Muckman

iTrader: (2)

I picked up a big valve DART head with +1mm intake and exhaust valves and want to figure out which cams I can run without V2V contact BEFORE I order them. I am only looking at Skunk2 because I am familiar with their cams.

Skunk2 tells me I can run the Tuner2 cams but absolutely NOT the Pro1 cams because the primary and secondary profiles are bigger than Tuner2. My tuner told me the Tuner2 cams have too much duration to make good power. The previous owner of the head told me he ran the larger Pro2 cams. Doesn't that negate what the Skunk2 rep said?

I intend to degree the cams when I install them but I’m hoping to choose wisely before I purchase the cams. I’m looking for experience from anybody who’s running a big valve head. I’d like to know how much cam can physically fit with big valves.

The setup is a 2.0L B18C, high compression, E85 fed, GT35R.

Muckman

iTrader: (2)

Maybe pictures will help entice responses.

TheShodan

iTrader: (14)

So this is now going to be a GT35R and not the GT30R 60 trim correct? Because if you told Skunk you were using the GT3076R -13, he would have been correct. Not so much with the GT35R. Rule of thumb is that for the Pro1 cams, you need about 61lbs/min or more for them to work properly.

the other company that I recommend is the Web Cams.. Stage2 35-452 Or similar grind. They seem to really work well in competition for larger turbos over 53lbs/min

Muckman

iTrader: (2)

Yes GT35. Skunk2 wasn't informed about turbo size nor did they ask. We are specifically talking about v2v interference. The Skunk2 rep told me Pro1 cams will causes v2v interference when the previous head owner said he ran larger Pro2 cams with no problem. The problem is Im getting conflicting information on what will work with large valves. Id like to run Pro1 or Tuner2 cams with the GT35.

EsotericImage

iTrader: (8)

clay it?

Muckman

iTrader: (2)

I dont have the cams to clay. Should I buy multiple sets of cams to clay?
Im looking for people who have experience with big valve heads that can say "X cam will work" before I buy it.

kbouchard1092

What would make it different from a reg honda head with 1mm oversized valves? is the dart head that much different? im sure alot of people use 1mm oversized valves with honda head and big cams... I have no experience with Dart heads. i dont think there that commonly used. How much are you paying for it?

TheShodan

iTrader: (14)

For GT3582R or above you'll be fine with a Pro1. The reason they didn't want you to use it was because the size of turbo wasn't discussed. Typically most ask about turbos under the 61lbs/min requirement. They were concerned about whether or not you were using oversized valves.

Muckman

iTrader: (2)

Its not different. Its a Honda head ported by DART.

DraginX

I have oversized valves also and contacted skunk 2 last week about running their pro 1 cams and they told me the same thing. Said they DO NOT recommend their pro cams for anything with oversized valves. So I am in the same boat as you and have been researching like crazy trying to figure this all out. I was thinking Brian Crower stage 3's but don't want to run into the same issues with them. Someone must be running oversized valves and big cams??

TheShodan

iTrader: (14)

There's a difference in not being recommended and not allowed. Skunk2 is concerned about the V2V clearance first. I still think it can be done, but that some adjustments can be made. the key is which turbocharger you're using.

Again, there's also the Web Camshaft that can be used.

DraginX

Why do you keep insisting what turbo is being used, when the main concern is v2v clearances? I don't see how that matters for this particular issue? Maybe I'm missing something? I know to run the pro1's you want to have a big enough turbo to run them properly but how does that affect v2v clearancing?

00Red_SiR

You can run the pro 1 cams on a head with oversize valves but you MUST have the head off, to check the V2V clearances as you rotate the cams. By doing this, you will find out what range of adjustments are safe BEFORE you install the head and cams. Then when you start adjusting the cams on the dyno for best power, you'll know how far you can go and still be safe. Degreeing will not guarantee no V2V contact since you're not using stock valves. Adjustable cam gears are a must as well. Skunk 2 tuner 3 cams might be worth looking at from what I understand, this comes from guys running turbos that experiment with a lot of different cams.

TheShodan

iTrader: (14)

Otherwise, yes, you're correct with that.

Muckman

iTrader: (2)

Let’s just assume we are all running GT42's so we can move past this issue and concentrate on what cams won't cause valve contact.

00Red_SiR, I intend to degree whatever cam I install. The intention of this thread was to simply confirm if the cams being considered would definitely cause V2V contact or not. Did you mean the Tuner2 cam like Shodan suggested? The Tuner2 cam has as much lift as the Pro1 cam but more duration.

Skunk2 explicitly told me the Pro1 cam was not allowed on big valves heads yet the Tuner2 cam with the same lift and more duration is safe? That makes no sense. The previous owner of my big valve head ran Pro2 cams so it’s possible.

TheShodan

iTrader: (14)

Ugghh.. I'm done. Its BEEN done with Pro1s as long as it was 61lbs/min or better. Muckman.. you're at a point now where its either do it, or don't and try something else like a Web Cam..

I think this will just drag on too far without anymore usable input..

