Twisted: Week 200 - CHT probes, Spinner and Fun with foam

Hours to date: 1842.75

Another couple of slowish weeks progress as I've been riding my Benelli on track days - got to let off some steam now and then.

I've made up some deflectors for the front cylinders - see pic below. These are to reduce the cooling on the front cylinders so that they match the same CHTs as the rear cylinders - which is better for the engine. I've started off slightly big and can reduce them as needs be. I used a pic of Pete's ones as a guide.

Onto the CHT probes which are really straightforward to fit - at least they should be! On one side the cut outs machined into the baffles were too small and so the probe would not quite fit in. A little careful work with the Dremel and they fit okay now. Save yourself a lot of hassle and machine these out by 2mm all the way round before fitting the baffles.

The spinner is coming along. Just got to sort out the nut plates on the back now. I also want to make up some fillets to fill in the gap at the back.

Next job was to make some male moulds for the inlet baffle connectors.

Before doing that though I had to determine the position of the inlet rings themselves. I've gone for 15mm space behind the prop - I know that some in the USA go for 10mm so I've erred on the side of caution here a bit by adding 5mm. They do want to be nice and close to the prop though to take advantage of the high pressure pulses of air that will come off the prop.

Many hours of cutting and sanding later and I had a pair of foam blocks shaped for the task.

They are 30mm too deep - this is to allow for overlap onto the Ali baffles which they will be attached to eventually with screws and nut plates.

A thin layer of micro slurry was added next.

I slightly screwed up the starboard one on width so I added some micro to the side to build it up.

After a light sand with 180 grit paper it was a quick shot of primer which helps you see where the pin holes or gouges are.

Next up was body filler to fill those holes and more sanding then primer again and finally gloss black paint.

All that's left to do now is to wax these about 6-10 times to provide a good release. Hopefully I do a better job than last time with the oil cooler ducts as the gel coat really stuck to the moulds and it was a pain to get them out.

As you will see from the photos the moulds are not perfect but they are good enough for the inside of a duct - it should end up being pretty smooth.