Group buy: LZ9 Camshafts?

[ericjon262]

Is there any interest here in a Group buy for LZ9 cams? I'm looking into having cores made, so far, the options I've explored put a finished cam at about $1000, but these would be a drop in camshaft, with the capability of retaining VVT.

[Shaun41178(2)]

If you're going to do this, you're gonna have to go all in. Don't worry about group buys. If you make them, people will buy them. The first ones to do 3800 cams just had to invest up front and wait for enough sales to make their money back. Same for vvt cams for the LS engines.

I'd do a mild and a medium. Going radical on vvt cams isn't really necessary and the r@d on ptv and setting up vvt stops would consume a lot of time and that equals money. So I'd go like a 207/210 on one and maybe a 215/220 on the other. Keeping lift the same as stock will allow factory valve springs to still be used, or a cheap .550 ls6 replacement for 75 bucks.

Keep in mind, vvt cams for LS engines used to be provided. Maybe they still are. I don't know. But I did a search months ago to see what options there were and what lifts and durations they were made with, and I gotta say many were out of stock. I don't think there were gonna be any new ones made either unless custom order drop ship from manufacturer

Remember, if you go so big on your duration, to where you have to use vvt limiters, than you're essentially installing a non vvt cam, so why not buy a non vvt cam for less money yes I think a vvt cam is not worth the extra cost for 99% of people who is gonna use this engine in a swap. Know your clientelle

[ericjon262]

I'm not in the camshaft business and am not trying to profit on the sale of cams through this group buy. I will need a special cam for a project I'm looking into, and said cam would not be able to be produced with a regrind, however the grinder I have reached out to is able to do it with new cores. They have a 20 cam minimum.

[Shaun41178(2)]

I'm not in the camshaft business and am not trying to profit on the sale of cams through this group buy. I will need a special cam for a project I'm looking into, and said cam would not be able to be produced with a regrind, however the grinder I have reached out to is able to do it with new cores. They have a 20 cam minimum.

I hear ya. I am assuming all cams are gonna have the same grind specs. Clearly you're gonna have to share the specs before unless you think that owners of this engine are gonna shell out $1k for a cam with no shared specs. Again, know your clientele.

Whatever the specs you decide to have ground on these new cores, which I am now assuming exist and you have found, not everyone is gonna want those specs you are gonna offer.

Like I said, if the cam has too much duration/lift, you have to install a vvt stop. So that will have to be provided(by you?), or a part number that one could get that would work with the 60 degrees vvt mechanism. They exist from companies, but none tested in our engines. That would have to be verified. And as said before, if you are locking the vvt from moving it's full range, you're bringing the expensive vvt cam closer to working just like a non vvt locked cam. So why pay nearly double for that?

I understand group buy will bring price down so it doesn't hurt to ask which is what you're doing. But if I was to guess, I'd see you going at this all by yourself. So you pay for your 20 and try to sell over time, or pay a lot more for your one off.

[ericjon262]

the cams would be ground to the end users desired specs. want 110 degrees of duration on the intake and 365 on the exhaust? go for it. want to reverse flow the heads and change the lobe order so the exhaust is now the intake? sure thing champ. VVT limitations are being looked into, with another possible option on the table as well.

[The Dark Side of Will]

I thought one of the reasons LS VVT cams were on the market is for totalitarian states where mods have to stay emissions "legal". Some of that may have been related to early inability to tune VVT or difficulty getting a VVT-delete tune through emissions monitors. I thought both of those "problems" had been "solved".

Since a whole lot of 3900 engines are swapped in situations where emissions legality isn't a concern, I wouldn't expect much overlap.

That's a difficult problem to get data on.

What's the specific use case that has you wanting an upgraded VVT cam?

The following opinion is based on years old data, so YMMV:
The selection of valve events that allow LS/LT engines to pass OE emissions requirements is pretty narrow. This is why those engines have low original specific output and wake up so much with bigger cams... the OE cams are restrictive for emissions reasons. VVT allows greater flexibility in meeting emissions, and broadens the torque curve. The emissions aspect is the primary reason, though. Remember that even direct injection is used for emissions and fleet fuel economy reasons, not power.

So if a bigger fixed cam can meet or exceed torque output of the factory VVT setup at all points, why go to pains to keep VVT?

