Hi All
Does any know were you can get a cylinder head cast in Aust.
I have a high compression head for using methanol, that has been welded, what welding rods used I don't know.
My concern is the expansion and contraction may weaken the build up weld and it will let go creating a rooted motor.
I can supply the head to be used for the cast.
Ian's pistons for the 720 are built proof.
Cheers Drew

email (option): bronte.nolan@bigpond.com

Anyone who does lost wax castings.
Are you looking for alloy or iron ?

email (option): bsansw1@tpg.com.au

You could try speaking to Doug Fraser at Emu Engineering in Melbourne as he could possibly have some newly cast alloy heads.

email (option): njgreen@bigpond.net.au

Thanks for your info and contact,will keep you posted.
Cheers Drew

email (option): bronte.nolan@bigpond.com

Hi Trever.
I was hoping to get a head cast in alloy, i have a head that has been built up with weld to increase compression and hoping it could be used as a plug to cast a new one?.
I am not the full bottle with casting work.
Cheers Drew

email (option): bronte.nolan@bigpond.com

I figured that was what you were thinking about.
Doug would have a better finger on who was doing castings down there.
Most foundries up here have closed down and as the auto industry I would expect almost all of the remaining ones to close.

Lost wax is the process of using your original to make a wax original and then melting the wax out to make the right shape hole for your head.


Up here Shore Process Castings is about the last man standing.
I think Dural is still there and perhaps Dint'e .

Stenco only cast in Zn-Al alloy .

There are some smaller family businesses in the gold fields towns that still get by doing jobbing work but the EPA is hell bent to ensure nothing is made in Australia any more.

email (option): bsansw1@tpg.com.au

Hi

Let me know what you find. I need to talk to Doug too, must do that next Wednesday. I found a place near Broadford, or roughly that way here in Vic, that could do the casting in alloy, but not heat treatment for T6, which was what I thought I'd need. Nigel mentioned Doug and I've failed to open my trap and find out more..,next week, I promise!

I'm hoping to get Geoff Morris to look at the frame repair this coming Saturday, see other thread, he's in Broadford, I'll let you know how that goes.

I wondered about machining from solid, cost for that might be favourable if you can make the 3D model, I've been trying software out for that as a backup plan.

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

A T6 is not hard to do,
Just outside the temperature range of a domestic oven
It gets a solution treatment just below the melting point arouns 540 Deg C for 1 hour per inch of cross section then quenched in boiling slaty water.

Ageing ( or precipitation hardening ) is done by heating to around 200 Deg C for 3 to 8 hours so you can just about do it at home.

However as there is nothing in an M20 head I am not sure if I would bother to heat treat it at all.

What you do have to remember that an alloy head needs to be substantially thicker than a cast iron head so you can not just take a CI head and get it copied in alloy.
While the T6 temper is a lot stronger and has a higher tensile strength, what is needed in the side valve head is stiffness and stiffness is not drastically changed by heat treatment.

If you do go the cast alloy head get a thread insert either cast into the head or fitted post casting.

They will probably want to cast it in Al-Si-Cu ( 380 ) alloy but I would go for a strait Al- Si casting myself, using secondary ingot ( thus picking up some Cu, Fe & Mn for free ) and use a strait Al-Si like whatever 401 is called now days, I think we went down the USA nomentalture route which made a lot more sense than the hotch pots we used to have of Australian & British names.

If you want to go a bit further afield, Hasco in Balarat have their own in house heat treatment. When I was at Sims they were a big customer

email (option): bsansw1@tpg.com.au

Hi Trevor

thanks, that's handy input, I hadn't considered that the heat treatment was more essential for a head with inserts for seats and guides!

Yes, plug insert was in the plan but I'd only considered post casting, including in the casting is a nicer option, and yes thicker, i.e. can't just copy the cast iron head. That wasn't so much of a concern as the plan is to create a CAD 3D part to arrive at the plug for the mould.

The place I found was talking around $400 for the casting in AC601, I'll try Hasco too as that's no big difference for me on distance, it's still in the 'postage stamp' :-)

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

Hi All.
The plot thickens with casting a head.
Thanks for all the advice , it is so valuable.
Doug Fraser at Emu Engineering is not picking up his phone as yet, will keep all posted if any spare heads available.
Cheers Drew

email (option): bronte.nolan@bigpond.com

Hi Drew

Assuming Doug is as the general meeting on Wednesday (and assuming I am) I'll make sure to ask him about the heads! I need to anyway for my salt project, so this is just giving me no excuses!!!!