00Red_SiR

If you want to try and degree in the cams that's fine but you'll need to check your safe ranges for V2V clearances first. The answer you're after isn't a black and white one. For instance, I can run my pro 2 cams at 0-0 barely, while others running the pro 2's cannot and that's with everyone using stock valves. That's because Skunk I believe (whether they admit it or not) has altered the cams slightly on various production runs to allow them to be run at 0-0 without touching valves because so many people were having problems which was giving skunk bad publicity (even though it was the users fault for not checking clearances or degreeing first). Because of this, Skunk often has no idea what production run of cams, anyone has and therefore must play it safe and say that everyone must degree in their pro series cams and check clearances. That being said, if I was running oversize valves, I couldn't run them at 0-0 and I'd need to know what cam gear range settings weren't ok BEFORE I started trying to dial them in on the dyno or trying to degree them. So in that sense, the answer for me is that I won't have any V2V contact with stock valves but I will if I run oversize. I can still run oversize as long as I know what adjustment ranges are safe and what isn't. Get the picture?

I was actually suggesting the tuner series 3 cams as I've seen some pretty good results with those and the Blox C's (Jun 3 copy) and HSL's on some turbo cars. I'm an all motor guy though so I don't have any direct experience with those cams on your specific turbo, so I'd be going on an "experienced gut feeling" which I know isn't fact and it's why I didn't challenge what Shodan was saying. It's something that I would do if it was me because I feel most turbo guys leave a lot of free power on the table by not experimenting with cams. In the all motor world you realize that all the basic cams will work and make power but the "right set of cams" is what sets one build apart from another and makes the power you want.

As far as the pro 1 series vs the tuner 2 series goes, lift and duration are factors yes but it's the different cam centerlines that affect V2V contact or not. I'd be willing to bet that you'd be hard pressed to get any V2V contact with the tuner 2 cams, no matter where you adjusted the cam gears. The Pro 1's are a different matter and when using oversize valves, you'll have no margin for error and must check the clearances but you will be able to run them.

TheShodan

iTrader: (14)

Well, this is why I suggested the Tuner 2 over the 3 because of the similarities of the secondaries with the Pro1. I AM a turbo guy and I've seen TONS of success with the Pro1 cam on turbo cars, but ONLY WHEN THE TURBOCHARGER WAS DESIGNED FOR A SPECIFIC AMOUNT OF AIRFLOW OR ABOVE.

The use of the Pro1s over the last 3 years is how the "all motor cam on turbo cars" phenomenon started in the first place. But unlike the all motor guys who have the time and energy to experiment with several types, with turbochargers, the amount of time needed to dial in everything correctly is tripled..That leads to a higher cost in which other things have to be addressed in the turbo world.

I myself will be trying the SKunk2 Tuner 1s over the CTRs I currently have in my TA project, to do precisely what 00Red is talking about; a bit of experimentation based on certain info. Brian@Skunk2 is allowing me the opportunity to do some testing on the dyno and the circuit so that we can get some real world data so that I can give some impartial feedback as to their use compared to others. I'll probably not switch back, but we'll see.

NotAJDMFanBoy

Skunk2 told you not to run pro1 cams, but the owner ran pro2 cams? If this is really the case and has been done, why would it be a question of if it could be done? Whether it's smart to or not is another matter.
You can't go by advertised lift alone when comparing cams. Different companies will advertise a cam as being slightly different than it actually is for marketing, or use different ways of measuring lift. Also, few companies list specs of all 3 lobes.

Skunk2 may not have tested that setup or they may have and believe it doesn't allow enough room for error. It's probably just a liability thing, so if you blow up your motor, it's all on you.

I think that sums up the situation. If bigger cams have been run, it can be done. However, as TheShodan said, there is a concern over the cam specs, valve size and the size of the turbo. He knows a lot more about turbos and probably engines in general than I ever will.

I don't understand the allure of running an all motor cam for turbo. All motor cams have less lift but more duration, and turbo cams are the opposite. I have Crane Stage 1 (essentially CTR replicas) cams because a friend was parting out his turbo engine. Obviously I didn't do a ton of research, but I'

Turbo-LS

iTrader: (4)

you can run the Pro1's but as stated above you will need to check v2v clearence so you know the range of adjustability you advancing and retarding the cams on the dyno you have so you dont have valves hitting eachother

And like Mac said you need to be running a 61lbs or higher flowing turbo so the pro1's to flow properly otherwise they will choke the motor and give you less performance than a smaller cam like the tuner1's.

the tuner2's are from my understanding about the same size as the pro1's just different lobe seperation, someone correct me on that please if im wrong

tepid1

You'll be fine with the pro 1's and oversized valves. I run the Web pro's with oversized valves and no issues here. You just need to know your v2v and p2v. Make a spreadsheet and move the fvck on! No need to over think anything here.

When chosing cams you need to heavily consider turbo and exhaust manifold design. It has a HUGE affect on the dynamics of the system. That's why Mac is asking so many turbo related questions....

tepid1

The newer version of the Pro 1's are different from the initial released Pro 1's. Like you stated they changed the centerline of the camshaft because of retards not degreeing their motors....

00Red_SiR

That's probabably because you don't really understand cams. If you do some research, you'll find that most people using turbos make more power on all motor cams than they do turbo cams. There's a science to everything mechanical and the way it all works together and for the most part, lift and duration are good for making power on turbo and all motor engines, it's the amount of overlap that usually causes power loss or issues on both types of engines if it doesn't match what that engine wants.


Tuner 2's have similar VTEC lobe profiles to the pro 1's and perform "similar" in VTEC but the pro 1's have larger primary lobes and are a more advanced cam compared to the tuner 2's, especially with their ramp rates/angles. Centerlines are also different but the pros will make more power everywhere over the older tuner 2's.

Turbo-LS

iTrader: (4)

Thank you

DraginX

What would be considered safe tolerances between the valves to avoid v2v? 0.050"? bigger, smaller gap??