Lifter ? sbc Hydraulic/stocker

[Rick Unterseh]

I'd like to know as well..... Alex, PM sent

[Reed Granrt]

If you all dont mind, I would like to comment some of the subjects that has been addressed. If you understand, this is a deep subject for my shallow mind but I know it will open the door for criticism and that is the way we learn.
Some place in this thread hydrodynamic wedge was discussed in connection with cam and lifters. You cannot have hydrodynamic wedge with relationship of cam too lifters. I wished we could. Hydrodynamic wedge can only be achieved with hydrodynamic lift. Theoretically hydrodynamic wedge is achieved as a member (crankshaft) rotates and pulls an oil film with it and then oil pressure is applied. If the pressure is correct, the crankshaft will go into hydrodynamic lift and will actually go into flotation with equal amounts of oil all around. If the pressure is too low or too high, the proper amount of flotation is not achieved and the crankshaft is either high or low in the wedge and the crankshaft can drop down or be pushed up and be riding on nothing but the oil film, but NO hydrodynamic wedge. Cam and lifter cannot have nor achieve hydrodynamic wedge as there is no pressure applied to put either into hydrodynamic lift and achieve flotation. The lifter is only riding on the oil film that is present or dragged into. This is two surfaces that is separated by a thin oil film and it is called elastohydrodynamic lubrication. It is only protected by the strength of that oil film. This is one of the reasons that synthetics has come into its own in the last few years. They can design and make synthetics that can withstand and hold that film strength even with the severe pressure applied with those huge valve springs used today. If the film strength breaks down and we get actual rubbing, it is called mixed lubrication. This is where DLC coatings have come in as of late. This has become a huge science in its own especially out of Germany. I hear people saying you cannot use this camshaft and or lifter with DLC coating. This is really a misnomer in that there are several matrices out there that can have DLC coatings applied. We have salesman that says you can do this and do that when in reality you can but only if the proper DLC is used. You cannot in all likely hood use the same coating on a cast lifter that you use on a alloy steel lifter. You also have to take into account what the DLC coating is rubbing on. Whether it is steel or cast or ?? Yes there are DLC coatings that will work on steel camshaft and another type that will work on cast camshaft but, in all likely hood, they will not be the same. Most of the companies here in the states can only apply a small selected variety of coatings and most have been developed for Indy or Nascar type engines. Just lately, has companies began to move into drag racing but the problem arises because of the different varieties of materials being used.
Also I saw a discussion of moly based coatings for camshaft/lifters and or bearings. I stopped using moly based engine assembly lube close to a year ago. Lake Speed Jr. told me of moly clashes with certain oil. He addresses it on the Joe Gibbs website. It makes you aware of why we can have problems on start up and even more so if we use coated bearings. Dart has just recently addressed this issue thru Melling in this article

http://www.enginebuildermag.com/Arti...conflicts.aspx

Moly paste can really raise havoc with bearing coatings as well as certain other coatings but especially with moly additive oils, which is a large percentage of racing oils. Moly also will blind most oil filters not to mention that it will not stay in suspension very easily.
Ok I have said enough and you can poke fun at my thoughts. I can take it cause the woman of the house can twist me inside out
reed

[ron mattson]

You can run a tool steel lifter on a cast cam with proper breakin and lubricant selection, with that being said you can run a tool steel lifter with the proper coating on multiple cams of the
right material/treatment processes with no issues. I have ran tool steel lifters from a few suppliers for over 5 years without a single failure using a few procedures and the cams have
been sold and look like new, i have reused one set of lifters on 3 cams and switched back
and forth with no issues. If things are done right you can run any oil you want, hope that makes things as clear as possible.

[Alex Denysenko]

All PM's replied to.

Thank you.

Alex