Ask and ye shall receive
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So here is what can be done with a multi axis CNC...Steve was also very kind and went extra on the intake valve... Its actually a cut down intake from the 3.0. So its not the true RSR size, but its the biggest that can fit in the tighter valve angle of the smaller motors heads.
Steve tells me that his ports almost flow to the same extent as the 2.8 RSR heads, but aren't 43 mm drain pipes. They are actually oblong, 39 wide, 41 mm tall. Interestingly the bulk of the meat removed is from the roof. You can actually see spots on the floor that were stock (not touched by the CNC). Steve told me that makes a big difference getting the air around the coroner. In addition, I figure the smaller port volume will make a big improvement in actually having a midrange
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Just to be clear, I went 'crazy' mostly because having driven an 2.0S I didn't think it was enough. I guess it is from too many two strokes in my youth (All yamahas: DS6s, RDs, and RZs). When I say enough, it is more about how the power hits than how much. I don't have any issue with something I have to 'baby' driving. My only requirement is that it has to idle well. No stalling. If I stall it off the clutch, that's my problem and part of the fun.
Lastly, for now, is the rockers. Going with the lash cap type. Had them redone by electric chrome and grind. I need to chase up some rocker shafts, but not quite sure yet what to go with. Optimal would seem to be the nitride shafts, but they are hard to find anymore. There is just no room to have a bushing in the solid rockers. The stock might be too soft. That said, I have heard wonders about Gibbs motor oils and running steel cams on stock rockers with no issues.
I could DLC the stock rockers, but then the wear would be on the hard to get rocker rather than the easier to find shaft. Or could have both pieces DLC coated and not worry about it.
And that's where things stand at the moment. Would very much like to have a long block by the new year, but there are so many odds and ends to get thanks to building from pieces parts rather than starting with a complete motor.
Only other goodies (suppliers) I can think of are JB racing for the AN fittings and Supertec for their head studs and 906 cooling tin...and not least pelican parts for all the odds and ends like miscellaneous studs and extra bits you don't get piecemeal that eat your wallet
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Lastly will be the intake. Would like to go with one of the repro high butterfly units, but that aint gonna happen at $6k... so I snagged a cheap set of T MFI TBs to cut up... ahem... 'port' to the heads. Since the meat is out of the top of the head from the CNC work, lots of metal will need to come out of the intake to match. I figured I will match the bottoms, then send off to someone to open up and install bigger throttle plates. Would like to then top that with fiberglass intake trumpets for a 911R look to go with the inline 6 MFI unit (rather than the side by side).