MILD THUNDER

iTrader: (3)

As far as valve materials go, they really aren't rated so much for the max temperature they can withstand. It has to do with fatigue life, tensile strength, resistance to chordal fractures, deformation, and so on. How well the material works with the valve seat, and so on. It's not that if you put a "severe" duty exhaust valve in an oven at 1500 deg, its going to melt like chocolate, and the "extreme duty" will be fine. It has to do with heat, vs pressure. The valve is not only subjected to high temps, its also subjected to extremely high cylinder pressure during combustion, and of course, seat pressures . This is why titanium valves are not recommended in marine offshore engines. Titanium does not do well with the frequent temperature fluctuations of the valve, and therefore, has a limited lifespan. Sure its light, but While it may be just fine for a race car who swaps valves out frequently, its not for the guy who's looking to get 200+ hours out of his valves.

Exhaust valves, need a good quality material, that can go the distance. Whether its manleys "Extreme alloy", or Ferreas "super alloy", those are just trade names. One uses "inconel", and another uses "inconel" with a blend of Nickelvac 800 alloy. Nickelvac or its other names, aren't some made up snake oil blend.

http://www.americanspecialmetals.com...yAlloy800.html

As often as we hear about "inconel valves" being a MUST for a marine engine, rarely are things like stem clearance, valve seat widths, valve seat material, ever talked about. All of those things take a part in cooling of the valve, and should be considered for a marine engine. Narrow seat widths that work in a drag car, don't really have a place in a marine offshore engine, as well as excessive stem clearances, guide lubrication, cheap seat materials, etc.

I am not suggesting ferreas exhaust valve is better than manleys "inconel", but I just see so many guys on the internet, throwing the word "inconel" around, as if manley is the only valve that can be run in a marine engine, and everything else is risking failure. "inconel", isn't manley's proprietary invented material. It's been used by eaton, and other companies as well. I do agree, if you tulip or hurt a manley extreme duty valve, you have issues. In my prior post, I was simply stating, that if the OP's engine builder is a ferrea dealer, or simply likes ferreas valves, they offer a product, that will work just as good as what Manley offers. Just like some guys like JE pistons, doesn't mean CP carrillo, diamond, etc are of a lessor quality.

MILD THUNDER

iTrader: (3)

From article in engine builder magazine

Quote:

Ferrea offers three different primary product lines of stainless steel and alloy valves: the Competition Plus Series, the 6000 Series, and the 5000 Series. Urrutia points out that within the Competition Plus line, there are four to five different stainless materials to choose from. “It mainly entails the exhaust valve side, because what really perturbs any valve is the heat and spring pressure. Those are really the two main factors that you have a big area of weakness on an exhaust valve. Bang for the buck, it’s an area where most engine builders venture first, and then see if there’s a possibility for titanium if their pockets are that deep.”

The 5000 Series is more performance oriented toward street rods, muscle cars, and similar applications that are often cruised on the weekends or driven for extended periods of time. The 6000 Series represents the middle ground between the other two lines, which is aimed at the cost-conscious bracket racer or weekly oval and dirt track racer with engines that often utilize high spring pressure, big roller camshafts, and large compression ratios that lack the use of power adders. Both of these lines are available only in stainless steel, and once you evolve to the Competition Plus series, there are four to five variations of stainless steel that utilize exotic alloys.

Ferrea utilizes three to four differing blends of stainless steel that make up a particular valve. The differences between the differing blends is primarily the heat range to which they can withstand.

The first among those is what’s known as an EV8, which Urrutia describes as being incredibly strong with great memory and because of it’s wide use in all forms of manufacturing, is a common blend in foundries around the world and quite popular for valves – especially on the intake side. EV8 is comprised of chromium and nickel and Ferrea adds tungsten to the mix to make it suitable as an exhaust valve, as well. Also on the intake side is IN751 – an inconel –

From there you get into some more exotic materials and alloys involving exhaust valves. These include VB54, a high-heat stainless steel blend with a high nickel base that’s used exclusively for exhaust valves for combinations composed of forced induction and nitrous oxide. Also on the exhaust side is Nickelvac N80 that sports nickel and tungsten for handling even higher temperatures – upwards of 1,850 degrees fahrenheit. And finally, you have what Urrutia calls the ultimate of their stainless steel exhaust valve blends; Nickelvac 800. These are used in large diesel engines, Top Fuel Dragsters and Funny Cars, and turbocharged road racing vehicles where the most extreme of valvetrain environments and heat exist.

MILD THUNDER

iTrader: (3)

How can you not like a company that offers a 40 % discount to military members. Thats pretty cool.

MILD THUNDER

iTrader: (3)

I don't know what year your RV engine is, but GM was putting "inconel" exhaust valves in their truck engines for quite some time.

14 apache

iTrader: (1)

Has anyone noticed the chrome on ferreas valve stems is kind of thin? I have seen them worn through and you can see where the Inconel is welded to the stainless or steel. I have not seen this with manley valves.

Young Performance

That is awesome. More companies should do that. Because of what those guys do, we can do what we do.
Eddie

KevD815

I did not know that! Its out of a 1991 Wannabango.

MILD THUNDER

iTrader: (3)

This would be a federal mogul replacement for the OEM valve. I don't have the GM number handy . Stellite faced inconel valve

http://www.fmmotorparts.com/fmstoref...neExhaustValve