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Valve seat materials
Seems like a topic that never gets brought up. I see everyone always saying how "inconel" valves must be used for Marine. But what about the seats?
Full Force Tim, and a few others, have had issues with excessive exhaust valve seat wear on the AFR heads, after a relatively short time. I noticed Dart is using "powder metal" seats, as does Engine Quest, while AFR uses a standard ductile iron. I think I remember reading somewhere, that Teague marine installs "Tucker" valve seats in their heads , which are a really high quality seat. From some of the articles I've read on the topic, seems most of the OEMS have gone to powder metal seats, as they last a very long time. |
The powder metal seats are a "cold casted" seat. With the cold casting there is much more control over the grain structure. From my own experiences Tucker seats are the best. Even in turbo car motors they hold up the best. Sterling uses Copper Berilium seats in all his motors along with Inconel exhaust and intake. This is a big no no in the marine world. His motors have a mandatory yearly tear down and valve job at a minimum if you are luckily and a lot of times valve seats are beat so bad they need replaced. Throw in a Tucker seat and all your issues go away. I'd really like to get some input on the Durabond seats before I continue with my winter project. Great topic for discussion.
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You mentioned several cases of 'wear' with afr's... Are the seats wearing or are they getting pushed into the aluminum?
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I've spent the morning reading a paper from a study the EPA, and department of agriculture wrote on the effects of valve seat recession, and unleaded fuels. Paper was written 30 years ago. They did several farm engines, but they also did a 454 Chevy engine. They ran it on strictly unleaded with cast iron valve seats, then steel valve seats, cast iron with lead additives of various concentrations, for 200 hour tests in each scenerio.
The worst setup, that suffered the most exhaust valve seat recession, was the straight unleaded, cast iron valve seat. By 60 hours, the valve seats were already showing .015 of valve seat recession. By 140 hours, the seat recession on some cylinders was up to .030. The next worst, was the steel valve seat, straight unleaded. Valve seat recession by 60 hours, was in the .010 range, and by 140 hours, was up to .020. Better, but still not great. Using a lead /lubricant in the fuel, at a mixture of 250lbs per 1000 barrels of gasoline, the cast iron valve seat recession, stayed under .005 for 140 hours. Using a mixture of .1 gram per liter of lubricant in the fuel, by 140 hours, the cast iron valve seat recession was basically not an issue at all. In the valve seat world, engines running a dry fuel, like Propane, Natural gas, must have special valve seats. Reading that article , almost makes me want to consider running a lead substitute like this in my fuel https://www.redlineoil.com/content/f...ech%20Info.pdf |
Im sure most know this already, but for the younger guys who may not.....back before the days of "unleaded" gas, we had leaded fuel. There was a transition period, where both fuels were available at the pump. The epa pretty much got rid of leaded fuels, in the days of the catalytic converter introduction. Back then, if you had a car that required leaded fuel , and did not have the hardened valve seats for unleaded fuel, and you ran unleaded fuel, the valve seats didnt last long.
Today, all engines must run on unleaded obviously. For oem engines to last the 150k mile emission standards, a quality valve seat must be used that can go the distance. Must be why they have now gone to sintered powder metal exhaust seats. As we know, the marine engines run very hot exhaust temps. A quality seat material must be used if you want to get life out of the valve seats. Our camshafts, springs, hp levels, are getting more extreme every day. The valve seats must not only seal the valve, but also have to transfer that extreme heat to the cooling system. Take an extremely hot valve and seat and slam them together with aggressive cam profiles, unleaded fuels, lean air fuel ratios, and then a basic ductile iron seat, its not surprising some guys are seeing this early valve seat recession on the exhaust valves. |
Originally Posted by MILD THUNDER
(Post 4493657)
Im sure most know this already, but for the younger guys who may not.....back before the days of "unleaded" gas, we had leaded fuel. There was a transition period, where both fuels were available at the pump. The epa pretty much got rid of leaded fuels, in the days of the catalytic converter introduction. Back then, if you had a car that required leaded fuel , and did not have the hardened valve seats for unleaded fuel, and you ran unleaded fuel, the valve seats didnt last long.
Today, all engines must run on unleaded obviously. For oem engines to last the 150k mile emission standards, a quality valve seat must be used that can go the distance. Must be why they have now gone to sintered powder metal exhaust seats. As we know, the marine engines run very hot exhaust temps. A quality seat material must be used if you want to get life out of the valve seats. Our camshafts, springs, hp levels, are getting more extreme every day. The valve seats must not only seal the valve, but also have to transfer that extreme heat to the cooling system. Take an extremely hot valve and seat and slam them together with aggressive cam profiles, unleaded fuels, lean air fuel ratios, and then a basic ductile iron seat, its not surprising some guys are seeing this early valve seat recession on the exhaust valves. |
Brodix sells tungsten steel seats I have run them and they seam to work well.
