OK guys and gals, I need some advice and constructive criticism from the Nailhead bunch. I am sure I am beating my head over this way too much, but trying to get it right the first time. OK, so I am in the midst of getting things together for the 401 going into the GS. For the most part it is going to be a cruiser with the occasional trip to the track. I want it to be pretty healthy. So here is what I got going on so far. 401 +.045 over Tom's Forged Pistons @ 10:1 compression QJet Intake ST400 w/ JW Modified SP Converter Will be installing 3.36 or 3.42 gears in the rear For the time being, it will have the stock Qjet Intake, stock heads, and exhaust manifolds. I have plans to build a set of headers, and hopefully in the not too distant future start doing some porting work on the intake and heads. So I want a cam that will benefit from these mods and not really hold me back once I start to do the additional work, if that makes sense. I was thinking along the lines of the TA 413-401 cam. I also called Carmen today and got his input and he gave me a few options from what he has on the shelf. Here are the stats for comparison. Valve Lift In. Exh. Lobe Center TA 413-401 .517/.517 234 244 113 Carmen 1 .470/.480 218 228 112 Carmen 2 .490/.500 230 236 112 Carmen 3 .470/.470 244 244 112 - Modified W30 Grind Carmen's second option is in the ballpark of what he said he would prefer prior to him letting me know what he had on hand. He said about 230-236 with a 110-112 LC. I trust his judgement and sounds like it would be a good grind. I just would like to hear what others think as well. Like I said, I want to to sound pretty healthy, but I also want it to perform. Shouldn't be a difficult feat for the Nailhead. Thanks in advance for anyone's input. Much appreciated.
Without babbling on like I did last time we chatted, I like Carmen's 2nd cam although I'd prefer it on a tighter LSA, like 108 or 110*. I feel like it would perform better, and it should give more of the sound your after.
I agree with Andy :TU:. I don't run that cam. But looks like a good cam. My car has a old kennebell c114 cam and my dad 65 Gs runs a old poston nh400 cam.
Thanks for the input guys. Andy - I know not of this babble you speak of. Lol. I know we recently discussed this. I do love the choppy sound, but I am also performance driven. So, I am willing to give up some of the sound for something that will perform better. I kinda have this underlying goal to go sub 13's in street trim. Lol. It's possible. Not sure how likely, but possible. Thanks Dan appreciate the feedback. I over analyze everything, hahaha. These decisions haunt my dreams. Bob - Stop tempting me! Lol. No, I thought about going solid lifters, but I am not going there just yet. For now I am going to stick with hydraulic until I can put together funds for roller rockers. I don't need to tempt the stock rockers with a solid setup. I need something reliable. I am tired of not having my car to drive on the weekends. Maybe by that time Tom will have his roller rockers squared away and I can pick up a set. Once I have roller rockers in then I will be more willing to step up to a solid lifter or a solid roller cam. But until then it stays hydraulic for peace of mind. I think I may be leaning towards Carmen's cam over the TA, just for the little tighter LSA. Even though it doesn't have quite the lift or duration of the TA cam though. Gotta think it over a little more.
Johnny, you obviously aren't in a rush. Comp will custom grind you a cam, if you select lobes from their master catalog. I think all they needed last time I checked was 2-3 weeks lead time to get a cam blank in stock. Hell, I think TA might even offer a full on custom grind. I'd suggest you go that route instead of settling for an off the shelf setup. My cam has done me well, and I can't knock it for that, but I do wish I wouldn't have been impatient and gone with exactly what I wanted. I know I am always open to discussing stuff if you want to chat or have me run dyno simulations. If you don't have my email address shoot me a PM.
If you decide to go custom,a hyd. roller grind should work sweet!!:Brow: I think Competition Products sells roller lifters for a Nail Head,same lifters as a 455. No need to break in the cam and no need for oil additives or special oils.GL Derek
Thanks Andy. I definitely appreciate all the help. And you are right, I am not in a rush. I have time between the machine shop finishing up and we still havent ordered the pistons yet with Tom. I would love to look at a few options on the dyno program. I know they arent exact with the Nailhead but it would be interesting. My knowledge on cams is limited, obviously, so my issue will be knowing what will and wont physically work with duration vs LSA. I dont think I have your email so I will shoot you a PM. Thanks again!
A roller would be sweet and one day it will have a roller in it. However, that still raises the issue with the rockers. The rockers and rocker shafts are the weak links in the nailhead. So going with a roller which increases the ramp adds stress to the rockers. While I may not have a problem, right now thats not a risk I want to take. So for now I will be sticking with a hydraulic flat tappet cam.
What will add to the stress is the valve spring pressures required for a "Roller Cam". All that extra weight via lifters, pushrods, etc. all add up to needing MUCH stronger springs. The ramp rise I don't think I'd be as concerned about because the stock "Nail" as opposed to most other engines with a .842" diameter lifters have an average rise of approx. .003-.0035 per degree of cam shaft rotation. An average "Roller" has approx. 008". Most "Nails" stock from the factory are approx. .0069". So stock the rise is close to a roller as it is. Tom T.
Thanks Tom. That makes sense. Appreciate the input. If you dont mind my asking, being that we have discussed my build a little and I have covered it here, do you have any input on what a good hyd cam would be for my application? Whether it is a cam listed here or a custom grind, curious what your input would be. Just trying to get as much input from the Nailhead gurus as possible.
