Subject: [TR] Octane

From: TERRY SMITH <[email-masked]>
Date: Sun, 23 Sep 2018 09:26:25 -0400 (EDT)

Just curious.  Why is Premium gasoline recommended for a TR3 (and I suppose other Triumphs?)while regular is just fine for other vintage cars.  I know it's to prevent knocking, but how and why?  Does it have to do with being a short-stroke engine or something?  

Thanks, everyone,
Terry
** [email-masked] **

Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archive

---

From: Geo Hahn <[email-masked]>
Date: Sun, 23 Sep 2018 07:51:21 -0700

--===============2629744465173961978==

--00000000000087256805768b0193

Terry -

I rather think it was due to compression ratio more than anything else.
But you may just have to experiment a bit to see what works (adjusting
advance, listening for ping).

My TR4 uses premium at off-brand stations but seems okay with regular from
Shell or Chevron.  My TR3A doesn't seem to care what I put in it, runs fine
on almost anything.

Geo

On Sun, Sep 23, 2018 at 6:26 AM, TERRY SMITH <[email-masked]> wrote:

> Just curious.  Why is Premium gasoline recommended for a TR3 (and I
> suppose other Triumphs?)while regular is just fine for other vintage cars.
> I know it's to prevent knocking, but how and why?  Does it have to do with
> being a short-stroke engine or something?
>
> Thanks, everyone,
> Terry
> Donate: http://www.team.net/donate.html
> Unsubscribe/Manage: http://autox.team.net/mailman/
> options/triumphs/[email-masked]
>

--00000000000087256805768b0193
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Terry -<div><br></div><div>I rather think it was due to co=
mpression ratio more than anything else.=C2=A0 But you may just have to exp=
eriment a bit to see what works (adjusting advance, listening for ping).</d=
iv><div><br></div><div>My TR4 uses premium at off-brand stations but seems =
okay with regular from Shell or Chevron.=C2=A0 My TR3A doesn&#39;t seem to =
care what I put in it, runs fine on almost anything.</div><div><br></div><d=
iv>Geo</div></div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote"=
>On Sun, Sep 23, 2018 at 6:26 AM, TERRY SMITH <span dir=3D"ltr">&lt;<a href=
=3D"mailto:[email-masked]" target=3D"_blank">[email-masked]</a>&g=
t;</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0=
 .8ex;border-left:1px #ccc solid;padding-left:1ex">Just curious.=C2=A0 Why =
is Premium gasoline recommended for a TR3 (and I suppose other Triumphs?)wh=
ile regular is just fine for other vintage cars.=C2=A0 I know it&#39;s to p=
revent knocking, but how and why?=C2=A0 Does it have to do with being a sho=
rt-stroke engine or something?=C2=A0 <br>
<br>
Thanks, everyone,<br>
Terry<br>
** <a href=3D"mailto:[email-masked]">[email-masked]</a> *=
*<br>
<br>
et=3D"_blank">http://www.team.net/donate.<wbr>html</a><br>
Archive: <a href=3D"http://www.team.net/pipermail/triumphs" rel=3D"noreferr=
er" target=3D"_blank">http://www.team.net/pipermail/<wbr>triumphs</a>=C2=A0=
 <a href=3D"http://www.team.net/archive" rel=3D"noreferrer" target=3D"_blan=
k">http://www.team.net/archive</a><br>
<br>
hs/[email-masked]" rel=3D"noreferrer" target=3D"_blank">http://autox.=
team.net/mailman/<wbr>options/triumphs/ahwahneetr@<wbr>gmail.com</a><br>
</blockquote></div><br></div>

--00000000000087256805768b0193--

--===============2629744465173961978==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============2629744465173961978==--

---

From: "dave" <[email-masked]>
Date: Sun, 23 Sep 2018 11:44:52 -0500

Imho its all about compression ratio.   I believe once you get to about 9:1
you need premium.

Wikipedia shows it to be 9:1.  
Wikipedia show a TR4 and TR4a at 9:1, which makes sense, since they are
extremely similar to a TR3
W shows a TR250 at 8.5:1
W shows a spitfire at 8:1

I think that's your answer

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of TERRY SMITH
Sent: Sunday, September 23, 2018 8:26 AM
To: [email-masked]
Subject: [TR] Octane

Just curious.  Why is Premium gasoline recommended for a TR3 (and I suppose
other Triumphs?)while regular is just fine for other vintage cars.  I know
it's to prevent knocking, but how and why?  Does it have to do with being a
short-stroke engine or something?  