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I wondered about adding two stroke oil into gas. Have a good buddy who used to be a serious motocross racer. Ran 100:1 in his 4 stroke bikes when they came out, gave him a big advantage over others actually. Made more HP, everyone thought he was nuts and were baffled when they ordered tear-down inspections of his bikes only to find that they were bone stock. People accused them of running cheater overbore kits and were surprised when the overbore pistons they happened to have wouldn't fit down the jugs. They also use to run their two stroke bikes at closer to 20:1 and made more hp as well.
The biggest thing with the EPA meddling in our fuels seems to be what they are removing, usually has some lubricating property. Lead out of gasoline which was a great lubricant. Now they have pulled sulfur from diesel which is also a great lubricant. Notice how your older diesel engine lost MPG after the EPA low sulfur mandate took effect. A little two stroke oil also assists with cylinder ring sealing. That makes more HP. Also reduces upper cylinder friction. That frees up more HP. I don't see too many disadvantages to it. Throw some Klotz in your tank....smells great too! So, does this mean that most valve seat related issues are due to improper lubrication rather than force of valve impact/bouncing/cam profile? Does the lubrication provide a film cushion on the seat preventing the propagation of the impact forces to the head material is the reason behind this? |
Originally Posted by MILD THUNDER
(Post 4493654)
I've spent the morning reading a paper from a study the EPA, and department of agriculture wrote on the effects of valve seat recession, and unleaded fuels. Paper was written 30 years ago. They did several farm engines, but they also did a 454 Chevy engine. They ran it on strictly unleaded with cast iron valve seats, then steel valve seats, cast iron with lead additives of various concentrations, for 200 hour tests in each scenerio.
The worst setup, that suffered the most exhaust valve seat recession, was the straight unleaded, cast iron valve seat. By 60 hours, the valve seats were already showing .015 of valve seat recession. By 140 hours, the seat recession on some cylinders was up to .030. The next worst, was the steel valve seat, straight unleaded. Valve seat recession by 60 hours, was in the .010 range, and by 140 hours, was up to .020. Better, but still not great. Using a lead /lubricant in the fuel, at a mixture of 250lbs per 1000 barrels of gasoline, the cast iron valve seat recession, stayed under .005 for 140 hours. Using a mixture of .1 gram per liter of lubricant in the fuel, by 140 hours, the cast iron valve seat recession was basically not an issue at all. In the valve seat world, engines running a dry fuel, like Propane, Natural gas, must have special valve seats. Reading that article , almost makes me want to consider running a lead substitute like this in my fuel https://www.redlineoil.com/content/f...ech%20Info.pdf |
Originally Posted by MILD THUNDER
(Post 4493546)
Seems like a topic that never gets brought up. I see everyone always saying how "inconel" valves must be used for Marine. But what about the seats?
Full Force Tim, and a few others, have had issues with excessive exhaust valve seat wear on the AFR heads, after a relatively short time. I noticed Dart is using "powder metal" seats, as does Engine Quest, while AFR uses a standard ductile iron. I think I remember reading somewhere, that Teague marine installs "Tucker" valve seats in their heads , which are a really high quality seat. From some of the articles I've read on the topic, seems most of the OEMS have gone to powder metal seats, as they last a very long time. |
Looks like Redline changed their product.
https://www.amazon.com/Red-Line-6020...ead+substitute Hey, folks - Be careful! I just received a big order assuming this was the same product I have been buying for over ten years. Imagine my surprise when the 12 ounce bottles now said "One bottle treats 25 gallons" as opposed to the Redline I had been buying in the past that said "One ounce treats 10 gallons" - Even though the Redline product number (60202) hadn't changed! I called Redline and talked to their chief technical guy (Dave Somebody) who somewhat sheepishly admitted that the formulation had changed and that one bottle now treated just 25 gallons instead of treating 120 gallons. How they can do this without changing the product number (60202) is beyond me. Talk about unethical behavior and greed!!!!! For gosh sakes, at least change the product stock number if you have any ethics at all!!!!! How pathetic when greed comes into play - this is already a very successful company so they certainly didn't raise the price in order to survive! Just greed - I'm changing suppliers on just principle! |
some of the younger folks may not know what tetraethyllead is,do a google search and you will learn about it.
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We used to run Copper Beryllium in Oval Track Engines , stopped because of wear and health affects . Moved to a Copper Alloy with DLC Coated Ti Valves .
Some of the Dirt Oval guys are running some kind of seat coated with TiCN to keep the wear down. |
Originally Posted by mike tkach
(Post 4493816)
some of the younger folks may not know what tetraethyllead is,do a google search and you will learn about it.
