the dyno pulls are completed, the valve train is pretty much set.
If you have to continuously adjust valve lash, you better check push rod wall thickness, spring rates and use a shaft mounted rocker arm or add some stud girdles, that support the rocker arms properly.

I like that isky lifter design with bushings instead of needles. I worked in common rail pump design for a long time and we never even consider needle bearings in our lifters.

You guys bring up some great points. Another benefit of the solid roller, is if the lash IS out of spec, it may help track down a problem before it gets ugly.

With that being said, I can understand why certain guys do not want to mess with solids. Lots of boats, including mine, with the stellings headers, are a biotch to get the valve covers off, and alot of bilges are extremely tight. Some bilges you cant even get into, like my old Formula. Everything I did I had to do leaning on my chest or bent like a monkey. Pulling the valve covers and running thru all the valves at the end of every season, could get tiresome. For me, being kind of a gear head kinda guy, the solid rollers do spark my interest. I've got alot of buddy's though, who want the power, the sound, the speed, but don't even wanna change their own spark plugs, let alone run thru the valves. I know that with the right setup, good components, lash shouldnt change. But you still gotta check it. Getting to that point may be the hard part.

Great info guys.

MT- I'm leery of opening up my boat engine for more advanced preventive maintenance. Oil changes are no prob, but I don't have a local mentor to help me avoid the pitfalls. Couple that with the short boating season and a hydraulic cam is a no brainer.

That's one of the reason I appreciate these threads so much, the banter brings those nuances to light.

You probably do, but... Like me you have to figure out who they are.
So far for me the only one I know to trust is haxby 6 hours away.

That sounds like an awesome lifter and those particular lifters have my attention. Could you (or anyone) please tell me how many hours without failure so far have you seen the latest Isky needleless solid roller lifter design at work in a Marine supercharged hi-perf engine application since they have come out with it approx 7-8 years ago? I am very curious to know as they have now been on the market for several years at this point.

(I cannot quite remember the particular name of the Isky lifter in question at this moment, but it has the bushings instead of the needle bearings and Isky advertises it to be about 350% stronger than a conventional solid roller lifter with needle bearings.)

Just an fyi but pretty much everyone is making needless now.

There's a thread on a other site that talks about a guy losing an Isky roller-

Yes it is a car, but that cam seems like something a boat would have and the engine had 25,000 miles on it.

Anything posted by that particular "engineer" should be taken with a bucket of salt. According to him 5w30 automotive oil is better then any racing oil for your high performance big block. In fact, most generic box store conventional oils are way better then any synthetic racing oil..

Anyway, back to the Isky EZX rollers. They're awesome. I inspected a set last year that had 227 hours on them in an engine that spins 7000rpm, and makes 1300hp. I did the top end, but couldn't find a reason to swap the lifters out. Gonna try and get another 50 hours out of it before I do the bottom end, and will send them back to be rebuilt at that time. The valve lash on those engines was adjusted twice in four years. They probably should've been rebuilt while I had the engines apart, but they looked perfect so I rolled the dice..

Are the I sky's your preference?

After reading so many horror stories about needle bearing failures, I converted one set of my solid roller engines over to the bushed rollers. I rechecked the lash after the first couple of hours usage and found no change in lash. Overall I'm sold on the design, but unfortunately I don't have much time on those engines since the switch to give a longevity report.


FWIW, I feel the advantages of solid rollers offset the need to check the lash once per season in my case. It only takes me a few hours to do both engines (taking my time), but both of my boats are staggered... if I had a tight side by side I too would likely want hydraulic rollers due to the hassle of getting the valve covers/exhaust off.


EDIT: I went with the Crower Endramax lifters for my Big Chief heads when I did them.

Yes. The Morel's are a really nice piece too, but I'd rather support Richard and Isky. Their customer service is excellent, and so are their products.

Well, that is...something. Thanks for the heads up Alex.

I am not here to put anyone on the grill---I thought that by now, after several years of this new Isky solid needleless roller lifter being out on the market, that some boater would say something like,...."yeah, I have been running these lifters on my twin blown offshore engines for 450 hours to date with no problems!", however, I have not heard that from any boater yet, but to be fair, I have not heard any bad news either.

Here's kinda how I am looking at this---at least, it is one perspective;---if I am going to pay twice the amount for the Isky needleless lifters at $1250 or so per set, then would it be safe to say that I should reasonably see at least twice the amount of hours before rebuilds vs a conventional style lifter with needle bearings for that kind of money?

