Ferrea Racing Components manufactures a wide range of hardcore performance valvetrain components and has been involved in an immensely broad spectrum of the automotive industry. With experience ranging from the OEM side, to the top levels of motorsports such as Formula 1, along with everything — and we do mean everything — in between. If an engine uses poppet valves, chances are Ferrea, and by extension, its marketing director Zeke Urrutia, have had their hands on it.
Here, Urrutia answers ten of the questions you submitted, on subjects ranging from valve material, size, and length, to valvespring loads and RPM limits.
In a turbocharged DOHC application, would oversize valves be a cost effective enhancement? How would I determine how large to go with the valve sizes? – Doug Cutler
This is a good question. This used to be a very common situation about 10-to-12 years ago. Oversized valves used to be a thing where you had no choice but to go with oversize valves, because the turbochargers weren’t as efficient as they are today.
Because the efficiency wasn’t there, what you would mainly look at in this situation was the efficiency of the cylinder head, and trying to get every last bit of flow out of it. Today, that has completely changed. Now we have great turbochargers along with fantastic technology and data which allows you to have full control of the system.
With all of that great technology, it has allowed us to get back to standard-sized valves, because the efficiency is so great. Now, standard-sized valves do the job, and the trend has been (especially on multi-valve cylinder heads) to use a standard-sized valve in a turbocharged application.
Even looking at two-valve heads, the valves really aren’t getting any larger. Some applications are trying to push the intake charge a little faster on the intake side. So they have been playing with intake valve sizing a little, but through it all, the exhaust valve sizing is staying the same.
How many RPM can your 6000-series handle? I’d almost guess you’ll say it depends on the cam profile and spring pressure, valvetrain stability, etc. Would 8,500 rpm be out of the question? – Steve Peyer
This is really a myth. RPM really isn’t an issue with our valves, in general. When you jump into the 6000-series, which is basically our middle-of-the-road valve, you get into decent materials. It’s a valve you can run with high spring pressures in a roller cam application.
RPM really doesn’t affect the valve, what affects the valve is having the proper valvespring to control the valve, with the right profile on the camshaft. If you have a great camshaft, and the right spring pressure, and you want to twist a 6000-series to 9,000 rpm, it’s not an issue. You’re going to face an issue of weight more than anything, more so than an issue with the valve handling the RPM.
Whether you get a 6000-series or Competition Plus-series valve you’re not going to have a problem with RPM. It’s just controlling it properly with the right valvetrain, and trying to get as much weight out of the valvetrain as possible.
That .750 to .800-inch lift area is really a gray area for stainless, and once you are past .800-inch, titanium is a must. – Zeke Urrutia, Ferrea
I work at an automotive machine shop where we sometimes do diesel cylinder head repair. I have noticed that the Duramax valves are coated with a black nitride coating, and those valves are amazing. We don’t have to grind them, the stems are never worn, and they’re just perfect every time. Yet, they are seldom used in other applications. If GM uses it by the millions of valves; why is it not being used more in other applications? – Bill Starks
This is an interesting question. When we do black nitride on our valves, we don’t suggest that you go in and machine the valves, because depending on the thickness of the coating, you’ll probably take the nitride off, and then the metal is left unprotected. So it’s good that you aren’t machining them.
Why you don’t see them more often is a little difficult to answer. One part has to do with seat materials and the hardness required in some applications. Some diesel applications have a Stellite valve seat insert on the valve itself, and the seat in the head is also Stellite as well.
That hardness is needed, and you can get that through nitriding. The nitriding process [like the Stellite seats] increases the hardness of the valve. As soon as you break through, or wear through that shell the nitriding provides though, you’re going to run into wear issues pretty quickly. You don’t need that hardness in a standard application.
