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Old 01-22-2019, 09:17 PM
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Sure you can drop in a aftermarket cam for better performance that's really the premise of their business, though GM sets the initial benchmark for all others to follow. Some want increase performance but not overly stress the valvetrain while retaining a smile on ones face.
Hey I'm not about to get into a pissing match about why GM puts the .525" cam into their engines cause I don't know & I don't want to speculate. Still learning LS platform from my old school SBC past from forums like this. You're probably more experienced than me..... maybe you could help make a recommendation to the OPer he's looking for help.
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Old 01-22-2019, 09:50 PM
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OP went from a 216/220 112+? To a 218/226 116+3 and lost performance, I think that is what we need to talk about here.

You added a little exhaust duration and slightly reduced the amount of valve overlap with the second cam. I think that should be a lesson to the donkey dick peddling folks around here haha
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Old 01-22-2019, 10:02 PM
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Originally Posted by stockA4 View Post
I think that should be a lesson to the donkey dick peddling folks around here haha
I don't get it
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Old 01-22-2019, 10:39 PM
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Originally Posted by 98CayenneT/A View Post
I don't get it
Obviously op did not need to swap cams yet he was sold something he did not need and now he's having to do it a third time, and should probably go for an even shorter duration than before.

A camshaft spec is always a compromise and what is recommend, even by a expert vendor may not be the best choice. A lot of people read on here and still go for the cam that is to big. That's all I meant by that.
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Old 01-22-2019, 10:47 PM
  #25  
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Originally Posted by stockA4 View Post
OP went from a 216/220 112+? To a 218/226 116+3 and lost performance, I think that is what we need to talk about here.

You added a little exhaust duration and slightly reduced the amount of valve overlap with the second cam. I think that should be a lesson to the donkey dick peddling folks around here haha
So the lesson is that 4 degrees of overlap is worth more power than two degrees of intake duration and six degrees of exhaust duration?

Let's assume for giggles that the first cam had 0 advance, so a 40 degree IVC. (-6 overlap)
If the second cam had been 218/226 at 114+3, it would have the same IVC and overlap, still with the +2 intake and +6 exhaust duration.
How would that cam drive, and how would it perform?
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Old 01-22-2019, 11:12 PM
  #26  
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I would imagine opening the exhaust a little earlier could still hurt the low end a bit, but it might carry on a few more rpm past peak though but I doubt it would be any quicker, It's interesting because you always hear that more exhaust duration is needed the more restricted the exhaust is but maybe there is more to it.
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Old 01-23-2019, 04:50 AM
  #27  
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Originally Posted by G Atsma View Post
The reason GM puts that cam and the ASA cam(also .525 lift) in their crate engines is one word- WARRANTY. This way they can use the LS6 springs with the .525 lift and never worry about valvetrain problems. This is why you're better off getting the std. LS3 engine and put in a better cam of your choice.
Truth to that IMHO. GM doesn't know the owner will check valve springs and replace as needed as normal maintenance. Likewise, replace retainers and other hardware. My 224/224 .581/.581 lift cam ran flawlessly for 130,000 + miles, of course valve springs & hardware were changed as maintenance items. Always let the car warm up. Still ran fine when pulled for a bigger motor.

Likewise, the demands for a good road race cam with max durability are different than for a hot rod or 1/4 mile cam.

I agreed with Pulse Red that LS's really like the .~600 lift cam on the intake side.

Wish I had a good cam suggestion for Red Pulse.
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Old 01-23-2019, 06:56 AM
  #28  
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Originally Posted by Pulse Red View Post
I'm getting a different tune and intake from a new shop so now looking at a new cam to replace my Cam Motion Torque Titan 218/226 .595”/.587” 116+3 while I'm at it. This is a good cam, you could not get that much closer to factory while still making good power IMO. It delivered on my initial desire for a very smooth and quiet cam with no lope but I have found that replacing my previous 216/220 .600/.600 112 cam with this bigger cam I lost too much low down and responsiveness which would not be as noticeable in an F body but is important on the street in a manual car of the weight of my 2004 Monaro (2004 Pontiac GTO equivalent). Surprisingly I also lost top end power, dropping from just under 400 rwhp to under 380 rwhp (lower reading than US dynos though) but its the responsiveness I miss.

Originally I was just going to go back to a 216/220 like my old cam but since I'm starting again with a new shop anyway I thought I would look at options. I know you guys in the US don't believe in baby cams for a 5.7 but you guys know your LS obviously so does anyone want to recommend a replacement? Its only a street car, not raced at the track any more and doesn't do much freeway running. I understand that I will probably not be able to get as good manors as the current cam I will need to shorten the LSA/ decrease overlap which is ok within reason but I want to achieve the following:


- Excellent low to mid range to support my heavy car
- Responsive and not laggy (sharp under 3000 rpm)
- Smooth and not too much lope
- Hopefully regain some of my lost power

I'm guessing I will also need to replace the valve springs with duals to support .600 lift and over and the pushrods I fitted with this cam.


