HOHN

Good, job, Don. Looks like you and Joe have been doing the homework for sure!

I'm not sure everyone quite grasps how significant this development is. These tappets reduce valvetrain mass AND will never realistically wear out! A cam will last a VERY long time-- and no worry about break-in.

Don, I was curious as to what you discovered about valvetrain harmonics with these. How does the ceramic affect the harmonics? Where does it move them? I would imagine that they shift the harmonics up high enough to where a relatively low-revving CTD would benefits in that regard.

Of course, maybe CTDs don't have issues with valvetrain harmonics to begin with?

So, Don-- when are we going to get the beehive valvesprings and matching retainers???? Titanium, please

Justin

BigBlue

Don, my list requires winning the lottery. The plan for my truck is low 12's, maybe high 11's and still be reliable enough to drive daily.

MCummings

Is there any concern with a billet cam wearing out the cam bores in the block?

I did not go to a billet cam because of hearsay that told me the block material is softer than the billet cam, and would therefore require machining to add cam bearings in teh cam journals of the motor...

Looks like I'll need some seramee tappets as soon as my 200Lb valve springs take control of my OE tappets.... (Yesterday? )

Merrick

Don M

No problem with using a billet cam in the cast block. The high pressure is in the cam lobes, not the bearing journals. You may not want to use a billet cam in the engine you decide to use for your high miler tow rig...but why would you need that anyway.


For the street driven trucks I have cast billets here. Not 8620 steel. They are blank and have never been ground. This allows me to grind anything. The limitation of the cast cam IMO is the higher rpm strength.

For the radical drag racing and higher RPM...we go to 8620. This design of course does not need to be in a daily driver.

Don~

Lil Dog

Simply amazing technology here Don. Very impressive.

Must be the porousity of the ceramic that helps in the oil retention? Or am I off base?

J-eh

Stamey

I'm thinkin you're off base on this one. The ceramic is sealed, kind of like a coffe cup, so that oil and anything else CANNOT soak into them. The key here is the coating, like pottery glaze, that is very hard and slippery, due to it's smooth surface. If this coating were not on the tappets they'd wear right through, probably quicker than the stock tappets.

To illustrate, scrape the side of one of those red ceramic flower pots with a screwdriver or old knife and see how deep you get in 10 scrapes. Do the same thing to a coffee cup and see how deep you get, using the same pressure. You'll see that the coffee cup doesn't even notice the screwdriver, but you damaged the flower pot.

My only worry about these tappets is that they may be too hard. I am now treading on thin ice because I only have a basic knowledge of this type of mechanics, but I'd think you'd want the tappets to have a little give in them to keep them from eventually crumbling from the pressure. If the tappets have enough support around the outside, such as from the bore they ride in, then this may not be an issue, but I still wonder about the flat area that rides on the cam having enough support.

I suppose the testing these have been through have already disproven all of my fears, but I wish I understood it better.

Chris

Lil Dog

Thanks Chris.. That makes sense on the finish anyway.. I was just wondering on the surface coating's ability to form a strong oil barrier. It seems from the low wear reported on the cam and the tappet that the oil is taking most of the hit or something would give.

Don M

Lil Dog,

The density of this particular material is very high. Some of the ceramics are not though.

Stamey,


These tappets have been tested to successfully operate at contact stresses of 1.0 to 2.4 GPa (150,000 - 350,000 psi) with no measurable wear to the ceramics or the companion metallic components. They make an excellent tribological couple with steel and iron. They actually tested at a wear rate 10 times lower than the best chilled iron tappet and iron camshaft like Cummins gives us from the factory at higher pressures ( 290,000 psi VS 475,000 psi ) with the lubrication cut back by a factor of 7

HOHN

Don, can we soon expect Cam/lifter packages from F1?

MCummings

Don, are your 8620 cams blank also?


How soon can we see ceramic pushrods?
That seems to be the weak point next...

Maddog has allready bent a few running high boost and high RPM.

I had a bent one in my motor, BatteringRam had a bent one in his, Chris Strickland has broken a few.

Think a ceramic (or billet) pushrod could be in store?

Merrick

Don M

The pushrods are done. I finished them last month. IMO, the chrome moly variety is a better choice if the budget is tight.

They are 6 times cheaper than ceramic.

Yes, the 8620's are blank. They start out life as a 3" round rod/bar of 8620 billet and get rough turned on a CNC lathe. The lobes are then ground in rough and the cam is nitrocarburized to make it hard on the surface. Since the 8620 has no carbon in the alloy. Its then straightened and finsih ground.

Bent pushtubes in the Cummins can come from improper valvetrain geometery. Some of this is from the base circle on the camshaft being cut down when making a performance cam out of a stock, already ground cam.

BigBlue

Great. Now I've gotta add a set of high performance pushrods to my list. STOP MAKING STUFF DON!!!!!!

MCummings

I think he'd have to take a permenant nap 6' under to stop making, and inventing ingenious stuff.

Don,
Both Chris and I' cam's were stock. His actually broke out of the blue... Mine was just bent.
Maddog's valves may have been improperly set.

Merrick

PumpDaddy

Don, in the picture it appears that the color of the "ceramic" is blue. If the coating is what I'm thinking it is, it harder than a preachers ya know what, if your pricing on the coating is too high, I know a shop around here that does it. They used to spray heads, manifolds, and tops of pistons for some racers. They also spray the ceramic on headers to keep the heat in. If you're interested, send me a pm and I'll send you the company name and contact, they do dang good work and beat every body elses prices, but that stuff can't be machined in a regular lathe, it's HARD as the hubs of hell.

PD

Idaho CTD

PumpDaddy,

The tappets are full ceramic not coated steel. There are extremely hard.

Nathan