DC20 Super C2 Profiles

chris_seven · 05-17-2012, 05:12 AM

DC20 Super C2

I have a couple of questions about these cams and would appreciate some information.

The first question is can they be ground from a standard 3.0SC cam without welding.

The second is can they be used with stock CIS Pistons without valve clearance issues if times at 2.0-2.4mm at the overlap setting.

Finally will the standard CIS deal with the increased overlap.

Thanks

KTL · 11:36 AM

Chris,

I installed the Super C2 DC20 on my 3.2L engine in the '87 Carrera. Stock 9.3:1 USA pistons

The cam can indeed be reground from a SC/Carrera cam. No welding required. I had DRC do this to my '87 3.2 stock cams.

I initially timed my cams to the middle (2.2mm) of the required 2.0-2.4mm spec and did not have enough piston-to-valve clearance. I believe I had to set mine to 1.8mm lift at TDC overlap. The actual critical area for piston to valve clearance im my case was about maybe 10 degrees after TDC overlap?

I know SC pistons are slightly different than Carrera pistons, but I thought my case was worth mentioning.

Did a search and found I did share something on this before

Cam timing with DC20's

Edit......... lastly, I don't believe the DC20 has more overlap than stock. According to DRC website, the lobe separation is the same for both SC/Carrera cams and the DC20, which is 113 degree separation.

chris_seven · 05-18-2012, 03:37 AM

Thank you very helpful - so there will be issues with Euro Spec 3.0 litre engines.

911-32 · 911-32's Garage

Chris - there is a UK SC running Super C2 cams. Check on impactbumpers.com, its user BruceB. Cams may even be for sale soon. Complicated story so better to contact him direct.

Edit - not directly relevant but I am running Supercup cams (similar) in my 3.2 with std pistons. My cams came from Camgrinder

chris_seven · 05-18-2012, 11:19 AM

I have some cams that I believe are Super C2 and they are too close on the exhaust valve even when timed at 1.8mm.

I am in the process of measuring the profile as I am now doubtful of the cam grind and I am going to try to produce a model that calculates the position when the valves are nearest to the pistons so we can try to make some sensible measurements.

I think the SC piston is more of a problem than a 3.2 but once I figure it all out I will try to explain.

Thansl