The current combo is as follows:

Higgins CNC Ported 241 heads
Pac 1218 single valve springs
LS7 Lifters
Manley Pushrods
Stock rockers with brass trunnion upgrade
Rollmaster Double Row timing chain
25% underdrive pulley
Ported stock TB with stock LS6 manifold
OTRCAI with 85mm MAF
1-5/8 short headers with 100 cpi cats
Twin 2.5" Stainless exhaust
3.91 Diff Gears with TrueTrac



Thanks in advance!
I have puzzled over this one on and off since you posted it. I would not have thought you'd see the kind of results you have seen. That cam motion cam should be a pretty good drop-in cam with similar IVC valve event as the GM LS6 cam, but more overlap. In fact, it is similar to a stealth cam I've been tossing around the idea of in my wife's 6.0...

Everything I am about to type assumes you have already verified your cats are not plugged and you're not dealing with a cylinder misfiring or dead.

The nearest I can figure is that you lost dynamic compression (although by the math, not very much) and it negatively affected everything, making it more sluggish, etc. The other thing I noticed is your EVO event is 10 degrees earlier on the cam motion cam vs your old cam. To me, all of this points to compression. Generally, with lower compression, you need the exhaust valve to stay closed longer (open later). Higher compression, the work is extracted sooner, so you can open the valve sooner. Similarly, higher compression would restore what you lost on the later IVC. Now, admitedly, I don't design around DCR, but I do still reference it. I also don't know the quality of fuel you have available whether it be 93 octane, 98 octane, kangaroo sperm, etc, but given 93 octane, and thinking reliability and drivability, here is what I would be thinking:

1. Compression -- Regardless if you keep the current cam (I think I would) or swap back to your old one or go with a third option, I would strongly recommend milling the heads down to 61cc. That will give you that explosive throttle response and extra punch I'm thinking you're after on either cam. Also, go with a thinner head gasket, but no thinner than 0.041. A generality, but as you increase cam size, compression should follow it. 61cc will get your dynamic compression into the 8.5-8.7 range, which is great for low end grunt and throttle response (Up from 7.8).

2. Valves -- whether or not you swap heads, grab a set of LS6 valves or turned down LS3 valves. Then you won't need dual springs and can run PSI 1511, which are very light. Between the ls3/6 valves and the psi springs, you can easily cut a pound to a pound and a half out of your valvetrain. Doesn't sound like much, but you'd be amazed

3. Pushrods -- if you are running comp 7.4" x 0.080, then you are likely fine. Edit -- nevermind, yours are manley. Leave them in, they are fine.

4. Cam -- this is the tricky one, and I think in the end your current cam will run smoother than your previous cam due to less overlap (higher negative overlap). In concert with more compression, I think you'll be pretty happy. If you're dead set on swapping, here are some things to consider:
...a. 43 degree IVC is about right for a 5.7 if you do not plan to rev to the moon. Will peak right at 6300 rpm. (current cam is 42, old cam is 40)
...b. 50 degree EVO is about right for a 5.7. (Current cam is 52, old cam is 42)
...c. LSA is a result of valve event calcs, so don't focus on it too much. look at the overall valve events. there are really long threads explaining this, I won't go into it here.
...d. I know the heads don't flow much better at .650 lift than .550 lift, but I still like to go extra lift. The reason is longer duration at the lower lifts. a short duration, fast ramping cam will make better intake vacuum, good for low end torque and throttle response..
...e. If you're reading this and saying "I'm not milling my heads or doing head work of any kind because i've already done that having mine ported", then I would honestly swap the old cam back in or maybe go even smaller to say 214/218-112+0. This will have less overlap than your old cam AND higher DCR which will help that throttle response out.
...f. If you're reading this and thinking "OK, nothing to lose from compression", then I would keep the cam motion cam in there and see if you're happy. Now, I'd even think about a modified version of that cam but with lift at .625/.608 for some extra punch.

6. Miscellaneous -- Some other items to consider...
...a. kudos to you running a dual exhaust. It may be a benefit to step up to 1-3/4 headers
...b. lighter clutch or at least lighter flywheel. You would be amazed at how much difference a lighter clutch can make in terms of waking the car up.
...c. Please re-read the second paragraph of this post. The cats being plugged, even partially, would completely explain the issue. I had a catted Y a few years back brand new, cats were plugged.