[FieroWanaBe1]

T The emissions aspect is the primary reason, though. Remember that even direct injection is used for emissions and fleet fuel economy reasons, not power.

https://www.youtube.com/watch?v=qqu0V_iMBow

Fuel takes up space where air mass only would be, and makes changes to the charge mass viscosity across the valve hurting flow. Latent heat does not make up the difference.

VVT has its benefits for a camshaft small enough for adequate piston to valve clearance. There are clear winners in low end torque for the same cam with variable advance vs fixed.

the emissions only trope may have been the case in the 90's but modern engine have more specific output in all aspects because emissions forced MFG's to improve all aspects of the combustion process on pump gas.

[The Dark Side of Will]

I am well aware of the power advantages of DI.

OEMs incur the expense of DI for emissions and CAFE reasons.

[The Dark Side of Will]

VVT has its benefits for a camshaft small enough for adequate piston to valve clearance. There are clear winners in low end torque for the same cam with variable advance vs fixed.

I didn't say there weren't.
But if the engine has the PTV clearance to run VVT with a small cam, and is not otherwise constrained--e.g. with a "lift rule" to save the valvetrain, or emissions check requirements--then the engine has the PTV to run a bigger cam with fixed timing... and that's what most car guys are looking for.

[FieroWanaBe1]

Most of us in the fiero world forget that behind an autotragic with a lot off mass, The benifits of a early torque curve and the need for proper stall in the converter become glaring when cruising.
I would think a fair amount of LZ9 people might apprecitae a very broad curve that starts early and doesnt fall off especially powering a 4t65.
There are those too that want simplicity. The ability to tune with the Ti32 level of processing power has its draws, but i doubt those users would fork over 1k for a camshaft.

[ericjon262]

I thought one of the reasons LS VVT cams were on the market is for totalitarian states where mods have to stay emissions "legal". Some of that may have been related to early inability to tune VVT or difficulty getting a VVT-delete tune through emissions monitors. I thought both of those "problems" had been "solved".

Since a whole lot of 3900 engines are swapped in situations where emissions legality isn't a concern, I wouldn't expect much overlap.

That's a difficult problem to get data on.

What's the specific use case that has you wanting an upgraded VVT cam?

The following opinion is based on years old data, so YMMV:
The selection of valve events that allow LS/LT engines to pass OE emissions requirements is pretty narrow. This is why those engines have low original specific output and wake up so much with bigger cams... the OE cams are restrictive for emissions reasons. VVT allows greater flexibility in meeting emissions, and broadens the torque curve. The emissions aspect is the primary reason, though. Remember that even direct injection is used for emissions and fleet fuel economy reasons, not power.

So if a bigger fixed cam can meet or exceed torque output of the factory VVT setup at all points, why go to pains to keep VVT?

it's worth mentioning I said

with the capability of retaining VVT.

not that retaining VVT would be required or desired in every application. these camshafts cores would be able to be ground to almost any specs, so if someone is looking for a mild cam, retaining VVT, they can get it, if someone wanted to change the firing order, they could do that, if they wanted to go nuts and make they're own custom heads and change the lobe order on the cam and go to pro-mod cam specs, they could.

as I have been working on these ideas, I did make a call to MAST Motorsports and asked them about VVT cams, for a while they were promoting them heavily, when we talked, I was told that in their testing, they did make a better torque curve compared to a similar locked out cam, I asked why they no longer produce them, and I was told there just wasn't a big market for them, and that most customers preferred non VVT, I would guess because it simplifies the tuning process.

[Shaun41178(2)]

, I asked why they no longer produce them, and I was told there just wasn't a big market for them, and that most customers preferred non VVT, I would guess because it simplifies the tuning process.

It's not just the tuning process, the vvt cams were approx $100 plus more dollars over a non vvt. TSP sold their cams a few years ago for around 360 bucks. Summit sells LS cams for as.low as $300 today still!
GPI has their vvt cams for $470!
Comp cams stage 1 is $515
That's huge. It's 25-30% more, and you still have to use a vvt cam stop, so you don't get the full amount of advance and retard. So why pay more?

Vvt angles have to be dialed in at every rpm. If you can swap in a non vvt, make more low end tq.and high end HP, over a tiny vvt cam, and you don't have to tune all the vvt, and you spend less money, it's a no brainer. THATS why there wasn't a big market for them

Eric, your market is probably gonna be with the impala, and Malibu and g6 crowd, guys wanting more power but still on a pcm with programmed vvt capability already. I'd hit those FB groups and message boards

[Shaun41178(2)]

https://www.hotrod.com/how-to/check-out ... ining-vvt/


Upgraded vvt cam ,but phase limiter has to be installed. Lost tq and HP all the way up to 5200 rpm. Just like going from a non vvt stock cam, to a 220+ duration non vvt cam.

