(Morrigan, as a synonym of Morgan of Arthurian legend)

Monday, 23 November 2009

More engine parts cleanup

No photos but have attacked the sump, timing cover, bell housing and bell housing adaptor castings with marine clean. Pretty pleased with the results, still some spots of muck and grease to get off but will need a pressure washer and wire brush to get them.

Cleaning was prompted by crystal flakes growing off the castings, the engine must of been through some serious salt early on in its life. The stuff is still there in places and will take a wire brush to remove it.

Am going to keep the castings with the painted engine block under my desk at home for the moment, its better than the damp of the shed. Will get around to sorting of the roof out and applying a coat of waterproof sealant, then the de-humidifier will need to do less work.

Sunday, 8 November 2009

Painting Head & Block

Managed to get a coat of paint on the head and block, I'll wait till the first coat is dry and then put a second coat on tomorrow evening. Once its cured the head will be re-built and the block is getting mothballed till I can afford the parts.

Ready for painting

First coat on

looks good with the cam cover

Saturday, 7 November 2009

Machined head and Block

Collected the block and cylinder head from Engine Services in Edinburgh, they've done a good job with skimming the block and head, honing the cylinders to remove the glaze and cutting the 48 valves and valve seats.

The plan now is to paint up the block and head, and build up the head. I cant afford the parts for the rest of the engine this month so that will have to wait. The main thing is to get paint on and protect the surfaces.

unclean head

Cleaned head - Valves

Cleaned head - Top

Cleaned Block

Cleaned Bores

On another point I found the receipt for the tyres which are barely used; Pirelli PZERO ROSSO 99Y XL priced at £204 each! With the alloy wheels that's ~£1200 all told... if I can sell them for £600-800 then that would pay for either the whole engine re-build or for a good sized milling machine for producing the throttle body's. at this point I'm ering towards the milling machine.

Sunday, 1 November 2009

Engine rebuild stuff

Well dropped the block and cylinder head off at 'Engine Services' in Edinburgh on Saturday, the parts will get dipped, the head and block are going to be skimmed, the valve seats and the valves are getting re-cut (the valves whilst i wait, when i go and pick the bits up next week) and finally the cylinders are having a 'glaze-bust' or light hone to re-condition the bores.

Spent 6 hours stripping the old paint and corrosion from the cam cover and polishing it up as far is possible for aluminium casting. the bare pars have had a coat of Eastwood Extreme high temperature paint / Lacquer. which i will also use on the bell housing and gearbox when i've cleaned them up.

From this

To this - freshly painted Cam-cover

Saturday, 24 October 2009

Cylinder head stripping

Spent today stripping the cylinder head, removed the cam shafts, springs and valves. All of the exhaust valves had a thick layer of coke which took a while to remove. The inlet valves were cleaner but a couple had exhaust coke so some of the tappet shims will need adjusting to get the valves sealing right.

The head needs cleaning along with the block and then the remaining carbon deposits carefully removing without damaging the aluminium. The valve seats will probably need re-cutting as the deposits will likely have scored deeper than is practical to remove by grinding/lapping.

Cylinder head

Camshafts, valves & retaining half-shells

original and cleaned up exhaust valve

stripped head

stripped head

Saturday, 10 October 2009

Engine dismantle

Well the sheds are complete and shelves are up. Current mission is to strip the block and get it sorted before any more of the parts become impossible to source and the prices go even higher.

Storage shed

Storage shed now has the de-humidifier running as there is no damp-course, in an attempt to keep the rust a bay, as the block is growing small crystals on it, which is not good. As soon as the block is stripped I'll get it cleaned, honed and painted in short order.

Rear components

I can wait until the engine is done before tackling the suspension as replacement parts for the engine are few and expensive, so it needs doing asap.

Gearbox, hubs etc.

Getting the engine up on the stand was tricky, as my boss has my engine hoist at the moment, so added block at each end until it was high enough to attach the stand and tip it upright. Which was a little nerve wracking.
Will try the stove at full burn tomorrow evening and see how the chimney behaves and the heat it will give out.

Engine up on stand & Wood burning stove

Have removed the pistons and dosed them with silicone spray, they can live in the storage shed without rusting hopefully or getting dusty.

Engine devoid of pistons

...And place in an oven at 200'C...

Sunday, 27 September 2009

Cylinder Head removal

Well I managed to get the head of the engine today, all of the cylinders are in good condition, there is some coke on the piston crowns and the cylinder head needs a good de-coke, and likely the valves re-ground and the tappet shims re-doing.

The whole lot could also do with a good steam clean, will see if i can find somewhere to clean the block and head and also give the cylinder a de-glaze, to get everything back to new..

Hone-marks still in cylinders!

