Originally posted by dave.g.in.gansevoort
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Hydraulic v. Roller lifters
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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.
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Originally posted by squirrel View Postheh...the barometer will determine whether or not the front wheels go up in the air on my Chevy II.
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.
Flying south, with a flock of bird dogs.
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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.
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"If it don't go, chrome it!" --Stroker McGurk
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Originally posted by SuperBuickGuy View Post
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.
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).
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Originally posted by cstmwgn View Post
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).Doing it all wrong since 1966
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Originally posted by squirrel View Postyeah, 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.
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.
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Originally posted by dave.g.in.gansevoort View Post
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.Doing it all wrong since 1966
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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...
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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.
Flying south, with a flock of bird dogs.
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Originally posted by Beagle View PostThe 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.
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.Doing it all wrong since 1966
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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...
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Originally posted by dave.g.in.gansevoort View PostSo 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...Doing it all wrong since 1966
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Originally posted by SuperBuickGuy View Post
bigger mountains from the kinkymaggots?
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Originally posted by dave.g.in.gansevoort View Post
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...Doing it all wrong since 1966
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