Solid roller lifters......
12-03-2014, 01:06 AM
#51
(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.)
Last edited by KAAMA; 12-03-2014 at 01:09 AM.
12-03-2014, 04:43 AM
#52
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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.)
(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.)
12-03-2014, 06:16 AM
#53
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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.
.
He runs a 467ci Mark IV BBC in his street Hotrod, that see's a lot of "spirited driving". The rev limiter is set to 6800 rpm, though the most common normal rpm seen is in the 3000 to 3500 range. his cam specs are 243*/249* duration at .050 tappet lift, 112 LSA, and .668 lift. Lash is .008 cold, .014 hot with aluminum heads. Spring pressures are 210 lbs on the seat, and 525 lbs open. His solid roller lifters are .842 diameter ISKY EZ Roll bushing type.
He runs a 467ci Mark IV BBC in his street Hotrod, that see's a lot of "spirited driving". The rev limiter is set to 6800 rpm, though the most common normal rpm seen is in the 3000 to 3500 range. his cam specs are 243*/249* duration at .050 tappet lift, 112 LSA, and .668 lift. Lash is .008 cold, .014 hot with aluminum heads. Spring pressures are 210 lbs on the seat, and 525 lbs open. His solid roller lifters are .842 diameter ISKY EZ Roll bushing type.
12-03-2014, 07:47 AM
#54
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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..
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..
12-03-2014, 08:01 AM
#55
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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..
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..
12-03-2014, 08:05 AM
#56
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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.
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.
Last edited by SS930; 12-03-2014 at 08:13 AM.
12-03-2014, 08:35 AM
#57
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12-03-2014, 09:14 AM
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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..
12-03-2014, 09:37 AM
#59
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?
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?
12-03-2014, 10:29 AM
#60
MarineKinetics
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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.
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.
Last edited by rmbuilder; 12-03-2014 at 10:32 AM.
