Steve_K

That's the bunny. Steve

There's a film on YouTube showing the 7 manufacturing process which shows them sanding this joint flat after welding. No filler in sight. Steve

that doesn't work, try https://www.screwfix.com/p/arctic-products-metric-o-ring-selection-box-225-pcs/4312j?_requestid=402176

I use a Garmin Zumo bike satnav and, while they are more expensive, they have bluetooth built in and are pretty waterproof. The bluetooth can be linked to your phone but if you have an intercom with a bluetooth dongle, its a bit of a faff to set up. I only got it all working once and couldn't be bothered since. Steve

Thanks Shaun, magic! Steve

Thanks Shaun Steve

Just as an experiment I posted the original text into an Add New Comment box to see if things changed... When I posted a new topic (https://www.lotus7.club/forum/chitchat/aly-caterham) There was no format options box on top of the Body box. Clicking on the Text format options at the bottom just takes you to the top of the page. Carriage return didn't break the text. It also happened when I created this post. My first post was made using Chrome Version 64.0.3282.119 running on Linux Mint 18.3 (64-bit). This post was made using Firefox Quantum V58.0 (64 bit) also on Mint. Steve

When I posted a new topic (https://www.lotus7.club/forum/chitchat/aly-caterham) There was no format options box on top of the Body box. Clicking on the Text format options at the bottom just takes you to the top of the page. Carriage return didn't break the text. It also happened when I created this post. My first post was made using Chrome Version 64.0.3282.119 running on Linux Mint 18.3 (64-bit). This post was made using Firefox Quantum V58.0 (64 bit) also on Mint. Steve

The linked advert calls this a 'circuit breaker'. I'm aware that some circuit breakers are designed against a duty cycle which only involves its protection function. While they can be used as switches for security purposes, if they aren't designed for it, they might exhibit a shorter useful life. I don't think this is a safety issue so you pays your money and takes your choice... Steve

Its probably not a dedicated 'running in' oil. ISTR my RS175 Duratec was delivered with mineral oil (grade unknown) for running in. CC's instruction was to fill with 5W/50 fully synthetic after running in for between 500 and 1000 miles. As it happens I left it in until about 2000 miles as it seemed to be running OK. Steve

I've just done some checking on Google. While the 2.3 Duratec seems to have balancers, it looks like the 2.0 doesn't although I didn't find anything definitive, just an absence of info. Sorry. Steve

This may be a red herring but doesn't the Duratec use internal balance shafts to counteract the 4 cylinder engine's intrinsic secondary out of balance forces? The shafts run at double crankshaft speed which might explain the highish frequency observed. Maybe the engine was supplied with the timing for the shafts out of kilter? Steve

I know nothing about K series engines but could oil be leaking into the cylinders down the valve stems? As long as the leak was small but continuous, it would be almost invisible. Steve

In engineering terms JK has it right. The compression ratio is a key term in determining thermodynamic efficiency of an engine. The higher the ratio, the higher the energy available to do work. The problem with high ratios is the tendency for the fuel/air mixture to detonate, i.e. explode (and in relative terms it is an explosion rather than the usual 'burn') before the spark is passed. To counter this detonation the higher octane fuels are actually harder to ignite by compression. Note that the amount of chemical energy available from the various octanes is more or less the same in engineering terms. Steve PS FWIW the theoretical relationship for the thermodynamic efficiency is given by (1-1/R)^(Ɣ-1) where R is the compression ratio and Ɣ is the ratio of specific heats or Poisson constant. I think this is right but its been a long time since this came up last. Don't bother working it out for your own engines as the real world is a lot more complicated than the theory implies - gamma isn't constant. BTW Petrol's star rating relates to the delay period between the spark discharge and the start of the pressure rise. More stars, lower delay period.

XRX627H nice classic green and yellow. Nice to see. Steve

FWIW gas solubility in liquid is directly proportional to pressure and that's pretty much any gas or liquid. Any reduced pressure will help. In the jet example I mentioned, normal system pressure was around 3000 psi so the amount of gas dissolved was huge. Mostly it actually doesn't matter until the fluid passes through a restriction (such as a shuttle valve) at high flow rates when the gas comes out of solution due to the local lower pressure. The response of the valve can be fairly strange when the working fluid changes... Steve

Intuitively this seems sensible. While the solubility of air in oil is small, if you double the pressure to 1 bar say, you'll double the amount of air dissolved in the oil. Old jet aircraft used to use a deaeration rig to place hydraulic oil under a low pressure to release dissolved gas. Worked amazingly well but a waste of time really as the gas was reabsorbed as soon as the Hyds were repressurised. Steve

While octane number relates to anti-knock, the star rating really relates to the delay period between the spark and the start of the pressure rise. Higher the star, the shorter the delay. I don't think the distinction makes a lot of difference when it comes down to it. Steve

Has anyone done a direct comparison of something based on silicones and something based on those things? No comparison data but I am aware of a problem some years ago where carbon composite became contaminated with silicone during production. The parts in question suffered from low bond strength issues when bonded to other parts. Post production cleaning was ineffective. The presence of silicone could compromise the ability to repair damaged parts. Not a big issue but it might catch someone out. Steve

I remember that story. It had to go back for rework. Steve

How about a lightweight double-skinning job? A layer of balsa wood (5ish mm) bonded to the ally covered with a couple of plies of carbon fibre should give more stiffness in all directions. There are plenty of videos on Youtube about how to lay up the CFC using the bonnet as the pattern. Steve

If you mean VIN Number, mine is stamped on the drivers side top chassis rail under the bonnet. Steve

I'm not sure about the "1.5 times the diameter" standard but I have come across having a minimum of 1.5 threads protruding from the nut to show its in good engagement. This is from aviation practice. Steve

When I did my first oil change on a Duratec I just kept adding oil until it showed on the dipstick. I didn't take any measurements but it seemed a bit more than 4.5l. It was less than 5 though. If I had to guess, I'd estimate about 4.7l. Steve

Thread resurrection... I found the following "Steel Shaft Vs Carbon Fiber Shaft" just by chance: It looks like a CFC shaft might be an expensive option and I still think it might not be a long life item under road conditions but there are possibilities. Steve