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

601 is an odd choice for a head.
It is the Al alloy with the highest fatigue strength and is mostly used for car wheels but if that is what they generally cast down there then go with what they know
$ 400 sounds a bit steep but if you are getting a pattern made off a drawing probably 2/3rds of the price is the pattern.
Are you intending to supply them with a 3D printed original to cast off ?

Back when I wore a metallurgist hat Bantam racing was becoming popular.
The standard way to make a Racing bantam head was to mill it from an extrusion billet front or back end.
When Rheem started to make back extruded alloy gas bottles, the extrusion plugs were almost exactly the right size for a head and they were a Mn/Mg wrought Al alloy, totally the wrong thing to make a head out of but very few ever failed although a few blokes killed a lot of cutting heads because it did not machine particularly well.

email (option): bsansw1@tpg.com.au

Hi Trevor

$375+GST was the rough estimate, that was based on working from a blank / pattern, so shouldn't have the costs of translating a drawing to the pattern. My idea was to generate a solid part from the 3D model as a 3D print. Of course there's potential that I wasn't clear in the discussion and we've got crossed wires!

All depends what Doug says, if he's done this already then somewhere in Vic there's a pattern which has been used for casting.

Agree AC601 wasn't what I'd thought of, but it's better to keep with what they know and isn't that critical. After all the reason for the ally top is heat transfer out of the block.

I also have the decision on valve guide if I change to a 'better' material I need to have forced lubrication, but if I keep to the cast iron I have to 'suffer' wider tolerance and I guess higher wear. At present, given that the engine is aimed at a speed trial then I think I'm ok to keep to cast iron. But I'm sure I'll change my mind before I start that part!!!!

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

got any photos of the head you are trying to replicate ?


did you get a cost if they do a few of them? - may be interested - i'm in melbourne.

anyways -was at the australian nabiac motorcycle museum last week :

had this m21 594cc salt racer - pity i didn't get a photo of the whole bike BUT the head i thought was interesting - unfortunately no idea what it looks like inside :

looked like it was machined from solid:


note plug position - seems to be between the bore and the valves - not over the exhaust as per std head location



the pipe is from a hole in the fairing -looks like it was to direct air straight at the exhaust flange/pipe

actually a bit of sleuthing on the web and here it is :

http://www.dlra.org.au/profiles/587.htm

holds the australian record for 350 APS VG :

Special Construction Partial Streamlining , vintage engine gasoline at77.532mph in 2009

the 350 is 350cc - but the info board on the musuem bike said 594cc - so wondering if it had been destroked to 350cc -or side valves get a derated engine size?


the dlra website now says the record for this class is 89.423mph set in 2016 by a different bike

but i suspect you may know this .....





if only khaki green ...

Hi 9

Oh wow, that's brill. It looks pretty much like I've been thinking.

Wonder if the plug move is simply to clear more radical valve lift or to promote a better burn. That's a lot of different preference on that. One thread I looked at did some like for like tests (not an M20 / M21 engine) with just the plug moving and found very little difference.

This head looks just like I have in mind. I haven't progressed with my CAD work yet...the money earning job keeps getting in the way just recently. I have a while before I need to fix that part, and I've just pulled the box apart too, I'm hoping it won't look as bad once I've cleaned it all up...a quick glance looked poor (most teeth pitted, and more play on the input shaft than on the output bearing and that was shot...)

I'll check on higher volume casting, and also let you know what Doug F has to say.

There's another 350 APS VG (HBR Salt Special, Home Brew Racing) they're a QLD lot, I think. They've run faster but I think that when they ran the conditions weren't right. Here's some photos.












Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

Usually you build up the head to make distinct inlet & exhaust tracts.
Thus more of the combustion chamber is over the piston and the plug gets shifted to the left to the top of the combustion chamber.
There was a piece on WM20's in the Victory Library where they reckoned you can shift the plug over the top of the piston by enlarging the timing hole.
According to the blurb that allowed them to run more advance.
I very cleverly downloaded the whole article and converted it to a Semantic Greatworks document and stored it on a 100mb zip disc, remember them ?
Remember how computers were going to make paper copies redundant ?
So if anyone has an old Mac running system 6 on an 040 chip with a Zip drive and a copy of Greatworks I can supply the details, and people wonder why I don't store stuff on the cloud.

email (option): bsansw1@tpg.com.au

Hi Trevor

I noticed that the Victory Library item wasn't there, Google finds it but the link doesn't work, frustrated me! As I like an ICT challenge...if you can email that zip file or is it that the drive itself is unreadable by any machine, even so something should be able to read the image, there are a few things I might be able to try. You're right about files formats though, similar thing happened in work over only about 5-10 years! PDF is much more stable and has stood the test of time better, but even so has some issues!!!!

