Solid Roller Lifters on a Hydraulic Roller Cam?

[Road Grabber]

So I've been watching a lot of episodes lately of Engine Masters and ran across this episode that seemed like a topic that would be interesting if not already discussed because I myself am in the process of refreshing a 440 with a hydraulic roller cam with hydraulic roller lifters which makes me very apprehensive because my original cam in the engine was a flat tappet purple shaft 284/484 cam that's been used for over 35 years without a flaw. It's been mentioned many times about new flat tappet cam lobes being wiped out during break in period due to crap steel ( or whatever...). I never had this problem years ago but it seems to be enough of an issue that many people have given up on flat tappet cams and have switched to roller cams.


The dependability aspect of the hydraulic roller lifters and durability was my first concern. I chose a Howards roller cam because that was supposed to be what the "upgrade" choice now since roller camshafts are used so much in modern day engines.

After watching this Engine Masters episode I was looking for some feedback and maybe some actual application experience switching out hydraulic rollers with solid rollers on a hydraulic roller cam. Note it is mentioned in this video that solid rollers are not recommended for street use because of aggressive profiles.

1. Will using a solid roller lifter stand the test of time without shedding roller bearings throughout the engine and ruin it? Has this issue been "solved" by using bushed solid roller lifters? Or even hydraulic roller lifters for that matter. Is bushed a better roller lifter choice? Would choosing a lifter that is bushed have been a better to protect the engine if the lifter fails?

2. Am I over thinking this? Will the Maximum Effort Retrofit Howards hydraulic roller lifters that are made by Gatorman be reliable enough at higher rpm and not float so long as the spring pressure is right? Howards recommended 175# seat and no more than 425# at full lift.

3. Would it be better to use a solid bushed roller on the hydraulic roller cam to get the full benefit of the lobe profile design especially at higher rpm since the hydraulic roller lifters are prone to float above 5500 rpm?

5. Has this swap to solid roller lifter on hydraulic roller cam been proven for durability? The comments after this video episode say it has been used many times before without issues as long as the valve lash is correct. - .004 lash?

6. Is the hydraulic roller cam actually "easier" on the solid roller than a cam designed for a solid lifter making it compatible for the street?

7. Lastly barring further comments, if this is the best thing since sliced bread for hydraulic lifter "deficiencies" and what if any modifications or changes are needed besides maybe longer pushrods? And know proper valve lash?

Watch this episode below and tell me what you think. Pretty interesting.
When they switched out to a solid roller lifter there was both a torque and hp gain.

Engine Master Episode Link

 

[Bird 426]

How about this, put hydraulic rollers in it and gap it like a solid roller. There are pros and cons for each.

 

[PRHeads]

That’s a lot of questions……..I’m not going to address most of them, but will instead offer up my overview on the whole retrofit HR in a BBM thing.

If you’re looking for consistent high-ish rpm power(5800-6000-up), you’re probably better off not using Hyd lifters(HR or HF).
I feel what most people attribute to being “valve float” with Hyd lifters is actually lifter collapse.
The refill rate & quality of the refill can’t keep up with the bleed down, and the result is the plunger ends up at the bottom of the lifter body, which effectively makes the cam much smaller, and at that point the power just noses over.
(Limited travel Hyd lifters exist to address this phenomenon)

So, eliminating the hyd mechanism solves that problem.

In my mind, the HR cam/HR lifter is a viable option for someone looking for a low maintenance combo that can provide decent performance, at moderate RPMs, with less of a risk wrt the cam failure than FT cams.

The down side to running SR lifters on them is, the profiles are designed to operate with zero lash.
In reality, even with a cold lash setting as tight as .004, at normal operating temps that could easily end up at .008-.010”, which will result in some level of impact loads presented to the lifter wheel and axle…….. by a camshaft profile that doesn’t have a clearance ramp designed to gently take up the slack(like what a SR profile would).

I think it’s probably fine for a low use street car or bracket race situation, but it wouldn’t be my choice for something that’s being built for max reliability.

If you find someone thats done the HR cam/SR lifter deal, that has achieved the long term level of reliability you’re looking for, I’d say copy their recipe exactly.

Basically, to go this route you just need the lifters and new pushrods.
Quality bushed SR lifters will be in the $1100+ range.

 

[gkent]

How about this, put hydraulic rollers in it and gap it like a solid roller. There are pros and cons for each.

TOTALLY ridiculous !! ANY hydraulic lifter is designed to have preload. Solid lifter cams need lash. PERIOD.

You can install a solid "roller" lifter on a hydraulic "roller" cam - just make sure the lifter has "lash". Just how much - maybe start at .012, after all, being a hydraulic cam it won't have crazy lift.

A solid roller cam would likely have too steep of a ramp on the lobes and would just beat the crap out of hydraulic rollers.

 

[DanielSlocum]

If your not an engineer at a minimum....probably not a good idea to try to reinvent the wheel i.m.o. .

 

[Road Grabber]

Appreciate the discussion. People have commented on YouTube claiming it’s been done many times. I was wondering if someone here had done it.

Bushed lifters for $1,000 is beyond my budget…But investing a bunch into a build and have lifter failure is a larger loss.

The lifters I bought are supposed to be good built by Gatorman. I called Howard’s and confirmed they do make that particular lifter.

 

[Bird 426]

Well, if my statement is ridiculous, not going to put his name out here, but pretty sure most here think quite highly of him, and is recommended ALL of the time. He asked me to try it, SB stroker has hydraulic roller adjusted at about .010 cold. Been this way for 4 years, it didn't cure my problem, but it works just fine.
Not going to argue it, no one has to duplicate it.

 

[Road Grabber]

TOTALLY ridiculous !! ANY hydraulic lifter is designed to have preload. Solid lifter cams need lash. PERIOD.

You can install a solid "roller" lifter on a hydraulic "roller" cam - just make sure the lifter has "lash". Just how much - maybe start at .012, after all, being a hydraulic cam it won't have crazy lift.

A solid roller cam would likely have too steep of a ramp on the lobes and would just beat the crap out of hydraulic rollers.

That was the possible justification mentioned in the video for being able to use a hydraulic roller cam to do this because it’s design was not aggressive like the cam designed for a solid roller cam.
Again these guys on Engine Masters had no experience doing it but heard about others were doing it. That’s why they used it as a theme for testing out the plausibility for using solid roller lifters on cams designed for hydraulic rollers. The show ended without a conclusion because there wasn’t much proof of durability among their experience. They knew it produced more power but no one wanted to be the one to test it out for themselves.

 

[Geoff 2]

Many people, including me, have used sol lifters on hyd cams, both roller & flat tappet. Make sure you keep the lash tight 006-008, hot. I would not use lifters with needle rollers, only bushed.