'Pressurised' Roller Lifters
There have been threads and articles re. pro's and con's of roller lifters and whether hydraulic or solid rollers are best for certain applications. One thing for sure is that it seems a number of users or solid roller lifters have experienced lifter failures. Many people seem to exclude the idea of solid rollers for street operation citing oiling issues with typical street operation (i.e low rpm use and extended idle periods) which, yes I guess is a potential problem IF using a race spec' cam/lifter/spring set up with very high spring rates and perhaps if an engine has lower pressure than ideal at idle. Certainly the pro's and con's of suitable oils with ZDDP additive etc are also part of the issue.
It seems that two or three of the cam and lifter manufacturers are now marketing what they are describing as 'pressurised' solid roller lifters, which I guess (as presumably getting their oil supply from the lifter gallery) would theoretically seem to address some of the low rpm oiling issues.
For me the 'engineering' and efficiency benefits of a solid roller win 'hands down' (theoretically anyway) and a solid roller application for street use with 'sensible' valve lifts and spring pressures is surely the way forward? - thoughts/comments./'real world' experiences?

 

Most of the mfg's offer pressurized lifters. Crane has had it for years ...but they don't make a big deal about it. Comp has it, Morel has them , Lunati is Morel...etc.

The most reliable out there I believe is the bushing type. Morel and Isky sell them. Not cheap but they do well. I have a buddy with several years on a set of Isky's that are still perfect. (He just ckd them last weekend). It's a 7000+ RPM motor that he drives everywhere and beats the heck out of.

I've used Comp, Crane and Lunati pressurized in mine over the years. In fact I got one of the first sets of Comp prototypes to test and then after 2000 miles we rebuilt them to use their improved axle assy. I used them for years and rebuilt them a couple of times. I've got Crane's in it now and they are excellent pieces.

My cams are in the .775" lift range usually with crazy spring pressure. I typically rebuild/replace them every couple of years depending on how many miles I put on them. Until this year that was typically 4-6K miles per year. Sometimes more. There was always at least one 2000+ mile road trip in the mix.

Solid rollers are fine for street use with cams that aren't too crazy and if you keep an eye on them for lash issues.

But these days...I have to admit the *good* hyd lifters like Crane and Morel's are doing 6500+ RPM in big blocks with no issues. Smallblocks are going over 7000 easily. Just need the right cam lobes in there and the right lifters.

JIM

 

if you use a solid roller cam on the street use a rev kit to keep the rollers in contact with the cam lobe at all times so you don't get any "skipping" that cause roller or lobe problems. a small .003 deep flat on the side of the lifter from the middle recess down will allow extra oil to the roller. this also works well with a flat tappet cam to get extra oil to the lifter cam lobe interface

 

maybe the oil keeps the rollers a little cooler just seems to me most the issues were addressed above.

Using old Crower non oiling lifters street use idling etc not too many miles but in there for yrs so far so good.

Honestly I dont worry about it. Have checked lash many times 0 movement. When something sounds funny then Ill check into it.

Everything wears out just part of the game

 

One can always rely on Hot Rod Jim to respond to a technical thread - (don't you sleep Buddy?} - seriously though thanks for comments - I am contemplating the 'move' over to a solid set-up prior to stack injection install. I wonder if anyone on here has 'street' experience of the Isky or Morel 'bushed' lifters - expensive perhaps even compared with stock roller lifters but perhaps good insurance?

 

This is the street car with the 550 HP 388" in it I described above. He drives it everywhere every week and usually it's just like this.

He had found a shortblock to rebuild one time and wanted me to do it. It had hypereutectic pistons in it and I told him the only way I'd do it was if we put a rev limiter on it because I know how he drives. He decided to wait a while and this is what we came up with!

JIM

 

Most GM V8 engines have been equipped with hydraulic roller lifters since 1986....

 

I watched that video of him going through the gears. Wow!

 

He's an animal! We're both gear bangers at heart since high school...so being able to spank one pretty hard helps!

In that video it has a wide ratio Muncie in it....the boy can drive!


Just for fun....and not to hi-jack too bad (hey..it has pressurized solid roller lifters in it!).....here's a video of mine at the track one night....grabbed 4th right at the 1/8th mile mark.





JIM

 

I'm running solid rollers partially out of nostalgia (my engine started life as an LT-1) and partially to endure higher spring pressures.

In the end, we backed off the spring pressures a bit (to 160# at seat) to increase durability, but this came at the expense of redline. Engine was built to be good to 7k+ RPM, but we'll redline at 6,500 (probably set MSD box at 6,300 or 6,400) to make sure there's no valve float. I'm running a ~0.590 lift cam.

The biggest thing on solid engines is lash. Too much, and those roller tips take a huge beating. Weak springs, and it gets even worse. Too many RPM's and it's worse still.

I'm running a Comp XR286 cam with a "tight lash" (0.016/0.018) spec. I'm running aluminum heads, so we're actually going to tighten that up even more on the test stand. I may end up in the 0.012 range (cold adjustment) before it's all done. We're also running really nice Comp lifters in hopes that they last.

Valve crashing is a solid roller killer. Hydraulic lifters at least have 'cushion' if you get outside the sweet spot. Solid lifters just get destroyed.

 

that is why i say run a rev kit to keep the rollers in contact with the cam lobes at all times. production hyd roller lifter are under pressure all the time to keep the rollers rolling on the cam lobes.

 

Experiencing some 'expensive' sounding noises from under the hood I was thinking of upgrading to a lower lift 'street' roller with a similar lift to the one you described. Are we not going a bit extreme with concerns about lash? - justified with some super mother .750" lift with a radical cam - a 'softer' (sub '600" lift) cam with lower spring pressures surely would have gentler ramps and lower loadings on the roller tips?

 

Maybe. I like it not sounding like a mechanical cam with all the ticking.

Plus, I pulled 2 horribly bent pushrods out of my engine before I disassembled it. And my valve crowns were all chipped up.

Granted I was running a flacid 60# spring pressure (1978 springs), but I'm starting off by being a little nutty about lash. That's the starting point for all the problems.

 

Good lifters with correct clearance, correct spring pressure (hint: higher than most folks think) and routine maintenance seem to be the trick.
The springs on those rev kits don't stand a chance at 7 grand - big valve springs have a tough enough time keeping everything where it should be with 300-400lbs of seat pressure. I saw a high speed video taken in a lifter valley with a rev kit, will post it if I can find it. There wasn't a single spring that stayed seated above about 6500rpm, they were bouncing all over the place.