Hydraulic v. Roller lifters

[SuperBuickGuy]

I'm with Dan on this one, having built a test cell with him at our old place of employment. It only really sucked when it rained as there was a leak in the ceiling and our controls kept getting soaked. But nevr mind that...

one variable at a time and either control temperature and humidity like the diesel cells did, or measure and record the variables and make your important a-b-a tests when the conditions are similar. Oh and no one ever seems to worry about the barometer. To control that requires more$$$ than even the government was willing to spend.

And guess what? It's really worth paying attention to...

Chad Reynolds posted the video on the front page - while I may not see eye to eye with him, I wonder if he had watched the video prior to posting....

[Deaf Bob]

Early derby motors we tried hydraulic cams..
When the motor was really hot they ran like crap.
next we tried solid lifters. These seem to make the motor consistent
guys always say you gotta run the valves every derby, we have found that to not be true..
when you run hot, oil thins. Then the plunger gets plunged. Losing lift
Chatted with another derby guy who loves screaming 283’s in his and he says solids lets him stay running longer.

[Beagle]

heh...the barometer will determine whether or not the front wheels go up in the air on my Chevy II.

What, Rain? or DA?

I don't take videos too seriously when picking parts or any other thing. One of the first videos I saw of yours suggested I might want to drink bleach if I'm bored. Hee hee. I miss that car.

[squirrel]

yeah, the 55 was fun, but wouldn't pull the front wheels.

this is the last day of 2019, the air was dense...and it was rainy that day.

[cstmwgn]

I'm thinking about pulling the 427 out of my Corvette this winter to be sure everything is still fine inside the motor - while I'm at it, I may swap the redzone rollers out because the internet rumor (and one I attempted confirm or deny by contacting Isky) is their race version lifters put more oil on the cam - but that makes for low oil pressure at idle. I was trying to avoid a problem someone else had where a roller lifter came apart and filled the oil pan with needle bearings... but we will see, it's running fine now, and 18 psi at idle isn't optimal but it is enough.... I'm not sure I'd ever chance another flat tappet cam - it just isn't worth it. That said, now that the top is lashed correctly, it's been really reliable and I really like it.

In my opinion there are better choices. Again, IMHO, a bushed lifter will give you more durability and a longer fuse so you have more notice before parts end up in the pan. I have grenaded one needle bearing roller lifter and know first hand how much damage that will do by the time you figure out what is wrong!

I recently switched from Crower to BAM lifters- BAMs are a DLC coated bushed lifter.
What I have noticed is that the lifter body diameter has a large effect on oil pressure. As an example, the Crower bushed/pin oiled lifters are about .001 small which cost me ~ 5 - 7 lbs at 3,000 RPM when hot (multi hour cruise).

[SuperBuickGuy]

In my opinion there are better choices. Again, IMHO, a bushed lifter will give you more durability and a longer fuse so you have more notice before parts end up in the pan. I have grenaded one needle bearing roller lifter and know first hand how much damage that will do by the time you figure out what is wrong!

I recently switched from Crower to BAM lifters- BAMs are a DLC coated bushed lifter.
What I have noticed is that the lifter body diameter has a large effect on oil pressure. As an example, the Crower bushed/pin oiled lifters are about .001 small which cost me ~ 5 - 7 lbs at 3,000 RPM when hot (multi hour cruise).

again, this is hearsay, but I guess there are two, different RedZone lifters. The race (which can cause idle, oil pressure problems) and the 'standard' which don't. As far as lifter diameter, it was spot on.

[dave.g.in.gansevoort]

yeah, the 55 was fun, but wouldn't pull the front wheels.

this is the last day of 2019, the air was dense...and it was rainy that day.

So is there a correlation between barometer and distance the fronts come off the track? Just saying, you could write an algorithm, write a program for an ap, and make a million...

I'm sure by now there's a plug in device for measuring barometric pressure, temperature and humidity in some form for smartphones. Probably cheaper than those weather stations everyone is selling.

[SuperBuickGuy]

So is there a correlation between barometer and distance the fronts come off the track? Just saying, you could write an algorithm, write a program for an ap, and make a million...

I'm sure by now there's a plug in device for measuring barometric pressure, temperature and humidity in some form for smartphones. Probably cheaper than those weather stations everyone is selling.

I can just hear the dyno racers saying "well, that motor would pull the tires on a car (if we ever put it in a car) in X circumstance." Not sure Squirrel would be happy to know he gave dyno racers one more number...

[dave.g.in.gansevoort]

One thing to remember, Squirrel is spot on about: we don't race no steenkin dynos! They are great tools for doing the type of research that Dan and I were involved with back in Ann Arbor, evaluating engine emissions controls efficiency, or developing new engine technology (remember the combined cycle engine, Dan?). And for racers who are trying to extract the highest efficiency from a given engine combination, looking to refine the details. But again, there are too many variables to pay attention to when trying to say mine is (choose your terminology and insert here) than yours.