I've ordered a bunch of cleaning a painting supplies from Frosts which will allow me to progress through the various components and get them back to new.

At this point its looking good.

Monday, 21 September 2009

Throttle methods

Have been thinking about various throttle mechanisms, the options are:
  • Butterfly valve
  • Roller barrel
  • Twin roller barrel
  • Sliding plate
  • Twin roller profile
  • Iris (I've not seen any constructed like this, and would have poor flow characteristics - variable orifice plate)
  • Flaps (sort of a twin butterfly)
  • Twist mesh (slightly off the wall, and would need fatigue resistant filaments, but would be like the iris but with a venturi profile)
The primary search criteria is to extend the part throttle opening characteristics, i.e. to reduce the rate of opening for better control. But this also means keeping the fuel well mixed with the reduced air flow, and stopping it from ending up on the side walls.

Have played with roller barrel throttle bodies and believe that the size requirements are constrictive. The advantage of the butterfly is that it directs the air flow towards the injector at low flow rates thus encouraging mixing.

The construction for the butterfly version should be achievable through suitable casting and milling operations. Will need to save up for a large milling machine, and stepper motors to convert it to CNC, looking on the web a pretty sizable mill can be had for ~£700. With stepper motors available from ~£100 for a set of 4, but this is a long way down the line, need to build up casting kit first.

Saturday, 5 September 2009

Engine Model

Well, I've digitised as much of the engine and gearbox as is useful for design purposes (need some more detail in the mounting area, but have to clear the garage before i can get access).

The engine is standard 3.2L Jaguar AJ6, I've yet to work out how I'm going to weigh it and find the CoG, but with suitable levers there is always a way.

Initial Digitised AJ6 engine model

edit: got the garage cleared, and noticed how big the engine is (Huge!), its going to be interesting getting this all together into a vehicle. First job is to get it stripped and order parts before they become impossible to locate, thats if the liners are in good condition.

Tuesday, 18 August 2009

Throttle body calcs-4

This is a second attempt at creating a fluent analysis of a throttle body, this time utilising MSC Patran to produce the volume mesh. I now believe that for straight forward meshes that Patran has greater capability than GAMBIT.

Second attempt throttle body - Rhino3D

The throttle body model was generated in sections, this will allow quick production of the varying throttle angle models to be run through. That is once i work out what i am going to be looking for.

Throttle volume meshed in Patran

Meshing coincident volumes in Patran, when you have more than six sides requires a little ingenuity. Because the software cannot recognise that the faces of the volume parts meet, it will not produce the same mesh on both. Therefore you have to create a surface mesh on one face. Mesh the volume, then disassociate it and associate it with the adjoining face, before meshing the adjoining volume. In this way you can create matching volume faces which will equivalence into a larger volume. In this way the model is split into a top section of the air horn, then throttle butterfly, then a profile change from circular to oval, and the final section for mounting the fuel injector.

Spliting / Guiding surfaces for volumes

This allows great control of the meshing process. GAMBIT will now only be used for applying the face properties to the finished volumes. Only TET4 meshes are able to be read from a patran neutral '.out' file, into GAMBIT.

Mesh in Fluent

The Fluent run is progressing smoothly, with a steady reduction of continuity residuals. And the results are in...
Fluent output

Fluent output - looking down the bore, (vortices rather like an owl)

Fluent output

Sunday, 16 August 2009

Throttle body calcs-3

Decided to have a play, and get a CFD model of a throttle body put together.

Based on the head inlet area of 15.5cm^2 the throttle body needs to have a diameter of roughly 45mm, allowing for a 5mm shaft for the butterfly valve.

First throttle body test

Close up detail

After several hours playing around trying to mesh the model, I gave up and dropped a dimension, as 2D runs a are much easier to build and run. Generally the numbers should be ignored, but the flow lines are usually pretty indicative.

CFD Throttle @ 5250rpm - 45deg opening

Fluent close-up

But there is scope for setting up some runns with varying throttle opening, inlet pressures. Then can develop injector positions to get the best mixing arrangement.

Saturday, 8 August 2009

Throttle body calcs-2

Well i have extended my calcs for the throttle body to include the variation of both engine rpm and also the throttle angle. This gives the total mass of air inducted by the piston during one cycle. Usefull for showing the inducted volume limitations, I need to update it for the actual area of the inlet on the head, which is the main bottle neck.

The methodology is somewhat brute-force, This pic uses 1000 throttle angle points, 1000 rpm points and 1000 piston angle points. So 1x10^9 calculations, but that is what octal core workstations are for...

Engine speed 0-5250rpm, throttle opening from 0-90deg

edit: One interesting point to note is that idle RPM is 800, this is well clear of ~400rpm where the mass inducted reaches its highest for throttle angle vs RPM.

