Heading in and out.
ฝัง
- เผยแพร่เมื่อ 27 เม.ย. 2024
- We're getting pretty slick at fitting the cylinder head and removing it again. The new head fits a treat and has good compression. The Dynastart has a slightly easier time now but still isn't up to the job, so we'll crack on at planned and make a decompressor. At least we know not where we're going, and after opening the holes in the head we can treat again. Lots of work with not much to see, but all essential stuff.
#chopper #engineering #custom #engine #head #motorcycle
In this video you can see how thin-walled the sleeve was, from what I have read limiting the thickness was necessary to ensure adequate heat transfer for cooling. Remember too that there is a film of oil between the sleeve and the cylinder wall as I understand it engine boost had to be limited or the side loads on the sleeve from the piston travel could squeeze the oil out ! . Also from the same loads there could be flexing of the sleeve into the transfer ports leading to metal on metal "clipping" . Development of the sleeves was an epic and expensive journey for Sir Roy Fedden and the team at Bristol who arguably had the best aero engines in the world at that point all of which were poppet valved. The development of a suitable alloy was contracted out to a specialist firm who experimented with literally hundreds of variations before finding something that worked and the cost was biblical for the time. The sleeves were centrifugally cast (spinning mould) then ground nitrided and honed to very precise tolerances using cylindrical grinders ( I think centerless) and Sunnen cylindrical hones from the US then in short supply on both sides of the Atlantic. I read somewhere that Lord Beaverbrook had a hand in "redirecting" a shipment of these that was bound for a large US aero engine maker. Bristol's sleeve valve engine range included the Taurus, Hercules, Centaurus and Orion with the latter being massive but never brought to market. I think all but the taurus shared the same sleeve just stroked for capacity changes. Independently the Napier company was having huge challenges developing a sleeve for the Sabre and eventually the powers that be insisted Bristol help them out . Bristol refused to release their IP for sleeve manufacture but did supply sleeves from the Taurus which in a happy coincidence turned out to be the right size for the Sabre. It was Henry Ricardo who arguably started Bristol down the sleeve valve path, Ricardo commented that Octane ratings for petrol in the UK in the 1930's was inconsistent and poor somewhere in 60's or thereabouts leading to all sorts of problems with knock. The sleeve valve was more tolerant of low octane fuels due to the absence of a glowing red (white ? ) hot exhaust valve. Of course by the battle of Britain 100 octane fuel was available and poppet valve technology continued such that the sleeve valve advantage was eroded. Finally I do recall reading the sleeve valve radial engine had significantly better volumetric efficiency than its equivalent poppet valve competitor., it just "breathed" better.
I want to hear this thing run so, so badly. ❤
Ahhh. Yes. This is quite insane
Hanging on the edge of my seat for every episode.. an amazing project
Wow you got guts (Bristol) ship shape hold on tight when you start up that bad boy (try a shot gun starter old school airo starter unit I don't think a electric starter will work (big big battery???? Or fly wheel starter wind her up (then engage) at speed like on the old plane s ??? Good luck 😊😊😊
Engine looks pretty good like that...Yeah, go ahead and mount it in that position - shouldn't be too hard to remount the gearbox/final drive to suit.
Haha, yea that would be bonkers! Engine stuck out to one side for no reason 🤔
Does the starter also double has the generator?
Good question. I was wondering that..
Where did this motor come from?
Have a look through the channel. It's our own design. 💪
When the piston is at TDC how much clearance is there between it and the underside of the head ?
Loads. I know that's not a precise answer but I'm not able to check at the moment. It's plenty though, an inch plus.
@@StoneEngput some play doh in there, set to tdc then take it apart and measure
I can stick my whole finger in the decompressor hole. (Or a ruler). I'll measure when I'm home. Playdo would be a good alternative though.
32mm, I measured it this morning. That's from the piston crown to the underside of the head. Should be enough 😁
Can't be a real bike =no kick starter 😄 ( no i don't want to try it either)
Can you make a video were you af fitting things en building
Stuff think that wil boost de viewers an makes also little more coins to 😊
If you mean be in the video, I am now and then. I'm in the next one briefly.....
@@StoneEng I think he means, fitting and building. Probably thinking a time-lapse of you assembling/makings these parts.