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I bought a brand new set of Brodix heads 2 seasons ago. At the end of the second season the engine started running poorly and was down on power. Did a leakdown and all cylinders were leaking between 30-60% out of the exhaust valves. Pulled the heads and the exhaust seats were beat to death. Had around 70 hrs on them. I don't know what the seat material was, but it didn't work very well in my little blower motor. Brodix has the castings back in their possession right now and are going to put in some better seats they said. If I can find out what they are putting in, I will post it here. In all fairness though, I did get a half tank of 87 octane at a marina in TN by mistake shortly before it started running bad. The knock sensor may have removed so much timing that the EGT's went through the roof. The Manley extreme duty valves held up perfectly though.
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Originally Posted by Black Baja
(Post 4493821)
Some of us younger folks are lead advocates. If it wasn't a vital lubricant / octane booster I think they would have removed it from AV gas completely. Let's be real about lead. Everyone worries about the health problems that could be associated with lead (which is a myth) however we have airplanes flying over head burning tons of leaded fuel. Gravity tells me that all the exhaust emissions from an airplane is going to fall right on top of me. But yet I don't have lead poisoning... :-)
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Originally Posted by mike tkach
(Post 4493837)
i only wish you were correct in saying lead related health issues are a myth.i,like you know the benefit of leaded fuel.you can,t really believe lead is not a health hazzard.
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Maybe thicker seat margins should be used ?
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Originally Posted by SB
(Post 4493861)
Do thicker seat margins make the wear less ?
Modern engines put much higher levels of thermal and mechanical stress on valve seat inserts. To handle the more severe conditions within these new generations of engines, the OE-Manufacture is equipping them with high tech sin-tered valve seat inserts. The normal cast iron valve seat will not adequa-tely withstand the demands of this new engine environment. |
Originally Posted by mike tkach
(Post 4493837)
i only wish you were correct in saying lead related health issues are a myth.i,like you know the benefit of leaded fuel.you can,t really believe lead is not a health hazzard.
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Off the web
Selecting Valve Seats for Gas and Diesel Engines By Larry Carley Hard working diesel engines, performance engines, and engines that run on dry fuels such as propane or natural gas produce a lot of heat in the combustion chamber and often require valve seats that are harder and more heat-resistant. Stellite, chromium, cobalt, tungsten and nickel alloy valve seats are commonly used for such high heat applications as are tool-steel valve seats. Beryllium-copper or copper-nickel alloy seats are often used in racing applications, typically with lightweight titanium valves. Average combustion temperatures in a street performance engine can range from 1,400 to 1,700 degrees F. Nickel alloy cast seats can usually handle 1,400 degrees F with no problem, while cobalt is good for up to 1,650 to 1,700 degrees F. With nitrous oxide, temperatures can soar to 4,400 degrees F, which can make some seats become hard and brittle. This increases the risk of seat cracking and failure. For ordinary passenger car and light truck engines, however, temperatures are lower so iron alloy valve seats are perfectly adequate. Iron alloys are less expensive and easier to machine than hard, high temperature alloys. But in recent years, powder metal seats have become the norm for most original equipment passenger car and light truck gasoline engine applications. Powder metal valve seats are very different from cast alloy seats. Powder metal seats are made by mixing various metal powders and then pressing the powder under extremely high pressure (up to 100 tons!) into a mold. The seat is then baked at high temperature to sinter (partially melt) the ingredients so they stick together and form a homogeneous matrix. The end result is a valve seat that has very consistent and uniform properties, and requires minimal finish machining. The neat thing about powder metal technology is that you can combine various ingredients that would not normally mix together if you were trying to create a cast alloy seat. Consequently, solid lubricants can be added to the mixture to improve machinability and wear resistance. What’s more, the powder can be blended differently for different types of applications. Infusing the mix with copper, for example, can improve the seat’s ability to conduct heat for high heat applications such as dry fuel engines, marine engines or motorcycle engines. Powder metal seats often show little wear at high mileage. Consequently, if you are rebuilding a head with powder metal seats, the seats may only need a light touch-up. But because of the work hardening that occurs with powder metal seats, they can be difficult to machine. The naturally smooth exterior surface finish of a powder metal seat also improves the metal-to-metal contact between the seat and its counterbore in the cylinder head for better thermal conduction. Adding a radius to the outside corner also makes installation easier. The powder metal matrix also has a certain amount of elasticity that helps retain the seat in the head with less interference fit. That’s why many original equipment powder metal seats are installed in aluminum heads with only .002 to .003 of interference fit. |
Originally Posted by SB
(Post 4493861)
Maybe thicker seat margins should be used ?
