What's the Best N/A Cam?

Discussion in 'SN95 4.6L Mustang Tech' started by fshawn50, Aug 28, 2009.


  1. hotstang_46

    hotstang_46 Member

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    wow, that's a new one. I've had none with mine nor the dozen or so people I know who have installed them over the years. You're not going to get PTV with the Vt stge II with a proper install and especially but not necessary a good degree. I can't even remember a thread on here, EVER, with a mention of that with this cam. :shrug:
    #21
  2. 40oz

    40oz Member

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    The problem is that without going into great detail, he's just another guy selling his own cams.

    No matter how honorable his intentions, the fact that he stands to make money off of telling people other cams can cause issues calls into question his character. It's one thing to claim your cam makes more power or better drivability or whatever. It's another thing to make claims that competing products *will* cause issues.

    Obviously a thing like a cam needs to be installed *properly* or it can/will cause the valves to hit the pistons. But I've met some of the guys at Hitech, have done work for them, and have a real hard time thinking they are ignorant of issues, much less careless.

    So unless Nick at Modular Headshop is willing to go into detail, it's just underhanded tactics to sell his own cams. I'm not saying he is a bad guy, just he isn't giving people a chance to see anything but him knocking the competition. He's being unfair to himself.

    I was just thinking this threads underscores a need for a comprehensive cam sticky to lay out the issues and proper way to degree a cam to avoid bad scenes like this thread is starting to get in my eyes.

    I have no reason to think VT cams, Hitech cams, Modular headshop cams, and all others are not *ALL* worth the money. This isn't a zero-sum game. There is more than one way to skin a cat, and more than enough market to go around. One doesn't need to enter the market trashing the competition. How would you feel if you designed a cam for one of the other companies, and some guy at some shop you never heard of started telling people on the internet that your cam wil trash your head?

    Most of us should know that a cam needs to be degreed to get the most out of it and to maximize the benefits. I'd have an easier time buying a cam from a shop that shares their knowledge about how to properly install it than one that says "All others will ruin your engine!"

    I will still have a shop put it in, but a shop that will tell you how they do what they do will easily sway me to their side and convince me they have the knowledge worthy of my money. Vague warnings tell me the shop doesn't really understand what they do. Fair or not, it's their words and they should pick them more carefully.

    Selling fear drives my dollars elsewhere. That said, I am NOT saying this Nick at Modular Headshop is a hack. I'm sure he knows his stuff and is more than willing to share it in person. Just let's stop with the vagueness and just say all but the mildest of cams need careful installation. I'm down with the whole "lift != power," but can we get beyond "all other cams will make you cry" BS?
    #22
  3. CobraRed_96_GT

    CobraRed_96_GT Active Member

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    I don't really see this. We have one source saying X=PTV. I, and others, are asking for reasons, specifics. Pointed to some info which I tried to break down and refute based on my non biased (financially) perspective. Thread is not exactly doing anyone a disservice.
    #23
  4. 40oz

    40oz Member

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    "In my eyes."

    IMHO, I'd rather see specifics than hear about other threads on other forums, just like you. That's what I mean about "bad scene." Bad for Modular Headshop, not as in "soap opera."

    I don't know that anything needs refuting. Anyone who has looked seriously into a driveway cam swap should know degreeing is highly recommended/mandatory. That's why I have an issue with the whole "PTV" thing.

    And why I would like to see a concise and explanatory cam explanation and install sticky thread. There are enough good cam how-to's and degreeing threads that a knowledgeable member could be very helpful in bringing them together. If nothing else as a "why to degree" along with a "how to degree" type post.

    I'm not looking for a how-to so I don't have to pay a shop, more as a "here's how it all works together" type thing. So I am a better, more informed consumer instead of an idiot buying "magic stuff."
    #24
  5. TGJ

    TGJ New Member

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    Going back, I know of at least 2 VT Stg 2 N/A cam installed cars that had PTV on the get go. Like I have always, said that was due to install. What has been a new thing is that VT Stg 2 N/A cammed cars with Comp springs were floating valves and then having PTV. These owners were blaming the Comp Springs. A few of them upgraded to Crower Springs and then it all happened again. It must be the springs...

