Inconel exhaust valves, when do you need them?
 

When do you need Inconel exhaust valves and when are quality Stainless valves OK?
I am finishing my mild build 454 and trying to decide if I need Inconel exhaust valves. Boat is recreational in use but building to about 450ish HP.
What are determining factors for Stainless vs. Inconel. As everybody that has built an engine knows the budget is already blown so cost is a factor.
Thank you for your assistance.

300 to 400 bucks now could save you a few thousand down the road, IMO it's piece of mind

You will get alot of opinions on this going both ways. They are in deed an insurance item. In my experience I have run with them and without, It all depends on your tune, and some will say how you run your boat.I run & always have run super charged motors in my boats and don't use them anymore, I run very hard and yet to have a problem. I have also built several NA motors for others and gave them the choice. It all depends on your budget. In a mild motor I would spend that money on other upgrades.

On your power I would not worry about Inconel valves. I ran some motors just like what your building and ran the nuts off of it never a problem.

My builder is of the same opinion. He say he uses them only on blower motors. I don't want to skimp on important stuff at the end of the build but I also can not see going overboard. I have very basic knowledge in subject so all opinions welcome. The builder suggest Ferrea valves, any comments/suggestions on valve selection greatly appreciated. Thank you.

You will need Inconel valves if/after a regular SS exhaust valve fails. In a boat you have extended runs at high RPM (compared to short burst of high RPM in automotive application) so the marine exhaust valve gets significantly hotter for extended periods. You can save $ on the block, heads, intake/carb, rigging, etc. but the exhaust valve is not a good place to cut a corner.

not knowing what kind of boat you have or how you run it makes it tough to say if you need them or not.i think merc put them in the 365 mag and up.if you can find the xtra cash put them in,you might sleep better at night.if you don,t put them in now you might find out that you needed them sooner or later,jmo.

my .02....for what the Inconel valve costs I would never build any engine over 400 hp without them, to me it's just stupid.... because it costs a ton more when the head snaps off and destroys pistons, and cracks a cylinder wall....

Any engine builder should recommend the Inconel for Marine use.... I would hope anyway..


first pic, regular stainless valves in my warmed up 420's with merlin heads, happened twice, the first time it didn't break piston and made some marks, flew out the exhaust... I replaced valve with another stainless valve, then the following season the hole in piston picture you see.... stainless valve failed, rebuilt engine completely pull all 4 heads put in Inconel never had issues again.....
[ATTACH=CONFIG]547206[/ATTACH][ATTACH=CONFIG]547207[/ATTACH]

The valve picture is my INCONEL after a fuel line got crap stick in a brass fitting and leaned out BAD, if that was a normal valve it would have broke.....[ATTACH=CONFIG]547205[/ATTACH]

Ferreas super alloy exhaust valves are commonly used in BIG power offshore engines by some high end builders. Also very popular in big high boost , nitrous stuff.
Supposedly they are good for 700 more degrees than manleys "inconel".

If your builder is a ferrea fan/dealer, i would ask him for the super alloy exhaust valves, and 6000 series intake valves.

"Inconel" is a trade name. GM used two piece inconel valves, that were prone to breaking. Not all valves are created equal.

No valve material is going to compensate for a bad tune. Guys break or tulip stainless valves because they were lean, or retarded timing, then blame the valve itself.

So Ferrea 6000/intake and super alloy exhaust? I believe he (engine builder) was looking at 5000/I and 6000/E. maybe 6000/I and 6000/E.

I never use Inconel or Super Alloy on NA builds. There's no need and the last thing I want is extra valve weight to contend with. Most 400-500hp blown apps can use a good quality stainless and be fine but the rule of thumb usually is to use them when using any power adder.

Thanks everybody for the input. I think I made my decision. Ferrea series 6000 intake P/N 6126 and Super Alloy P/N F2120P exhaust.
Special Thanks to Ferrea for providing a 40% Military Discount (Active or Veteran on line orders). This discount makes the "Insurance Policy" affordable while getting the best protection. Any last suggestions before I pull the trigger?
Thanks again.

Make sure you check guide clearance. Different valve manufacturers have different stem diameters.
One question I have...if you're willing to spend the money on the Super Alloy, why not the Competition Plus on the intakes? If you're NA, I'd run the Comp Plus on both intake and exhaust and never lose a minute's sleep. Another thing I'd look at if you're at that point of the rebuild is switching to 11/32 valves. It's an easy conversion for any competent machine shop and getting weight off the BB Chev. valve train goes a long way for longevity and reliability. I know some seem to think 3/8 valves are an "upgrade" for marine stuff but I will wholeheartedly disagree.
JMO

+1 on the competition on Intake heck it is only $4 a hole. Thank you.

