[Land-speed] Kirkhams are at it again ...

[Dave Dahlgren]

A precision casting would make a bunch more sense once you get past 2 
pieces. machine time is big money unless you have nothing better to do. What 
is left out of most video deals like this is the fact when you machine away 
that much material the material jumps all over the place. There is no way 
you can remove over 80% of the 'billet' and go straight to finished sizes as 
the video suggests. I have turned over 100 lbs into 15 for various projects 
and generaly you machine down to 0.100 to go and forget about working on it 
for a week or so while the material works out it's issues with stress. I 
don't have an oven to stress relieve but time is your friend lacking one. it 
does not just go 'boing' but creeps over time until it settles to a new 
shape that you did not have in mind. If it was machined directly to finished 
size it is actually junk all hype set aside. The 'forging' as well lookes a 
lot like rolled plate and there is a real big difference. Generally you 
forge in a die with a very large steam hammer or similar and have yet to see 
one that is a rectangle with sawn ends. The 'Kirkham University' was equally 
amusing Solid Works Surfcam and a Hass VMC is the staple of every mom and 
pop job shop around here and has very little to do with high end stuff I 
doubt you could get a job in a small shop if not familiar with them. Oh well 
as usual things no one wants to hear from me but a realist rather than a 
believer in hype.
My take your milage may vary. Dave
----- Original Message ----- 
From: "Wester Potter" <wester6935 at comcast.net>
To: "Kirkwood" <saltfever at comcast.net>; "LAND SPEED LIST" 
<land-speed at autox.team.net>
Sent: Tuesday, February 08, 2011 7:01 PM
Subject: Re: [Land-speed] Kirkhams are at it again ...


> It was done in wood first and critiqued by some experienced automotive
> engineers.  There are others on this list who saw the machined wood block. 
> I
> have photos.  The suggested changes, primarily in gasket surfaces, are
> reflected in the aluminum block.  To see more go to their website and see 
> the
> machined aluminum space frame they built for a customer's car.
> www.kirkhammotorsports.com/
>
>
> On Feb 8, 2011, at 2:38 PM, Kirkwood wrote:
>
>> My thoughts precisely, Ed. When I first saw it I thought "why isn't that
> CAM
>> being done on a wood pattern?"
>>
>>  -Kirk.
>>
>> From: "23weldon" <23.weldon at comcast.net>
>>
>> Any of you guys out there close enough to the biz of making race engine
>> parts to know the real pluses and minuses of cast vs billet blocks?  From
> an
>> engineering standpoint I'm having trouble understanding why they don't 
>> cast
>> and finish machine this thing rather than machining it complete. (snip . 
>> .
> .
>> )