Author Topic: Two Cylinder Engine  (Read 38008 times)

Offline Roger B

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Re: Two Cylinder Engine
« Reply #315 on: April 04, 2021, 01:05:36 PM »
Next up is the induction pipe and slide throttle. The slide throttle is a reduced size version of the one on the horizontal engine and the induction pipe is made in a similar way. The angled pipe was supported with a piece of 5mm rod to stop it collapsing in the vice. Rather than use a flange to hold the injector I decided to make clamp based on the design George Britnell used for his pipe clamps. The initial boss was made of stainless steel in the hope of having a stronger thread but it wouldn't wet with the silver solder so I made a replacement from 3mm brass rod. As before I used a centre drill to open up the hole into the main bore to avoid it cutting into the side of the tube. The bush was then split with a razor saw.
Best regards

Roger

Offline Admiral_dk

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Re: Two Cylinder Engine
« Reply #316 on: April 04, 2021, 08:49:13 PM »
If it wasn't for the "missing throttle valve" - I would say that you have moved your inlet + injector design forward a few decades - but as usual, it might just be me missing a few pointers  ;D

Offline Roger B

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Re: Two Cylinder Engine
« Reply #317 on: April 05, 2021, 04:45:16 PM »
Thank you Per  :) I am learning a lot through all these fuel injection experiments. Nothing actually broke on  the diesel in the last trials  ::)

On with missing throttle. The various parts of the body were milled to size and the slide was taken down to a fairly precise 8.0mm. The slot was then cut in the body with an 8mm endmill to 2.05mm deep giving an easy running fit. The port (is that the right word??) was drilled 5mm and recessed 6mm for the induction pipe.
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Roger

Offline Admiral_dk

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Re: Two Cylinder Engine
« Reply #318 on: April 05, 2021, 09:25:03 PM »
That should do it.

On my big bike I see a few mm. from the throttle valve to the injector. I think that is done, so you get the maximum amount off turbulence to help mix the fuel and air ....
The injector is located closest to where the biggest amount of air pases the throttle when not fully open.

Notice the closeness and the four Laser drilled holes in the pic.
« Last Edit: April 05, 2021, 09:44:30 PM by Admiral_dk »

Offline Roger B

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Re: Two Cylinder Engine
« Reply #319 on: April 07, 2021, 07:29:07 PM »
Fuel injector and throttle positions are completely variable. Older F1 injected into the trumpet before the throttle. Road cars will inject onto the inlet valve after the throttle. Too many things to learn  :thinking:  ::)

Lots more holes to drill and tap, but unfortunately the hole in the end of the slide drifted and the slide had to be remade  :( All looks ok now just the full throttle stop to turn up.

Dave just needs to make 12 for the 917 engine  :stir:  :)
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Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #320 on: April 10, 2021, 03:41:46 PM »
The full throttle stop rod was turned from 1.5mm silver steel and threaded M1.4 at both ends. I turned up some more M1.4 nuts from 2mm brass hex. The idling stop is an M1.4 cap head.

The manifold assembly was then fitted to the engine to sort out the linkages. I will initially need separate controls for the throttle and pump stoke so I can work out a suitable relationship for different speeds and loads.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #321 on: April 17, 2021, 03:12:33 PM »
I started with a bracket for the throttle control lever. It is designed to allow a face cam to be fitted to adjust the pump stroke as well if required. The levers were then cut from 3mm aluminium.
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Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #322 on: April 17, 2021, 03:17:08 PM »
I didn't have suitable die holder to thread the pivot shafts M3 so I concocted one from an Apex die holder and one of the adaptors from my big tailstock die holder. I do need to design something better for the Proxxon.

The throttle lever spindle is held in the bracket with a grub screw, but the bracket is intended to be used as a bearing in the final system.
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Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #323 on: May 01, 2021, 11:16:52 AM »
On with the linkages. The stroke adjuster link is tapped one end to allow for the offset connection to the adjuster wedge. The throttle linkage is two shortened M2 model aircraft joints.

Next up clean it all up and assemble. Just a couple of pipes to make  :)
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #324 on: May 02, 2021, 03:54:55 PM »
I tried the stroke adjustment linkage with the starter. I will need more friction to keep the position and at minimum stroke the wedge 'toggles' out and jams. I will have to make a support so the link cannot drop too far.


The piping was finished and installed. The injector pipe is soft soldered as the pressures should be somewhat lower.

The timing cover hit the injection pump excentric pivot so it will need to be milled out a little more.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #325 on: May 09, 2021, 07:59:50 AM »
I milled a cutout in the timing cover and assembled it ready for a quick trial. Not very successful  :( there was a fuel leak from around the delivery valve. I removed the valve and the end was crushed so the ball was trapped. I had obviously got something wrong.

I checked the measurements in the top of the pump element and made a new delivery valve, increasing the parallel section from 0.5mm to 1.5mm. I then made a support for the end of the stroke wedge from 0.3mm phosphor bronze.
Best regards

Roger

Offline Roger B

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Re: Two Cylinder Engine
« Reply #326 on: May 09, 2021, 08:04:44 AM »
Time for another unsuccessful trial  ::)

It started raced away and the wedge flipped out upwards  ::) This control system was fine with a horizontal pump where gravity kept the wedge in place but it needs some more work in this configuration  :headscratch:

There was also still a fuel puddle on top of the pump but I think this is coming round the pump element. I need to check the O rings are undamaged and are suitable for Alkylate fuel (they are not suitable for alcohol but are fine with diesel).
Best regards

Roger

Offline Admiral_dk

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Re: Two Cylinder Engine
« Reply #327 on: May 09, 2021, 09:58:18 PM »
I'm still impressed with your persistence - can we increase the scale / grade  :thinking:
.... but there is probably only one result that will satisfy you - and that won't be medals etc.