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iTrader: (2)

personally on a street engine I would go with a tool steel retainer.i think we’re just splitting hairs when it comes to 2 grams for a street engine .

IGN-1A

FIRST, I DO COAT my "intake" Ti retainers with a DLC.
Second, I use Ti ONLY on the intake side valve, "steel" valves.
The reason deals specify with this subject, unsprung mass.

MuhThugga

Yeah, tool steel retainers are the way to go on a street engine, especially when you are looking at lower end titanium retainers.

G Atsma

Your writing style EXACTLY MIMICS that of Lance Nist. Is "Eric" a pseudonym??

DavidBoren

Is there a point where lobe lift, ramp rate, or spring pressures demand the use of steel, regardless of one's desires to save weight/reduce mass?

I don't see any logical reason to run Ti retainers on only the intake valves when the exhaust valves are seeing the exact same rpms.

Sure, the exhaust lobe is sometimes less lift, but not always. And yeah, the exhaust valve is smaller, but that doesn't always guarantee it has less mass than the intake valve... intake valves are often hollow or titanium, themselves.

And honestly, how much difference does a coating on the retainer really help? Despite the advantages of DLC, in general, and even with its ability to adhere to titanium especially well, I don't see its advantages actually offering anything to a Ti retainer.

The stress the retainer sees is not going to be necessarily lessened in any significant way by a coating that reduces friction. At least, I think. I could absolutely be wrong, so please learn me something if I am mistaken. Is something else going on with the DLC/Ti retainers that I am not seeing? Does the DLC protect against heat, thus keeping the titanium from fatiguing as fast and becoming brittle?

IGN-1A

I have used DLC on Valves, Retainers, Piston Pins, both Steel and Ti. pins.
This has stopped wear on these items.
Titainum is SOFT though a good high heat material.

MuhThugga

Honestly, I would love to see some engine dyno tests done where the only changes were valvetrain weight: replacing the steel retainers with titanium, reducing and increasing spring diameters, reducing and increasing spring pressures, etc. I know Holdener did some video recently comparing dual and beehive springs, but the springs were barely equitable in specs. I think the one spring was something like .150" away from coil bind whereas the other one was like .070," and one set had steel retainers while the other had titanium. There were no controls whatsoever.

But, you know, free video on YouTube and all that jazz.

IGN-1A

The engine valve train needs to be accelerated.
Many here will install a "light" flywheel to allow the engine to increase RPM at a faster rate.
Steady State, bench dyno, operation will not show a HP increase though the HP to operate the valve train should be less with light valves.

MuhThugga

I'm less concerned about peak numbers and am more interested in changes in the overall curve.

ddnspider

iTrader: (26)

Ditto.....only Ti here too for years and years.

ddnspider

iTrader: (26)

Haven't seen you on here in a min. Lance right?

G Atsma

That's what I'm thinking....