    I have seen a lot of videos of cammed 2V that have valve train noise. It is quite a common thing. I have always wondered what that noise is. One of the racers that ran VT Stg 2 N/A cams down in Texas, ran his car to 7000 RPM at the track. His car wasn't a daily driver and his car had valve train noise from the get go after the cam install. He tore the engine down to rebuild it with a higher compression ratio and he found something. All 8 Pistons had intake valve marks on them and was wondering what caused that. He was happier than a pig in **** that nothing was damaged. People said he had faulty Crower Springs that checked out fine and are currently in the new engine. On his new engine, he has valve reliefs cut into the pistons and he checked the timing and clearances, guess what no valvetrain noise either. Common thing with cars above, all had noisy valvetrain from the get go after the cam install. Really makes you wonder...

    I personally run a big 2V cam and I have Comp Springs, but I do have valve reliefs and my cams were checked for clearances and degreed in. Strange I don't have any valvetrain noise. My built 2V runs quieter than my 3V.

    Now Nick comes along and starts researching what others are actually timing their cams at and what kind of clearances they are seeing. Strangely enough, the clearances Nick is seeing and what others have seen is explaining why the cars above had PTV...

    There is a few more VT cammed cars that had PTV and the owners are remaining silent about it. I have had a lot of heated debates in the past on this board with some of the people running VT cams, I know 2 of them lost their built engines because of PTV and they are remaining silent on it...

    I learned something new. There is 2 versions of the Hi-Tech Stg 2 N/A cam. There was a revision to the cam about 11 months ago. The new Hi-Tech Stg 2 N/A cam, the timing specs have been retarded a bit. Why did they do that? Could Nick be right?
    #25
  6. navarro98gt

    navarro98gt Member

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    My car has quite a bit of valve-train noise and I suspect that it’s PTV. Over the winter I plan on taking it apart to see if there are any signs of PTV.
    #26
  7. CobraRed_96_GT

    CobraRed_96_GT Active Member

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    My car had valvetrain noise big time, one from head one not. Replaced the heads with my ported PI's and the valvetrain noise is still there minus the head's noise - but with the heads were off none of the pistons had kiss marks. But, this is pretty minimal valvetrain noise - worst I've heard is compcam - but 262's make as much noise as the 274's i've heard. Why would 262's be PTVing? Even thier specs clear the standards preached in this thread.
    I think it's important not to go at cam specs with a competitive mantality. You started with specs, and now you're focusing on brands - which shouldn't be interchangable, certain cams are out of the range of those specs and others arent from the same brand. Your posts sorta sound like mission statements, TGJ. I've seen an engine in my club fail due to improperly installed stock cams - should we start attacking Ford?
    #27
  8. TGJ

    TGJ New Member

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    I stated specs. and popular problem cams in my 1st post in this thread.

    I went into further detail on the one that apparantly doesn't have "known" issues...
    #28
  9. TGJ

    TGJ New Member

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  10. CobraRed_96_GT

    CobraRed_96_GT Active Member

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  11. 40oz

    40oz Member

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    #31
  12. 281CI96Coupe

    281CI96Coupe Member

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    Marginalizing the Intake Valves

    I've talked to someone who got there Hitech stage 2's installed on there sn95 modular gt, and he said that he sent his intake valves to cut so that it wouldn't have ptv issues. I read the thread and I didn't see anyone touch on this topic. He got the lip part of the intake valve machined so everything would work smoothed. What do you guys think? that shouldn't be a problem at all right. By the way I am looking into buying hitech's for future reference.
    #32
  13. scupking

    scupking Active Member

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    No issues with PTV on my Hitech Stage IIs they went right in. I didn't even change the valve springs.
    #33
  14. 281CI96Coupe

    281CI96Coupe Member

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    Yeah it shouldn't be a problem with the 99-04's since they have more of dish then 96-98's! With PI swapped car, the intake valves will hit with that cam without some modifying to piston itself or intake valves.
    #34
  15. CobraRed_96_GT

    CobraRed_96_GT Active Member

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    Nate, the 96-98's actually have more clearance - it's more about the orientation of the valve seat in relation to the squish deck than to the piston comparing 4.6's because even if the dish changes (like 23CC) the crown stlll comes up to the same TDC height in order to maintain stock quench.
    #35
  16. nickmckinney

    nickmckinney Member

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    My first post here so be gentle please!

    I wrote that FAQ pretty quickly and whenever I get a new question I add it in, I haven't had one in a while so it has remained stagnant. If you all want to help me write some more I can get some ideas from this thread as its going pretty technical.

    I don't diss other companies cams other than the issue that they don't tell you what their clearance value is even when you ask them. I had one person bend valves with the early Hitech Stage 2 spec, another bent with VT Stage 2, and another with Comp 270. When I tested for myself finally as I could not find the expected clearance value anywhere I found some pretty horrible numbers. On my end I was only doing the cylinder head work and those cams were the ones I recommended as that was what I was under the impression of really worked good. Well after paying out of pocket for some repairs I decided to get some in and test for myself.

