

| Subject: | Re: Commentary on Air Cooled Cylinder Heads |
| Date: | Tue, 25 Jun 2002 16:39:43 -0500 |
Silly question: AMC--who is this or what is it an acronym of? Joe On Tue, 25 Jun 2002, Robert Donalds wrote: > I currently use new AMC heads on my rebuilds for the following reasons > the type 4-2 heads take a beating and see hotter temps than most other air cooled heads with the exception of the zambonis ice resurfacers that use a type 1 single port fueled with propane. I have stopped tiring to rebuild OEM heads due to the fact that most cores are just plain old used up. The AMC heads have gotten a bad name because they have in the past dropped seats like the OEM heads did. The current version of the air-cooled AMC are staked in place and I have not seen any of these newer staked heads loose seats or have any issues with seats that have gone soft (pounded out). The AMC heads are made of a different alloy that is much less likely to crack but the new alloy also tends hold the heat a little more so they do run hotter. > Aircooled type 2-4 engines need all the help they can get to keep the heads and pistons as cool as possible. In my rebuilds I currently use a cam with higher valve lift but not more duration so as not to affect the injection system. I hone the cylinders for more piston to skirt clearance as well as notch the con rods to spray oil at the pistons. > the only other options I offer is a 2mm larger valves 42 intake and 36 ex with the extra hard seats and a high flow valve job nices upgrade > > Bob Donalds > Boston Engine > http://www.bostonengine.com >
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