Author Topic: Fuel injection systems  (Read 96689 times)

Offline Admiral_dk

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Re: Fuel injection systems
« Reply #60 on: December 01, 2015, 08:23:35 PM »
Quote
Roger, been quietly following along with great interest.

Me too - the very few who has solved this puzzle before are not sharing their knowledge (not that I blame them), but you are doing it in public and if (I should say when, shouldn't I ;) ) you solve it = we all win  :whoohoo:

Offline Roger B

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Re: Fuel injection systems
« Reply #61 on: December 02, 2015, 07:53:24 PM »
Thank you both for your interest and support as I slowly plod away at this  :ThumbsUp:   :wine1:

I turned the nipple with a 59° cone to try and ensure that it sealed at the end. A quick check with marking blue suggests that it's a reasonable fit. Unfortunately I did it up a bit too tight for the trial and crushed the end so the pipe no longer fits  :(  I will make a new one with a slightly shorter land to get an extra thread engaged.

When I make the next one (for the actual diesel I will need to silver solder a clamping flange on) I will offset the bore to get yet another thread and also probably use M6x0.5 instead of M5x0.5
Best regards

Roger

Offline Roger B

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Re: Fuel injection systems
« Reply #62 on: December 06, 2015, 06:41:08 PM »
A little bit more: This time I soldered the pipe into the nipple before screwing it up tight. The 1mm drill is in the end of the pipe to stop any solder getting in. The bore for the needle was lapped in the same way as the pump bore and the pieces were all cleaned in the ultrasonic bath.

Next I need to sort out the delivery valve for the pump as well as an operating mechanism.
Best regards

Roger

Offline Admiral_dk

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Re: Fuel injection systems
« Reply #63 on: December 06, 2015, 11:26:11 PM »
Great progress  :ThumbsUp:

Offline Don1966

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Re: Fuel injection systems
« Reply #64 on: December 07, 2015, 12:56:24 AM »
So does this mean we have a working injector? Looks great and you have my attention.

Don

Offline Roger B

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Re: Fuel injection systems
« Reply #65 on: December 08, 2015, 11:21:29 AM »
Thank you both  :ThumbsUp: I don't know yet if it will work, but I have managed to make all the parts according to my plans  :) I need to order a selection of springs to allow me to set the injection pressures. The first planned trial with petrol injection into the intake will require a much lower pressure (10 Bar ??) than for the true diesel operation (50 Bar+). I did think about winding my own, but to get consistency I would rather pay a little and have correctly post heat treated ones.
Best regards

Roger

Offline Stuart

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Re: Fuel injection systems
« Reply #66 on: December 08, 2015, 05:35:33 PM »
Roger

When you come to silver solder very small stuff I use silver solder paste no extra flux required

I have used it for doing nipples on 1/16 odd copper pipe and never had a bung up you need just a smear

Cup alloys have it

http://www.cupalloys.co.uk/home/

Lee springs are good and provide the data that you will need


Stuart
« Last Edit: December 08, 2015, 06:39:39 PM by Stuart »
My aim is for a accurate part with a good finish

Offline Roger B

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Re: Fuel injection systems
« Reply #67 on: December 09, 2015, 08:59:08 PM »
Thank you Stuart  :ThumbsUp: This time I have soft soldered the nipple to the pipe so I can remove it later if needed but that paste looks interesting for the future. I have ordered the springs from HPC as they also had 2mm key steel which I have been looking for as well as no minimum order quantity  :)
Best regards

Roger

Offline Roger B

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Re: Fuel injection systems
« Reply #68 on: January 04, 2016, 07:08:07 PM »
Finally back on this. I have started making a simple stroke adjuster that will use a tapered wedge based on the system used on the Lanz Bulldog. I have also received my selection of springs so I can continue with the pump delivery valve and injector.

As I don't have a 2mm slitting saw I cut down the middle of the plunger with a 1mm saw and then made two additional cuts to bring it to 2mm. I was concerned about the saw deflecting but this did not seem to be a problem.

Unfortunately I broke the tip of a centre drill in the stroke adjuster body  :( This time I followed a suggestion from one of the posters on here and ground the middle of the broken drill away and used it to trepan around the broken tip so I could remove it  :)
Best regards

Roger

Offline fumopuc

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Re: Fuel injection systems
« Reply #69 on: January 04, 2016, 09:12:45 PM »
Hi Roger, I am quietly following along.
Kind Regards
Achim

Offline Don1966

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Re: Fuel injection systems
« Reply #70 on: January 04, 2016, 10:52:22 PM »
Still with you Roger.............. :cheers:

Don

Offline Roger B

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Re: Fuel injection systems
« Reply #71 on: January 05, 2016, 07:04:51 PM »
Thank you both  :wine1:

I milled out the slot for the control wedge and then milled the wedge (4mm key steel) to 10° and used this to set the plunger to mill a matching 10° on the end.
Best regards

Roger

Offline Roger B

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Re: Fuel injection systems
« Reply #72 on: January 31, 2016, 03:32:08 PM »
As I had received the required springs I decided to try the pumping system. The delivery valve holder was drilled 3.1 for a 3mm ball. The annulus left is of similar area to the 1mm bore connecting pipe.

Unfortunately, but not unexpectedly, the thread on the injector union failed so I opened out to M6 x 0.5. I was able to centre the nozzle using the original 0.8mm centre drill then cut the old thfread out with a 5 mm end mill, open out to 5.5 mm and retap. I also made a new nut with a small recess to allow an extra thread or so to engage.
Best regards

Roger

Offline Roger B

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Re: Fuel injection systems
« Reply #73 on: January 31, 2016, 03:39:18 PM »
Having fixed the damaged thread I could put the system together with a temporary tank (part of a float chamber for my first engine) and try it with some cooking alcohol. It took a lot of effort to get the air out of the system but was finally rewarded with some dribbles and drips along with one or two good sprays  :whoohoo:

There was quite a lot of leakage from the back of the injector. I'm not sure if it was past the needle or from the union.

I've tried to capture some of the spraying on video, but it's not very good  :(

<a href="https://www.youtube.com/watch?v=Au2usbHQmKg" target="_blank">http://www.youtube.com/watch?v=Au2usbHQmKg</a>
Best regards

Roger

Offline Don1966

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Re: Fuel injection systems
« Reply #74 on: January 31, 2016, 04:00:40 PM »
Cool Roger, it's a start anyway. It does look like some progress to me. Keep it coming......... :ThumbsUp:

Don

 

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