Mike Simard

Hi Shmark, it's great to see you here and not sipping mimosas with your new Ferrari associates!

The gun drilling is indeed tricky and not possible with normal equipment. I have to send those out to a place with a machine as big as a house and pay them alot of money. A hollow tube is stronger than a solid round but the cams need no extra strength, they will never break like a cast one and are now one of the strongest parts on the car.
There are several reasons I did that but mainly it's because the cams are the result of me making something I love and design and high quality being all important, not cost or ease.
If I knew of a way to spend time and make the design or quality a tiny amount better, that would be done. That sounds crazy when there are suppliers selling easy to make but poorly engineered crap and the mass consumer expects instant gratification from buying something cheap with no problem with it being crap, it was only to fulfill thier need to have "it". The whole reason I'm into Porsches in the first place is an appreciation for quality and I would much rather make high quality stuff that few buy than mass sell what I wouldn't want to use myself.
Sterling and the others that have my cams are getting workmanship that is beyond what is expected and I really enjoy doing that for them because I appreciate their trust to make a critical part.
So in other words, I drilled them because it's better than not drilling them

BTW, the material is not 4150M.
It is a high strength alloy with a unique hardening procedure that is only done for me and my cams and I feel very good about it. That's one of the most expensive parts of making these and makes the material choice more expensive to use than even 8620 but it will give a very hard, wear resistant surface. Lifter compatability is always a concern. Greg Brown has an absolute solution for that though. If he builds you an engine with my cams you're getting the most reliable cam-lifter compatability in existance.

AO

I was told but a guy way cmarter than me that by gun drilling a rod that is subjected to torque alng its primary axis, you essentially are removing the fulcrum, making it more rigid and liss like to break. It makes sense in my mind, but I don't know the math or engineering behind it AND I DON'T WANT TO KNOW.

Mike, you're making some kick *** stuff. Keep it up!

123quattro

I'm running those lifters in my Audi. I've been spinning it to 8200rpm for ~15,000 miles. They work great.

Drilling the shaft makes it stronger in the durability sense. With a hollow center there is no point for stresses to concentrate and the fatigue life goes way up.

Darklands

He told me the open deck bores have the problem of vibrations at high RPM ,so the head gasket rings can went oval/smaller in the long term.
Mike prevent this with his new steel cylinder sleeves.
I think we should say on a long term prospect the engine can reach 100000 km with this configuration or the mod is crap.
If your goal is driving the engine for a limited time you can do silly things like very high rpm or to much boost.
But hopefully you have a clear failure mode or you can take the next engine for try and error.

123quattro

It has to work for 60,000 miles or it's crap? 1. I don't think that will be the case here. 2. I wouldn't mind throwing a new set of head gaskets on a really high performance engine every 3-5 years even if it were.

shmark

The guys I hang out with do their own maintenance. As a result they're more into hard liquor.

I'd still like to know how that big house does it. Low or high speed, bits made from unobtanium, cutting fluid distilled from phoenix tears, rods held in place by the hand of God? Just seems like a nearly impossible thing to do and yet there it is.

123quattro

It's probably very similar to how a gun barrel is drilled. There should be plenty of videos on youtube about that. I'd post one, but I shouldn't search that from work.

Mike Simard

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.

Vilhuer

I could use some more low down TQ as 2.20:1 US S4 diff in automatic GTS and high lift S3 cams do not work together. They start to wake up around 4.5-5k while revs drop closer to 3k on upshifts. There is over 1k dead spot on every gear. Next 5.7L GTS crank + 103mm piston bottom end build might fix the problem but if variocan bits are really cheap why not...

Lizard928

Keep in mind that the variocam bits will not really work with the stock engine management.

So plan to go to standalone EFI.

You are also able to advance the cams which will help bring the power curve back down.

Vilhuer

I would build standalone box to run cam adjusters based on rpm feed and keep stock LH & EZK. I will probably change stock base lobe S3 cams in and see if it helps somewhat before 5.7L bottom end is ready. Though few degree advance is one option also.

Fabio421

Colin, please explain why they wont work with the stock engine management?

Sterling, have you considered selling this technology? Why not re-coup your investment in time and money by re-producing this for others?

blown 87

There is nothing to control them with the stock setup.

dr bob

I'm guessing the flappy solenoid signal, programmable with the ST box, might make a suitable cam timing shift signal. No flappy with ITB's right?

Lizard928

Bingo,

there is no way to turn them on/off.

I have spoken with Sterling about these and I know that he had a great deal of fun trying to get them to work left/right as they were setup correctly for the passenger side, but the drivers side would be running the cam in the wrong position...