Hydraulic roller lifters?

[Paul G]

I am going to ask the machinist's about using solid flat tappets instead of hydraulic rollers. I am eager to hear thier take on it.

If I understand it correctly the benefit is greater valve control at higher RPM. Which equates to more HP at the top end. But is a SFT giving up anything at the bottom end? Usually you dont get anything without giving up something?

[firefighter3931]

I am going to ask the machinist's about using solid flat tappets instead of hydraulic rollers. I am eager to hear thier take on it.

If I understand it correctly the benefit is greater valve control at higher RPM. Which equates to more HP at the top end. But is a SFT giving up anything at the bottom end? Usually you dont get anything without giving up something?

Challenger340 (Bob) gave an excellent description of the inherant flaws associated with a hyd lifter valvetrain. You have to consider not only the bleed off from loose lifter bores but also the weight of the roller lifter itself. Hyd Roller lifters are much heavier than their flat tappet counterparts. 

That additional weight coupled with the increased spring loads required for the more agressive ramps ultimately limits their function at high engine speeds. Lots of guys will claim that rokller cams have been used for years in production engines with great success. That is true but those cam profiles are very mild with very soft spring rates and gentle lobe profiles. You won't see a 400lb spring in a production motor and most are well under .500 valve lift. Those blocks are more precision built with better tolerances than our older high milage production blocks.

The advantage to a solid lifter is that there is no oil pressure variable to be concerned with....the coupling is solid and not dependant on a hyd crutch (oil) to maintain it's integrity. I've allways used solid cams and had great success. The tight lash solids are quiet and make excellent power. If you really want the best street setup the way to go is to have the cam nitrided and use an EDM style lifter that direct oils the cam lobes. Use a good oil like Brad Penn racing with lots of EP additives and keep the spring pressures reasonable and it will last forever. 

My last solid flat tappet cam required very minimal valve adjustments over a 5 year span. I checked them at the beginning of each season and most of the time the lash was in spec. It only takes 30-40 minutes and i liked to have a peek anyway just to make sure everything looked good under the valvecovers. 


Ron

[Mike DC]

  
                         
As I understand it, the benefit of roller lifters isn't the ultimate HP/TQ numbers.  It's about broadening the power curve below the peak & smoothing out the engine's attitude.  

Rollers get the valve entirely open faster without increasing the ultimate amount of duration that it spends open.  Racers typically wouldn't see so much gain from it because of how they build engines.  They are already willing to put up with a grumpy attitude from the engine for the sake of power.  But street drivers, who might actually limit their chosen duration for reasons other than HP, would benefit from the rollers.  




Are those streetable gains cost-effective on a B/RB wedge?  

That's a different issue.  

[Ghoste]

With a solid roller the advantage is that you can use very steep ramps on the lobe.  With the hydraulic roller, I think it was an oem move just to reduce rotational friction?

[Cooter]

Bottom line is more power from solid roller cams are great for an engine that gets torn down every 8 passes, but for the majority of us, we refuse to pull one down that often for an extra 50-75 hp.
I'll just screw on another NOS kit on my SFT cam to make up the difference.

[BSB67]

Just take half the money you were going to spend to build the hydraulic roller PROPERLY,  and buy a good solid cam and adjustable valvetrain. You will make just as much, if not more power, be reliable, and spend half as much cash doing it.

Or plow the extra savings back into the cylinder heads and get more power for your $

[Ghoste]

What style lifters are in your 67 BSB?  Your combo seems to work very well.

[BSB67]

Do you think some builders are turning to hydraulic rollers in an effort to get away from the lobe wipe issues?  

It seems that most that post on this forum are kinda confused on some aspects.  For you, this is a fun hobby, for the machine shop guy, its a living.  He is trying to put his kids through college.  Most of the guys on here are novices.  When a novice walks through the doors at a performance engine machine shop, the guy knows it in 30 seconds.   He also knows that his margin will be relatively small, likely not a bunch of repeat business, probably a lot of his time training you, knows that mopar guys are actually cheaper than most others in the hobby, and finally, you'll probably try to make him responsible for every problem you have a year after the motor is built.  

I don't mean to offend any of the professionals on here, but once the machine shop guy sizes you up, he will instinctively chart a path to make you the customer happy but with the least amount of potential issues for himself.  The hydraulic roller is "perfect" for this.  He knows you'll never know that the valve train is going south at 5300 rpm, he know that you really will never know if it makes 525 hp, or 450 hp.  And he knows that you won't wipe a lobe.  Most machine shops now have dynos.  The dyno is not really for you, it is for them.  They know that the motor leaves their shop without an issue.   Ultimately, If it spins the crap out of the tires from a 20 mph roll and is indestructible, you both get what you wanted.  Happy story.

I have seen this play out probably 10 times.  The machine shop guy steers someone in a particular direction.  The customer gets what they agreed to, and usually the owner is very very happy. Then someone takes them to the track and they notice that, relatively speaking, there stuff seems slower.  Even then, they sometimes don't figure it out.  It is easy to blame tire spin, or gear, or convertor, all disguising the fact the motor is actually an under achiever.  None of these guys would ever know if they did not go to the track, and know someone that understands a time slip.  

