HKS Vcam Step 1 to step 2+ without buying uprate kit q's?

[brian_s30z]

My goal for this year was to have a built 2.6 with HKS Vcam step 2, but working in the defense/aerospace industry we've been hit hard this year which has me holding off on a build.  I still want to do the HKS Vcam step 1 since it will work with stock internals and give's me a good opportunity to bundle it up with Dr-25 on a custom harness I'm making. Ultimately I would like to upgrade to Step 2/pro when I do build the motor, but paying $1k  for an upgrade kit sucks. The kit includes new Variable unit, 264 8.7 cam, and new valve cover gasket. 

So after some research online I found (thanks Piggaz) that HKS' step 1 variable sprocket unit has a mechanical wedge which limits it to 30°, so if removed gives you the full Step 2 / Pro 52° (??) Has anyone been able to confirm removing the wedge functions exactly like a step 2 / pro unit?

My next question is camshaft.. Yes you can regrind it, but what about a new camshaft? Kellford Cams offers Rb25 cams to work with VCT unit, Rb26 cams, and can make custom camshafts... Can a new cam be made to work with V-cam?

Thank you,

Brian

[GDZ32]

Just leave the Step 1 as it'll work magic on a stock or built motor, or wait and get the HKS Step2 pistons and Vcam Step2 at the same time. My car has run Step1 Type-A Vcam on a HKS Step2 2.8 with -5's and then I upgraded to Vcam Step2, the gains are minimal, if none at all. I wouldn't be modifying anything when the motor gets built. 

[Piggaz]

You would need to confirm the lobe angle of the step 1 cam. The step 1 is only wedged on 1 side so you would think/assume the lobe angle would be different than a step 2 BUT I can’t confirm that as I have no measured it.

Rb25 and Vcam cam shafts have nothing in common. This is essentially an EJ25 system that has been shoehorned to make work on an RB26. 
You’d be better off asking for an EJ25 nose and grooves that has the lobes spaced to suit an RB26 with a profile of “x”. My bet is they won’t want anything to do with it. 🤣

The thread below has photo’s in it showing what I’m talking about.

https://www.gtr.co.uk/threads/vcam-step-1-and-stock-turbo.504185/

 

 

[burn4005]

step 1 is a 248 degree 8.7mm camshaft with 30 degrees of advance (20 degrees locked out with steel block)

step 2 is a 264 degree 8.7mm camshaft with 50 degrees of advance.

you can use the actuator with the block removed to give the 50 degrees but you will need to purchase the step 2 camshaft or get your step 1 248 degree camshaft ground to a lower base circle and reground to a longer duration.

[GTSBoy]

32 minutes ago, burn4005 said:

or get your step 1 248 degree camshaft ground to a lower base circle and reground to a longer duration.

Or, you just buy a new cam from Kelfords with similar specs? Probably better than butchering the original HKS cam.

[r32-25t]

Are you saying kelford have the correct blanks for the vcam?

3 hours ago, GTSBoy said:

Or, you just buy a new cam from Kelfords with similar specs? Probably better than butchering the original HKS cam.

 

[GTSBoy]

I'd like to think that their cam blanks would have enough meat on them to put any reasonable profile on them.

[Piggaz]

32 minutes ago, GTSBoy said:

I'd like to think that their cam blanks would have enough meat on them to put any reasonable profile on them.

Small issue though. The Kelford blank for an RB 26 won’t have all this stuff going for the Vcam to work. If it was as easy as regrinding a blank then it would be a piece of piss.

[GTSBoy]

What the hell does that shit do? What the hell can that shit do, in that location on a rotating cam? Do they add some Hall sensors or something to pick up position?

[Piggaz]

Yep. A fair bit of shit going on.

[brian_s30z]

20 hours ago, burn4005 said:

step 1 is a 248 degree 8.7mm camshaft with 30 degrees of advance (20 degrees locked out with steel block)

step 2 is a 264 degree 8.7mm camshaft with 50 degrees of advance.

you can use the actuator with the block removed to give the 50 degrees but you will need to purchase the step 2 camshaft or get your step 1 248 degree camshaft ground to a lower base circle and reground to a longer duration.

Glad to hear. Now it's only the camshaft I need to worry about. HKS doesn't sell it separately, but would like to reground a 264 to begin with.  

[brian_s30z]

How many wires are your ECU's using to run the VCAM without HKS controller? I got an Haltech Elite 2500.

[r32-25t]

4 wires. 2 from the position sensor and 2 to the solenoid 

[burn4005]

On 11/14/2020 at 12:58 PM, brian_s30z said:

Glad to hear. Now it's only the camshaft I need to worry about. HKS doesn't sell it separately, but would like to reground a 264 to begin with.  

Yes they do

https://www.rhdjapan.com/hks-v-cam-system-version-up-camshaft.html

[burn4005]

The actuator is actually a modified Subaru EJ unit.

Oil is fed through ports in the camshaft just in front of cylinder 1 lobes, there are internal passeges drilled that feed that oil to the actuator bolted to the front.

It's not simple but it is certainly possible.

The grub screws that stick out for the vvt sensor are just a threaded hole with a long grub screws and lock nuts.

[GTSBoy]

I was just thinking about this and figured that the grub screws would have to have been possible to copy if you had access to an original HKS cam to see where they have to go. I was thinking of shrink fit steel rod/stake/plug. But grub screw + loctite is just as good.

[burn4005]

Just copy the position on the old cam. It doesn't matter their phasing as long as they are spaced at 120 degrees and not near the cam home pulse timing wise.

Any new ecu that is capable of generic VVT would have no problems with it.

[GTSBoy]

I was thinking in terms of making sure a copied cam would work with the original HKS controls. But otherwise, yes.

[brian_s30z]

Spoke with Kelford, they said:

"We do plan to release a Vcam replacement cam but we aren’t there yet, we still need to get our casting modified so we can machine the oil feed.     This will be sometime unfortunately"

Good news! ... My Vcam step 1 is on its way to me. 

Attached is closer picture of vcam camshaft.

[Piggaz]

1 hour ago, brian_s30z said:

Spoke with Kelford, they said:

"We do plan to release a Vcam replacement cam but we aren’t there yet, we still need to get our casting modified so we can machine the oil feed.     This will be sometime unfortunately"

Good news! ... My Vcam step 1 is on its way to me. 

Attached is closer picture of vcam camshaft.

That’s great news. About time someone pulled their finger out. Hopefully they have a few different grinds. 👍