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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>. 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">
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charset=UTF-8">
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Hi FOT,
<div><br>
</div>
<div>I used Larry Young’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 Gillander’s #24
they could share? Just curious. Maybe it’s at the pointy end
of the list below?</div>
<div><br>
</div>
<div>Rick McCurdy, here’s the cam reference list Larry put
together, below, and I’d sure be curious what Rick Parent’s
software would say I should have done!!! </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> </div>
<div><br>
</div>
<br>
</blockquote>
<br>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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