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Old 25 Apr 2010, 21:17 (Ref:2679618)   #26
rkshanahan
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Join Date: Jul 2003
Location:
San Diego, CA, USA
Posts: 79
rkshanahan should be qualifying in the top 10 on the grid
Martin,

The original cam for the SCA was the F1 profile. It has .402" lift and 324 deg. seat to seat. Like you, I was thinking I would end up using something more like 300 deg. seat to seat for the SCB, but I was waiting for the flow data to see if additional lift was going to be useful.

Since there is no data on the SCB (it appears Cosworth only built one) I am having to make up the specs as I go along. I am planning on using the 4.825" rods unless they don't leave me with enough room for the larger dish in the piston. The piston guy is supposed to get back to me next week about whether I have enough compression height. If not I will have to custom make some shorter rods.

I noticed that an earlier post to this thread noted that Keith Duckworth said the SCA needed too much ignition advance to be efficient. I am trying to figure out what I can do to the shape of the dish in the piston to make the chamber "faster". I am working with the piston guy on this, leaving large squish areas and such, but I don't know what else to do. Possibly this is why the "high swirl" intake ports were so important.

Regards,

Rob
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