And lets not even try to discuss inter facility dyno number comparisons. We were involved with the industry and an SAE working group doing round robin test programs. Looking at the numbers and trying to make sense of those numbers are what made Dan and myself what we are today. But I'm much better now...

[Beagle]

The real question is how many times Richard says "Kind of close", should kind of let you know it's "kind of close" representation... I think context is important here. What I think he is trying to convey is that you have to take lash into consideration - real news flash for us - but for the new guy getting this information for the first time, it is a consideration the new guy may not have thought of.

If you take the spec of the Hydraulic he is using and compare lift numbers to the Solid he is using, then include lash from the solid into the lift equation, they are closer than the specs indicate from the cam card. In this example of the two as close as the company offers profiles for a HR and an SR cam for a BBF, lift comes in at .611 compared to a .640 (intake only). The apparent .029 difference is not .029 when you take the .018 lash out of the Solid.

Lunati Voodoo Hydraulic Roller
Duration @ .050 (Int/Exh): 231/239 ;Gross Valve Lift (Int/Exh): .611/.611

Lunati Voodoo Solid Roller
Duration @ .050 (Int/Exh): 231/237 ; Gross Valve Lift (Int/Exh): .640/.650 ; Valve Lash (Int/Exh): .018/.018

In the real world, I'd fully expect the solid above to have much more aggressive ramp rates and make more power. I'd accept manufacturer provided parts in exchange for real world testing.

[SuperBuickGuy]

The real question is how many times Richard says "Kind of close", should kind of let you know it's "kind of close" representation... I think context is important here. What I think he is trying to convey is that you have to take lash into consideration - real news flash for us - but for the new guy getting this information for the first time, it is a consideration the new guy may not have thought of.

If you take the spec of the Hydraulic he is using and compare lift numbers to the Solid he is using, then include lash from the solid into the lift equation, they are closer than the specs indicate from the cam card. In this example of the two as close as the company offers profiles for a HR and an SR cam for a BBF, lift comes in at .611 compared to a .640 (intake only). The apparent .029 difference is not .029 when you take the .018 lash out of the Solid.

Lunati Voodoo Hydraulic Roller
Duration @ .050 (Int/Exh): 231/239 ;Gross Valve Lift (Int/Exh): .611/.611

Lunati Voodoo Solid Roller
Duration @ .050 (Int/Exh): 231/237 ; Gross Valve Lift (Int/Exh): .640/.650 ; Valve Lash (Int/Exh): .018/.018

In the real world, I'd fully expect the solid above to have much more aggressive ramp rates and make more power. I'd accept manufacturer provided parts in exchange for real world testing.

did you just bring us back to the topic? whoa.

But again, my point is his "kind of close" isn't at all, as a matter of fact, it's the opposite of what is true. The only way it's kind of close is if you circle all the way around the logic and arrive at the opposite side....

That and barometric pressure will cause uncontrolled wheelies.... there's an app that proves that.

[dave.g.in.gansevoort]

So I've been ruminating on this thread, and I had a brain fart. In the back corners of my mind I had a remembrance of something from a design course way back in college. The course, kinkymaggots, er, that is kinematics. The gist of the flashback is that a cam, when designed for roller lifters, can be considered as having a larger base circle. It will coincide with the center of the roller and a circle at that radius from the cam centerline.

What that means is that a cam can, if properly designed, have what would be impossible take up ramps for a flat tappet cam. This should allow for more radical cam timing. Like I said, just a random neuron firing...

[SuperBuickGuy]

So I've been ruminating on this thread, and I had a brain fart. In the back corners of my mind I had a remembrance of something from a design course way back in college. The course, kinkymaggots, er, that is kinematics. The gist of the flashback is that a cam, when designed for roller lifters, can be considered as having a larger base circle. It will coincide with the center of the roller and a circle at that radius from the cam centerline.

What that means is that a cam can, if properly designed, have what would be impossible take up ramps for a flat tappet cam. This should allow for more radical cam timing. Like I said, just a random neuron firing...

bigger mountains from the kinkymaggots?

[dave.g.in.gansevoort]

bigger mountains from the kinkymaggots?

Good question. I don't have an answer. It's been years since I have had anything to do with cam specs. The last time I looked at a cam it was to help with a failure issue a certain cam company was having. That was 20 years ago, so...

[SuperBuickGuy]

Good question. I don't have an answer. It's been years since I have had anything to do with cam specs. The last time I looked at a cam it was to help with a failure issue a certain cam company was having. That was 20 years ago, so...

funny you say that, a certain cam company couldn't explain why the ramp was screwed up the cam they provided to me.... they did give me a discount on its replacement... lucky me, no?