Were talking about the amount of hours before rebuilds on both needleless design and with needles of the conventional design----or am I looking at this the wrong way?

The 75 hr top end refresh for the 1075 is driven primarily by the cycle value of the aluminum rocker arms, not the use of a solid roller camshaft. There has been significant emphasis on the well-defined, finite levels of fatigue (and the specific cycle value) incurred using this material in a rocker. This is a necessary criterion in order to maintain the warranty customers’ demand with the product. The 1075 has a valve spring rate, seat and open force that are not out of line with those rates being seen in most performance hydraulic roller applications today. In this case these cycle values are not driven by elevated spring loads, but strictly cycles.
Stress levels incurred with specific output exceeding 2 HP per CID are not consistent with service intervals remotely approaching 200 hrs. regardless of the use of a mechanical or hydraulic follower.

Do solid rollers have a disproportionately high failure rate compared to hydraulic roller lifters?
• The vast majority of lifter related failures stem from improper components destabilizing the system, not from design or material related issues. The lifters are nearly always collateral damage, not root cause elements.

Do solid rollers overstress valve train components?
• Quite the opposite, the elimination of a potential source of deflection can assist in mitigating conflicting harmonic frequency disturbances.

Don’t solid rollers require “heavy valve springs forces” proportionately to a comparable hydraulic roller?
• No. Seat/open force and rate are determined by the mass, acceleration (of the valve train) and ultimately the desired RPM. If you have two lobes (solid/hydraulic) that create the same valve path, the spring requirements will remain constant. Spintron testing demonstrates many failures a result of both inadequate AND excessive spring forces.

Do solid rollers “hammer” valves by the use of lash ramps?
• No. Properly designed solid roller cam profiles have lash ramps that bring the wheel off the base circle and transition it to the opening flank with negligible shock loading to the system. IF you experience excessive shock loading, that can be mitigated by the use of correct system components.

Do solid rollers require constant maintenance?
• There is no valve train in a performance application that is a zero risk design and zero maintenance application. If the engine in question is generating > 1.4 HP/CID and you forgo periodic valve train inspections you are leaving the engine open to the types of failure we see here, and other forums on a regular basis. In the vast majority of failures the lifter is NOT the root cause of the failure as stated above, it is collateral damage due to negligence of the person in charge component selection, assembly, and maintenance.

I think you are looking at it in the wrong way.........no offense meant. The extra money is for the piece of mind that there can never be any tiny needles flying around inside your engines. And yes, I do run the ISKY EZX lifters in my engines.

I can't believe rockers are so frequently aluminum either. Bad application there.

Hogie,
The interesting thing about the use of aluminum in that application is that T&D offers a steel rocker arm as an option. The premium on the steel upgrade would be approximately $650 per set. While that premium is not insignificant, the fact that the steel rockers do not have a material driven cycle value, their service life would compensate for that premium 10 times over the lifespan of the engine. For an engine of that caliber it would seem like the steel upgrade would be a foregone conclusion.

Bob

Bushed lifter bores are not a necessity in either a hydraulic or mechanical lifter scenario. What is critical is proper lifter to bore clearance. Next to compliance and lack stiffness in the valve train, improper lifter to bore clearance is responsible for more lifter failures than any other oversight. Too little clearance, you stick a lifter in a bore. Too much clearance, and lifter suffers from lack of support in the bore, excessive side loading, and 16 major oil leaks into the oiling system. Using a bushing will salvage a block that has excessive clearance or erratic bore concentricity.

Bob

I think many people overlook, the lifter bores. A micrometer and a dial bore gauge are a must for this job. Either a new block or a used block, it should be checked. 2 ways of fixing it; 1 with lifter truing the block with bushings or same tooling going to a .902 lifter or larger.
Most people, do not want to spend the $$$ since there wasn't a catastrophic failure before with a lifter, the issue is ignored. It would be the same as putting a engine together without checking bearing clearances.I myself use a BHJ fixture for this in my mill which has different tooling and setup fixtures, that pertain to specific blocks and deck heights.
As Bob, stated; 16 oil leaks. Those 16 oil leaks are going to affect the oil supply to the lifter and more so, using a hydraulic or a Hi Rev hydraulic lifter, that will further translate into lack of oil supply to rocker arms and cooling of valve springs.

When evaluating a lifter bore, is one looking for a glass smooth finish or more of a cross hatch pattern?

Second, how prone are the lower HP Gen VI blocks to lifter bore wear? 502mags, HP 500's, etc.

