About 5 years ago my son bought a, ( possibly), soft head and made inquiries as to whether or not it could be re-treated.
Below is the email he got from a local company.
Other projects took precedence and he never made use of their services, so I cannot vouch for them in any way whatsoever.
However, at the prices mentioned it'd have to be worth a try wouldn't it ?
Especially if the head is pretty much regarded as worthless.
Ralph.
"Yes we can do this, generally without too much drama. We have done plenty of lotus/ford twincams over the years and I don?t remember any major headaches with any of them.
You don?t necessarily need to remove all inserts etc, the most important thing is that any copper based metal parts must be removed. This would normally be parts like bronze valve guides, brass frost plugs, copper washers, etc.
If the seats and guides are steel or iron, they can stay in (check with a magnet if in doubt). If you do leave the seats in place then they will possibly fall out during the heat treat anyway. The guides normally stay put ok.
Heat treatment of aluminium castings is quite a severe process so it's not without some risk, however these are a reasonably robust casting and as I said earlier we have done plenty without issue.
The main concern with heat treating aluminium is distortion/bending. We take all precautions we can to minimise any distortion but there is still risk. From memory the Lotus TC has the cam tunnels machined directly into the head so this means you can't tolerate much distortion before significant machining will be required to reclaim it. Most commonly with a nice robust head like this you will get away with just a simple skim on the top and bottom faces and everything is good, but please consider in the worst case you may have to go to the extent of some type of straightening operation or possibly line boring the cam tunnels.
Cost will work out about $100.00 + freight + GST and it will take about 4 days.
Regards,
Adam Walmsley
Heat Treatment Quality Engineer
This email is covered by the Heat Treatments Ltd Disclaimer at:
http://www.heat-treat.co.nz/disclaimer.htmHeat Treatments Limited
PO Box 57025
Owairaka
Auckland
New Zealand
http://www.heat-treat.co.nzPH: 0064 9 621 0020 Ext.252
DDI: 0064 9 621 0432
FX: 0064 9 621 0019
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