[FWDLK] 57 D-500-1 question

[Wayne Graefen <wgraefen@xxxxxxxxxxxxxx>]

Here is where the 15 HP (the standard B was actually 340 HP)  REALLY came from.  It had nothing to do with the addition of the 4-bolt truck exh. manifolds.

 

Wayne

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----- Original Message -----

From: Gil Cunningham 

Sent: Friday, September 26, 2003 6:06 AM

Subject: Re: 57 D-500-1 question

Hi All:
According to the AMA specs, the 355HP was achieved using a 10.0 to 1 compression head.  The revision date for the 355HP/405ft-lbs engine in the specs was 4-16-56.  The existence of the head must have been earlier, since on either 2-4-56 or 3-8-56 it was specified that AGR-31 sparkplugs be used ONLY with the 10-1 head.  The official announcement letter for the new head availability is 6-13-56.  It states the part number of the 10-1 heads are 1730369-1, and that they are not interchangeable with the C300 heads of 1955.  It also notes the basic timing should be set at 0 to 4 degrees BTDC.  The optional 3" diameter exhaust and 15 X 9.5 L wheels do not seem to have any connection with the HP changes, as both were entered into the AMA specs on 12-5-55.  Hope this helps.   Gil