[68WarDog]

I keep hearing running a solid roller on the street is not a good idea. However I’ve been running one for about 8 years without a hint of problem. The cam is an ole UD 254/ 262@.050. .640 lift with 1.65 HS. IIRC spring pressure is 200 on the seat, 650 open. Hot lash is .026. I run Amsoil 10w40. 30/35 hot idle, 60/65 running pressure.Changing oil once a year and lash has never moved. Now for the question, if a problem should develop, what should I keep an eye on?

[Steve C.]

Already mentioned, keep an eye on the valve lash if it goes away or won't stay consistent there is a potential issue. Also the lack of adequate valvespring pressure to control the valves is a potential killer on a solid roller street set up.
We monitor the valve springs with a LSM brand on the head pressure checker, there are other brands but that is a good one. Just be aware this type of tester can vary slightly as measured on the cylinder heads vs a bench tester like a Rimac machine.

Is it this cam ?

https://forums.maxperformanceinc.com...ight=Ultradyne

If it is those lobes they are Harold's original designs with slower ramps and standard valve lash .026-.030.
In a old UltraDyne catalog within the Pontiac section it was listed with a 108 lobe separation with these comments:

"400-455 Street and Strip, 3500 converter. Strong bottom end."


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[68WarDog]

Yes, that’s the cam. Didn’t realize it’s been 12 years. But we did install a mega brace. For 8 years, averaging maybe 1k/ miles per year the lash hasn’t moved. Will keep an eye on the lash. Thanks

[Steve C.]

Consider one of these....

https://www.summitracing.com/parts/m...8aAs5IEALw_wcB

Again keep an eye on the spring pressure. Was that 200 on the seat 12 years ago ?


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[68WarDog]

Yes to the 12 year old 200 seat pressure. Don't think that spring tester will measure 650 open, or is the open pressure measurement required?

[Steve C.]

That specific brand/model was only to show one example and does not represent any endorsement. They allow you to check the seat pressure.

They can be a bit awkward to perform this while the engine is in the car. You need to pay attention to position on the rocker and pulling with both arms while in as good a position as possible to get good results. Do it a few times.



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[Steve C.]

FIRST, I'm not here to say you have loss of spring pressure. You stated you have been running without a hint of problem.

OK that said, but here is a tid bit for interest regarding loss of spring pressure.....

The reality about valve float is that the first place the spring loses control of the valve is on the closing side as the valve approaches the seat. The intake valve is the heaviest of the two valves, so any loss of control will happen to the intake first. The intake bounces off the seat during closing. Every time the valve bounces, it also allows cylinder pressure to escape back into the intake port instead of being captured to make cylinder pressure. If allowed to continue, this valve bounce will kill power and also tend to reduce the effectiveness of the springs. If it leads to enough reduction in pressure roller lifter damage can occur.


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[HWYSTR455]

Yup, monitor lash, look closer at lifters if you see a 'decay' of adjustment.

Considering the length of time, checking seat psi is a good idea too.

I've run a number of SRs on the street without issues. The one engine went 225k miles.

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[Formulajones]

Everything Steve mentioned are all good points and should be taken into consideration.

I've had and used that spring checker myself for 25 years or so. After using it a bit you get a good feel for it, and it's handy for a quick check of spring seat pressures that at least gives you a good ball park idea.

8 years at 1,000 miles a year I'd say so far so good. Like Steve mentioned that's a fairly gentle lobe profile. A lot of todays solid rollers can get fairly aggressive on the lobe design to the point that the general accepted spring seat pressure among a lot of engine builders to run on the street is about 240 lbs. seat pressure with some of those lobe designs.

Even that takes it's toll, and only lasted about the mileage you are at with your current cam before it ate 2 lifters on dad's engine. And that was a tight .014" lash solid roller, using Amsoil Z Rod oil as recommended by Tony Bischoff and the engine idles with 40 lbs. of pressure hot, and hovers around 65-70 psi cruising. Those were also the expensive bushed rollers with pin oiling.
None of that seemed to matter. In the end it still ate itself.

Getting more aggressive with lobes and spring pressures starts to lead toward that direction. Quite a few success stories on street cars with less spring pressures on solid rollers though, but that is the key to their longevity, the lighter spring pressures. As long as it's controlling the valve, again milder lobe profiles.

Steve has been down this road a lot lately

[Steve C.]

Yes, I've been down the road on solid roller lifter failures...