The Carmen #2 cam is getting into the higher-performance territory. You might want to bump up your compression ratio to keep the low end power. You'll have to do the DCR calculations to see where it ends up. I had a couple of custom cams I made up using Dyno 2003 and lobe profiles from Comp Cams. Got good results with an ex lobe that was 2 steps bigger than the intake. I still need to retrieve all that stuff from the computer that died. If you are planning on roller rockers later, pick a cam with a little less max lift and ramps that are not too steep..... the rockers will get that back and you don't want to overdo it and stress components too much. Roller cam.... Isky once offered a 'Rev kit' that used springs that installed in the lifter valley to add some pressure to the lifters. http://www.iskycams.com/pdfcatalog/2004-05/page21.pdf A quick search shows it's been discussed on Speed Talk.... take a look there.
Hey Tom,I think a good beehive style spring would help a lot to control the valves and bring the spring pressures down. What do you think? Derek
Thanks for the input Walt. I knew I could count on you to chime in, I just had to be patient! All those numbers I posted should be at a 1.6 Ratio. I understand with Tom's Rockers that ratio is actually higher, per your previous findings. I think if I were to stick around .500 lift then I should still be good with Tom's pistons. If I remember correctly Tom said the pistons should be good for up to about .700 lift. Obviously at that point I should be restricted by the valve guides and springs and not the pistons. I don't have an issue with going a little higher on compression, but apparently you buddy Don does. Anytime I have mentioned going a little higher, like 10.25:1 I get, "We should probably just stick around 10:1 for this build". I think he is just concerned about the engine pinging on pump gas. He also is playing on the side of caution cause he knows I want something I can just get in and go and be reliable. I just keep playing with that fine line, lol. I mean who doesn't want more power and to go faster? Isn't that the whole point. Haha. Now as far as trying to figure out what my DCR would be with Carmen's #2 cam, I guess I need to call him back and find out what the rest of the info off the cam card is. I am pretty sure the duration he gave me is at .050" so not sure how I would get an accurate Open/Close degree for the valves with those numbers. And I haven't figured out enough in coming up with a custom grind to calculate all that out either if I want to try something on my own. Guess it's back to the books!
Something else to tink about is having the flow of your heads checked if you had any port work done. With that kind of info a custom cam grinder would be a good way to go. Derek
No port work done yet. Hopefully get that started within the next year. Once the race car is back up and running and this car is back on the road, it will be time to pull out the plans for the flow bench and get started building.
I have to jump in on this one. I have a roller cam I would like to use. I measured lift and it's only .432 / .438. I'm ok with the lower lift as I'm mostly stock except for doc mods. my question is lifters 455 are compatible? I got out of tom's response since ramp up on these engines is high anyways no worries using stock springs and rockers? thanks for letting me jump in. Gary
66bulldogGS, That lopey idle caused by more overlap (tighter lobe centers) also comes with the benefit of more throttle response, a raised torque curve, and more cylinder pressure. It will also drop like a rock after max rpm. This will allow your headers to do what they are designed to do. Get this working right and you'll see better mileage, too. Same goes with your ported heads. Now's the time to do these. Perfect for what you need. Wider lobe centers give a smoother idle, a lower torque curve and hang on just a bit longer after peak power. On mild apps. like this, they often are recommended when folks are perceived to not want a slightly rough idle, or as a crutch to lower the cylinder pressure curve to tolerate poor gas. Definitely not good for a heavy car. You are at the stage where you can choose your compression level. I'd go with more overlap. It's already mentioned to tailor your DCR, do this. Don't go with too long of a duration unless your heads are stellar, gears are deeper, and converter looser. Play with header calcs. As pointed out, the ramps are fast already and a roller would not help until you maximize the rest of the engine. Of course use good oil if flat is used. The rev kit REALLY helps on street driven rollers that see idle time, to help keep the roller wheel in contact with the cam, and near valve float where skating or skidding would be fatal to the lifter.
Ok I have more work to do. Need to degree cam and get real information from cam. Lift, duration (could be too much for application) lob separation. It might just be a cool piece to learn from or all out performance. More to follow thanks.
OK, well I am back with an update. Yes it's been a while. Too long in fact. So long that I missed out on the cam I wanted with Carmen. Snooze you loose I guess. After spending an extended period talking with Carmen about my setup and the cams he has in stock or orders regularly we came up with a decision. It kinda plays on the safe side for now, but I think will get me what I am looking for. I am sure a few guys here on the board already have the same cam installed as it is nothing new. It's a version of the W30, not sure which specifically, but it is a 232/232, .470 lift, 110 LC. I really wanted a split duration cam, cause that is what everyone says runs best. Carmen actually told me he isn't having them made anymore cause he doesn't feel they show enough improvement over the single patterns he carries. He still has the smaller dual pattern in stock, but not the one I was looking at. I would have gone with the larger 244/244 version of the W30, but Carmen said I would be chancing it with having enough vacuum for power brakes and possible p/v issues. So I thought hard about it for the evening and had a chat with the Uncle, and we decided this would be a good place to start. I wish it had a little more lift, but I figure if I can get my hands on a set of Tom's Roller Rockers once he has them back up and going, then I will get closer to that .500 number anyway. I think it will sound good and still run pretty well, which is my main goal anyway. Once I get it on the road and then to the track and see what it will do, then I can go from there. I'll get more custom with it later. I will be working on an additional set of heads for porting and stuff anyway, so I can then tailor that set for better performance via porting and make the adjustments needed to run bigger lift if that's what I decide to do. I am still set on making sub 13.0 passes on street tires. We will see if that happens or not.
