This is the process required to produce new cast iron heads...something considered to be relatively easy by many. I think it illustrates broadly what is involved and gives at least a rough idea of the potential costs...never mind a profit!
1)The pattern.
There are two ways of going about this...one is relatively cheap, the other expensive.
a)Find a very good original head. Prepare this to be suitable as a casting pattern. Blank all existing holes, build up any faces that require finish machining so that the casting produced has sufficient material to carry this out (cylinder head bolt bosses, gasket face, spark plug seating) This would be done by bonding material of a suitable thickness in place after cutting and shaping to suit.
After this spray the casting with high build primer and flatten down to provide a smoother surface to ease removal from the casting sand box. I would estimate around 16 hours for this job..plus materials
b) Employ a pattern maker to produce a wooden casting pattern. This is a highly skilled and labour intensive job...cost today? Around £1500, so really it's a non starter for low volume production.
2) The casting.
Locate a foundry familiar with this type of work.
The castings themselves are not too expensive..cast iron was and still is a cheap engineering material.
Quantity is governed to a certain extent by practical batch numbers..not just for the foundry but for the CNC machine shop who will have to handle the next stage. In my experience 25 would be the absolute minimum for the CNC shop..so 25 castings.The castings will also need to be fettled by the foundry after casting.
3)Finish machining.
A jig will be required to hold the cylinder head for the first operation (skimming the gasket face) so that must be made before they arrive at the machine shop..or they will have to be paid to make it. About 6 hours labour should cover that..plus materials and the time taken to design it. However, to cut down on loading and machine time at least 2 jigs are needed. That way the operator can unload and mount one component while the machine is working on the other..so that would be 12 hours labour for the jigs.
Machining..
Operation 1. Mount cylinder heads and skim gasket face to finished size 25 off.
Op 2. reverse head, clamp down. Drill and spot face 10 off cylinder head bolt holes, drill, spot face and tap 1 off spark plug hole and 1 off timing plug hole. x 25 off. That would complete the machining.
Additional costs..Programming time for the CNC mill.
How it works with CNC facilities is that you pay the programming charge then a fixed rate per hour for machine operation.
So, take the machine cost per hour, multiply it by the hours needed for the whole job, add the programming cost and you have your price per part.
The last time I was quoted for this type of work the rate was £50 an hour so that could now be regarded as the minimum. Programming cost is also worked out on time.
I haven't factored in casting costs as I have no idea of the current charges.
Other costs...which also have to be accounted for, are transport costs between the various locations, tooling ,materials and machine shop costs in making the jigs and preparing the original casting for the foundry..If only one batch of 25 heads was made these costs would need to be distributed between the 25 components. Obviously the more that are made the less cost per unit piece. The catch is the initial cost goes up before you have anything to sell and, crucially, you have to find more customers for the finished product. That is where the guesswork starts..can you find the customers and what will they be prepared to pay?. Ian

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

It sounds to me Ian as if you'd need to ask £250 for something that people are currently prepared to pay about £100 for.

They're needed for restoration projects but those that have a good one are not going to wear them out very quickly.

This sort of thing mostly seems to be viable where a component is needed for racing.

I do know a pattern maker who is very cheap if thats any help and the company, I say company, but it's two brothers who work from a house and have a furnace in the garden who do make Manx Norton heads and such like. I once asked about a Harley gearbox shell and they said £500 for the pattern and approximately £50 per machined gearbox case, so it could still be on, I can enquire again if you want me to

email (option): davmax@ntlworld.com

Thanks Dave...but I have no plans to do this job currently. My posting was really just to illustrate to anyone not familiar with this sort of work what is involved and to highlight the amount of work and investment that is sometimes required to put even a relatively simple product into the market place.
I have learned a lot about the process people go through in making a decision about whether to buy something or not.
The majority of people in this case would like to buy a good original head. They would also accept one with light, repairable damage.
If presented with a more expensive new head a decision must be made as to what that should cost.
Up to a given, but undetermined price, just about everyone will buy one. Go a bit further and some people will buy one. Go beyond that..even if it is a fair reflection of the cost of making it... and people decide not to buy one in the hope an original will turn up sometime.
Only if they pretty much believe they will NEVER find one will they grit their teeth and pay the money at this price. Working out what those limits might be only comes from an intuitive 'gut feeling' for the market. Not a precise method..and you don't want to get it wrong. Especially on an expensive project.
Working from these observations I look to select parts for manufacture and these have to meet certain criteria to be viable.
The part has to be reasonably hard to find and there needs to be a demand.
To warrant the investment in time and money and the fact that the money might be tied up for some time I have to be able to realise a certain percentage of profit...after all there are other things I could do with the money and it is a 'business' exercise.
Lastly, I must be able to bring the part to market at a price that the majority are prepared to pay.
If a potential component does not fulfill these criteria I can't make it...it's that simple.
Currently I don't think the time is right for cylinder heads...they will be too expensive and I don't think the demand is that strong. There is also another issue with cylinder heads...weight. Shipping overseas will add a lot of cost and that may tip the balance (literally)on the 'buying decision'. At the end of the day it is largely a 'cosmetic' exercise buying a new cylinder head..it's not like a broken piston. I suspect if people conclude the price is a little too high the old one will still work OK..and that original might still turn up for less..Ian

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

I'm trying to create the market force for you Ian...........by buying up every original one I see!!!

email (option): davmax@ntlworld.com

Hi Ian... Thanks for these two long post which alone must have taken up much of your valuable time. I really had no idea of what is involved here and I have learnt something today reading this, so the thread is good! I can clearly see what your saying now and I guess the bit about the heads being purely cosmetic is what it's all about. The old 'broken' fin heads that most of us seem to have, have to make do until such time costs in producing new ones, would be cheaper.