I run a Super Comp SBF that is making just north of 1,250 horsepower. This is a drag race engine. It currently has stainless steel intake valves and I shift at 7,800-plus rpm and sometimes even see 8,200 rpm. Would there be any real world benefit to running a titanium intake valve? The engine uses shaft mount rockers with a solid roller camshaft. – Vernon Pitts
The fact that you make 1,250 in a Super Comp engine, turning 7,800-8,200 rpm – that RPM is a little low. Really, we would probably need the amount of lift being run to make the decision to go with titanium intake valves, and that’s not included here.
Is this a candidate for titanium? Sure. We do have a majority of the Super Comp guys we deal with running titanium valves, but certainly not all of them are. Really, we’d need some more information. But the titanium intake valves certainly are beneficial, drawing that weight out of the valvetrain.
Stainless is definitely a viable option in this application as well. It’s really going to come down to the amount of lift you are running on this one. If you have a camshaft that is well over the .750 lift mark, then we would definitely steer you towards a titanium valve at that point.
That .750 to .800-inch lift area is really a gray area for stainless, and once you are past .800-inch, titanium is a must. If you run stainless with that much lift, you’re going to be changing valvesprings literally every single race, and those springs better be dead-on from the factory, every time.
I am running a small-block Chevy with 190 pounds of seat pressure and 560 pounds open. I am also running 45 pounds on each lifter with a rev kit and stud girdles, and I am still having valve control problems. The engine is in a bracket race car and I am shifting at 7,500 rpm. I am running 6 psi of boost with a Weiand 144 blower on E85. The valves are 2.02-inch intake and 1.60-inch exhaust. The cam is a solid-roller with 252 degrees of intake duration at.050, 260 exhaust at .050, 114-degree lobe centers, .610 intake lift ,and .620 exhaust. With 6 pounds of boost, the intake valves shouldn’t need more than an extra 20 pounds of spring pressure, should they? The engine runs great, but is really high-maintenance. I have to readjust the valves constantly. I’m afraid that it will have a major problem before too long. – Doug Coffman
You’re on the right track. We typically do equate the amount of boost to RPM as well as lift of the valve. So really, there are three equations to be put into the number here. Without the length of the valve specified, we’ll have to guess there, but the RPM is fairly low.
Dealing with these numbers — we do take into consideration lift, RPM, and boost — we have a formula that we’ve put together which also takes into account the weight of the valvetrain components as well. Rocker weight, valve weight, spring weight, even the weight of the locks and retainers are all considered when determining a valvespring pressure.
Looking at these numbers, and assuming some weights, it looks like you’re low on spring pressure. With some general weights for a 2.02 intake and 1.60 exhaust valve, it looks like you would want to be at about the 230-pound mark on the seat pressure, and around 600-pounds of open pressure.
We also factor in a margin of load-loss in the calculation. Today, we talk about load-loss in the five- to seven-pound range, but see some stuff go as much at 10 pounds. We like to put that into the equation. That way, in case there is a load loss, there’s extra poundage built-in, and the spring is where it needs to be.
I’m getting ready to prep a set of vintage Ford Cleveland Iron 4V heads for drag racing. Can I swap out the 11/32-inch stem valves and go to a smaller diameter stem to shed some valvetrain weight? I’m replacing the guides and buying new valves either way. – Jeff Nagy
This is fantastic. We do have a lot of guys in the Cleveland market that do this. We suggest the reduction of valvestem diameter in this application. You will definitely see an uptick in RPM and drastically drop the weight. Cleveland heads usually come with 3/8-inch valves, and going to 11/32-inch is an improvement. So going from an 11/32 to a 5/16 valve will be an even larger improvement. You’ll probably see about 300-400 rpm more out of the engine.
There is definitely a sweet spot increase on the 4V Cleveland stuff. We get a lot of guys that come back to us and say that their drivability has gone way up, and the mid-range and top-end have both picked up, with the smaller valve stems’ lighter weight.
What are the most significant factors in selecting a 7-degree valve lock vs. a 10-degree valve lock? What about other lock angles? I’ve done some reading and the discussions seem to offer as many pluses as minuses for both. – Greg M.
