Thank You Dave for being so generous by sharing this terrific story
Don't know if I have read it right, but can the inlet ports be sleeved?
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| Aussie 8 Port https://www.ausmini.com/forums/viewtopic.php?f=5&t=99606 |
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| Author: | Ian_B [ Thu Jan 30, 2020 5:44 pm ] |
| Post subject: | Re: Aussie 8 Port |
You know exactly what you are doing You are sharing your development .You are a good man .Carry on I know this will end very well. |
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| Author: | Scoop [ Thu Jan 30, 2020 8:51 pm ] |
| Post subject: | Re: Aussie 8 Port |
Mind blowing stuff Dave. I am really enjoying your work. |
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| Author: | Gambo [ Fri Jan 31, 2020 8:16 am ] |
| Post subject: | Re: Aussie 8 Port |
This is absolutely brilliant, love the work that has gone into it. If you decide to do a production run, might be interested in one.... |
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| Author: | simon k [ Mon Feb 03, 2020 7:56 pm ] |
| Post subject: | Re: Aussie 8 Port |
just wow - utterly wow I guess you're going to use an Arden type camshaft? |
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| Author: | Dave P [ Tue Feb 04, 2020 7:15 am ] |
| Post subject: | Re: Aussie 8 Port |
simon k wrote: just wow - utterly wow I guess you're going to use an Arden type camshaft? Yup! What they refer to as an 8 port cam. Same one used on the Weslake too. |
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| Author: | Dave P [ Tue Feb 04, 2020 1:32 pm ] |
| Post subject: | Re: Aussie 8 Port |
Chapter 5 “Can’t think of a quote” At the beginning of this story I said how I had not been able to get a copy of any Leyland drawings. As I was working through this project, I found that I could reverse engineer about 90% of the data I needed. Another 9% could be found on the ‘net. But that last 1% was a bit of a problem. Specifically, the fit between the guides and head… So, I asked for some help on the Ausmini forum and got some feedback from “winabbey” who had a copy of the head drawing and was happy to share it with me!!! Wish I had asked for help on the Ausmini forum earlier! Ironically this did not have that one piece of info I needed but it did let me check a lot of my reverse engineering and helped to get the machining a whole lot better. (I did find the tolerance I needed in the end; more later) The first thing I did was compare the head stud, valve guide and pushrod hole patterns with the drawing. I wasn’t too far off, all within +/-0.5mm. of the Leyland drawing, but I still corrected everything to the exact spec. Ironically, I had just had a 6 mm ally plate laser cut to confirm the fit of the head to block… It did fit so I was within the tolerance of the oversized head stud holes. For reference the “front centre” stud (between 2 & 3 spark plugs) is a sized hole, all others are over-sized. When fitted the head can move about this stud. (Do any of us take the time to get the head as straight as possible on the block!) When you think that modern heads are located with dowels etc. this is a bit surprising but made the head a whole lot easier to make as my positional tolerances could be a bit looser. I have very little machining experience and no equipment so this was never going to be something I could do myself. Luckily, I have a colleague who does and has! And would do it at very reasonable Mates Rates. I gave him the CAD, a set of my drawings, a copy of the Leyland drawing and of course the castings. This was his initial 11 steps to happiness: Attachment: Machining 1.JPG Attachment: Machining 2.JPG Couple of things that changed, firstly he didn’t need to counter bore the plug holes, and there is an oil way drilling missing. But it should give you an idea of the amount of machining required for what is a very simple head! (Imagine a twin cam like KAD’s) In reality fact he did not do all of each step at the same time. We also discussed reaming for the guides and cutting and fitting the Exhaust seat inserts and agreed that this was something that I would give to a professional engine reconditioning company as they would have the experience and correct equipment to do the job correctly. If you remember the casting images; we had some casting defects on the main face, as we machined the head they all disappeared except one which turned out to be a hole into the water jacket. This was a real surprise and a downer. However, a bottle of wine (or two) later we thought about it and realised it was not over the compression ring or the combustion chamber so we felt it could be brazed up later. Actually; it is where there is a brass insert on the 1275 head to cover a core venting riser, I thought I had given the sand cores enough venting routes through the water jacket holes but apparently not. If I did more castings I would add a vent there, just like BMC did… Hmmm. Attachment: Slide1.JPG Attachment: Slide2.JPG Attachment: Slide3.JPG Attachment: Slide4.JPG Attachment: Slide5.JPG