Thanks for your time in explaining this.
LJ.

Or until someone in India starts making them.

email (option): robmiller11@yahoo.co.uk

Hi LJ..I'm glad you thought my 'ramblings' were worthwhile. It will never get cheaper to produce these heads (in the UK)..but eventually, through scarcity, the cost of a good original will rise to the point where there is a 'convergence' between the cost of an original and the cost of a new one. At that point the new one becomes viable.
As Rob mentioned..they may well be reproduced in an economy that has lower costs before that time and as long as they are made well enough that would be a good thing. I don't think anyone really cares WHERE things are made..I certainly don't..as long as they are WELL made...Ian

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

talking about a CNC mchine what about machining one from a solid billet once the programs is loaded should be cheap

I dont think it would be cheap. The amount of programming would be massive. Lots of tool changes and machine time as well. I dont think we would like the look of a billet head either. There really isnt a cheap way to make something as complex as an aircooled cylinder head.

The process is as Ian described. That really is the best way. If it is ever to be done I think it ought to be done to replicate the most common original heads. While a bronze head would be nice... You would push aside the purists from stage one.

Its only a matter of time before a good new manufactured head is a worthwhile venture. Along with many other things. Good bronze copies of the common control levers. I am looking at this being in the USA. You cant get anything like this here. The chances of running across a good head or various bits at a swap meet (jumble) are very very slim.

It is a small market. Even if you had all of these things nicely done and for sale, you wouldnt have many customers. Maybe if someone with the right equipment just wants to donate their time to the longevity of these bikes? %20void(0);

email (option): micran1234@yahoo.com

Ian, Without wanting to labour this too much, I wonder if bronze might not be the way to go. I know you said the costs would be higher. But do you have any idea how MUCH extra bronze would cost, and whether it would be harder to machine, etc?

The reason I ask is just a question of human nature. Bronze is a "classier" material than cast iron, and (as you say) shifts the heat away better (though not better than aluminium, apparently). And bronze is much more durable than cast iron. Therefore, I wonder if people would consider bronze to be a upgrade worth investing in.

Purists could simply paint the bronze black, safe in the knowledge that the cylinder head is a one time purchase. Also, non-purists with bobbed/custom M20s, or anyone thinking about building a "performance" M20 or sprinter would also go for the bronze (or perhaps stick with aluminium alloy if they were serious about speed).

Also, many "purists" are very happy with stainless on their bikes and 12-volt electrics. So I don't see that bronze is a major emotional leap. Additionaly, there are already plenty of M20s rolling around carrying parts inappropiate to the model year.

Bronze wouldn't cost any more to post or transport. I don't suppose the casting moulds would add extra cost. It seems to come down to materials and perhaps machining.

Put simply, the bronze would perhaps be considered by many as an upgrade, whereas cast iron or aluminium alloy would simply be seen as an "expensive replacement". Bronze would be unique.

But would the extra cost make this unfeasible? Just a thought ...

email (option): dannydefazio@sumpmagazine.com

Hi Danny, Your arguments for the use of Bronze are entirely logical from a practical view point. Also, I think you may be correct about the fact 'purists' might be prepared to compromise as there are no visual implications for this material once painted.
I would have to enquire to establish the exact difference in cost but consider this...cast iron has always been used for a multitude of different castings throughout industry because of its very low cost.
Bronze is an alloy containing significant amounts of copper...a material that is currently at an historical 'high' on world commodity markets.
An additional problem with bronze is also that its 'shrinkage rate' when cooling is greater than that of cast iron so casting off an original head would not be an option...the resulting casting would be significantly smaller. That moves it back into the area of specialist pattern making and cost wise its best not to go there.
Finally, I don't currently think it would be possible to make an iron head in this country that would hit the market at the right (an acceptable) price so a more expensive base material with higher pattern costs wouldn't be an option at all..unless perhaps, it was being fitted to a Brough Superior or similar...Ian

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

Thanks, Ian. Makes sense to me.

email (option): dannydefazio@sumpmagazine.com

isnt jay lenno involved in the making of a replica Brough Superior i assume they cast new head and other parts

I've been on to my guy at the foundry, he dosen't do cast iron unfortunately, but he reckons that they could be done for about £20 to £25 unmachined (he could do this extra) in high silicon aluminium and can do them in bronze no problem, but warns that scrap prices are high at the moment, but you could start collecting your own scrap to get one done when you have enough weight. They would be done to the cast iron pattern and he said that if used with the solid copper head gasket instead of the composite one it should be pretty trouble free. He knows bikes pretty well and has already done Manx heads and Ulster heads and although he's not au fait with the M20 head he does know that it may be possible to build up a cast head to allow for shrinkage to avoid him having to make a pattern. My friend lives down the road from him and he's coming over to see me so I can give him a head to see if he really needs to make a pattern or if he can get away just building one up .

email (option): davmax@ntlworld.com

That sounds really promising Dave! and once again the purist can paint the alloy head black if they wish, and wouldn't alloy be better still than bronze? Price sounds good too!

It would be no extra effort to add the squish band to the head for those which would want a bit more performance

email (option): davmax@ntlworld.com