Personally, I won't build a marine engine (that's all we build) without Inconel or Super Alloy valves. It's just not worth it to me. I'm not so much worried about the heat as I'm worried about some water hitting a smoking hot valve. That's my biggest worry. All it takes is a few drops of water from reversion, leaking header, whatever, to hit a hot valve and you could be in for a really bad day. It could happen very easily. While it's not guaranteed that it will fail, why take the chance. I've said it before and i'll say it again. I'm not building engines for myself. I'm building them for guys that, in most cases, beat the crap out of them like they were rentals. I have to make it as solid and dummy proof as I can. I can not rely of them to be on the lookout for potential problems, water leaking, etc. For some, it's a stretch to check the oil. That's just the fact of the matter.Some are great about paying very close attention to every little detail, but they are in the minority. If a few hundred can give us both a piece of mind, then it's worth it. I don't even give my customer a choice. I just put them in the quote and that's that.
Eddie

Eddie, I pulled the trigger on Ferrea Comp Plus for intake and Super Alloy for exhaust. The deal maker on the Super Alloy for me was, as you pointed out, water. I really don't want to even think of a valve failure. I truly appreciate your learned input. I'll be calling you in the near future to send you my Stainless Marine risers for O2 bungs installed.
Thank you for your input.

Glad to hear that you went with the Super Alloy. They are very nice pieces. You will sleep better at night. lol
I look forward to hearing from you.
Eddie

Iconel also not a bad choice if you have a Bravo drive. Never know when it will get stuck in reverse on a windy day and have to run in 5 miles with reverse only. Even with dry exhaust water still comes up the pipes. Just my .02 for anyone thinking of cheaping out.

Go with Iconel valves with marine or see result photos in early post!

yeah,,merc racing doesn't know what they're doing,,your so much smarter than them.525efi and 1075's seem to run for hundreds of hours because they they're unreliable.
1 set of offshore engines makes you far from anything close to an expert.

could all come down to tuning, if you tune with wideband and have it right may be fine for a long time, but most do not so they are indeed insurance if they exhaust valves get overheated

The water is a good point. Most of my marine experience has dry ex so that makes good sense.

Not to be a dickhead!! but the failure temp of Inconel is less than what aluminum piston failure would be, however strong enough to withstand a top fuel environment... the tuliping that occurs just prior to failure could be used as an early warning device therefore limiting catastrophic engine damage... having an exhaust valve that can withstand 700ish degrees more would make that manufacturer "Super" yes but would that extra be the very difference of costly additional damage??? I'm no rocket scientist, but I'd say that if you destroy an Inconel valve you have some other major issues that require attention!!! JMO

Was thinking the same thing...

Just curious what valves are in merc black motors, as on another thread, people are saying they are getting 500 or more hours on engines untouched.

Mine had basic GM stainless. I'd bet that is all they ever got, as these were essentially truck engines with a different camshaft, oil pan, etc.

I think only 385 and up got Inconel, but I could be wrong.... as far as 365's and such... the lower power levels and RPM seem to keep a lot together lol

Only asking because shortly after buying my boat I was looking at a power adder and was advised that a valve upgrade was prudent and necessary which I understood, but the op is only looking at a mild build , l agree insurance is good, but over insured is merely casting money to the wind.

[QUOTE=GLENAMY 242SS;4371534]When do you need Inconel exhaust valves and when are quality Stainless valves OK?
I am finishing my mild build 454 and trying to decide if I need Inconel exhaust valves. Boat is recreational in use but building to about 450ish HP.
What are determining factors for Stainless vs. Inconel. As everybody that has built an engine knows the budget is already blown so cost is a factor.
Thank you for your assistance.[/QUOTE
]
As the OP I feel my question was answered. You may need to read between the lines on some of the responses but I think my take home answer is:
1) When you use power booster.
2) If you even dream any water may get to the valve. This was my rational for buying the "Insurance Policy".

Thanks again all who shared their knowledge and experiences.

Regarding the "black motor" and "truck motor" valves. I have a former Winnebago 454 in my boat with bone stock heads. Straight up truck motor. Keep in mind its probably only 300hp but I will run sustained 4500rpm across Long Island Sound without issue and have been doing this every summer weekend for 3 years.

So i guess the moral of the story is wimpy parts + proper tuning = reliability!

Personally I will never run a regular stainless valve again why take a chance for 200.00 more.... It's small amount of money to ensure you are ok like Eddie Young said, I learned hard way 2 times that was enough...

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.

From article in engine builder magazine

Quote:

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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.

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

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.

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.

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

:readinghelp:If Mecury used them on HP motors I whould go with that!Research 2nd to none:food-smiley-007:

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

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