I actually did a video on this last year [which we covered here] and got a lot of great questions from it. Degree on locks really depends on how much you want to pry apart the retainers. 7-degree is pretty much the standard throughout the industry. GM, Chrysler, and Ford have all done 7-degree components for over 50 years. It’s pretty much the OEM standard and is also used in a lot of crate engines and some racing applications today.
It comes down to the fact that the 7-degree taper is easier on the assembly than a 10-degree. The 10-degree tapers further and hugs the valve a little closer and tightens itself a little more than a 7-degree during use. So on disassembly, it becomes more of a nightmare to do than a 7-degree because the taper locks everything together tighter.
We actually offer three different lock angles here: a 7-degree, a Super-7-degree — which is actually an 8-degree — and a 10-degree. The 10-degree stuff is used in a lot of high-end competition engines in NASCAR, NHRA, and Pro Stock, specifically. It grips that area of the valve much, much harder and allows for less movement of the components, and in the end, it’s a little extra security in preventing the lock from disengaging from the valve if there were some harmonics that build up in that area.
For the most part, a 7-degree will work in most of the applications you’ll see, and It really comes down to difficulty of disassembly and personal preference. Those 10-degree locks can really be difficult to get apart.
I’m trying to build my ultimate street engine, where I would like the valvetrain parts to be really lightweight and still reliable for 80,000-100,000 km. How durable can be a spring retainer made out of 7075-T6 aluminum with 35 microns of hard anodizing surface treatment? Do they need steel shims between them and the polished Manley springs? Will the 7-degree retainers with 7-degree steel locks work well in contact with aluminum retainers? – Sergio Rivera
We’ve tried to do some of this. It didn’t really work out for the best, for us. We’ve tried a variety of aerospace alloys, and engine designs and sizes. We’ve tried plenty of surface coatings, too, including gold nitriding. The aluminum, no matter the alloy or coating, will flex. That’s the issue you will always face: the higher rate of flex. It occurs throughout different areas, and depending on how the retainer is designed, the flex is just too much to overcome.
You can solve some of the issues, like the premature wear where the retainer contacts the spring, but you will face some issues with the steel lock and aluminum retainer, and then the flex points that occur. You will have some wear, and some hairline fractures because of those issues.
I would say that it’s just not feasible to do what you’re suggesting out of aluminum, even with the steel locks. You could maybe look into designing a tool-steel retainer to take advantage of its strengths, to be almost as light as titanium, but have the strength and maybe 60-70-percent less flex through that area, and minimal to no wear on the tool-steel.
My engine builder tells me that engine valves can break when running E85 because the valves don’t get hot enough and are brittle at the lower operating temperature. What does Ferrea have to say about running E85? – Jim Miller
This is a great question. There are multiple points to be made, and there is some validity to what your engine builder is saying. The key here is to run the proper type of stainless-steel valves in this application. You need to have the proper elements in the alloy of stainless steel that you’re using for the valve.
For example, Inconel isn’t the best to run with E85, or really, any other exotic materials or Super Alloys. They have very high temperature ratings, and it’s never a good idea to run the higher-rated stainless materials with that type of fuel because it just doesn’t generate enough heat. Those types of materials need temperature to operate correctly. Things like the material’s flex and memory only happen at elevated temperatures inside the cylinder heads.
You aren’t relegated to only standard materials with E85, just nothing too exotic because of the lower operating temperature. I don’t want to start sounding like a material science seminar and get boring, but if you keep it to a stainless material that isn’t an exotic, high-temperature alloy, and you’ll be fine.
Will using a longer valve result in improved airflow? – Tom Urbanczyk
No, that would have no bearing on the flow. Your valve is still opening the same amount, you’re just affecting where it’s being opened from. Valve length doesn’t dictate airflow unless you’re playing with some kind of timing change based on the longer valve. But, I don’t really know how that would work in a practical application. Maybe if you were to add half-an-inch and were able to alter timing to hang that valve open it might, but nothing in the practical realm of just adding length to a valve.