Sam, I am not sure what an "AA" head is, but I am sure they are all similar. I purchased mine replacement heads at Great Plains and had the cylinder head machine work done by them as well.
https://www.greatplainsas.com/0154a-/-043-cylinder-head.aspx Then can do the dual spark plugs machine work. They can do 10mm, 12mm, or 14mm no problem. You can actually mix the types; my recent set has 12mm on top and 10mm on the bottom. 10mm is fine for our VW engines. Thanks, Rob Schmitt N1852Z (over 1000 hours) Lees Summit MO -----Original Message----- From: KRnet <[email protected]> On Behalf Of Samuel Spanovich via KRnet Sent: Wednesday, June 28, 2023 9:28 PM To: [email protected] Cc: Samuel Spanovich <[email protected]> Subject: KRnet> VW AA Cylinder Head Dual Spark Plug Question Question for all the VW guru’s out there regarding dual spark plug setup, specifically with AA Volkswagen cylinder heads. After one year of use with single ignition (the same ones that made it across the country with me for the gathering last year), I recently took my AA heads in to get them machined for a second spark plug, in hopes of converting back to dual ignition. I told the machinist originally to keep the same size plug as the original spark plug (12mm x 3/4” reach). However just before the machinist was supposed to perform the work, he informed me that these particular heads (the AA ones) do not have enough metal up near the combustion chamber and they are not thick enough to support a 3/4” reach spark plug (he said he measured the width with calipers, and compared it to an older MOFOCO cylinder head of mine, and the AA head was supposedly not as thick. I asked if it would be possible to machine the second spark plug port for something smaller, such as a 10mm x 1/2” reach plug. He sounded like it would physically fit, however he sounded a little hesitant about running that small of a plug into a fairly powerful engine (~80 HP). My question is whether or not it would be safe to have this type of setup (1x spark plug 12mm x 3/4”, and a secondary plug 10mm x 1/2”). I was fairly certain older VW heads accepted 14mm x 1/2”, so I was a little surprised when the machinist said he wouldn’t think a 1/2” plug would suffice. Any input would be greatly appreciated; just trying to make sure I’m not missing something completely obvious here. V/R Sam Spanovich Sent from my iPhone -- KRnet mailing list [email protected] https://list.krnet.org/mailman/listinfo/krnet -- KRnet mailing list [email protected] https://list.krnet.org/mailman/listinfo/krnet
