Head in the Oven time!!!

[carrierdave]

Has anyone put there twin cam head in the oven before?

Is it better to use a gas oven or electric - Fan or conventional?

Seriously - I am going to replace the valve guides and exhaust seats and was wondering what would be the best way of heating the head up?

Any suggestions would be appreciated.

Dave

[john.p.clegg]

Dave
Maybe teaching my granny to suck eggs....but... when I did mine beforehand tack welded some steel across the valve seats which aided extraction...don't forget to have the right size drifts at hand to remove/insert the seats and guides....made mine by turning some steel bar to profile using the guides as a guide...

John

[twincamman]

I wasn't that brave ---I found a shop that did water cooled VW heads and paid them as I was terrified of a valve seat falling out at speed -- -ed

[reb53]

Dave,

Put mine in the oven to get the guides out.
Turned up a steel drift and they came out without problem. This was a long time ago so don't remember temperatures.

I didn't do the seats but like the idea I saw somewhere of getting some scrap valves, (off anything), that will fit up inside the seats and tack welding them to the seats. The stems would fit up the guides as per usual but it doesn't matter if they are a loose fit. Then when everything is heated up you can drive the seats out by hitting the ends of the stems.

They would at least come out square and it sounds a lot easier than messing around with chisels (!) as per the book.

Obviously you'd have to do the seats before doing the guides.
Are you sure you want to do this when machine shops have so much clever, and accurate, gear these days?

Ralph