Still finishing off the garages, need to;
  1. Repair the roof - DONE
  2. Replace the smashed sky-light -DONE
  3. Board up the broken windows - DONE
  4. Fabricate a front & hang a door - DONE
  5. Move spare parts, tyres and stock out of main workshop - DONE
  6. Re-arrange the tool cupboard - DONE
  7. Build a work bench - DONE
  8. Apply a second coat of floor paint - DONE
  9. Install wood burning stove and fabricate chimney - DONE

Saturday, 1 August 2009

Throttle body calcs-1

Got side tracked with building a calc tool for evaluating the effect of a throttle body. From first principles I've used the displacement of the piston to find the volume, then pressure, mass flow, new mass in cylinder and then velocity through the throttle orifice.

The calcs need to be checked through, but the order of magnitude is about correct.

5250rpm throttle opening from 1deg to 90deg
Volume (cm3)
Velocity (m/s)
Pressure (bar)
Mass (grams)

Thursday, 30 July 2009

Precision tube

Heard back from Corus, who have provided names of a couple of possible suppliers, (given that I wont be needing 20 tonnes of the stuff).

So we have:
Barrett Precision Tubes

Hub le Bas
edit: Have BS EN 10305 ERW in 6.1m lengths, prices range from £1.70/m to £3.15/m so a very rough guess would be £150-£200 for the chassis steel. Will need some extra for making up a jig to build it on, but these are good prices.

Both UK based, and from the stock lists of le Bas have 40x40x2 RHS in S355 grade, so emails sent to both to see what else they have and current prices.

Monday, 27 July 2009

Polybush properties

In order to accurately model the vibration response I need to have the material properties of all the components in the system. The most obvious is the steel framework of the vehicle, which is straight forward. Then we have the other suspension components; Springs, Dampers and Bushes.

Springs are reasonably easy to obtain data for, and the length and rate are usually available off the shelf in reasonable incraments.

Dampers and Bushes are trickier, Having spoken to polybush they have furnished me with some data for their 75 Shore-A hardness range of polyurethane.

Polybush 75 Shore-A

The data for 65 and 85 Shore-A versions is also available, will work with this first and see if I need a harder compound.

Tuesday, 21 July 2009

Steel sections and Grades

Well after a fairly unsuccessful search for some high yield (355+MPa) steel box section, I will probably resort to Corus Celsius 355 SHS and CHS. The 2006 guide has sections with 1.5mm thickness which would be good to use, It turns out that the 1.5 thick sections are an international size, I have been advised to contact Corus in the Netherlands for further info.

Corus blue book
Corus Design of SHS welded Joints
Corus SHS welding guide

I have also located a good source of stress / strain data for various steel, which is useful for enabling non-linear analysis to be carried out on the structure, i.e. crash simulation.

SINTAP report UC/07

Below is the true stress strain curve for S355J2 material as used for Corus Celcius 355 prosducts

True stress strain curve for S355J2 steel

This should allow details analysis to be carried out, (I use Patran/Nastran at work so have can use this for linear, non-linear and other analysis), hopefully there will be some interesting stuff to work out.

There are some more possibilities for sections in the Corus 'Precision tube' range, these are products designed for the automotive industrys which cover a wide range of sections and wall thicknesses. And more importantly come in a range of grades covered in under EN 10025, so S355 J2 should be an option.

Thursday, 16 July 2009

Source of construction and use regs

After much trouble trying to find the regulations for construction and use (attempting to get a copy of sweet and Maxwells 'encyclopaedia of road traffic law' I eventually found Hughes guides which for £11 will send you a CD with all of the road traffic law including the construction and use regulations, with updates for a year. Apparently these are used by the police as reference guides.

In addition the build will need to be assessed to the new IVA requirements, these can be located on the VOSA web site.

Sunday, 12 July 2009

It begins

This will be an extended post to chart the progress to date.

Donor vehicle was a 1990 XJ6 3.2l straight six with 5 speed manual GETRAG gearbox, purchased from ebay for a grand total for £600.

A somewhat delboy styled vehicle, not for long...

Nice straight six, need to see the condition of the bore.

Once secured from its original home in Poole the mechanical components were quickly extracted and the now empty shell taken away by the local scrapyards hiab.

In the garage, bonnet off

A good bit of stripping

The engine and gearbox comes out with mills to spare

The empty body loaded and off to the scrapyard

Chunky gearbox and engine

Front suspension assembly

Rear Suspension assembly

Pile of possibly useful electric and vacuum parts

Front suspension

Hefty diff and rear wishbones

Engine stripped of its ancilaries

Front and rear assembly stripped all usable parts laid out.