listen,,merc uses some of the god damn hardest seat material,,I know,,I've cut them,and they get pounded/widened.good thing is,,it takes less material to get them back in good shape. |
Originally Posted by MILD THUNDER
(Post 4493865)
Off the web
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Maybe dipping valve seats in flex seal would be a good idea.:bunnydance: It performs miracles. :D
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Originally Posted by sutphen 30
(Post 4493866)
no,,they just start bigger and keep getting bigger.
listen,,merc uses some of the god damn hardest seat material,,I know,,I've cut them,and they get pounded/widened.good thing is,,it takes less material to get them back in good shape. |
Originally Posted by MILD THUNDER
(Post 4493869)
Id imagine cutting a basic iron seat is prob alot easier than the harder seats? The cutter speed prob also needs to be compensated too i would think? Im sure they average machine shop doing a set of heads for a weekend camaro , would rather work with an iron seat when doing valve jobs
oem's aren't all that bad,,those merc seats,,be like,Damn. |
I know how the low seat deal can be a *****! We use a Newen Epoc CNC single point seat cutter. We made a pair of valves with .500 diameter tooling balls sunken in them . Put them in the seats , and measure down with a depth mike . Lowest seat gets cut first . The rest follow suit.
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Looks like the standard automotive dart heads, get ductile iron seats
https://www.summitracing.com/parts/drt-19300136 And the "marine" version gets powdered metal https://www.summitracing.com/parts/drt-19300132m |
Originally Posted by MILD THUNDER
(Post 4497415)
Looks like the standard automotive dart heads, get ductile iron seats
https://www.summitracing.com/parts/drt-19300136 And the "marine" version gets powdered metal https://www.summitracing.com/parts/drt-19300132m |
Originally Posted by Black Baja
(Post 4497491)
Good eye. And if you notice the auto version has titanium retainers and marine has steel. I think that there is something behind that as well. I've been told that TI retainers actually put more harmonics into the valvetrain...
I've run Ti retainers since as far back as I can remember,2001.remember paying $89 for them thru Howard,,now they're way more.:D |
The TI retainers should move harmonics to a higher rpm range, but supposedly they do wear faster. May be negligible in boat use. There are lighter weight steel retainers out there.
I remember the Jump too S30. Just under $100 and then boom, $200 or so. Guess the Chinese don't deal with titanium. LOL. |
Originally Posted by SB
(Post 4497501)
The TI retainers should move harmonics to a higher rpm range, but supposedly they do wear faster. May be negligible in boat use. There are lighter weight steel retainers out there.
I remember the Jump too S30. Just under $100 and then boom, $200 or so. Guess the Chinese don't deal with titanium. LOL. |
Doh, I was saying negligible in the sense of boat use is a lot less than car use.
Anything to take weight out of a BBC valve train (especially) within reason usually pays off, especially when going to higher 5k range and above. Edit in: even though sbc's don't have this issue near as much with their inline valves, straighter pushrod angles, and smaller valves and lighter springs, GM going to even a smaller stem valves, hollow and sodium filled valves, beehives - talking small retainers here too - has really upped the rpm with hyd roller cams. Obviously we can not use this small valve , lighter weight valve, and tiny retainer....but it just re-amplifies what one is up against with the BBC. |
last night I contracted the aliens that landed in my back yard to make me new valves and seats,,can't tell you the new material,,said they kill some cows.:D but they're really light,,next up,,super low duration w/ super high lift cams.:D
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Originally Posted by sutphen 30
(Post 4497511)
last night I contracted the aliens that landed in my back yard
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Originally Posted by SB
(Post 4497508)
Doh, I was saying negligible in the sense of boat use is a lot less than car use.
Anything to take weight out of a BBC valve train (especially) within reason usually pays off, especially when going to higher 5k range and above. Edit in: even though sbc's don't have this issue near as much with their inline valves, straighter pushrod angles, and smaller valves and lighter springs, GM going to even a smaller stem valves, hollow and sodium filled valves, beehives - talking small retainers here too - has really upped the rpm with hyd roller cams. Obviously we can not use this small valve , lighter weight valve, and tiny retainer....but it just re-amplifies what one is up against with the BBC. |
Originally Posted by SB
(Post 4497512)
I sent them over. Did they tell you ? :)
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In reference to young guys and leaded fuel, I worked at a full service (yikes!) gas station back in the early 80's when leaded fuel was still available right next to unleaded. I can't tell you how many gas tank filler necks I modified to accept the larger leaded fuel pump nozzles and how many "test tubes" (anyone remember that name?) I installed. No one wanted to run unleaded even in cars designated for "Unleaded Fuel Only".
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Originally Posted by Knot 4 Me
(Post 4497518)
how many "test tubes" (anyone remember that name?) I installed. No one wanted to run unleaded even in cars designated for "Unleaded Fuel Only".
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Bump to the top.
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