flyrotary@lancaironline.net Mailing List Archive

Hi Finn Yes. That’s why I ended up with the 32mm ID Primaries. It was the best I could find and when squashed, that tube fit the primary intake shape pretty well. I tried to keep the dynamic effects of the OEM manifold (shortened to lift peak torque and dynamics up to 6000 and 7200rpm), but if I was to rebuild, I think I would just have clean runners as Tracy opted for into a plennum chamber. Tracy wrote that his 4 port was producing 215hp @ ~21g/hr from memory which is better than we are seeing. Steve > On 22 Dec 2020, at 10:45 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote: > > Thanks Steve. > > 1/8" wall is a bit too heavy for me. 1 mm or 0.04" would be more to my liking. > > Looking at at manifold drawing it looks like I need 33.5 mm (1.319") ID tubing. > > Seems the closest I can get is 1.5" OD with 0.049" wall. 35.6mm ID. > > What I really need is 1-3/8" OD and 0.028" wall but have not been able to source that. > > I might end up just wrapping existing runners with more fiberglass/epoxy. > > Finn > > > On 12/21/2020 9:11 PM, Stephen Izett stephen.izett@gmail.com wrote: >> Hi Finn >> >> My notes show (from measurements of hem intake) that the Renesis 4 port primary and secondary runners are 30mm diameter. >> I used the original secondary runners after cutting and turning the manifold ~180 degrees. >> I used 32mm ID aluminium tube with a 3mm wall thickness for the Primaries. >> >> Steve Izett >> >> >> >> >> >>> On 22 Dec 2020, at 9:56 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote: >>> >>> Couldn't understand why it kept "idling" at higher and higher RPMs (3,500 at the end and had to cut fuel and turn off the EC3 to shut it down). >>> >>> I had made the primary runners from the plenum to the intake ports with 0.016 alum rolled and covered with fiberglass and epoxy on the outside. Seemed a simple way to go from oval at the port/manifold to round in the plenum. >>> >>> Obviously I completely underestimated the amount of vacuum that the engine can pull or pump. Perhaps if I had added multiple layers of fiberglass ... >>> >>> So I need to use thicker tubing or pipe. >>> >>> Anyone here that can remember the size of tubing they used? (OD/ID and or thickness) >>> >>> Finn >>> >>> >>> >>> >>> >>> --- >>> This email has been checked for viruses by Avast antivirus software. >>> https://www.avast.com/antivirus >>> <pecjblkaceeipnaj.jpg>-- >>> Homepage: ï¿½http://www.flyrotary.com/ >>> Archive and UnSub: ï¿½ http://mail.lancaironline.net:81/lists/flyrotary/List.html >> > > > > Virus-free. www.avast.com