Recent content by Chaffe

It’s a good solution, All car petrol engines use these now, you can get them for pennies second hand. Also for the signal you can use 12v no issues as it’s just a logic signal, which makes the wiring even easier. I use mine with points on one engine and a magnetic Reed switch on another. Very...

I just use an automotive COP, one thing does whole job, hall sensor triggered, easy to wire up and cheap.

A gauge is a gauge, as long as the range is correct it will work fine.

If it runs I’ll be delighted 😁

I will do, I don’t have the time or inclination for a full thread, but will certainly highlight any new breakthroughs.

No leaks at all so far, the screwed connections were surprisingly easy to make successfully. It will hold 40 bar (500psi) for several seconds too, which is promising. I will focus my efforts on a 40 bar injector and then the engine itself now.

Thanks, I think it will be adequate, I will now continue work on my engine and try complete the project in 2022…. As for gauges this was surplus’s from a job at work, but something off eBay would do? I don’t think you will need one above 100 bar… but you never know!

Looks good!

I have done some maths and I think 40 bar injection pressure will work with 45 degrees injection timing. Cylinder pressure at that point will not be high. The injector should withstand 650bar cylinder pressure with that spring too, assume 8kg spring and the size nozzle I am running.

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Some success with the “old” style injection pump, Minh-Thanh what injection pressure does your injection pump achieve? What pressure are you popping your injector at? Chaffe

Simple answer is heat, heat is lost to the cylinder walls, piston, head and the fuel. The smaller the cylinder the less heat energy you will get from the air charge. Physics don’t scale very well, especially when it comes to thermal dynamics.

lovely job! this engine is the pinnacle of small petrol engines, a modern classic. Look forward to the finished article.

Hi, I have what I consider to be quite a good bore (size and finish) in my cast iron pump, the piston was in fact not machined and I tried to use ground stainless bar, it is too small… I’ll make a piston when time permits. The check valves seem to be the real test for me 😂 I will try a tapered...

You’ll not get emery or scotchbrite in a 2mm hole, 11mm deep…. ideally I would want to polish it with a ball soldered onto a brass rod, with compound. I believe the new design with a 30 degree seat and slightly larger ball will be better.