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I was going to keep out of this one but am not capable of it. :)
I run Larry's original design cams. I'm not quite sure who is making
them now - Ken Knight had some made last go-round. It's fast but not as
peaky as the Erson 24 - coming out of a turn at 3000 rpm is fine, 3500
is better, pulls through 6500 RPM, not sure where it drops off - haven't
had the courage to rev that high.
Most of the front runners (to my knowledge at least) run the Erson 24.Â
I ran a modified one of those (experimental) and hated that one because
it was even worse at low RPM than the Erson.
We ran an Isky 666 cam early on and it might be more suitable for a less
highly stressed engine. It was tractable and pulled through 6000, not
sure about higher - I suspect going over 6000 won't be worth it. With a
built engine, ported head, all the goodies it's not as fast / powerful
as the Larry or Erson ones.
The Isky would be easier on the valve train. Larry's profile requires
full diameter stock lifters - if you've gone with the GT40 lifters
sleeved down it'll wipe the cam. One set of lifters I bought from BPNW
they had put a chamfer around the edge to break the sharp edge and that
was enough to wipe a cam too. It's pretty high lift so you need to have
your ducks in a row for there not to be spring bind, have the seat
pressures right, and consider valves and springs a replaceable wear
item. I suspect the same is true for the Erson 24 grind as well. I
believe there's an Erson 23 grind which is less radical that might be an
option.
I'm trying to point out possible "off the shelf" items that don't
require you to send a profile to a cam grinder...
The Erson ones are hopefully still available from Brian Howlett / BFE /
www.BritishFrameandEngine.com. Not sure who's making the Larry Young
design ones now.
Cheers, Tony Drews
On 1/22/2023 11:30 AM, Larry Young via Fot wrote:
> The numbers for Erson/BFE #24 mentioned by David and Henry is the last
> one in my list and has the longest duration. Like Henry said, if you
> drop below 4,000 your dead.
>
> I got interested in the history of cam design. According the Speedy
> Bill Smith (Speedway Motors) the real innovators after WWII were Ed
> Winfield and Collins of Harmon-Collins (see the book "Souping the
> Stock Engine). He said their designs were heavily copied by the
> others. I think Kas's cams were designed by someone from Harmon-Collins.
>
> I certainly don't have the experience of many others on this list, but
> I'll contribute a few comments on what Rick has said. Cams is a
> subject that is mysterious (Rick said "black art") to many, so it is
> easy for them to be fooled. There is nothing mysterious about it. I
> agree that most people put to much emphasis on peak HP rather than the
> entire range you will operate in.
> Â - Larry
>
>
> On 1/22/2023 6:46 AM, David Gott via Fot wrote:
>> Hi FOT,
>>
>> I used Larry Youngâ??s site to learn a lot about cams and their
>> relative effects on engine performance with some crude engine
>> modeling software, in the quest to pick the right cam for my wants,
>> building a strong mid range engine, trying not to spin over 6,000 if
>> I can help it with a stock based crank. Â Â Does anyone happen to have
>> the specs on the Gillanderâ??s #24 they could share? Â Just curious.
>> Â Maybe itâ??s at the pointy end of the list below?
>>
>> Rick McCurdy, hereâ??s the cam reference list Larry put together,
>> below, and Iâ??d sure be curious what Rick Parentâ??s software would say
>> I should have done!!!
