928sg stage II ITB's and New Cams......
09-11-2010, 09:34 AM
#62
The drill bits are hollow with internal coolant passages which are supplied by a high pressure pump which blasts chips out of the holes. The drills can be steel or carbide. They have a funky cutting face shape and look nothing like a twist drill. The flutes are straight and only one side cuts. Sharpening them is unusual but I enjoy it.
I do gun drilling here but smaller holes such as 3/16" going 8" deep. I run a carbide drill about 1000 rpms for that and if anything goes wrong I lose a drill and a part, I have some here with drills permanetly in them
To do a big camshaft hole takes a serious machine, more than will even fit in my building.
It's not something that everyone will want. You can add $400 for gundrilling 4 billet cams.
I do gun drilling here but smaller holes such as 3/16" going 8" deep. I run a carbide drill about 1000 rpms for that and if anything goes wrong I lose a drill and a part, I have some here with drills permanetly in them
To do a big camshaft hole takes a serious machine, more than will even fit in my building.
It's not something that everyone will want. You can add $400 for gundrilling 4 billet cams.
09-12-2010, 07:09 PM
#63
Administrator - "Tyson"
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Sterling, this is awesome. With all the ups and downs with this project it's great to see you sticking with it.
Most people would have tossed in the towel a long time ago.
Most people would have tossed in the towel a long time ago.
09-12-2010, 08:21 PM
#65
Not that I am spending it right now, but I believe that even on a budget, the smart money is in the heads and intake. Because when you blow a rod or piston, etc - you usually an save these pieces of the engine - heads, lifters, cams, etc. So several thousand dollars for the cams, over 1000 for the properly coated lifters, headwork in the 4k range, and you have 15,000 in the top part of he motor. Put that on a normal bottom end, and have some fun.
09-12-2010, 08:37 PM
#66
Nordschleife Master
Sterling -- Since you have the very light rotating assembly, you should turn the engine over as high as necessary to see where the true torque peak is. Ott's engine with ITB's and B1 cams is limited to 6500 rpm, at which point the engine is possibly nowhere close to it's power peak. You can find out where the peak with your bottom end, just follow the arrows! ;-) Best, Tuomo
09-12-2010, 08:45 PM
#67
Nordschleife Master
On the variocam system:
These are some random thoughts, might be off base here. One situation in which I think that variocam system can be really valuable is trying to pass emissions test with a really big cam. The variocam feature can get the low rpm emissions to an acceptable level, and still give big-cam performance at the top end. With mild cams, there's little benefit from variable valve timing. With wild cams, there's a lot. Someone living in California might want to buy those heads and intake manifold, and then have Simard make crazy wild cams with a custom center bracket. The 968-size (or something) ports of Sterling's variocam heads might be just right for running the engine at 7500 rpm and one needs cams that want to play there, too. Just a thought.
These are some random thoughts, might be off base here. One situation in which I think that variocam system can be really valuable is trying to pass emissions test with a really big cam. The variocam feature can get the low rpm emissions to an acceptable level, and still give big-cam performance at the top end. With mild cams, there's little benefit from variable valve timing. With wild cams, there's a lot. Someone living in California might want to buy those heads and intake manifold, and then have Simard make crazy wild cams with a custom center bracket. The 968-size (or something) ports of Sterling's variocam heads might be just right for running the engine at 7500 rpm and one needs cams that want to play there, too. Just a thought.
09-13-2010, 10:36 AM
#70
Instructor
Mike is the only show in town for these so I'm not real sure why the need for any secrecy. It is not like I am going to start making camshafts in my garage and sell them to the 928 community at a lower price. 
09-13-2010, 11:10 AM
#72
Instructor
Not to be argumentative, but I believe a grind more aggressive than the devek B1 is beyond the scope of any regrind. Glad Mike is on our team. I'll shoot him an Email.
09-13-2010, 02:29 PM
#74
Administrator - "Tyson"
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It would be cool to see the ITB intake and Mike's cam on an otherwise stock S4 motor.