Crosshatch pattern, about the same as a cylinder bore ( oil retention ) a block from manufacture will have machined surface allowing for oil retention, but not the same as a finish hone crosshatch.
Your second question; it will depend on many variables. Sizing of bores originally, actual lifter diameter, service intervals, has there been any valve train issues prior. You will have normal wear over time, to what point that is; you will have to determine.

Thanks Mark

Great input here from you guys. My pants are getting tight with all this good tech talk. Now you guys got me horny for solid rollers in my next builds.

Great info as always Mark

Yes, that is a good point you make and I agree with you,....but does that mean your response is good and valid enough to nullify the curiosity of my question and moot enough to make it unworthy of discussion? Or am I a rebel without a cause?

Actually, I am really hoping to use these Isky needleless lifters----my engine blocks will be on the stands by the end of this week ready for assembly and it is time for me to make a decision, it's just that I'm still curious about this needleless lifter.

So far, Haxby looks like he's the best test bed thus far at 227 hours in a pair of 1300hp engines turning 7000rpm before thinking he must rebuild them at roughly 275 hours and I think that is impressive info so far. For as expensive as they are, I just thought for sure, after 7-8 years of production of these Isky needleless lifters, would have seen use up to 400+ hours by now in a pair of supercharged, Big Block Chevy offshore marine engines before rebuilding the lifters. Perhaps there is someone out there with the answer yet---I was just curious to know.

Kaama, that level of testimony is going to be hard to come by.

I think you will be hard pressed to find that kind of information for a couple reasons 1 not many know how to setup a valvetrain properly. In this case a catastrophic failure occurs and the blame is placed on anything and everything besides the real problem (piss poor setup). 2nd reason being that I could see is when you start playing in the big leagues pushing rpm's and cylinder pressure at this level I don't think people are going to neglect there engine for 400 hours. Every piece in the engine has a service limit and in my opinion at 400 hours you are way past the limit.

X2. 400 hours is way past the service life of any component in a supercharged bbc marine engine that is being used for what it was intended. Some of the components may still be ok, crank, rods, etc. but that doesn't mean they shouldn't be taken apart and inspected. Lifters are a wear item, just like valve springs. Nobody would try to get 400 hours out of a set of valve springs on one of these engines, and you shouldn't expect it out of the lifters either. It's not a lot of money to have them rebuilt, and the benefits of the bushing design far outweigh the cost difference of a needle bearing.

Thanks for all your input guys, much appreciated :)

I looked at the bushing style before I bought the Morels. My concern was on startup when the oil is cold the rollers would slide up the ramp rather than roll due to oil viscosity and high shear at those low tolerances, especially on the steep part of the opening ramp. The shear surface between the roller and bushing is significantly greater then the contact point between the roller and cam lobe. I suppose I could calculate out the shear force at the bushing diameter and the leverage the roller diameter offers to know what the ratio of forces really are. I guess my question is, has anyone seen excessive wear on the ramps of the cam with bushed rollers verses needles?

I understand your theory but my question is does it really matter? I know that they have experimented with different bushing materials and since going back on the market with the bushing lifter they have changed the material a few times.

This is exactly why we did not used the Isky bushing type lifters a when they first came out. Does anybody have any test or a true comparison on which type of roller lifter is best in an endurance application? Is the NASCAR Truck Series still allowing roller lifters? If yes, what lifter were the Truck teams running in 2014?

Ben, I'm sure they have the bushing material nailed down by now. Isky isn't a fly by night operation they have been around forever. With that being said it seems to me everyone is producing bushing style lifters except Jesel. I don't think there is any "magical" lifter out there. As long as the setup is right and proper maintenance is done there shouldn't be any failures.

My point is, regardless of what the bushing material is, even if it has zero friction, the shear of the oil in such close tolerances could be sufficient to cause the roller to slide up the ramp, especially in high lift aggressive cams that most of us are running. There is so much side load on the roller and the roller contact area is so small compared to the bearing area that it may be easier for the roller to slide up the ramp than roll over it. My concern is mainly when the oil is cold. It would not be out of the ordinary for me to pull the boat out in 40 or 50 degree weather with water temps in the upper 30's or low 40's. My 20w50 Amsoil is going to be just a little thicker than when it hits 200+. If bushings are the best thing since sliced bread, why are engine builders going to needles on cams? Not to diverge, but my 14,000 rpm 2 cycles were all needles on everything, granted when they went, it was catastrophic.