Comments on: 304 AMC heads http://www.goodson.com/blog/2009/10/19/304-amc-heads/ Questions, answers and discussion about engine building Wed, 10 Mar 2010 17:28:02 -0600 http://wordpress.org/?v=2.8.4 hourly 1 By: Jim http://www.goodson.com/blog/2009/10/19/304-amc-heads/comment-page-1/#comment-249 Jim Wed, 30 Nov -0001 00:00:00 +0000 http://stage18.vdgnet.com/blog/?p=604#comment-249 The 304 heads will accept hardened seats readily. The change from 30 deg to 45 deg usually picks up larger flow numbers at the cost of low end torque. The 304 heads will accept hardened seats readily. The change from 30 deg to 45 deg usually picks up larger flow numbers at the cost of low end torque.

]]> By: machine shop tom http://www.goodson.com/blog/2009/10/19/304-amc-heads/comment-page-1/#comment-250 machine shop tom Wed, 30 Nov -0001 00:00:00 +0000 http://stage18.vdgnet.com/blog/?p=604#comment-250 I diagree about the loss of low end torque. The increased flow (due to the change in valve face angle) results from a reduction in valve induced restriction. The cyilnder will fill better with no reduction in port velocity. This should actually improve torque. The addition of the larger valve may cause a small decrease in port velocity but that will be offset by the increased low-lift flow numbers Make sure the intake valve isn't shrouded too much. tom I diagree about the loss of low end torque. The increased flow (due to the change in valve face angle) results from a reduction in valve induced restriction. The cyilnder will fill better with no reduction in port velocity. This should actually improve torque.

The addition of the larger valve may cause a small decrease in port velocity but that will be offset by the increased low-lift flow numbers

Make sure the intake valve isn’t shrouded too much.

tom

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