Technical Finally a solution to the flat tappet lifter problem?

Excellent info. I can attest to reduced spring pressure for break in. Lost a few cams before I started reducing spring pressure. I also agree with the several hundred mile long break in period. Those new Comp lifters look nice!

 

Decent Info. From what I have seen, the vast majority of premature flat tappet cam deaths can be attributed to wrong spring pressures. Do NOT trust the spring / cam / kit manufactures. Measure and verify, and understand exactly what your cam needs based off the entire mass and geometry of the valve train. Cam manufactures use the same lobe geometry for nearly all engine platforms, and recommend spring rates based on a generic valve train. For example, a SBC with a 1.3:1 rocker ratio and lighter weight valves will require a completely different spring than a Ford FE with a 1.76:1 rocker ratio and much heavier valves, even if the same Comp 270H cam is in both motors.

 

Sorry man, but this video is full of crap. The entire section on lubricants is all bullshit. Also his explanation of spring pressure causing the zinc to be wiped off the cam, dude doesn't know wtf he's talking about. Reducing spring pressure may be a good idea, but it's not to keep the zinc from being wiped off the cam. FYI, zinc needs heat in order to activate, the heat comes from contact between the cam & lifter, the friction of the 2 parts causes heat, the heat activates the zinc which decomposes to form a protective film. The idea is to get the protective film to develop before the wear becomes problematic. And this same process occurs at every wear point within the engine, not just the cam/lifters.

And this also is part of why the rpm's needs to be elevated. Sure you want plenty of oil to be splashed up onto the crankshaft, but that's only part of the deal, the other is the way that oil protects moving parts. Lubrication of moving parts consists of different regimes, i.e. Boundary Lubrication, Hydrodynamic Lubrication, & Elasto-Hydrodynamic Lubrication. When there is no motion, the engine is not running, the parts can be in contact with each other; but when movement occurs oil on the surface of the parts is pulled into the load zone causing the parts to be lifted and separated so no contact occurs. That is the hydrodynamic lubrication regime. It takes motion to develop a wedge of oil between the parts that lifts and separates them and keeps them apart even under load. Until the motion is developed, that period of time from being at rest, until enough speed occurs that lubricant on the surface can be drawn into forming the wedge the parts are under boundary lubrication regime. This is when contact occurs, and where heat will be developed and zinc in the oil will be decomposed so that it will plate out and form a tribo film on the surfaces. So you want the cam turning at enough rpms to keep the cam/lifter interface in the hydrodynamic lubrication regime. Allowing the rpms to drop to the point where it falls out of that regime before the zinc has the opportunity to develop a tribo film will lead to harmful contact and wear at the surfaces. This is a simplified explanation, you can read far more about this by doing an internet search on the terms "boundary lubrication" and "Hydrodynamic Lubrication", and I didn't even mention "Elasto-Hydrodynamic Lubrication", which is the regime that exists when the lifter is at the tip of the lobe and the motion is rolling rather that sliding, as it is on the ramps. The Cam/Lifter interface experiences all 3 regimes in every revolution.

 

I'm with you blue. I'm not a lubrication engineer, but I read everything that you post about the subject. I also have a friend that is a retired lubrication engineer, and when we're at a car event it drives him batty to hear a car idling at 400rpm just to hear the camshaft lope, he always says "you're killing the lubrication of that engine", he's bitched at me personally for it. And as far as made in the US, that doesn't mean that it's made with quality material, kinda like saying "assembled in the USA". I believe it all comes down to doing things the right way and not taking things for granted. Oh and my buddy Jamie that owns the machine shop, just lost a roller lifter on his engine, guess it's not the end all solution to the problem huh?

 

It's on Youtube, gotta be true......

 

Very well explained Blues.

 

I wish the guy with reading comprehension problems would just put me on his ignore list and stop poking at me with stupid posts that always show how ignorant he is.

 

Blues, I plan to assemble a flathead Ford with a reground cam and new lifters soon. No new bearings, but will hone and replace the rings at the same time. What assembly lube should I use on the cam, and what oil in the engine for break-in? I will be using proven and tuned carbs and ignition, so I can rev it to whatever RPM you want as soon as the key is turned. Please give me exact brands and hopefully even part numbers.

 

Lmao! I guess I'm just lucky. To this day, with probably 50 small block Chevy builds, the only lifter/ camshaft I've ever wiped out was a VW!!! And if you know anything about them, the cam is oil bath lol. I watched a guy using a ball peen hammer to put his rod caps on once, I said that I don't think that should be necessary. He had a pile of rod caps laying there, he'd put the bearing half in it and go to town. He assured me that it was fine. As I stood there watching and keeping my mouth shut, his small block eventually stopped turning, and he was surprised! I think that there is something to be said about installing a clean, lubricated lifter, into a clean lifter bore, and mating against a clean properly lubricated camshaft. I always rotate my engine by hand once my pushrods are installed, too verify that my lifters are rotating. And I've put quite a few together without any cam lube. Always been STP. Now that I've said this, my next one will fail lol. But I guess I've had a good run at it!

 

Personally I wonder about the carnage that would occur should that wonderous plating ever start to delaminate

 

kinda like here...

