Why the hate for HR cams.

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aaronk785

aaronk785

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I've been looking at alot of builds using hydraulic roller cams and I am very impressed with the hp and torque with some pretty small roller cams. Seems like most people on here dispise them.
 
They despise hydros in general...."why not just run mechanicals and get the RPM bonus?" Its not like these cars are supposed to be quiet or maintenance free anymore.
 
I only run mechanical cams. Just thinking get more power with less radical cam and no maintenance and ticking. Getting older and my wife don't care for the noise.
 
A good Hydraulic Roller lifter is expensive and often unreliable.
The mopar ones have not been reliable and are still not super
cheap.
However, I run fairly High HP cars even on the street and only use
American Made Old School lifters.
 
Because everybody's hydraulic lifter right now is at the very least questionable. At the worst, a POS. Much less to go wrong with solid lifters and they make more power. Lastly, with a good quality rocker arm and shafts the "constant valve adjustment" thing is a total lie. With high quality parts, even an all out race engine MIGHT need a valve adjustment once a year. Then again, it might not. There's simply no down side.
 
Got it. Like I said I run solids and lash once every spring. Just thought I might go new tech. Sounds like the lifters are a problem. Thanks everyone.
 
And it has got so silly that one hyd lifter seller states that his lifters should be used with a certain centi/stoke value for the oil. Failure to do so, all bets are off.....
Harley Davidson in 1948 or 49 introduced the modern hyd lifter function. Detroit 'borrowed' the design. Originally, the hyd mechanism was mounted in the top of the prod, moved to the lifter body the following year. The mechanism was never designed to work with brutal valve spring pressure used today & it is no wonder that the lifters collapse/make noise.
 
I'm pretty sure it's just a couple of members of the 20,000 or so we have.

Also pretty sure the stock LA roller or Magnum roller lifters are just fine and as a bonus, can be reused no matter the (HR) cam that gets installed.
 
YY1 said:
I'm pretty sure it's just a couple of members of the 20,000 or so we have.

Also pretty sure the stock LA roller or Magnum roller lifters are just fine and as a bonus, can be reused no matter the (HR) cam that gets installed.
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It depends on the lobes. The factory lifters were designed for factory lobes. There are HR lobes out there today that piss off all the lifters.

That’s why it’s not worth it to me to run hydraulic lifters on anything, unless the end user isn’t competent to lash valves correctly. Sadly, there are far more in that group than I once estimated.
 
I’m going to be using one in an upcoming build thats quite larger then most use. (259/261 at 50. .649 lift) Went with it because I already had good quality slow leak down lifters that can take higher spring pressures. With the right selection of spring, retainer, rocker geometry, and lifter I think they can make great power up to 7000. I speced it all through bullet and they agreed. In the end a solid roller is probably just easier and more efficient to use. However for a bracket build maybe long term less spring pressure and softer closing rate will give longer life on valve seats?
 
Also I did run factory hydraulic lifters on a magnum with 225 at 50 cam with good results for hundreds of passes. 12.20s on motor. 10.90 on juice
 
I’m on the no hydraulic list. Why run a roller? So you can run a very aggressive ramp. Which needs significant spring pressure to control. Which hydraulics really don’t like. OEM(except for high performance applications) use rollers for less friction, not so they can run a crazy aggressive ramp. Also rollers REALLY don’t like to bounce. So if they do bleed down….
 
Has anyone successfully converted factory magnum/roller LA lifters to solids with machined spacers?

Alternatively, does anyone make a solid lifter replacement for factor rollers, so one could retain the factory dog bones and spider?

Just wondering if there's an option for someone with a magnum/roller LA to convert to a mild street solid roller if HR's are so bad.
 
I am running a hydraulic roller in the 440 I have in my '67 Barracuda. Works for me - I don't hate it. It is a Howards cam and I'm using their lifters as well.
 
1bad360duster said:
I’m going to be using one in an upcoming build thats quite larger then most use. (259/261 at 50. .649 lift) Went with it because I already had good quality slow leak down lifters that can take higher spring pressures. With the right selection of spring, retainer, rocker geometry, and lifter I think they can make great power up to 7000. I speced it all through bullet and they agreed. In the end a solid roller is probably just easier and more efficient to use. However for a bracket build maybe long term less spring pressure and softer closing rate will give longer life on valve seats?
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There is no way your valve train is anywhere stable at 7K with hydraulic lifters.
 
Rat Bastid said:
There is no way your valve train is anywhere stable at 7K with hydraulic lifters.
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7k would be max rpm. Most likely shift 6700-6800. Looking for peak hp 6500. Bullet speced the lobes, softer closing lobe. And said it will be stable to that with 165 seat 430 plus open which is what I have with titanium retainers. Will find out how it performs
 
I’ve always had good success with HR cams. That said, there is nothing better than a hard roller. And if your geometry is right, lash is a once a year deal on a street/strip type car. Funny I saw this thread today, as I just pulled a custom ground HR out of my daily. Who said they don’t like to bounce? Ding ding ding give that guy a cookie.
84D72233-7C4D-4074-8484-4B5739C32B2E.jpeg
 
Solid lifters [ FT or roller ] have three great advantages that hyd lifters do not have:
- they can never pump up....
- they can never bleed down...
- all else being equal, they idle smoother with more vacuum because of more positive valve seating.

The problem with post #11 & 'quality' slow bleed down hyd lifters, with big duration & high lift cams, presents it's own set of problems. You get a slow bleed down rate by tightening up internal clearances. That means the smallest amount of foreign material can jam up the lifter. The levering action imparted to a roller lifter [ not in a FT lifter ] as the lifter ascends the lobe distorts the lifter body & can jam the internal piston. This is the problem you get trying to get a square peg to fit a round hole.....
 
It's a true today as it was 60 plus years ago. Hydraulic lifters are for quiet passenger car operation and solid lifters are for performance. It really is still that simple.
 
I wouldn't say "hate" just much added caution do to recent reported hydrologic failures...
 
'68cuda416 said:
Maybe if you checked the valve lash more often than once a year....the whole point about checking valve lash frequently isn't because you have to it is all about catching a problem early.
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I don't disagree, but that seems to be a point of contention with those that don't "like" solid cams. It's never bothered me to recheck lash, but some seem to be allergic to it.
 
'68cuda416 said:
Maybe if you checked the valve lash more often than once a year....the whole point about checking valve lash frequently isn't because you have to it is all about catching a problem early.
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I said nothing about the frequency of CHECKING lash. My point was lash adjustment, when the valvetrain is happy and geometry is correct, is not as frequent as people seem to think. And the failure above was caused by a broken valve spring on a cam/valvetrain that has over 300,000 miles on it.
 
TT5.9mag said:
I said nothing about the frequency of CHECKING lash. My point was lash adjustment, when the valvetrain is happy and geometry is correct, is not as frequent as people seem to think. And the failure above was caused by a broken valve spring on a cam/valvetrain that has over 300,000 miles on it.
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Exactly the same point I was trying to make. People love to twist words.
 
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