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| Author: | Dave P [ Tue Feb 04, 2020 1:34 pm ] |
| Post subject: | Re: Aussie 8 Port |
And more Images: Attachment: Slide6.JPG Attachment: Slide7.JPG Attachment: Slide8.JPG Attachment: Slide9.JPG Nearly finished now just needed to get the guides fitted… |
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| Author: | braad [ Tue Feb 04, 2020 5:05 pm ] |
| Post subject: | Re: Aussie 8 Port |
Bravo Dave. Love the warts and all detail |
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| Author: | Stuwey [ Tue Feb 04, 2020 8:58 pm ] |
| Post subject: | Re: Aussie 8 Port |
Just. Amazing. |
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| Author: | Dave P [ Tue Feb 11, 2020 8:47 am ] |
| Post subject: | Re: Aussie 8 Port |
Chapter 6 “Yes Charlie” So pretty much up to date now, from my machinist the head went to Reflex Engineering here in Campbellfield where Glen fitted the guides, exhaust seats and cut the inlet seats. He also welded up the hole! I was assuming that brazing would be the way to go but Glen suggested spray welding which is his normal method for repairing iron heads. I was happy to be guided by his (far greater) experience and it has come out well. Got to say I was really impressed, Glen took the time to get everything perfect, even using another 1275 head he had “on the shelf” to check everything. Only issue we had was that the inlet ports were a smidge too large for the 35 mm. valves: I was over optimistic on my casting accuracy, so I am currently waiting for some 37 mm. valves from Minispares. I am a bit concerned that with the down draft inlets and 37mm. valves that I am over ported compared to the 29 mm. exhaust valves, but we will have to see. From Reflex all I had to do was mask and paint, having spent far too long thinking about the best colour for it! And then the first full dry build, as shown in the early pictures in this post. So that’s where I am now, I have one complete head and one casting, I have all the engine management sorted, including a complete homemade engine harness: Attachment: Engine Harness.jpg Gearbox is also sorted and the Mini itself is 95% complete; just need a new set of brake hoses as the UK ones are not “ADR” compliant. For the engine I need to build up a bottom end. And this is where things will have to stop for a while! Originally I wasn’t going to share anything until I had a running vehicle, largely due to the negativity I have received in the past. But “family” circumstances mean that I will not be able to put any more money into this project for some time, and to be honest I wanted to share what I had done as I was pretty chuffed with how it had turned out! I will keep adding updates with any small things I do; like the crank position sensor etc. but it may be sometime before we see it running. In the mean time thanks for all your support and encouragement, it’s much appreciated. |
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| Author: | 9YaTaH [ Tue Feb 11, 2020 3:42 pm ] |
| Post subject: | Re: Aussie 8 Port |
Thank You Dave for being so generous by sharing this terrific story Don't know if I have read it right, but can the inlet ports be sleeved? |
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| Author: | Mick [ Tue Feb 11, 2020 7:33 pm ] |
| Post subject: | Re: Aussie 8 Port |
 Wow! |
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| Author: | Dave P [ Wed Feb 12, 2020 9:29 am ] |
| Post subject: | Re: Aussie 8 Port |
9YaTaH wrote: Thank You Dave for being so generous by sharing this terrific story Don't know if I have read it right, but can the inlet ports be sleeved? Not sure about sleeving! I could have got seats put in but decided to go bigger valves. Second casting I have has slightly smaller ports, and is a bit better dimensionally... |
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| Author: | 9YaTaH [ Wed Feb 12, 2020 9:38 am ] |
| Post subject: | Re: Aussie 8 Port |
and, I was just wondering whether a flow application existed that complemented CAD etc (I studied Bernoulli's Principle a long, long time ago!), quick check today brought up this...Yee Har!  http://powerlab.fsb.hr/ped/kturbo/OpenF ... eb2007.pdf |
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| Author: | Bubbacluby [ Fri Apr 24, 2020 11:58 pm ] |
| Post subject: | Re: Aussie 8 Port |
No more updates on this? Not even during lockdown? |
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