A Titan

[Jo]

Roger as promised my external hone. It was originally purchased as a casting set from Bruce Engineering. I learnt recently that Bruce had borrowed one of Eric's (Muddled Engineer) commercial ones to make the original from which is why it has the nice curved shape but I see no reason why it should not be made from flat bar stock.

This hone is rather big (it is currently set at the 24mm diameter for the Titan piston), I will have to look at making some smaller ones to the crankshaft journals on some of the model engines.

Next I need to think about what type of lap to make 

Jo

[Roger B]

Thank you Jo, what sort of abrasive block does it use? The piston I will be making is 25mm diameter so that is the right size.

[Jo]

The casting set came with that blue-ish square stone. I couldn't tell you what type it is, it seems to be the same as is fitted to my cylinder hones. I know Polly sell the stones separately to the casting set.

Jo

[Allen Smithee]

Formula 1 Motor Cars.................where IMHO the size of your wallet is the main criteria for success as with Americas Cup sailboats. 

I'm afraid this is demonstrably untrue. Ferrari have pretty well always had the biggest budget of all the F1 teams, but only turned this into success during the Todt/Schumacher/Brawn era. Maclaren has one of the larger budgets but has achieved naff-all will it since 2008. Williams are also a well funded team, but from the late 90s to last year they achieved very little. The core reasons for Mercedes current dominance relate to innovation, engineering rigour and design brilliance. Money certainly helps, but it's just the table "ante" - without engineering talent and driving talent the money achieves nothing.

AS

[Jo]

Hi Roger, I had a look at my bag of odds and ends and those stones seem to be fairly common. I am not sure what the orange coloured ones are for but the white ones are the same as the white wheels on my cutter grinder all say Norton on them.

My come in handies acquired some new storage racks recently, it is amazing when you layout everything you have just how much you have acquired  In amongst the odds and ends were a set of boiler tubes for a Locomotive  so one of the tubes has had the opportunity of doing something better with their life and participate in being part of my new lap.

The tube has been cut down the side and then silver soldered to the steel inner. Once I have had my lunch it should be cool enough for a little dancing  .

Jo

[Roger B]

Thank you again. I will have to see what I can get here. I can see a piece of bar on the shelves labelled  Anzani 

[Ramon Wilson]

Jo - I'm afraid you may have to start again on the lap.

Firstly it should only be silver soldered along the leading edge of the copper, not for the full half circumference as any expansion will take effect from the edge. That may work in practice but I have no idea if it will for certain. The object is that the soldered area be as narrow as possible along the length of the copper allowing expansion to affect most of the circumference. I usually coat the steel part with soft pencil lead to prevent the solder taking right round.

The second thing is it appears you have it the wrong way round - when you turn it to size it will 'unwrap' itself as opposed to self tightening against the mandrel - don't want to see you 'catch a crab' as we say here abouts 

Regards - T

[Jo]

Jo - I'm afraid you may have to start again on the lap.

The second thing is it appears you have it the wrong way round - when you turn it to size it will 'unwrap' itself as opposed to self tightening against the mandrel - don't want to see you 'catch a crab' as we say here abouts 

Regards - T

  Yes I know.

[Ramon Wilson]

A minor set back - 'jest take yer time' - you're doing fine. (you should have lapped your liner before the piston though ) No matter you should be okay - you don't need quite the fit as a diesel.

I think too, given the engine, you ought to lighten that piston some more especially if you want it to 'rev'  .

T

Edit - Sue's just said she bet you said the magic words  something like 'Golly Gosh look whats happened there' perhaps

[Jo]

I don't think I used the term "payrise" when that happened 

So another lap, well the same bits of steel recycled, silver soldered on but  I think that with a single grub screw providing the pressure to open the tool that the two ends are not stable enough over the 60mm of the copper surface. The result is that the far end of the copper has sprung. I tried shimming it but 

Time to make an aluminium tapered lap like I used on the Stentor.

At least I have the race to look forward to: Don't anyone let on to who won else

Jo

[Ramon Wilson]

How long is the liner Jo?

The lap length (copper portion) needs to be about 65-75% of the liner's length. The cut away portion needs to be about 90-95% of the lap itself. The grubscrew expander needs to be in the middle of the cut away portion both ways.

Persistence is usually the provider of success 

T

[Jo]

  Thanks Tug, I had made it 60mm for a 50 mm cylinder,  I wasn't sure of the length so assumed like my aluminium lap it needed to be longer than the cylinder. Maybe next time I will try a copper lap again.

For now I have an Aluminium one mounted on a tapered shaft so it must be time to get all oily and be messy 

Jo

[ken rector]

Nice work Jo.

Where did you find the castings?

I'm a fan  of George Genevro and built his Crusader .60 as my first engine project.   I exchanged an email with him several years ago about castings and he said he was not in that business any more as he was living in a retirement home so I am surprised to see you have these.  You must have been saving them under your bench for quite some time.  George taught Industrial Ed at Cal State Long Beach and wrote a text book and articles for HSM and other magazines as you may know.  I found his instructions for the Crusader .60 very complete and easy to follow.

[Jo]

Hi Ken

The Titan castings came from one of the other members on this forum Eric also known as Muddled Engineer. I think Eric has more sets of Titan castings in amongst his several hundred (if not thousands) of other model engine castings.

I am of course doing my best to repatriate as many of Eric's engine castings as I can 

Jo

[Ramon Wilson]

Thanks Tug, I had made it 60mm for a 50 mm cylinder,  I wasn't sure of the length so assumed like my aluminium lap it needed to be longer than the cylinder. Maybe next time I will try a copper lap again.

For now I have an Aluminium one mounted on a tapered shaft so it must be time to get all oily and be messy 

Jo

Good luck with it Jo - try and get a nice taper toward the top from the exhaust up.

Very nice Crusader Ken 

Ramon