Hi Pete,
I gave the machine shop the message to remove .150 The forecast on CR
is about 11:1 with no pop-ups and 87mm pistons.
I think I have read that benchmark on the .010 = .1 CR. Based on another
table that was developed this MIGHT be a bit conservative. (Also, our
calculations are based on 87mm pistons) We are removing a fair amount of
meat in the chamber for flow, providing another variable.
Tullius Head-I have also heard about 'knife edge heads". I also read
somewhere that Triumph made up a special casting run of heads that found
their way to Kastner & Tullius.
I'll bet somebody has more to add to this.
Finally.....4-6 inches of snow forecasted for northern Iowa starting
tonight :-(
>----------
>From: dfullam@albany.net
>Sent: Tuesday, April 8, 1997 9:59 PM
>To: Alexander Joseph H
>Subject: Head Games
>
>Hi Joe
>
>I've been following the string on head milling/CRs etc. I remember reading
>somewhere that each .010 off the head raises the CR a tenth of a point. IE
>.125 off raises CR from 9:1 to 10.25:1. Many many summers ago I wrenched
>for a friend who raced a Morgan +4 SS. We built a new head and took off I
>think .180". (This was 34 years ago!) In the first race on it, one quench
>area warped into a little sine wave near the gasket. Toast. I got a look
>at Tullius' engine not long after that. He had so much off that the lower
>flange where the pushrod tubes go looked about as thick as a razor blade.
>
>
>Pete
>Dianne Boggess Fullam
>E-mail: dfullam@albany.net
>
>
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