Looking at the pictures of those heads my assumption would be that the generous cooling passages are a bit too generous. The air that comes in contact with the aluminum cools the head, not the air that just passes by through a big hole. I suspect that much of the air is going through the big holes near the top of the heads instead of passing over the fins. Aside from the overall reduction of air that comes in contact with the head it is also reducing the amount of air flowing over the fins on the bottom side that carry most of the heat in exchange for putting it on the top side of the head where it is less important.
Brian Kraut 904-536-1780 br...@eamanuacturing.com -------- Original Message -------- Subject: KR> VW Type 1 "DRD Racing" head reliability From: Mark Langford via KRnet <krnet@list.krnet.org> Date: Fri, April 28, 2017 5:05 am To: KRnet <krnet@list.krnet.org> Cc: Mark Langford <m...@n56ml.com> Those of you with any kind of short term memory remaining will recall that I took a serious look at Type 1 head cooling last year, in an effort to find some heads that had sufficient air passages to keep the VW Type 1 heads cool in a KR2. I settled on DRD Racing heads, which have some very generous air passages, _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
