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I use an industrial pipe gasket material, VALQUA No.6500. It was available in small sheets for model RC car engine exhaust sealing. I am using a 1mm thickness. https://www.valqua.com/product/sg6500/ I am sure there are many similar materials available.

Here is a run with the needle injector: The original Eisfeld model aircraft diesel engine used an open injector having also tried needle types. He then moved on to the current carbureted design. I have attached a translation of the original article.

Glad to hear you have got some runs from the engine :) Shame about the missing bolts but that is a relatively easy fix. I have been expermenting again with needle style injectors. They seem to run quite well but you always have the problem of fuel leaking past the needle. On one test run the...

Sorry to read about your setbacks :( I have used alum to disolve broken HSS drills and taps out of aluminium parts. It dosen't work with carbide tooling. You need a strong solution and some heat. It is slow and for a small deep hole you may need to agitate with some fine wire to remove air...

I started playing with fuel injection and diesels 8 years ago. I'm getting there :rolleyes:

Good Luck :)

For the injection pipes I use 2mm dia 1mm bore copper tube. Oil and fuel feed pipes are 3mm dia 2mm bore. These are connected with cone unions. There are various suppliers, I use Regner Dampftechnik: https://www.regner-dampftechnik.com/kupferrohr-verbinder

The tank height is not so much of a problem with diesel fuel. A volatile fuel like petrol needs to be under pressure at the pump inlet. I have been working with both fuels and keep the same height (the tank is fastened with a convenient screw on the head of my milling machine).

A test pump is always useful/helpful :) I would suggest that you turn it round so that the plunger is horizontal and the fuel inlet is on top. This makes it much easier to get the air out of the system. The fuel tank is about 0.5m above the pump.

I purchased it online from someone like this: https://www.abebooks.co.uk/Modern-Diesel-Automotive-Oil-Engines-Transport/30902675577/bd There are several versions available. I have a pre WW11 version and a post WW11 version. These were taken from the later version.

Dead volume does not seem to be a great problem as long as it can be purged of air. An air bubble of similar size to the injection volume will mess up the injection completely. The maximum fuel volume you will need for 56cc is less than 5mm3 unless you have a significant boost pressure from the...

Your combined pump and injector is based on the GM version I believe: The central bore for the spill port is similar to the Simms Uniflow pump. This was supposed to reduce the side forces on the plunger: The more normal Bosch CAV design has a spill groove leading to the helix. This gives a...

Ok, if I understand correctly injection starts when the piston closes the inlet/spill port and ends when the wedge cutout exposes the port. By my experience the piston should only return far enough to fully open the port and the working stroke should only displace the maximum amount of fuel...

What fuel are you using for your tests? Is it put under vacuum when the injection plunger returns? I had a problem with petrol (gasolene) vapourising during the return stroke with a port controlled injection pump. This showed up as bubbles in the fuel inlet pipe. This was resolved by...

Looking good :) Can you judge how even the injection timing is?

MEM does not have 'personal' blacklist. There are blocks of email addresses that are blocked by the forum software and I know that there are issues with .gmx addresses where they block MEM so the authentication fails. I am travelling atm but I am sure we can sort you out next week.

Akroyd developed the following: - Induction of air into the cylinder. - Injection of liquid fuel into a heated combustion chamber where it vaporised. - Compression to a few bar during which time the air and the vaporized fuel mixed. - Ignition caused by the heated combustion chamber. This...

A quick show and tell. This is my 25cc 4 stroke running at a moderate speed off load. There is some uncertainty about the emission factor for IR temperature measurements. I also made measurements with a contact probe (but didn't have enough hands to take pictures) which were around 300°C. This...

I started out with a self designed 3cc 4 stroke (16mm bore and stroke). This design was expanded to a 12 cc twin (20mm bore and stroke). Both these use 1/4-32 plugs. The others have been 25mm bore, but I think that Jason's 24mm bore may be better as the pitons and rings can be made from 25mm...

OK, I will put together a thread on fuel injection. Where should it go, 'General Engine Discussions'? MEM has a useful section for 'Engine Ancillaries'.