JET KART Engine Test Post Rebuild #4! 🔥🔥👍

October 2022 post Engine Rebuild

[@ArcturanMegadonkey]

I got a reply from Phill. I had that with the 150, I had to make the ngv inner at least 6mm thick and angle it 30 deg., it looks like his has no heat shield on the turbine front which will make the ngv even hotter and softer. mine were 316 stainless but would have been better in 310 or 321 grade. or better still inco 625. and there's a lot of weight on the turbine housing if the reheat is attached directly to it. on the gokart we did, i attached the reheat pipe to the engine casing and connected it to the turbine exhaust with a floating cone so the load was transferred straight to the case instead of to the turbine shroud. Phill Heward

[@ScottsCrazyBuilds]

Thanks for the info Paul and Phill. This NGV was originally 5mm thick now 4.75mm after first skim from warping. To angle the NGV and add a heatshield like a turbo CHRA I would need a shorter or at least redesigned bearing housing ☹️ any details on the floating cone arrangement would be appreciated though. I am trying to avoid re manufacturing the whole NGV if I can! Cheers Scott

[@ArcturanMegadonkey]

It's a bit of a common thing for radial inflow engines to warp the NGV, seen it a few times. It's been a long time but I think we tried to put more cooling air to the NGV area but using more secondary holes on the inner combustion chamber so it cooled more of the shaft tunnel and NGV and removed some material, this was back with Phil Heward's Panther and Mk4 engines. look brilliant in these runs Paul

[@ScottsCrazyBuilds]

Hi Paul, Thanks alot for your informative reply. You make a great point about potentially the issue being a thermal one instead of (or in addition to) a pressure one. I will have a proper think about how to best incorporate some changes for cooling when adding the slip joint to remove pressure loading!! Cheers Scott

[@ArcturanMegadonkey]

@@ScottsCrazyBuilds I've sent a link of your video to Phill Heward (Phoenix 30.3 inventor) he'll probably have a perfect solution to your issue, you might get a reply to the video from TigerScratch, that'll probably be Phill.

[@waspsnest]

@@ArcturanMegadonkey ive just mailed a reply to mr donkey, but forgot to say about the other trick of putting some of the dilution air on the combustor inner rear cone so it washes the ngv disc with cooler air, that drops the temp of hte disc and also reduces a bit of heat soak to the rear bearing

[@FirstLast-tx3yj]

I think it is a better idea if yiu built an FSAe style frame Should be much stable but also takes tons more effort! What are the dimensions on the compressor wheel??

[@ScottsCrazyBuilds]

Nice idea but it has to be a kart with no suspension to qualify for the jet kart world record!! 106mm compressor inducer 👍

[@FirstLast-tx3yj]

@@ScottsCrazyBuilds also for the startup you are using compressed air? What pressure in the tank Because your engine doesnt have the very slow sluggish startup?

[@ScottsCrazyBuilds]

@@FirstLast-tx3yj yeah scuba bottle charged to 230bar impinging directly on the compressor