Thanks, everyone,
Terry

http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "[email-masked]" <[email-masked]>
Date: Sun, 23 Sep 2018 12:42:24 -0500

--===============0855835557158934551==
	boundary=Apple-Mail-9AC15E5E-1EEB-4BA1-AA8E-754D8B9AFA26
Content-Transfer-Encoding: 7bit

--Apple-Mail-9AC15E5E-1EEB-4BA1-AA8E-754D8B9AFA26
	charset=utf-8
Content-Transfer-Encoding: quoted-printable

It=E2=80=99s all about compression, higher compression needs higher octane t=
o prevent the pinging/knocking that will damage the pistons.   That said, I u=
sually run regular grade in my stock TR3 or maybe step up to mid grade durin=
g the hot Texas summer months. =20
Bill B

Sent from my Handspring Treo

On Sep 23, 2018, at 9:51 AM, Geo Hahn <[email-masked]> wrote:

Terry -

I rather think it was due to compression ratio more than anything else.  But=
 you may just have to experiment a bit to see what works (adjusting advance,=
 listening for ping).

My TR4 uses premium at off-brand stations but seems okay with regular from S=
hell or Chevron.  My TR3A doesn't seem to care what I put in it, runs fine o=
n almost anything.

Geo

> Just curious.  Why is Premium gasoline recommended for a TR3 (and I suppos=
e other Triumphs?)while regular is just fine for other vintage cars.  I know=
 it's to prevent knocking, but how and why?  Does it have to do with being a=
 short-stroke engine or something? =20
>=20
>=20
> Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archi=
ve
>=20
> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/ahwahne=
[email-masked]

ash.net

--Apple-Mail-9AC15E5E-1EEB-4BA1-AA8E-754D8B9AFA26
	charset=utf-8
Content-Transfer-Encoding: quoted-printable

<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto">It=E2=80=99s all about compression, higher c=
ompression needs higher octane to prevent the pinging/knocking that will dam=
age the pistons. &nbsp; That said, I usually run regular grade in my stock T=
R3 or maybe step up to mid grade during the hot Texas summer months. &nbsp;<=
div>Bill B<br><br><div id=3D"AppleMailSignature" dir=3D"ltr"><span style=3D"=
background-color: rgba(255, 255, 255, 0);">Sent from my Handspring Treo</spa=
n></div><div dir=3D"ltr"><br>On Sep 23, 2018, at 9:51 AM, Geo Hahn &lt;<a hr=
ef=3D"mailto:[email-masked]">[email-masked]</a>&gt; wrote:<br><b=
r></div><div dir=3D"ltr"><div dir=3D"ltr">Terry -<div><br></div><div>I rathe=
r think it was due to compression ratio more than anything else.&nbsp; But y=
ou may just have to experiment a bit to see what works (adjusting advance, l=
istening for ping).</div><div><br></div><div>My TR4 uses premium at off-bran=
d stations but seems okay with regular from Shell or Chevron.&nbsp; My TR3A d=
oesn't seem to care what I put in it, runs fine on almost anything.</div><di=
v><br></div><div>Geo</div></div><div class=3D"gmail_extra"><br><div class=3D=
"gmail_quote">On Sun, Sep 23, 2018 at 6:26 AM, TERRY SMITH <span dir=3D"ltr"=
>&lt;<a href=3D"mailto:[email-masked]" target=3D"_blank">terryrs@comcas=
t.net</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"ma=
rgin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Just curious.&n=
bsp; Why is Premium gasoline recommended for a TR3 (and I suppose other Triu=
mphs?)while regular is just fine for other vintage cars.&nbsp; I know it's t=
o prevent knocking, but how and why?&nbsp; Does it have to do with being a s=
hort-stroke engine or something?&nbsp; <br>
<br>
Thanks, everyone,<br>
Terry<br>
** <a href=3D"mailto:[email-masked]">[email-masked]</a> **=
<br>
<br>
t=3D"_blank">http://www.team.net/donate.<wbr>html</a><br>
Archive: <a href=3D"http://www.team.net/pipermail/triumphs" rel=3D"noreferre=
r" target=3D"_blank">http://www.team.net/pipermail/<wbr>triumphs</a>&nbsp; <=
a href=3D"http://www.team.net/archive" rel=3D"noreferrer" target=3D"_blank">=
<br>
s/[email-masked]" rel=3D"noreferrer" target=3D"_blank">http://autox.te=
am.net/mailman/<wbr>options/triumphs/ahwahneetr@<wbr>gmail.com</a><br>
</blockquote></div><br></div>
</div><div dir=3D"ltr"><span>** <a href=3D"mailto:[email-masked]">t=
[email-masked]</a> **</span><br><span></span><br><span>Donate: <a hr=
ef=3D"http://www.team.net/donate.html">http://www.team.net/donate.html</a></=
span><br><span>Archive: <a href=3D"http://www.team.net/pipermail/triumphs">h=
ttp://www.team.net/pipermail/triumphs</a> &nbsp;<a href=3D"http://www.team.n=
et/archive">http://www.team.net/archive</a></span><br><span></span><br><span=
>Unsubscribe/Manage: <a href=3D"http://autox.team.net/mailman/options/triump=
hs/[email-masked]">http://autox.team.net/mailman/options/triumphs/wbeech@f=
lash.net</a></span><br></div></div></body></html>=

