Lifter testing; Stage IV complete

raygreenwood · Post by **raygreenwood** » Sat Jul 24, 2004 6:37 am

Charles/Jake...try www.accudynetest.com They have a very good technical explainations of surface tension testing, relatedASTM specs...and the ymake the best DYNE pens and testing equipment on the market. It is worth knowing. Who knows...maybe you can invent a bearing surface with superior oil wetting/holding properties. Ray

Kelley · Post by **Kelley** » Mon Jul 26, 2004 12:53 pm

what was that one photo of,,, chipping on the side of the lifter? how did that happen?

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Mon Jul 26, 2004 1:09 pm

Thats erosion.... due to incorrect heat treat of the lifter..

This is more than just a test of the lifter faces!

Kelley · Post by **Kelley** » Mon Jul 26, 2004 1:28 pm

well, I guess thats why they call em "moving parts". good to know that all surfaces are being tested,,,,, thanks, Jake, that actually answers several other questions I had.

proextreme · Post by **proextreme** » Tue Jul 27, 2004 5:48 am

What we are dealing with in a cam to follower relationship is whats called adhesive friction. This occurs when heat is generated at the tangent point of the lobe and the follower when extreme pressure is applied in the normal direction, and the coefficent of friction climbs. Surface finish is SO important to this relationship because of bearing area. The smoother the surfaces the more bearing area you will have to distribute the load and the lower the C of F you will have. Look at it this way, drive a nail in a 2 X 4, with your bare foot step on the nail. You know what happens at this point.Now remove the nail and step in the same location on the 2X4. You can now stand on the board with no pain. All you have done is increased the bearing area and the load(your weight) has not changed. This is the same relationship your cam and lifters have. The lifters must rotate for even wear and the surface of both the cam and the lifters need to be micro-polished. A rough surface to hold oil does not work. We are dealing with a hydro-static bearing when dealing with the cam and the lifter. The oil film on the surfaces compresses as the load is increased. If you have a large bearing area the oil will support the load ,but with a rough small bearing area surface, the pressure is too great for the oil to adhere to the surfaces. I hope this has helped.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Jul 27, 2004 7:24 am

Thats from the man himself!

raygreenwood · Post by **raygreenwood** » Tue Jul 27, 2004 7:41 am

That makes total sense. What method is used to measure surface finish. Are we measuring by microns? Angstroms? Could we help this by having oil squirters feeding a constant feed between those bearing surfaces? Ray

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Jul 27, 2004 8:08 am

Proextreme has a micropolishing process that we will be testing next on camshafts.

He and I have came to a conclusion that the surface finish of the camshaft has a tremendous impact on the break in, and initial wear of both parts- especially the lifters.

This is best illustrated when you look at the progressive pics and the wear data that we have collected since the testing began. The most amount of wear that we saw was between the 10-15 hour marks. Since then we have hardly seen any measurable of visual changes, even with increasing spring rates.

Pro extreme and I have a hunch and the next round of testing will include a cam that is micropolished on two lobes, and not on the other two. All the lifters we are testing with now will also be reground with a new face and radius and the Billet Pro Extreme lifters will be remicropolished as well...

seeing what I have recently, I feel certain that the issues can be solved easily- it might just mean that micropolished cams are going to be part of the ingredients to trouble free- no guesswork engines..

proextreme · Post by **proextreme** » Tue Jul 27, 2004 8:15 am

We mearsure using a profilometer with a .0004 dia. stylus. We measure in Ra micro-inch. On All of our drag and nascar engines we tap into the oil gallies and directly pressurize oil to the lobe. We use holley brass jets in these tapped holes to monitor flow. Remember the oil does two things, lubricates and cools. We need to cool the surface as well. Thats why one reason valve springs feel and spring pressure decreases. Valve springs go through harmonic distortion. We flood the springs with oil through oilers and we use a cup to shroud the spring to hold oil. Oil helps to quite down the harmonics and to cool the spring.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Jul 27, 2004 8:23 am

For years we have used rod modifications to help "wet" the lobes and lifters... Thats one reason why we have lost less engines due to bad cams and lifters than any other company for so long..

