Wallaby

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metalmad

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Hi guys.
Its about time I started a new project :)
This time I will have a go at the "Wallaby".
It is a 4 stroke twin and the Block and Sump are from Castings
The Castings are made by Bez and really look great !
Today I put in a good day on the CYL Head from Bar stock and thought it worth while starting with a pic of Bez pouring the Block. :)
You will find his post of the casting process here
http://www.homemodelenginemachinist.com/index.php?topic=14622.0








 

metalmad

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Today I did some Machining of the Exhaust flanges and started the intake. I used a smaller drill at an angle, to make contact with the valve hole and will use a die grinder later to curve the ports a bit.
I hope to drill the Spark plug holes tomorrow and maybe start the water holes.
I'm thinking of changing the plug from 3/8 to M10 for a CM6 and don't intend to go overboard trying to replicate the cored shapes of the water ports.





 

ShedBoy

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I have been looking forward to this build. Great work so far as usual :)
Brock
 

Lesmo

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That's not a bad days work, would probably have taken me three

Les
 

steamer

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Hey Metalmad,

Cool! :bow:
Did you do the curved siamesed intakes or did you simplify to straight ones?

I dreamed up a way to machine the curved ones as opposed to fileing them like Edgar did....but it will still be a lot of work with a special ball end cutter.

Dave




 

bezalel2000

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Hi Pete

Nice work,

you amazed me how quick you got that head machined. :bow:

Bez
 

metalmad

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Thanks Brock, Ive been looking forward to it too, but its a little daunting as its my first wet sump engine, not to mention watercooled Multy.
Hi Les I'm fairly happy with it so far but there is such a long way to go.
Dave, So far I have only drilled the ports undersize and will just use a die grinder to get the curves later, unless u can come up with something easier?
Once the spark plug holes are done, I may need to smooth out the combustion chambers anyway.
Hi Bez, I recon I'm getting Faster :big:
 

metalmad

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Hi Guys
My last post must have jinxed me :big:
Ive been arse up under my Stump grinder ever since, It sheared of a couple of bolts on the hydraulic drive engine and snapped the Chane as well.
I had a nightmere getting the sprocket off and just could not move an adjuster nut
( u know how it is, I guess )
Anyway I got her running again today, so I can do Fridays work tomorrow :big:
I roughed out the Wallaby cyl head cover plate too.
Pete


 

ShedBoy

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Work a nessecary evil :( I fly home from work tomorrow :)
I reckon I might do somting in d shed.

Brock
 

steamer

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Hey Metalmad,

I have a sketch of the tool somewhere....it is a modified ball 3/8 endmill with the shank reduced to 7/32 IIRC,

My plan was to drill in on the head straight but undersize, then mount the head on a fixture mounted to a rotary table, and using the modified endmill, machine the curved passages for the intake......

Haven't tried it yet.....but I think I will eventually.....

Dave
 

metalmad

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Hi Brock
Fly in, Fly out would be hard mate
Dave, I think I have a ball shaped rotary burr somewhere with a 1/8 shank,
Im planing to use that in my little air grinder.
From your reading of the plans, do u think the cyl head cover plate is installed with the recessed area to the top?
and if so, is it just cosmetic?
Maybe I might make a tappet cover with an oil feed to the rockers or something to make use of the recess!
Pete
 

steamer

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Looking at the GA shown in the first installment, it shows a flat top with no recess but the section on the head does show it. I too was leaning on making a rocker cover for this engine...The only glitch is the water outlet flange smack dab in the middle of the head. Maybe I'd go for two rocker covers and let the outlet be where it is.

Other than reducing the amount of area to make flat, I don't see why it couldn't be all flat.

I planned on making one piece valve cage/guides, but that would require machining the bores for the cages with the cyl head cover on so that they match up. You could pick up on you holes now though I suppose.

Dave
 

steamer

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And to your original question...I think the spot faces face up in the original design so as to provide a place for the sealing coat of paint he mentions somewhere in the article. ;D

Dave
 

steamer

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Oh and as far as the stump grinder is concerned...my condolences!

Next time you have her apart, put some "never seeze" on the rusted up bolts....They'll come apart easy next time...

http://www.neverseezproducts.com/

Dave

 

metalmad

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That one piece Valve cage is sounding like a good idea Dave!
I'm having problems reading the dims on my photocopy's anyway :big:
but the more I think about the cover, the worse it seems ::)
half the fun of watching a 4 stroke run is seeing the rocker gear.
Pete
 

Blogwitch

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If I could just give you a little advice.

Being from the land of where E.T.Westbury came from and having made a couple of his engines.

Take nothing on the plans as gospel.

Almost no rectifications to the plans have taken place ever since they were initially issued.

I have never built the Wallaby, but I made the whippet a few years ago, just after making a Cygnet Royal, and fairly recently researched the re-released Seal, and they still had the original errors on the plans. I am not talking minor ones either, but ones that could result in scrapping the main crankcases or heads if machined to some of the shown dimensions.

In all honesty, once the engines are built correctly, they run well, but make sure you do double check for fits and positions of/to other components before machining too much off.

What might pay dividends is to do a search for engine plan faults on the net. I found out a lot about the seal, and it put me off making it.


John



 

metalmad

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Sounds like a very good idea Bogs! I already have found two bad plan errors or plan faults that would scrap the case. The lifter pillars are down as 1-5/8 when 1-7/8 or even 1-15/16 is more like it! and the center head bolt holes are not 1-1/8 from the edge but are in fact 7/8 apart. The water exit port shows 5/8 on the plan and I believe this should be 3/8. On the dipstick the plans for the domed Cowl call for 11/32 (.34375) This is a obvious error, I made mine .675 OD which as the drawing shows is just under the .75 OD of the lower housing.
Another thing I changed which may be more to my lay out then a plan error but I had to leave my Cam bearings at .70 rather then the stated .75
I had not thought of doing a Engine Plan faults for Wallaby by E.T Westbury search, but I will do so as soon as I post this. Thanks again. Pete
 

steamer

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I went through the prints at one point and found a bunch of stuff....Once I find them I'll share.

Dave


Here's what I had in mind for the head/block.



 

metalmad

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Ummmmmmmm
I was not gunna make the pistons green, but if your really sure thats right? :eek: :big: :big:
Did not do much today and will think about sourcing some bronze tomorrow for the valve guides.
Pete
 
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