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Air-cooled cylinder heads
Posted: 09 Aug 2016, 18:18
by george2490
Evening,
Got some good, used cylinder heads.
Have decoked and waiting for valve spring compressor to remove valves.
What is best way forward, simple lap in or new valves and springs?
Heads look good loads of carbon in combustion chamber and evenly sooty plugs.
No cracks.
Any advice would be appreciated.
George
Re: Air-cooled cylinder heads
Posted: 09 Aug 2016, 18:59
by sarran1955
Hello,
Are they real CT heads (long spark plug hole).. or van/beetle heads (short spark plug hole)..
Real CT heads in good condition are worth making an effort on..
Valve seats re-cut, new valve guides and nice new Swiss valves.
If this is beyond your mechanical means, and you are not in a hurry, I shall be doing a series of heads for my CT in the Autumn.
Pm me if interested.
Ho Hum.. I suppose this will mean another video..
Cordialement,

Re: Air-cooled cylinder heads
Posted: 09 Aug 2016, 19:23
by george2490
Evening John, can't find any CT heads these are just good old beetle heads. Not sure whether to replace exhaust valves or just lap them in. I plan on a rebuild next year and have a cut case lined up for bigger engine. These heads are just for a years use but I need to find all fifty horses.
Cheers,
George
Re: Air-cooled cylinder heads
Posted: 10 Aug 2016, 19:07
by sarran1955
Hello,
Thanks for the quick reply,
OK.. so these are beetle heads..
I would fit new exhaust valves at least..
At 9€ a pop.. one of the hardest working components..
Here is one of my beetle motor videos..
https://www.youtube.com/watch?v=wGvhxtW8HN0" onclick="window.open(this.href);return false;,
Plough through and cylinder head recovery is well detailed.
Chances are they are of Mexican or Brazilian origin, so unless the valve guides are worn, leave well alone, (because they are often machined to odd sizes and have to be ordered individually..or lathed to fit.)
Pay particular attention to the spark plug threads.... the CT are 19 mm depth for a good reason..
AND YOU WILL HAVE TO USE W5AC BOSCH PLUGS
Take your time..do it right..a pair of known good 043 heads will always come in handy one day..
Cordialement,

Re: Air-cooled cylinder heads
Posted: 11 Aug 2016, 07:46
by george2490
Thanks John. Waiting for parts then I'll try to post some pics.
Re: Air-cooled cylinder heads
Posted: 11 Aug 2016, 08:43
by bigherb
Still check the spark plug length, late Mexican beetles with the ACD engine also used long reach spark plugs.
Re: Air-cooled cylinder heads
Posted: 11 Aug 2016, 10:59
by george2490
Will do, I have w8ac plugs that sit flush with inside of combustion chamber with only the electrode protruding. Long reach plugs w8cc were fitted previously and protruded some way into the chamber. Which is correct?
Re: Air-cooled cylinder heads
Posted: 11 Aug 2016, 11:54
by bigherb
george2490 wrote:Will do, I have w8ac plugs that sit flush with inside of combustion chamber with only the electrode protruding.
Those
Re: Air-cooled cylinder heads
Posted: 11 Aug 2016, 12:34
by george2490
Thanks Big Herb.
Very much appreciated.