Put yourself in the machine shop guy's shoes.  I doubt that any machine shop guy would recommend to a novice a fast rate solid FT cam despite the performance advantage.  It is just not worth the risk.

[Ghoste]

Interesting.  Never really thought about it that way before.

[BSB67]

What style lifters are in your 67 BSB?  Your combo seems to work very well.

A relatively mild, older school solid roller lobe profiles.  Although it is not called a "street roller" by the manufacturer, it is actually slower (less aggressive) to .200" lift than Comp or Lunati's "street roller" cams and there are solid flat tappet cam that are faster/more aggressive.  I use a pretty mellow valve spring, but because the ramps are also mild, the motor still maintains good valve control to 6800 rpm, although I shift lower than that.

[Challenger340]

Do you think some builders are turning to hydraulic rollers in an effort to get away from the lobe wipe issues?  

It seems that most that post on this forum are kinda confused on some aspects.  For you, this is a fun hobby, for the machine shop guy, its a living.  He is trying to put his kids through college.  Most of the guys on here are novices.  When a novice walks through the doors at a performance engine machine shop, the guy knows it in 30 seconds.   He also knows that his margin will be relatively small, likely not a bunch of repeat business, probably a lot of his time training you, knows that mopar guys are actually cheaper than most others in the hobby, and finally, you'll probably try to make him responsible for every problem you have a year after the motor is built.  

I don't mean to offend any of the professionals on here, but once the machine shop guy sizes you up, he will instinctively chart a path to make you the customer happy but with the least amount of potential issues for himself.  The hydraulic roller is "perfect" for this.  He knows you'll never know that the valve train is going south at 5300 rpm, he know that you really will never know if it makes 525 hp, or 450 hp.  And he knows that you won't wipe a lobe.  Most machine shops now have dynos.  The dyno is not really for you, it is for them.  They know that the motor leaves their shop without an issue.   Ultimately, If it spins the crap out of the tires from a 20 mph roll and is indestructible, you both get what you wanted.  Happy story.

I have seen this play out probably 10 times.  The machine shop guy steers someone in a particular direction.  The customer gets what they agreed to, and usually the owner is very very happy. Then someone takes them to the track and they notice that, relatively speaking, there stuff seems slower.  Even then, they sometimes don't figure it out.  It is easy to blame tire spin, or gear, or convertor, all disguising the fact the motor is actually an under achiever.  None of these guys would ever know if they did not go to the track, and know someone that understands a time slip.  

Put yourself in the machine shop guy's shoes.  I doubt that any machine shop guy would recommend to a novice a fast rate solid FT cam despite the performance advantage.  It is just not worth the risk.

pretty well stated summary of the sad situation these days.
The problem being.... some people are just NOT capable of owning what many reputable Engine Builders "could" give them ?
No Offense to anyone... but it's true.
Some Customers very simply... do NOT have the skill-sets or background... therein RIFE with pitfalls to said "reputation" of the Shop(if they are a performance Shop), so best to just price it beyond their means... Buh-Bye.

[fy469rtse]

Very interesting reading, not an expert by any means
But it seems I did my home work,
Always thought that the retro hydraulic roller lifters were to cash in on the guys who want the performance of solids but don't want the headaches of lash adjustment,
Always value your input challenger340
There's a build thread outline that needs your input, when you read it you will know better than most what's required at each level, it's to with the level of machining required appropriate to the engine that's intended

[randy73]

Is this just a BB issue, because I read on a couple of forums where people had good success using HR's in 340's, 318's and 360's. But all the good reviews used cranes retro sb lifters.

Concerned because I am going HR, but I am going for longevity, more so than performance.

[BSB67]

I've been saying it for years, minus the energy and effort Bob puts into his nice detailed responses, the hydraulic portion of the lifter has always been the limit on the lifter, putting a roller on the bottom does not fix the issue.  Not only do I agree 100% with Bob on every word,  But I'm seeing and/or hearing regularly (not always) the same issue with the fast rate FT hydraulics, depending on the same engine /lifter specifics Bob mentioned, oil weight, oil pressure, lifter/bore clearance, lifter quality (internal tolerances are CRITICAL)  do they oil out the face,  do they have pushrod oiling provision (wheather used or not) and not least of all, VS pressure.

I know of two professionals that are also distributors for popular cam companies that have pretty much stopped using and recommending the fast rate hydraulic stuff.  They have dialed back to cams with 0-0.050" rates around 48°ish and are seeing a little loss in lower power numbers, maybe or maybe not a loss at peak power, but a dramatically extended power range past peak. (i.e. more average power).

If you really care about making power, and you really want hydraulics, you better get serious about parts and machining.  Or buy soild.  The reality is, very, very few people on here really care about power, so any hydraulic will work.