 

Lots of factors at play in this equation. Spring pressure is a big one, so is proper lubrication. Another lesser known cause is lifter bores. They really should be checked and trued. Out of round = bad scenario. Not perfectly perpendicular to the lobe = bad scenario. No amount of work or forsight will do diddly if the lifter does not spin. Lobes need taper, as do the lifters. PROPER taper. Too much is bad. Too little is bad. This is why it's so important to find a competent machinist....and why they are so hard to find these days. It's also why e.v.e.r.y.t.h.i.n.g must be checked and not taken for granted that it's 'good out of the box'.

 

What's the thoughts:
1.3 rocker for break in
VS
Light springs for break in - then having to swap springs in the car ?

 

Lot easier to change rockers than to change valve springs

 

Agree, it's doable, but I can think of other ways to spend my afternoon.

Do the 1.3 rockers solve the issue? If the seat pressure is high to begin with, would the 1.3 rockers help ?

 

Good question, if a camshaft had a lobe lift of .250, a 1.5 rocker would make it .375, and a 1.3 rocker ratio would make it .332 lift. Doesn't seem like it would make a lot of difference. But I guess the spring pressure would have to be less at the lower lift?

 

I don't ever build exotic engines,.480 lift is a lot on anything I build. And springs to accommodate that lift. I believe if I was gonna build something with wild valve lift, and extreme seat pressures, I would go ahead and invest in a roller setup anyway.

 

I have a question on a few points in his video. I work in a body shop at a Chevy dealership why would they have zink additive for breaking in engines on the shelf if it was so bad for the process? Techs just change out long blocks now a days but still have the product. He said that the cam blanks were good and Arnott Chinese with that said it may be true but dosnt mean the quality of the bullet is better than let's say 25 years ago. I think the quality isn't as good as in the past no matter where it came from just food for thought.

 

buicks is what i race. notorious for having oiling problems. back when i raced nhra stock, when we built an engine, we start it up and go beat on it. if it was going to break, it was in the beginning. that never happened. now i send my cams out to be polished. no break in oil/grease. i use 4 quarts of regular amsoil 10-30 and its not the race version. no issues. 350 buick with a 671 on top and a kid driver who lies to me. lol

 

I’ve been running steel flat tappet cams in my GMC 6’s for over 45 years and never lost one. The highest spring pressure on the seat has been 135 and the cam lift is .380”. I’ve never let one idle less than 800 rpm. I’ve used different oils in the past but for the last 30 years I’ve used 15-40 Mobil 1.

 

Blue, I didn’t get the chance to watch the video sorry, I made it 2 minutes in and it sounded like the rest of the bull shit YouTube videos. I did read your post, it sounded like you knew something about this subject.

I’ve broke in a few engines and cams. And I’ve run the shit out of those engines. Not one failure. (I always did the 2500 for 15 minutes) I think some people spend a lot of money on an engine and are afraid to run it hard. ( They spent there paycheck and are afraid)They want to idle it or baby it. These things are made to run. Don’t baby them. They need to be run. Do some burn outs. To me it’s like an outboard boat engine. They hate idle. Run the dog piss out of them and there fine.

way to much bad info online.

 

Zinc is the medium that carries phosphate and under heat and pressure allows the phosphate to protect from metal to metal contact, galling, etc, when the base oil film is compromised.Various oil compositions contain just enough ZDDP to do the job, others have excessive amounts that do nothing, adding in the detergent composition can complicate matters, but in the end it's simply a matter of manufacturing expertise and quality of materials. Old methods, additives, and wives tales from back in the day, will not save junk in a box from turning into junk in your engine.

 

my self I never lost a cam ( wipe)
all over .500 for sbc
But its been 20 plus years since running / break in a hyd or flat tapped , This pass year in a combo I went with a Hyd R because of hearing about so many wiping cams , I wonder ( statement ) your Buddy said Guys idling engine So low RPMs??
I always set idle RPMs 1,000- 1,500,
So is cam wipes contribut to low RPMs after brake in ?? Also I would set timing & other adjustments before starting so I was able to go straight to break in.
Back then 80s 90s used Castrol , Pennsoil, Kendal
I pretty much run VR1 or other race oils

 

To add more shit......The softer break in springs rockers still need to have enough presure for proper break in....

 

I don't think he was talking about idle speed wiping or cam lobes, I think he was talking about lubrication in general lol.

 

Some of the video had merit. I have never lost a cam in 40-50 builds. Back in the day, we used STP to lube all the parts and poured the leftovers over the cam and assembled lifters. We were hip to cam lube and used it. Break in? We would do that sometimes on a Saturday morning with a fresh cam and go to the track and run it for 50 laps wide open.

I pre-oil my engines, go conservative on the initial lash and do what the cam maker suggests to break the cam in. I made sure the lifter bores are clean, I have honed them with a wheel cylinder hone or used crocus cloth on them. I always made sure the lifters were able to spin freely. I think this is a big cause of cam failures.

 

@Blues4U I for one appreciate you sharing your expertise in the lubrication field.

 

It has not been mentioned yet. I put the cam and lifters in the engine dry. I draw a line on each lifter. Then I turn the cam by hand making sure all the lifters rotate. A tight lifter can round a lobe fast. I then lubricate the cam and lifters. I reduce spring pressure for break in. 2500 rpm for ten minutes. I do this three times. I retorque the heads; reset the lash then cut the filter open. Works every time.

 

Driven gel type assembly lube and any break in oil will do the trick - personally I prefer Penzoil, but any name Brand brake in oil is okay. Leave it in for a few hundred miles.