Keeping things wet with the micropolishing I feel is the key to making these parts live- coupled with the awesome material that the Pro Extreme lifters are made from..

raygreenwood · Post by **raygreenwood** » Tue Jul 27, 2004 10:03 am

Glad to hear. The piston and cam lobe oilers are about the only thing I have totally finished on my current engine right now. I use jets and a seperate external galley. My brother micro polishes all of the reciprocating/contact engine parts in his shop, on his race engine. A method I won't get into...but should be known in some circles..refered to as "rimming" (sp). Basically a combination of micro polishing by tumblin in a specific media, after micro etching after filling select surface pores. We do this to the silicone wafers on our solar cells to some degree...(one of 17 processes)....we call it etch back. If New lifters are not available by the time I build, I will be micro polishing the cam, and the mint condition 6 year old Johnsons I have, at his shop. Unbelievable surface finishes. Unless you sell me something better...or I dive into ceramics

Ray

raygreenwood · Post by **raygreenwood** » Tue Jul 27, 2004 10:30 am

Maybe a slight amount of info may help some to understand the question about surface finishes. And this is simplified a bit.
When looking at a surface under a microscope that has been ground or polished, it looks like a mountain range. These terms describe measuring the peaks, the valleys and the distance between all of them...if that makes sense and giving the average of that rhythem in microns.

Ra: Is the roughness average in microns or micro inches. Its the area/height between the mean line of the peaks and valleys. So if the peaks are 20um high and the valleys are 20um deep...the mean line is "0" where from they are measured vertically.
Rq: Is an estimate of Ra...done by selecting a sinus curve rhythem to approximate rhythem of the Ra. In analog days...its was much easier to do a mathematical estimate of roughness by this method than hours of tedious mearuring just to get close enough.

When looking specifically at the peaks and valleys under a microscope...Rp is the height of the highest peak found in the whole range. Rv is the singular measurement of the deepest valley....Rt is the sum of these two. You would use these measurements found under th microscope, to select the sine curve to do the mathematical mearurement of Ra...without hours of testing the surface with tools.
Rz...is an expression of what was found in Ra....but only across a select measured sample length. It has more to do with regularity of the surface and how reapeatable or recurring the roughness average found in Ra. Many people say there is no direct ,exact correlation between Rz and Ra. The Ra is more of an exact quantity expression of rough or smooth in a number form. Rz...takes the Ra into account but tells you how uniform a surface generally is over a given length. Anyway...not bore you but thats what these terms mean. And there are loads more terms pertaining to different ISO, DIN, NIST standards...Ray

Plastermaster · Post by **Plastermaster** » Tue Jul 27, 2004 8:51 pm

I think the quality of the steel is also of importance. Any given material is capable of a limited amount of "polish". Take a clay tile for an extreme example. You can polish it until it wears away, but you will never get a shine out of it. I suspect that if you buy a cam and lifters from Joe Blow cams Inc. You might never get the quality of these billet lifters no matter what you do to them, except adding a coating of some sort. A common lifter may not be able to be made smooth enough nowadays.

Ron

Kelley · Post by **Kelley** » Wed Jul 28, 2004 7:42 am

Stupid question time:

Jake (or anybody), would "cryo" treatment work to stabilize these metal alloys for the micropolishing process? And I suppose if it were possible, would it actually be economically feasable?

I know it's always a question of "hardness" of the metal, and Ray thanks for the definitions of RA/RZ, but I'm trying to get over this mental block for the moment.

proextreme · Post by **proextreme** » Wed Jul 28, 2004 10:59 am

cryo tends to bring the carbides more closley to the outter surface of parts. The major reason most people use cyro is for maximum stress relieveing. Remember, the less residual stress you have in a material the stronger the material is. This because if a material has a maximum strength of 30 ksi and there is 10ksi of residual stress, your max yield strength is 20 ksi. Take the stress out and you have maximum yield of a material.
Proextreme