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Radial engine build


ptwizz
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Machining the cylinder heads for pushrod tubes with proper seals.

The original Russian design has steel pushrod tubes which are shoved into the rough bored holes in the head casting, presumably by a stalwart Russian woman (I've seen photos of the factory - all the stereotypes are based in fact!).

Much time has been spent recently machining unimpressive parts (pushrod tubes and collars, bushes etc).

Fairly soon I should be in a position to assemble all the valve gear and make a short video with the engine turning over slowly to illustrate the motion of the cam, followers etc.

57336439a6e75_2016-02-2421.48.58.jpg.50b

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Thanks for the update :-) :-)

If its OK with you, when the new site goes live I will turn this thread into a proper 'blog' as we will have a section for that.

It will allow you to drag and drop videos and pics in to a post (any file format) without the current agro and also make it easy for people to find :-)

I just cant't wait to hear it!

I started my book at about the same time you started your engine build... I have been having a race with you since, without you knowing! lol

SW :D

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OK with me Simon. It is my assumption that anything I post on the forum is in the public domain and anyone can do as they like with it.

So, what's the subject matter of the book? PPG? Helicopter? Film making?

I feel the 'race' thing has added some responsibility to the project. If I don't make progress, you have nothing to race against. :wink:

Another weekend of making small uninteresting parts. Another step closer to the sound of 7 cylinders on open exhaust stubs. :D

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"Meteorology for pilots" by Simon Westmore immediately has at least one customer.

However many times I read through the chapter in Cosgrove (and other sources) I fail to see how I am going to remember enough to pass an exam.

Approximately half of what the weather does is non-intuitive and I can't remember which half!

If it's "Meteorology for Dummies" (i.e. written like C for dummies) then you will have a ready market.

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  • 2 weeks later...

A family of swinging tappets. Each has bronze bushes pressed in and machined to finished size in-situ. The roller cam followers are off-the-shelf items. Alongside the tappets are the silver steel pushrod cups which will be hardened and pressed into the tappets.

57336439c1089_2016-03-2012.20.16sml.jpg.

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Assembly of tappets. All 14 swinging tappets are identical and interchangeable. The cam ring will be gas nitride hardened - one of very few operations that I can't carry out in my workshop. I could have salt bath nitrided it, but it's a little difficult to get hold of the cyanide salt (and there may be some health and safety whining).

57336439cf66f_2016-03-2012.46.22sml.jpg.

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All together again. At the first attempt to fit one of the heads with the pushrod tubes in place, I struggled for several minutes and couldn't get everything to play nicely. When I finally stepped back and let go of the head, it dropped into place on it's own!

It's amazing how much more easily things go together when you already know that they fit. The other 6 assemblies were a breeze.

Next job is the pushrods, which will be from 8mm aluminium tube (pre-anodised from Wickes of all places!) with hardened silver steel tips.

57336439d3bb8_2016-03-2015.07.52sml.jpg.

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  • 3 months later...

You know you`re in deep when you have to make a tool, for use on another tool, to make a part for the thing you`re making.........

Your patience is impressive, to go with your engineering skillz.

Are you making to plans, or ad-hoc?

How on earth for instance did you work out the cam timing on that beast?

What`s your (top-end) lubrication set up going to be?

 

Good work, i guess we`ll all have to be patient to see the start-up video...

 

Edited by Hann__
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Hi Hann,

toolmaking is all part of the fun of engineering at home. I have a collection of tools which were made by my grandfather, and a few made by my uncle, to which I am adding as projects progress.

I have modelled the whole engine in CAD and produced drawings for all the parts. To establish the cam timing, I first measured timing from a camshaft from the same engine that the cylinder heads came from. This was then translated to the ring cam, using a spreadsheet calculation. The cam timing / lift spreadsheet is relatively simple when compared to the one I created to calculate the dynamic balance of all the moving parts. That is a huge, rambling set of iterative calculations (which i suspect may have become self-aware).

Each cylinder head has it's own pressurised oil feed, with a spraybar arrangement to ensure that the valve guides and the exhaust port areas of the heads are liberally supplied. Most of this is for cooling rather than lubrication. The upper cylinders will drain via the pushrod tubes into the timing chest, then via the lower cylinders pushrod tubes into the lower rocker boxes. The lower rocker boxes will have drain tubes to a collector tank, where a scavenge pump returns drained oil to the main oil tank, via an oil cooler and filter.

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Thanks for the compliments gents. I should say again, I am only copying the work done by pioneers over 100 years ago. I am quite happy with 'slow burn' projects. As I tell my wife, if I said I'll do it, I'll do it. I don't need reminding every year.:-)

It's all a matter of perspective. To my mind, mechanical stuff is simple. I can see how the parts work together and get a reasonable feel for the loads involved, so when a calculation or test goes wrong, i have a good idea what to look for.

I am learning about electronics as I go along, so i can make my own ignition module, which will later be expanded to engine monitoring and possibly fuel injection. When a PIC doesn't do what I expect, it doesn't give me any clues (or more likely I have no idea where to start looking).

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  • 1 month later...

I have caused myself a further delay to the build, this time by deciding that the Russian valve rockers are just too crap to tolerate.

When I came to assemble the pushrods, I checked the lengths of a few in situ only to find that the clearances were all over the place. On investigation, the variation turned out to be in the rockers.

I have designed aluminium rockers with roller tips and improved geometry. I have turned the blanks for them (fourteen 75mm diameter billets, 42mm long) and started milling. When they are finished, I'll be back to where I thought I was 2 months ago.

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  • 1 month later...

Apologies for the radio silence on this project. My time outside work has been divided between motorcycles and the pursuit of NPPL(M).

While I haven't made much headway with machining parts recently, I have obtained a starter ring gear and starter motor which will be suitable for the radial.

When I have made all the major assemblies (i.e. finished the valve gear, made the supercharger and the oil tank) I would like to make a time lapse video, starting with the crankshaft mounted in a bearing and rotating slowly (driven by a small motor), then adding parts so that it is clear how everything works.

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