My thundercat - Page 23

Roflhat · 12 April 2021, 16:33

Quote:

Originally Posted by ThundercatRob

Is the goal to break 80mph?

Ideally yes!

Quote:

Originally Posted by jwalker

Yes, I was thinking exactly that, just a gust of 10mph and your wind speed will suddenly be about 90mph!!

When you put it like that it sounds severe, aerodynamics must really be coming into it. Still haven't trialled my covered bow idea, extending back from the trailing edge of the nose cone maybe 0.5m or so to reduce turbulence

GuyC · 12 April 2021, 18:41

If you extend the nose cone aft, is there a possibility that by reducing turbulence, you start to create lift?

Roflhat · 13 April 2021, 15:41

Quote:

Originally Posted by GuyC

If you extend the nose cone aft, is there a possibility that by reducing turbulence, you start to create lift?

Possibly but I wouldn't have thought so? the cover would be in line with the top of the tubes, which are parallel to the direction of travel

Roflhat · 02 May 2021, 13:22

Great week last week, was over in Skye for a few days and then made it to Easdale for Friday/Saturday. Covered 68nm on fri and 57nm on sat. Engine running pretty well although I think there’s water in the fuel, starting playing up a bit towards the end. Superb weather though!

ThundercatRob · 02 May 2021, 18:55

Great pictures

jeffstevens763@g · 02 May 2021, 20:12

Quote:

Originally Posted by ThundercatRob

Great pictures

+1 impressive lintel

Steve509926 · 02 May 2021, 22:20

Supurb pictures and looks like it was decent weather.

Roflhat · 06 May 2021, 07:27

A couple weeks ago my friend Rolf Magne Sunde passed away. I got in touch with him years ago about engines and tuning, and after Coniston I sent him my engine to tune. He was an absolute mechanical genius, lovely guy and we spent countless hours on the phone discussing all things Yamaha. He set a World Speed Record with one of these engines on an f4 catamaran at over 100mph in the early 90's which still stands today. We spoke every other day and he will be sorely missed.
I got this custom sticker made up a year ago to go on the new engine cowling which is now nearly ready to go on

John Kennett · 06 May 2021, 07:34

Sorry to hear about Rolf. I didn’t know him but it sounds like his spirit will be living on under that awesome cowl for a while yet!

Matt · 06 May 2021, 09:42

Well done for molding & vacuum bagging the cowl on your kitchen table.

Makes my occasional "engine in the dishwasher" when the Mrs isn't paying attention look like child's play.

Roflhat · 06 May 2021, 18:09

Didn't make the cowling myself, wish I had the skills! Was made by another friend of mine, Andy White. Very talented guy and did it free of charge, all to aid the quest of speed

Roflhat · 13 May 2021, 06:57

New cowling is now on, 3D printed an intake section in the back which is a lot bigger than the standard one too

AugutstLier · 15 May 2021, 22:33

Would love to see the intake�� Working on a 70 ce my self at the moment with 90 hp carbs and high compression head

Roflhat · 16 May 2021, 11:40

Quote:

Originally Posted by AugutstLier

Would love to see the intake�� Working on a 70 ce my self at the moment with 90 hp carbs and high compression head

What hull is it going on?
This is the final version, the original was a bit more fancy but wouldn't fit properly beneath the cowl

Roflhat · 16 May 2021, 18:23

Anyone have any ideas on this? Engine is running strange, mid range has massive hesitations. If I can get it up to speed it sort of clears. Has been running like this for the last few runs now, filter is full of this stuff. I've changed the fuel, run it through a water seperater and it doesn't seem to be water. Cleaned the carbs, checked fuel pump

jeffstevens763@g · 16 May 2021, 20:27

When I had problems with my 25 my filters were full of what looked like chalk /talc never got to the bottom of it only to say the IAC valve had water globules in it preventing tick over. My thoughts were sea water and the salt had stayed on the filter membranes the globules also I think was seawater as it stays in droplets longer than fresh water before drying out.

Roflhat · 17 May 2021, 07:13

My thoughts was seawater too, but not sure how it's getting in there...
Had a piece come off the fuel tank in Easdale so I know that's how it got in originally. Will flush the fuel system and clean carbs and go from there

Iankristy · 17 May 2021, 07:27

If you always buy fuel in the same station maybe switch suppliers?

Roflhat · 17 May 2021, 09:44

Good shout, I’ll drain the tank an get fuel elsewhere to try

jeffstevens763@g · 17 May 2021, 09:51

Quote:

Originally Posted by Roflhat

My thoughts was seawater too, but not sure how it's getting in there...
Had a piece come off the fuel tank in Easdale so I know that's how it got in originally. Will flush the fuel system and clean carbs and go from there

if you draw some from the filter and let dry then you will see if its salt