I use the Crower Cutaway Severe-Duty solid roller lifters with pin oiling option. Not long ago I lost one lifter after about 2600 street miles. All were sent back for rebuild, Crower had no clue why the one failed. A fwiw, my oil pressure had been fine. I use a custom Luhn Performance oil pump, T&D shaft system, synthetic oil, hollow stem intake valves, titanium retainers, etc, etc.... quality parts. And we stay on top of checking valve lash and spring pressure.

With all this in mind I just replaced the .709" lift UltraDyne MSP solid roller cam that was in use. It was replaced with another UltraDyne cam with slower ramps and less profile intensity but has the same .050" duration, and less valve lift. In addition it will require less spring pressure. My car is street only and not raced anymore and don't mind giving up the horsepower at peak power rpm. I have over 600 ft.lbs. torque from 4100 up thru 5400/5500 rpm.


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[HWYSTR455]

It was recommended on the last solid roller that I use Comp Endure-X lifters, have never used them before.

They have pin oiling, roller bearings, the link bar is removable, and have about 800 miles on them. I've checked lash twice, and will monitor closely. Fingers crossed.

EDIT: They are cut-away type.


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[Steve C.]

With the Crower solid roller lifters the HIPPO oiling feature usually has one oil metering hole to deliver lubrication to the needle bearing and pin. You can have them upgraded to two holes, one on each side of the pin.


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[Formulajones]

I forget what you told me your spring seat pressure is now Steve, but I was thinking it is now less than it was before.

From the failures I've seen and read about it seems 180-200 lbs. or less on seat pressure seems to be the area I hear about more success with solid rollers. Once you get up into the 220-240 seat pressure area on more aggressive profiles that need that pressure, more failures are reported.

For comparison a modern hydraulic roller lobe profile will generally see 150 lbs of seat pressure or less and they live a long happy life, and also have zero lash issues to deal with. I think those are the two contributing factors.

[mgarblik]

That's a nice, old Harold Brookshire cam grind. Faster opening rate might net you 5-8 HP. But is is gentle and slow, easy on valve springs and shouldn't pound the crap out of the lifters and rocker arms. As everyone has said, use your ears for some weird noises from the valvetrain. Check the lash regularly, and enjoy. If I had to pick a single weak link, it would be aluminum rocker arms over many years of use. But Harlan Sharp is better than most available. I wouldn't worry about it.

[HWYSTR455]

Would an additional oil hole be beneficial? The Endure-X oil hole points right towards the center of the pin, I forget where it points on the Crowers. But if the rollers are lengthwise on the axis of the pin, I would think it would fill the length of the axis since it's under psi. Just thinking out loud on that.

All springs relax a certain amount after initial use or 'break in', so in general, many chose a slightly higher psi on the seat initially than recommended. The rationale is that after that initial break in, it will be at the targeted/desired seat psi. I think there's actually a percentage that's used to calculate that, but I personally have not gone through that material/data/homework.


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[Steve C.]

Larry for my new cam the intake lobe used is the same as Harold's old 288R that he designed in 1980. It thought it was a 282 at .020 when it opened, a 252 at .050. Then it knew it was a 258 at .050 when it closed, and 294 at .020, still closing. Known for bottom-end torque, and good power everywhere. Based on a 1.5 rocker ratio and .020" lash it is rated with 288 at .020, 255 at .050, 176 at .200 and 0.4176" lobe lift. I worked with Tim at Bullet Racing Cams and he said years ago they used to run it with a Pontiac valvetrain mass as low as 180-190 lbs seat pressure. I choose a spring rated 220 lbs at 1.900, knowing it will lose pressure after run in. That and my intake valves are a larger 2.150" diameter and with a longer stem length for my 1.900" installed height. I believe when in doubt, run slightly more seat pressure... not less.


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[Steve C.]

Here is a picture of a cross section of a Crower roller lifter. It show the small 0.24" hole directly from the oil band to the needle nearings.

https://encrypted-tbn0.gstatic.com/i...CiU9g&usqp=CAU



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[Steve C.]

"All springs relax a certain amount after initial use or 'break in', so in general, many chose a slightly higher psi on the seat initially than recommended."

Regarding a loss, personally I've seen as much as 14 pounds on the seat after a dyno session. And recently I mentioned a build where the valve springs were set up for a hyd flat tappet application with an initial setting of 130 lbs on the seat, knowing they would lose pressure with run in. The actual pressure after a day on the dyno was 122 pounds.


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