Category Archives: Leak Hints & Tips

Notes on Drawings and Design
While in my opinion the Leak Compound is the best marine compound design on the market, it seems to be quite well known that there are a number of errors (and omissions) from the drawings for the Leak Compound. As a service to the community, I am publishing the errors I have found in the drawings and would welcome input from others as to any “quirks” they have found.

In the process I have also developed a reduction drive for the pumps (to allow the engine to rev faster) and a step-up drive for an alternator to provide power for burners, navigation lights and radio – creating the drawings for this have taught me not to be too critical of others mistakes – it’s hard … :-)

Comparing old and new valve timing

As a last post on the subject of correcting the valve timing on the Leak  Compound in Befur (prior to “sea trials” later in the year), here we will look at the results from the static (blowing) valve timing tests, and compare to the results prior to rebuild. But first a video of it running on air with the new timing…

I just updated this post to improve the pictures and ordering to allow simpler comparisons between old and new timing data.

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Valve Setting on a Leak Compound

This time we are looking at how to fix the problems with the Leak’s valve gear design. This is now part of our Leak Hints and Tips section on the known errors or problems with Leak design……

As we get to the end of January 2022, the tuning/rebuild/shopping of Befur’s engine continues, once this is complete we can get on with the list of hull and fittings-related work. But it seems we should at least explain what work the last few months have contained…

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A Digital Engine Indicator

The Digital Engine Indicator

The Digital Engine Indicator

As my first job was working as an Instrument Technician for Shell Research in the Applied Physics department, I became interested in the measurement of physical systems… thus I was interested in Engine Indicators as a tool for evaluating engine performance, and measuring valve events and gas-flow in steam and very large marine diesels.

 

An Engine Indicator – Wikipedia Commons Image

Given my later life in computing I concluded that a digital version of one of these instruments could be made to evaluate the performance of Befur’s engine.

I penned an article for The SBA’s Funnel magazine, but the publication of this has been delayed, so I am publishing it here for those interested.

It’s still a prototype, and in need of further development, but it has provided some interesting data – which at least prompted further analysis and investigations into what happens inside Befur’e engine…

I have attached to this post a PDF describing the Digital Engine Indicator, which you can read and download here

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Engine Rebuild – Valve timing analysis

As you may have seen from earlier posts, and here we are embarking on a major winter “shopping” of Befur, to address a number of problems.

Measuring the valve timing on the bench

One of these tasks is to analyse and reset the valve timing of the engine to improve efficiency and performance. Continue reading

HP valve to Cylinder Joint & Lubrication

From Experience two other issues to consider

While these are not drawing errors, they have emerged over the first 3 seasons with the engine, and should be considered by builders.

HP Valve Chest to Cylinder Joint

In the BOOK the designer suggests using Araldite? as a jointing/sealing material… its not a solution, particularly for this joint.

The joint between the HP Valve Chest and the HP cylinder is problematic, as the sealing faces are very thin, and the two components are only secured by 4 bolts, which are hard to tighten and not well positioned to ensure a steam tight joint.

My first attempt was using “SteamSeal” jointing compound  – this failed quite quickly.

The second attempt was using “Heldite” jointing compound – this failed within a few hours.

My last attempt was using “Oakenstrong” gasket paper, I had resisted this, not wanting to affect the overall block dimensions. However, rebuilding with gasket paper and jointing compound (Heldite) does seem to have cured this problem.

Lubrication of “small ends”

I spent a long time chasing a knock that appeared to come from the LP small end. Rebushing the piston rod and a new pin did not cure this, and it was clear that the pin was suffering.

This was finally cured by increasing the size of the Lubtech pump units feeding these bearings and slide ways. A “black” one (0.1cc/stroke) silenced the knock instantly.

I am sure that a better builder than me might make the sideway fits better, but the lubrication points at the bottom of the piston rods have to lubricate the “small end” and the slide-ways, and so need a heavy oil flow to ensure that both bearings are supplied on each cylinder, as I think the oil preferentially flows to the slide-ways, starving the bush at the lower end of the piston rod.

Is this the end? Probably not!

Timeframe missed a bit

Well, looking back the first post here was on 8th June 2011, and we aimed to finish and launch by 26th June 2015 – planning was never my hot spot! We did change the goal posts in mid-flight (adding a sail, loo, etc, and stretching her from  a planned 16ft to almost 27ft to get everything in, but hey we did get there!), and on the 20th July 2020 we took her for a steam and sail on Windermere with a cameraman (Roger Heise from the SBA) on hand to record her 2nd trip under sail (thank you Roger).

Notes on the Steam Bit

Before I inflict an album of sailing photos on you, a couple of notes on the steam side, especially for Leak Compound builders…. Continue reading

Steamboat Crankshafts – Lessons & Manufacture Pt#2

This post continues/concludes the story of manufacturing a new crank for Befur from the last post.

Here we can see the re-assembled engine with new crank. We are still to install all the ancillaries (reversing gear, lubrication, condenser and feed/air pump & alternator drive.)

It took 6-man days from receiving the crank back from the grinders to reach this stage.

Once we have tested it on air, we will reinstall it on the boat and undertake this year’s boiler test and check all is as it should be.

Machining Crank Pins

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Steamboat Crankshafts – Lessons & Manufacture Pt#1

Introduction

Those of you who have been following Befur’s progress will know that our first year in the water was marred by the failure of the crankshaft in the Leak Compound engine I built.

This post deals with the manufacture of a replacement, and the results of my research/experience into the approaches to building cranks for “small” (<20HP) marine steam plants.

Methods of Manufacture

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When a broken crank is good news!

Well we got Befur’s engine back into the workshop, and stripped it down to see if we could locate the source of the knocking we have been suffering all season.

Befur’s Engine ready to be stripped.

On lifting the crank out it looked perfect, and did not have any obvious loose or moving joints My heart sank, as this was really my only theory on what was wrong. Continue reading