--Apple-Mail-9AC15E5E-1EEB-4BA1-AA8E-754D8B9AFA26--

--===============0855835557158934551==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============0855835557158934551==--

---

From: Creig Houghtaling <[email-masked]>
Date: Mon, 24 Sep 2018 23:20:44 +0000

--===============3781134020082306309==
Content-Language: en-US
	boundary="_000_DM6PR19MB23629F0263FDF76EAC12C2EBEC170DM6PR19MB2362namp_"

--_000_DM6PR19MB23629F0263FDF76EAC12C2EBEC170DM6PR19MB2362namp_
Content-Transfer-Encoding: quoted-printable

Terry,

I think Geo has the best answer here.  Try regular and listen for knocking.=
  No knocking, all is good, don't worry about it.  (That last sentence is s=
trictly my opinion!!! Get information from others who know more to come to =
your own conclusion.)  Compression is what causes knocking.  But compressio=
n ratio of the engine is not the bottom line.  The actual compression you g=
et in the cylinder and when your spark plug fires is the bottom line for kn=
ocking.  Modern engines run higher than 9:1 compression ratio and run fine =
on regular gas.  That's because with modern electronics the ignition can be=
 adjusted on the fly.  With these old engines, the cam also plays a major r=
oll in how much compression you actually have in your cylinder.  If you hav=
e 2 engines with the same compression ratio, a mild cam can run well on reg=
ular gas and a hotter cam will knock on regular gas.  That is because the m=
ild cam is opening and closing at different positions in the stroke compare=
d to a hotter cam allowing for lower total compression of the gases in the =
cylinder.  Compared to the hotter cam.

Creig
________________________________
From: Triumphs <[email-masked]> on behalf of Geo Hahn <ahw=
[email-masked]>
Sent: Sunday, September 23, 2018 9:51 AM
To: TERRY SMITH
Cc: Triumphs
Subject: Re: [TR] Octane

Terry -

I rather think it was due to compression ratio more than anything else.  Bu=
t you may just have to experiment a bit to see what works (adjusting advanc=
e, listening for ping).

My TR4 uses premium at off-brand stations but seems okay with regular from =
Shell or Chevron.  My TR3A doesn't seem to care what I put in it, runs fine=
 on almost anything.

Geo

[email-masked]>> wrote:
Just curious.  Why is Premium gasoline recommended for a TR3 (and I suppose=
 other Triumphs?)while regular is just fine for other vintage cars.  I know=
 it's to prevent knocking, but how and why?  Does it have to do with being =
a short-stroke engine or something?