Doug Fraser wasn't at last night's meeting, and I'm not at the next one, so I'll have to wait, no bad thing to teach me some patience...

I've been thinking also about whether I should consider 500cc short stroke as opposed to a 720cc long stroke...I'm sure I read that the Bill Gough M20 revs were in the 8,000 to 9,000 region, and that would have to be a short stroke, somewhere around 82mm I think for the piston to survive...

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

I see if I can dig it out,
The discs are in a box with all that other stuff, like a SCSSI drive raid box with 8 x 500Mb hard drives.
Funny to think that in 1990 it was worth $10,000 & today I can get a Tb drive for $ 200.
Doug is riding up to the BSA National @ Cowra Oct 13 to 15 ( cheap plug ) so good chance he won't be at next months meeting as they like to ride on obscure back roads and considering it is the week after Bathurst he might come up a week earlier.

email (option): bsansw1@tpg.com.au

Many people will tell you that you 'can't' rev a side valve..

Bill Gough and H.D disproved that theory....Personally I can see every reason to rev one if your going for higher performance..For a start there are no pushrod to worry about and as a consequence cam profiles can be made more fierce and very high valve spring pressures aren't such an issue. This is because the various components of the valve train have to be kept in contact with each other in OHV engine and the inertia loads are also higher with an OHV unit.

I would speak to the manufacturer of any piston you choose to use to determine the safe rev. limit for it...The old ft/second calculations don't really apply to modern pistons and ring sets which can run faster generally...Also avoid any heavy car piston...Ian

email (option): ian@wright52.plus.com

Hi Ian

Yes, that's the conclusion I'm coming to having talked with a few people. I need to get some time to visit a local (car) engineer that a mate of mine has recommended, so I can plan what I want to try with the engine. Higher revs have to be the aim, which means maximum breathing. The other thing will be where to aim the bore / stroke. Whilst the figures normally used can be pushed a lot more with a fancy piston, there's still the rest of the bottom end to consider. At present I'm thinking to stay close to the 500 B33 figures, 85 x 88, as that leaves me with some room on the bore, 3m diameters increase, so 1.5mm off the walls, and the block I have is already +20 thou so only an extra 1mm. B33 and Gold Star cranks a direct fit (conrod length aside or are the mains different? I've been looking at the beautiful work that Phil Pearson does on Goldie pressed up cranks!

Re-reading the Bill Gough stuff I have from the web reminded me of all of this, that's I think claimed at between 8 and 9 thousand RPM. Which I guess would be about right for the >100mph on Baker's Beach. Mind that has two carbs to breath through, the regs for the class I'm aiming at won't permit two carbs, so I'll have top get the most from one.

I'll try to keep you all posted on this project. Present stage is looking (glumly) at the gearbox internals! Can't say I'm surprised but they're a mess, pitted teeth faces, every bushed gear is very sloppy on the bush, the main shaft had more slop side to side than the output gear in it's bearing. Fixing all the bushes isn't too bad, but the state of the gears bothers me and I feel perhaps I'd be better chopping it for a 'new' set! Oh and the outer case needs some work to put back the missing lump of alloy that should hold the kickstart rubber stop in place!

Sparks will be interesting too, as the regs for the class state 'electronic reactive ignition' is not allowed. There's a whole debate on the forum for that on what on earth the rule means...from which I think the conclusion is 'whatever you think you can get away with, but perhaps it should look like there are some points' Maybe a special pseudo magneto in place of the magdyno would be 'appropriate'

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

Hi Trevor

Good point; I can't make it as we're on hols on a road trip to Alice, Uluru and back, should give me plenty of time to plan the bike though!!!

I know what you mean about memory; I've just updated my laptop, it now have solid state main drive at 500G and a second standard hard drive at 1TB, and that was still a lot less than buying a new laptop...think it will also be less than I spend on this project too!!! In an ideal world I'll have it running at least to bring along to the International Rally next November, but that will mean a trailer to bring Bessie and Salty along...I'm getting soft!

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

See the other post ref. 'M20 cams for methanol/petrol' regarding bore, stroke, piston speeds ....Ian

email (option): ian@wright52.plus.com

Hi 9 and Drew

Followed up with Hasco as suggested by Trevor, and looks very promising! I'll send you guys an email with the discussion with Adam and Hasco so we can work out if we're after similar enough outcome. If you guys just want an ally head then that's a quicker / simpler approach (borrow one as the pattern), whereas what I'm aiming for will be a special pattern.

@9 - can you email me with your email.

Cheers

Richard

email (option): dickie.bobbie@hotmail.co.uk

Hi Richard.
Was it you that I was speaking to re M20 heads.
And you are heading to Lake Gardener at some stage.
Cheers Drew