[FieroWanaBe1]

https://briantooleyracing.com/btr-6-4-h ... shaft.html
"big" 228 degree cam w/ VVT limiters (a piece of aluminum sized appropriately)
VS stock 6.4 Car cam. no loss of torque below 2100 and +50Hp on top at 6500.
VVT has its place.

[Shaun41178(2)]

So one Dyno shows loss under 5k and one Dyno doesn't.

Then there is this. How true is it? Can't say.

Screenshot_20250402-015302.png (583.41 KiB) Viewed 16430 times

?

[FieroWanaBe1]

If you watch a few tech/interviews with Brian Tooley, he claims his cams are built targeting a specific set of closing events and overlap and will shorten up the Intake duration. until power drops, this is his claim that causes aggressive duration splits, but gives up minimal bottom end torque.

The cams from 10 years ago and today have very different timing events than they used to, at similar power levels. Spin-tron and A-B-A dynoing by the upstart companies have dethroned comp and the other big box names who don't have the versatility to change to the technologies like smaller outfits do today.

[The Dark Side of Will]

not that retaining VVT would be required or desired in every application. these camshafts cores would be able to be ground to almost any specs, so if someone is looking for a mild cam, retaining VVT, they can get it, if someone wanted to change the firing order, they could do that, if they wanted to go nuts and make they're own custom heads and change the lobe order on the cam and go to pro-mod cam specs, they could.

as I have been working on these ideas, I did make a call to MAST Motorsports and asked them about VVT cams, for a while they were promoting them heavily, when we talked, I was told that in their testing, they did make a better torque curve compared to a similar locked out cam, I asked why they no longer produce them, and I was told there just wasn't a big market for them, and that most customers preferred non VVT, I would guess because it simplifies the tuning process.

I infer from this that you expect the cores will have round lobes. Have you discussed this with the manufacturer and grinder?
Cores are usually produced with rough lobes that can be ground to a variety of finished specs without excessive material removal.

Grinding from round is a special service. Welding Rod Ferrari V12 Mark had that done on his custom billet cams... and had to exert some effort (and pay ~$100/lobe) to get Comp to grind his blanks from round.

[ericjon262]

not that retaining VVT would be required or desired in every application. these camshafts cores would be able to be ground to almost any specs, so if someone is looking for a mild cam, retaining VVT, they can get it, if someone wanted to change the firing order, they could do that, if they wanted to go nuts and make they're own custom heads and change the lobe order on the cam and go to pro-mod cam specs, they could.

as I have been working on these ideas, I did make a call to MAST Motorsports and asked them about VVT cams, for a while they were promoting them heavily, when we talked, I was told that in their testing, they did make a better torque curve compared to a similar locked out cam, I asked why they no longer produce them, and I was told there just wasn't a big market for them, and that most customers preferred non VVT, I would guess because it simplifies the tuning process.

I infer from this that you expect the cores will have round lobes. Have you discussed this with the manufacturer and grinder?
Cores are usually produced with rough lobes that can be ground to a variety of finished specs without excessive material removal.

Grinding from round is a special service. Welding Rod Ferrari V12 Mark had that done on his custom billet cams... and had to exert some effort (and pay ~$100/lobe) to get Comp to grind his blanks from round.

Based on discussions with the manufacturer, the cam cores would work out to ~$750, and the finished grinding would work out to ~$250. I specifically asked if lobe orders or firing orders could be changed, and they said they could be changed, which leads me to believe they are round lobe cores.

FWIW, When I reached out to MAST Motorsports, I asked if they had any recommendations for me, and one of them was to avoid doing any business with Comp Cams. Honestly, the few times I've dealt with comp outside of buying a shelf cam off summit, I wasn't very impressed. They suggested I reach out to a few other grinders, Cam Motion being one of them. At any rate, it appears as though there is minimal at best interest for these, so they probably won't happen, I can't fork out 20K for cams by myself, especially when I only need one or two.

[FieroWanaBe1]

Jones Cams has a good reputation. He is easy to deal with.