Thanks, everyone,
Terry

Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archiv=
e

[email-masked]

--_000_DM6PR19MB23629F0263FDF76EAC12C2EBEC170DM6PR19MB2362namp_
Content-Transfer-Encoding: quoted-printable

<html>
<head>
<meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Diso-8859-=
1">
<style type=3D"text/css" style=3D"display:none;"> P {margin-top:0;margin-bo=
ttom:0;} </style>
</head>
<body dir=3D"ltr">
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
Terry,</div>
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
<br>
</div>
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
I think Geo has the best answer here.&nbsp; Try regular and listen for knoc=
king.&nbsp; No knocking, all is good, don't worry about it.&nbsp; (That las=
t sentence is strictly my opinion!!! Get information from others who know m=
ore to come to your own conclusion.)&nbsp; Compression
 is what causes knocking.&nbsp; But compression ratio of the engine is not =
the bottom line.&nbsp; The actual compression you get in the cylinder and w=
hen your spark plug fires is the bottom line for knocking.&nbsp; Modern eng=
ines run higher than 9:1 compression ratio and
 run fine on regular gas.&nbsp; That's because with modern electronics the =
ignition can be adjusted on the fly.&nbsp; With these old engines, the cam =
also plays a major roll in how much compression you actually have in your c=
ylinder.&nbsp; If you have 2 engines with the same
 compression ratio, a mild cam can run well on regular gas and a hotter cam=
 will knock on regular gas.&nbsp; That is because the mild cam is opening a=
nd closing at different positions in the stroke compared to a hotter cam al=
lowing for lower total compression of
 the gases in the cylinder.&nbsp; Compared to the hotter cam.</div>
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
<br>
</div>
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
Creig</div>
<div style=3D"color: rgb(0, 0, 0); font-family: Calibri,Helvetica,sans-seri=
f; font-size: 12pt;">
</div>
<hr tabindex=3D"-1" style=3D"display:inline-block;width:98%">
<div id=3D"divRplyFwdMsg" dir=3D"ltr"><font color=3D"#000000" face=3D"Calib=
ri, sans-serif" style=3D"font-size:11pt"><b>From:</b> Triumphs &lt;triumphs=
[email-masked]&gt; on behalf of Geo Hahn &lt;[email-masked]&=
gt;<br>
<b>Sent:</b> Sunday, September 23, 2018 9:51 AM<br>
<b>To:</b> TERRY SMITH<br>
<b>Cc:</b> Triumphs<br>
<b>Subject:</b> Re: [TR] Octane</font>
<div>&nbsp;</div>
</div>
<meta content=3D"text/html; charset=3Dutf-8">
<div>
<div dir=3D"ltr">Terry -
<div><br>
</div>
<div>I rather think it was due to compression ratio more than anything else=
.&nbsp; But you may just have to experiment a bit to see what works (adjust=
ing advance, listening for ping).</div>
<div><br>
</div>
<div>My TR4 uses premium at off-brand stations but seems okay with regular =
from Shell or Chevron.&nbsp; My TR3A doesn't seem to care what I put in it,=
 runs fine on almost anything.</div>
<div><br>
</div>
<div>Geo</div>
</div>
<div class=3D"x_gmail_extra"><br>
<div class=3D"x_gmail_quote">On Sun, Sep 23, 2018 at 6:26 AM, TERRY SMITH <=
span dir=3D"ltr">
&lt;<a href=3D"mailto:[email-masked]" target=3D"_blank">terryrs@comcas=
t.net</a>&gt;</span> wrote:<br>
<blockquote class=3D"x_gmail_quote" style=3D"margin:0 0 0 .8ex; border-left=
:1px #ccc solid; padding-left:1ex">
Just curious.&nbsp; Why is Premium gasoline recommended for a TR3 (and I su=
ppose other Triumphs?)while regular is just fine for other vintage cars.&nb=
sp; I know it's to prevent knocking, but how and why?&nbsp; Does it have to=
 do with being a short-stroke engine or something?&nbsp;
<br>
<br>
Thanks, everyone,<br>
Terry<br>
** <a href=3D"mailto:[email-masked]">[email-masked]</a> *=
*<br>
<br>
=3D"noreferrer">
Archive: <a href=3D"http://www.team.net/pipermail/triumphs" target=3D"_blan=
k" rel=3D"noreferrer">
http://www.team.net/pipermail/<wbr>triumphs</a>&nbsp; <a href=3D"http://www=
.team.net/archive" target=3D"_blank" rel=3D"noreferrer">
<br>
hs/[email-masked]" target=3D"_blank" rel=3D"noreferrer">
http://autox.team.net/mailman/<wbr>options/triumphs/ahwahneetr@<wbr>gmail.c=
om</a><br>
</blockquote>
</div>
<br>
</div>
</div>
</body>
</html>

--_000_DM6PR19MB23629F0263FDF76EAC12C2EBEC170DM6PR19MB2362namp_--

--===============3781134020082306309==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--===============3781134020082306309==--