Soild FT is a beautiful thing IMO.  However, the fear of wiping a lobe is real.  My guess is the shops that are pushing HYD rollers are doing it for themselves, not the customers.  Win win for them.  No matter how big a moron the customer is,  there won't be a wiped lobe, and they know instantly which customers will never know if they have 525 hp, or 485.

[Challenger340]

Is this just a BB issue, because I read on a couple of forums where people had good success using HR's in 340's, 318's and 360's. But all the good reviews used cranes retro sb lifters.

Concerned because I am going HR, but I am going for longevity, more so than performance.

Randy,
I would be REALLY curious, to see the actual Engine Dyno Sheets from these people.... and I mean no dis-respect here... claiming good success with HR Cammed sb mopar engines ?  at what rpm ?
Have they Dyno'd... or are these "seat of pants" claims ?

Can't argue with CRANE hard part engine products these days  .... they are about as good as it gets.
although,
I have not tried their HR lifters specifically, the problems I have experienced/witnessed related more to external lifter clearances and Oil Pressure, as it would affect ANY "Hydraulic" Lifter... no matter how good quality.
But nonetheless, eliminating any potential HR Lifter "contributing issues" always helps.

[randy73]

I called Crane and several other retro HR lifer makers, Crane was the only one that said they designed theirs to not lose oil pressure, unless you have a severe lift, which I will not.

So I feel good again.

[BSB67]

I called Crane and several other retro HR lifer makers, Crane was the only one that said they designed theirs to not lose oil pressure, unless you have a severe list, which I will not.

So I feel good again.

That's good.  I guess everyone else said that they design theirs to lose oil pressure  Was Crane specific on what they do that others don't do?

Remember, it might not be the lifters fault, and there is nothing that Crane can do about that

[c00nhunterjoe]

I beleive every serious builder i know that uses them reccomends bushing the bores to control the oil loss problem with the mass production block tolerances. Some of them run chevy rollers too..... but that gets very costly and unless you are building a special purpose engine, you are wasting time and money, alot of money.

[randy73]

I called Crane and several other retro HR lifer makers, Crane was the only one that said they designed theirs to not lose oil pressure, unless you have a severe list, which I will not.

So I feel good again.

That's good.  I guess everyone else said that they design theirs to lose oil pressure  Was Crane specific on what they do that others don't do?

Remember, it might not be the lifters fault, and there is nothing that Crane can do about that

Was not saying no one else designs theirs not to lose oil pressure, I said they are the only's who told me that. Forget the exact reason, but they lowered something, I know that is not much help. I did not write it down. 

[c00nhunterjoe]

I called Crane and several other retro HR lifer makers, Crane was the only one that said they designed theirs to not lose oil pressure, unless you have a severe list, which I will not.

So I feel good again.

That's good.  I guess everyone else said that they design theirs to lose oil pressure  Was Crane specific on what they do that others don't do?

Remember, it might not be the lifters fault, and there is nothing that Crane can do about that

Was not saying no one else designs theirs not to lose oil pressure, I said they are the only's who told me that. Forget the exact reason, but they lowered something, I know that is not much help. I did not write it down. 

Its a sales gimmic. The issue is the lifter bores in our older engines. They were mass produced and the tolerances were not as tight as they need to be to run high rpms. Couple that with 45 years of abuse and there is even more tolerance between the lifter bore and lifter. The point is, nothing you do to the internals of that lifter will change the space between the lifter and the bore.

[Cooter]

Just got back from a buddy's house. He's old skool and built a 440. 13.5:1, .688 lift 272/284 @.050 SOLID roller cam, with Eddy heads. Just didn't have the heart to tell him after 10 years building that thing, that with nearly 800-900 # open pressure, it won't last 5k miles on the street.....

[c00nhunterjoe]

It will be a badass ride though......

[heyoldguy]

Just got back from a buddy's house. He's old skool and built a 440. 13.5:1, .688 lift 272/284 @.050 SOLID roller cam, with Eddy heads. Just didn't have the heart to tell him after 10 years building that thing, that with nearly 800-900 # open pressure, it won't last 5k miles on the street.....

Did your buddy actually say that he put 800-900# open spring pressure on that camshaft? If so, I just ask him why, 'cause that seems way excessive.

[BSB67]

Just got back from a buddy's house. He's old skool and built a 440. 13.5:1, .688 lift 272/284 @.050 SOLID roller cam, with Eddy heads. Just didn't have the heart to tell him after 10 years building that thing, that with nearly 800-900 # open pressure, it won't last 5k miles on the street.....

Did your buddy actually say that he put 800-900# open spring pressure on that camshaft? If so, I just ask him why, 'cause that seems way excessive.

You can run low 10s high 9s with eddy heads, pump gas, and gentle ramp solid roller ( 250/600 pressure) in a regularly driven street car.  Guys have been doing it for years without valve train failures.  Good lifters are a must.

Certainly a cam needing 8-900 over the nose is a mismatch for a street car IMO, and I have my doubts it would even go 5K.

[Ghoste]

I was actually kind of wondering what scenario does need that kind of spring?