I know it is easier to spend someone else's money on the other side of the internet, but given your goals, I think this is the best play. Hope this helps in some small way
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Old 01-23-2019, 09:23 AM
  #29  
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Nice post! O.P. Do you have the .006 duration numbers on both cams?
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Old 01-23-2019, 09:56 AM
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This thread has me seriously rethinking the cam timing I was considering for the 11:1 iron and cathedral 372 I'm building for my completly stock 02' Z28. It's going to have the stock ls6 intake, stock, exhaust manifolds, stock converter, and stock 2.73's. It's a year round daily driver. Is a 224/232-115+2 going to suck?
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Old 01-23-2019, 10:33 AM
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The cams are very similar (@ .050 valve events anyway) if it has the lift. The Ghost cam closes the intake 2 degrees earlier so it would bump up torque and would be a better match for your stock converter.
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Old 01-23-2019, 10:46 AM
  #32  
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Originally Posted by Summitracing View Post
The cams are very similar (@ .050 valve events anyway) if it has the lift. The Ghost cam closes the intake 2 degrees earlier so it would bump up torque and would be a better match for your stock converter.
See I really like that spec but I thought, sacrifice a little bit off the bottom for some more top end so I can sometimes really wind it out and hit 60mph in first with those 2.73's. After reading this I'll probably just start with the 212/218-115+0 that's in the 4.8 that is powering the car right now. Best part about the current combo is 60+ mph in first lol
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Old 01-23-2019, 10:59 AM
  #33  
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Originally Posted by NSFW View Post
So the lesson is that 4 degrees of overlap is worth more power than two degrees of intake duration and six degrees of exhaust duration?

Let's assume for giggles that the first cam had 0 advance, so a 40 degree IVC. (-6 overlap)
If the second cam had been 218/226 at 114+3, it would have the same IVC and overlap, still with the +2 intake and +6 exhaust duration.
How would that cam drive, and how would it perform?
They'd both have the same DCR assuming the same ramp rate. I'd guess the second one being +3 would have a more peaky torque curve, which sort of offsets the higher durations. I'd also like to know how they'd compare in actual driving (vs spreadsheet driving), and also how high can you go in advance before the mid/upper range turns to sh*t. How about +6 on that cam?
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Old 01-23-2019, 03:29 PM
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Originally Posted by stockA4 View Post
Best part about the current combo is 60+ mph in first lol
Why is that a good thing?
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Old 01-23-2019, 03:54 PM
  #35  
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Originally Posted by Ls7colorado View Post
Why is that a good thing?
It's just fun to rip all the way to 60 without shifting. I've done autocross with it and it was awesome. I just lock the trans in first gear and concentrate on my line. wot downshift into first at 40mph is always fun too.
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Old 01-23-2019, 04:01 PM
  #36  
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Id peek at that WS6 high lift hot cam (218/227 .600/.600 112+2 with -1.5 overlap) or Summits 8715 like Mavn is using.
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Old 01-23-2019, 06:33 PM
  #37  
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Originally Posted by Darth_V8r View Post
I have puzzled over this one on and off since you posted it. I would not have thought you'd see the kind of results you have seen. That cam motion cam should be a pretty good drop-in cam with similar IVC valve event as the GM LS6 cam, but more overlap. In fact, it is similar to a stealth cam I've been tossing around the idea of in my wife's 6.0...
Thank you for taking the time to respond in this way, its very much appreciated. Apologies for my long reply below but your post is worthy of a proper response.

I have to say I found the difference quite confusing myself, when I chose the new cam and imported it from the US I didn't think there would be as much difference as there has been between it and the cam that was in it. Due to this, I actually put the car into another mechanic to be checked out a few months later and it came back with a clean bill of health but I had the plugs and leads changed anyway and the car felt even smoother again.

I can say this, I put the car into the shop with no issues that I was aware of except that I got an occasional metal scratching noise from the engine that concerned me. It was running really strong still, lots of low and mid range grunt. Same as it had been for a long time. The tuner drove it before they started the work too.

When pulling the car apart it was found that the lifters were stuffing up and had just started to scratch the existing cam. I was not surprised, I suspected that this was the noise I heard as LS1 lifters often stuffed up on these cars in Australia. So the heads came off, LS7 lifters replaced the original LS1 lifters and the heads were refitted. The shop may have replaced the gaskets, I couldn't say. I didn't change the heads to 243 etc as these are relatively expensive ported 241 from Higgins Race Heads that are considered top notch and had previously given the car a nearly 40 rwhp boost in tandem with the 100 cpi cats. More than usual for those mods down here (some didn't believe it and the tuner was a little surprised!). They were setup to run specifically with the 216/220 .600/.600 112 cam as part of a package but I did them separately at the time to see the difference. They are milled for more compression but I was not given exact specs as they were purchased as part of a shop package. I am very curious about your valve comments though! I will read up on that ! The only other changes from here were swapping in the PAC 1218 valve springs, the Cam itself and the all new SD tune.