>>
>> Triumph Cams <https://www.tildentechnologies.com/Cams/TriumphCams.html>
>>
>>
>
>
> _______________________________________________
> fot@autox.team.net
>
> http://www.fot-racing.com
>
> Donate:http://www.team.net/donate.html
> Archive:http://autox.team.net/archive http://www.team.net/pipermail/fot
> Unsubscribe/Manage:http://autox.team.net/mailman/options/fot/tony@tonydrews.com
>
>
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<p>I was going to keep out of this one but am not capable of it. :)</p>
<p>I run Larry's original design cams. I'm not quite sure who is
making them now - Ken Knight had some made last go-round. It's
fast but not as peaky as the Erson 24 - coming out of a turn at
3000 rpm is fine, 3500 is better, pulls through 6500 RPM, not sure
where it drops off - haven't had the courage to rev that high.</p>
<p>Most of the front runners (to my knowledge at least) run the
Erson 24. I ran a modified one of those (experimental) and hated
that one because it was even worse at low RPM than the Erson.</p>
<p>We ran an Isky 666 cam early on and it might be more suitable for
a less highly stressed engine. It was tractable and pulled
through 6000, not sure about higher - I suspect going over 6000
won't be worth it. With a built engine, ported head, all the
goodies it's not as fast / powerful as the Larry or Erson ones.<br>
</p>
<p>The Isky would be easier on the valve train. Larry's profile
requires full diameter stock lifters - if you've gone with the
GT40 lifters sleeved down it'll wipe the cam. One set of lifters
I bought from BPNW they had put a chamfer around the edge to break
the sharp edge and that was enough to wipe a cam too. It's pretty
high lift so you need to have your ducks in a row for there not to
be spring bind, have the seat pressures right, and consider valves
and springs a replaceable wear item. I suspect the same is true
for the Erson 24 grind as well. I believe there's an Erson 23
grind which is less radical that might be an option.</p>
<p>I'm trying to point out possible "off the shelf" items that don't
require you to send a profile to a cam grinder...</p>
<p>The Erson ones are hopefully still available from Brian Howlett /
BFE / <a class="moz-txt-link-abbreviated"
href="http://www.BritishFrameandEngine.com";>www.BritishFrameandEngine.com</a>.Â
Not sure who's making the
Larry Young design ones now.<br>
</p>
<p>Cheers, Tony Drews<br>
</p>
<div class="moz-cite-prefix">On 1/22/2023 11:30 AM, Larry Young via
Fot wrote:<br>
</div>
<blockquote type="cite"
cite="mid:df77402b-9ffa-4593-9265-c2183eaf40f4@pobox.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
The numbers for Erson/BFE #24 mentioned by David and Henry is the
last one in my list and has the longest duration. Like Henry said,
if you drop below 4,000 your dead.<br>
<br>
I got interested in the history of cam design. According the
Speedy Bill Smith (Speedway Motors) the real innovators after WWII
were Ed Winfield and Collins of Harmon-Collins (see the book
"Souping the Stock Engine). He said their designs were heavily
copied by the others. I think Kas's cams were designed by someone
from Harmon-Collins.<br>
<br>
I certainly don't have the experience of many others on this list,
but I'll contribute a few comments on what Rick has said. Cams is
a subject that is mysterious (Rick said "black art") to many, so
it is easy for them to be fooled. There is nothing mysterious
about it. I agree that most people put to much emphasis on peak HP
rather than the entire range you will operate in.<br>
 - Larry <br>
<br>
<br>
On 1/22/2023 6:46 AM, David Gott via Fot wrote:<br>
<blockquote type="cite"
cite="mid:1681050315.254591.1674391564068@mail.yahoo.com">
<meta http-equiv="content-type" content="text/html;
charset=UTF-8">
<!--[if gte mso
9]><xml><o:OfficeDocumentSettings><o:AllowPNG/><o:PixelsPerInch>96</o:PixelsPerInch></o:OfficeDocumentSettings></xml><![endif]-->
Hi FOT,
<div><br>
</div>
<div>I used Larry Youngâ??s site to learn a lot about cams and
their relative effects on engine performance with some crude
engine modeling software, in the quest to pick the right cam
for my wants, building a strong mid range engine, trying not
to spin over 6,000 if I can help it with a stock based crank.
  Does anyone happen to have the specs on the Gillanderâ??s #24
they could share? Â Just curious. Â Maybe itâ??s at the pointy end
of the list below?</div>
<div><br>
</div>
<div>Rick McCurdy, hereâ??s the cam reference list Larry put
together, below, and Iâ??d sure be curious what Rick Parentâ??s
software would say I should have done!!! Â </div>
<div><br>
</div>
<div><a
href="https://www.tildentechnologies.com/Cams/TriumphCams.html";
target="_blank"
class="enhancr2_B610E089-AE3E-4B7D-8313-E7FFEE78E531"
moz-do-not-send="true">Triumph Cams</a>Â </div>
<div><br>
</div>
<br>
</blockquote>
<br>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre"
wrap="">_______________________________________________
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href="mailto:fot@autox.team.net";>fot@autox.team.net</a>
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href="http://www.fot-racing.com";>http://www.fot-racing.com</a>
Archive: <a class="moz-txt-link-freetext"
href="http://autox.team.net/archive";>http://autox.team.net/archive</a> <a
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