Stuart 10v Cylinder honing?

[Martin King 2Participant @martinking2]

Hi all,

Just finished boring my 10V cylinder and have ended up at .747" diameter to leave a bit for final finishing or honing.

Can you please tell me the best way to do this?

Do I go the split dowel and emery paper route or the posh flex cut hone at about £15? I used to have a car cylinder hone that was 3 sprung stones that did an amazing job; arethere smaller versions suitable for ME?

What do people usually use for this type of thing?

regards,Martin

[Martin King 2Participant @martinking2]

[Martin ConnellyParticipant @martinconnelly55370]

You can buy a set of brake cylinder hones with 3 sprung stones that go to small diameters. I do not know how well they will work for this application.

Martin

[mechman48Participant @mechman48]

I bought a small 2 stone cylinder hone of the 'auction site' only two weeks ago for use on my S10V cylinder…13mm – 64mm range,

**LINK**

Just the job, worked a treat, a good buy @ £11.98.

George.

[JasonBModerator @jasonb]

I have one of the sets of three sizes, for the 10 you will most likely need a two stone one as George suggests.

It may take a long time to get 0.003" off so best to hone until you get teh surface sinish right and then size your piston to suit the resulting hole.

J

[Ian S CParticipant @iansc]

Hone the cylinder to get the finish you want rather than the size, then make the piston to fit. If you keep going to get the full size .003", you risk either bell mouthing, or barrel shape hole. Ian S C

[Martin King 2Participant @martinking2]

Thanks guys, just ordered one!

martin

[Martin King 2Participant @martinking2]

Hi All,

The cylinder hone arrived OK and looks just the job!

My next problem that has me scratching my head is how to set up the cylinder for the machining of the port face.

I want to do this on my milling machine if possible using the vice which is spot on.

I have done the two ends and they are each now the correct and equal distance from the port openings as in the book. The bore is also now OK awaiting final honing.

The port face as cast is pretty flat but at a small but pronounced angle in the transverse direction, (rt angles to the bore)

As I am supposed to use the outside edges of the casting as reference for this operation I cannot seem to see how to set this up properly. Just me being dim I expect but would appreciate any help. I also need to mark the amount to take off which does not seem straight forward either!

Regardds,

Martin

[JasonBModerator @jasonb]

Easiest to hold it by the two ends in the vice

Marking out can be done quite easily with a simple scribing block or height gauge if you have one, set it for one side of the exhaust port, mark and then stand teh cylinder on its other end to mark the opposite side. Repeat for the inlets, this way you keep everything symetrical. Mark lightly as you don't want dirty great scribe lines across your portface

I tend not to mark out but find the centre of teh port face and use the mill to layout the slots. Again I would only roughly mark how much is to come off the portface and then measure from edge of bore to face to get the required thickness.

[Martin King 2Participant @martinking2]

Hi Jason,

That is how I intend to hold it in the vice but how can I guarantee squareness Left-Right before milling.? I cannot use the existing cast face as it is at an angle. The 10V sides are rough cast and rounded so nothing to bed a square against. The example you show has square sides so that I understand.

As said above I am just being dim almost certainly so sorry!

martin

[JasonBModerator @jasonb]

Its really just a case of eyeballing it.

[Martin King 2Participant @martinking2]

Hi Jason,

OK, thanks, just did not want to screw up after all the work! Really enjoying this first build and learning a lot as I go.

Funny really, I was dreading doing the standard and actually it went quite easily and was a great confidence builder.

Are you going to do a build series on your latest engine?

Best Regards,

Martin

[JasonBModerator @jasonb]

Yes I'll write up the entablature engine and do drawings much like I did for the Jowitt.

[mechman48Participant @mechman48]

I set up the cylinder as per the book in the 4 jaw chuck with equal thickness packing which helps to align the port face up for machining, to ensure squareness I ran a dti across the face & with some judicious nudging got an equal reading across the face.

When it comes to machining the steam passages I set up the cylinder on an angle plate set in the vice & squared up the steam passage calculated centre line with a square then drilled both steam passages. The book says the angle should be between 25* – 30*, my angle gauge shows 33* but given the casting discrepancies a degree or two either way shouldn't raise any concern.

Passages drilled…have come out nicely in the port centres.

George.

[Author]

Posts