When I picked it up the tuner was concerned, he said it didn't make the expected close to 400 rwhp (well we talk kw here so 300 rwkw), which I will add the car made previously on a few dyno in town. He also said "this cam doesn't go like your last one" . I thought, well, it is a more factory style cam, it probably feels slower back to back. Well, after driving it, this was definitely the case! The car used to be very strong on the street, it would surge off the line with very little revs and up to speed, lots of low down. Mid range kick down really got you moving and into license losing territory (not hard in a big city though!). Now, the car really doesn't get moving until 3000 rpm and then its basically over by 5500 rpm when surprisingly the old cam would carry better even though it never felt strong up top being so small. Kick down is sort of a long pause until the revs build. However, this is what the factory cam was like, so my thoughts were this is what is should be. A more powerful factory cam rather than the little hottie that was in it before.

So, based on this, I would be surprised if the car developed a mechanical issue, such as a blocked cat, between me dropping it off at the shop and me driving it home. Possible I guess but should have shown when the car was checked out I guess. I will add that the 100 cell cats haven't done many kms either for what that's worth. Right now the car doesn't feel like it has a serious mechanical issue, just slower than what it was. If you hadn't driven it before you wouldn't know it shouldn't be as it is now. When discussing this with shop that did the work he was adamant it was just the cam and to return the low down and mid range performance (I don't really care about the power figure TBH) I needed to change the cam. So that's how I came to where I am now, except I am using a different shop (nothing to do with the power figure) and Ive decided to try out an 85mm MAF rather than SD like my previous Cam tunes.

I accept that I wont have a cam as smooth and stock like as the Cam Motion cam I chose. I wanted it, I tried it (as everything said I shouldn't lose the performance of the previous cam) but I did and I do miss the responsiveness and low down/ mid range performance. So it feels like there is a compromise there. I need to have the smaller duration, higher lift less negative overlap (meaning more thump) to keep the performance where I want (I get that my desires for a cam are out of the ordinary, thus I didn't just buy another shop cam). I know the difference between -6 overlap and the the current -10 was quite noticeable even with good tuning so I would think going from -10 to -2 would be quite noticeable but I have to consider the end goals.

I think your cam recommendations are on the money and alas as mentioned I do want to change the headers (probably before I changed the cam just to see) but I have issues with ground clearance (and specifically my driveway). It is also interesting that I thought that smaller headers were better for down low power but on here I've read the opposite. I also do regret not going a lighter flywheel with LS7 clutch but people who did it said with this clutch it was too light.

You've given me lots to think about, thanks again for your post.
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Old 01-23-2019, 06:45 PM
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Originally Posted by Summitracing View Post
Nice post! O.P. Do you have the .006 duration numbers on both cams?
Heh, Ive been asked this before including by the new shop and I don't unfortunately. It would be quite helpful if I did!
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Old 01-23-2019, 06:47 PM
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Originally Posted by stockA4 View Post
This thread has me seriously rethinking the cam timing I was considering for the 11:1 iron and cathedral 372 I'm building for my completly stock 02' Z28. It's going to have the stock ls6 intake, stock, exhaust manifolds, stock converter, and stock 2.73's. It's a year round daily driver. Is a 224/232-115+2 going to suck?
I probably wouldn't second guess your choice based on this thread purely because for me there are a few unknowns. It hasn't been a straight forward modification path for me.
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Old 01-24-2019, 01:27 AM
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Originally Posted by Pulse Red View Post
I probably wouldn't second guess your choice based on this thread purely because for me there are a few unknowns. It hasn't been a straight forward modification path for me.
I think the best thing we can all gleam from your experience is that a few degrees of overlap is often more significant than a few degrees of duration for overall output. I'm just trying to build a tourqe pig 11:1cr 372 with some mildly ported 853's, max tourqe from idle to ls6 intake, max under the curve. I think I may need less duration and more overlap than I thought previously to reach my goal. Like you though, I unfortunately don't think longtubes would be realiable for my cars intended use though I know I'll be leaving power on the table. I'll probably just try the 212/218-115+0 I've got in my 4.8 "place holder engine" first while I try to think up something better.

​​​​​​Best of luck with your ride. I think the 214/218-112 that Darth suggested would work better than what you have now but with slightly less overlap than the 216/220-112 you had before maybe not quite as good. I think in your case it would be very helpful to know exactly how much static compression you are working with so you could really push the IVC to maximize your dynamic compression with whatever fuel your guys using down under. I think could probably go as high as 220-222 on the intake if you close it early enough and know a good enough tuner.

there's a cam out there somewhere that will perform better than either of the ones you have tried already. If it's too rowdy sounding you can always add an extra muffler or resonators to your exhaust. I think a two inlet single outlet muffler like a magnaflow at the end of your dual exhaust (it comes out on one side right?) would blend the note a bit and help to hide a healthy amount of overlap pretty well without hurting output any further. Just an idea.
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