    Comp 270 were changed in about 6 months after their initial release to give more clearance. One of my first sets of ported heads had bent valves and broken guides from the initial Comp 270 cam spec.

    Hitech Stage 2 are awesome cams installed at a 110 intake install centerline but you need to cut the intake valve lip. I could not get them to clear at 110 on my stock PI test motor. They changed from 110 to 112 somewhere along the way which does clear.

    VT Stage 2 still hold most of the NA records, they give about 0.005" installed at the 108 intake centerline on a stock PI head motor. Back in the day most of the fast cars were installing these cams with modified PI heads not realizing they had gained an extra 0.040" of piston to valve clearance with the aftermarket valve. Starkie, Tony Whetstone, and Kurt (Kurt02GT) all went mid to high 11's NA with this cam and modified heads. Kurt had stock ports but Manley valves on his combo. Starkie and Tony both had FoxLake style headwork done with aftermarket valves.

    I have yet to hear "valvetrain" tick after a new cam install on the many motors I have done. IMHO - if its making ticks right away the stock valves are cutting new spots into the pistons. Thankfully the stock PI intake valve with that thick lip is so stiff it can do this if the interference is only a few thousandths - about as self clearancing as you can get :D

    And as for selling cams, well lets just say that the amount of money I make selling cams doesn't even pay the grocery bill. There is very little money in cams sales for these motors once you take into account freight, credit card/Paypal charges, and the fact that the 2V cam market is so saturated already and with TFS and Lunati is now ultra saturated.

    It doesn't matter really who you get the cam from as long as you understand that the Achilles heel of the PI 4.6 is the piston to valve clearance issue. If you are willing to fix that problem first then the door is wide open for many different cam profiles. Also since the stock plastic intake manifold is the dictator of the powerband in the end, most of the cams perform close to the same once you tweek the entire combo. Case in point Johnny Langton has still one of the fastest NA 2V @ 112MPH with a 3800lb automatic IRS car with bone stock Comp 270 cams in NPI heads. After talking with him a bit we realized that the installation point he did on his cams could not be repeated in a PI unless it had valves and piston notches, well that is when my eyes saw the light. If you install his motor in a lighter Mustang its probably going to do ~116MPH. However I can't think of a single Comp270 PI head Mustang that is near 112MPH much less 116MPH.

    IMHO - VT hit something perfect with part of their Stage 2 spec and Hitech did the same with part of their Stage 2 spec. If you look at both those cams you see the Hitech are monster big intake and tiny exhaust compared to the VT Stage 2 but the VT Stage 2 still hold most of the NA records. Bullet probably went too conservative with 0.040" of clearance, I have good evidence that 0.015" seems to be enough to rev these motors to 6500 safely even on the stock springs.

    I will say that 222 intake duration with a stock PI valve and 228 intake duration with an aftermarket valve gives about 0.040" clearance on the 4.6 PI installed at a 110 intake centerline. 225 at 108 gives 0.005" with stock valves and 0.045" with aftermarket valves. 234 at 110 hits solid. These have all been measured on a test motor. Any more duration and/or earlier intake centerline (number getting smaller) lowers this spec and it doesn't matter who makes the cam or what name it is sold under. They all have to play by the same rules.
    #36
  17. 40oz

    40oz Member

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    ^ Thanks for posting. That's very clear. I went and read your posts on other forums and what you were saying bacame clear to me. I appreciate the fact you're sharing what you've found :nice:
    #37
  18. Mr. Rustypwnz

    Mr. Rustypwnz Advanced Member

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    hmmm... im kinda new to the 4.6, but I thought npi heads didn't do that well with like a vt stage 2 or the hitechs? im all for porting npi heads but would it make power and be faster than a pi head car? also didn't know tony whetstone had vt cams. his car runs 11.70s if I remember right, he's a cool dood!! id like to keep my car a npi headed car if possible...
    #38
  19. TGJ

    TGJ New Member

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    IMHO, I would go with a P&P NPI head over a P&P PI head for a built N/A car. FI, I would go with a P&P PI head over a P&P NPI head. NPI heads were not the problem, the cams and intake they had stock were. The main advantage of the PI head over the NPI head is the compression ratio bump. On a stock NPI car, it is tough beating the power gain of the PI head swap.
    #39
  20. 98COBRA281

    98COBRA281 Active Member

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    NPI FTW!!! ive been keeping my eye on this thread, because ive been wanting better cams..........
    #40

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