fot
[Top] [All Lists]

Re: [Fot] Six cylinder cams

To: Duncan Charlton <duncan.charlton54@gmail.com>
Subject: Re: [Fot] Six cylinder cams
From: McKearn McKearn <mckearn2@gmail.com>
Date: Sat, 31 Oct 2015 17:44:48 -0500
Cc: "Mike Piggot \(new\)" <mikeandjudypiggott@att.net>, FOT list <fot@autox.team.net>
Delivered-to: mharc@autox.team.net
Delivered-to: fot@autox.team.net
References: <CAAGAaPXf_FkOoep829e4ypy+32uhRpK1fuygCvBtbEz6LXPxXQ@mail.gmail.com> <DC55D9D9-5A4A-41E4-B01D-54BF6BE4E005@gmail.com> <563509C6.3090507@pobox.com> <B7E94A4F-C482-4219-8F81-66A268673080@gmail.com>
--===============0065384824979467585==

--001a1140f2ec95765705236e4a46
Content-Transfer-Encoding: quoted-printable

I can tell you that I already have a GT6 with a good flexible power band
and good reliability. It lacks quickness however, due in part to the TR6
engine which is not highly tuned  and I'm sure the gearing could be better
(3.27 rearend-Toyota T50 trans.)( Good for the highway.) My old car is
pretty much to the point where I don't want to do anything more to it so I
want to move on to another project.  This time I want to build a car that
snorts . I do however need to put it on and off the trailer and I'm not
thrilled about breaking parts with max. RPMs so I can't afford to go all
out.  I'm looking for quickness through the gears and good handling.
                                                         P.J.

On Sat, Oct 31, 2015 at 3:43 PM, Duncan Charlton <
duncan.charlton54@gmail.com> wrote:

> Larry=E2=80=99s comments make me wonder the precise intended purpose of t=
he engine
> mentioned by the original poster.  =E2=80=9CTrack days=E2=80=9D might mea=
n different things
> to different people.  Does P. J. want a good flexible power band, or does
> he need an ultimate dyno horsepower figure?  Does the motor have the gear
> set to be able to take advantage of an engine with very little low-end
> torque? How high among his priorities is the ability to be able to drive
> the car back on the trailer at the end of every track weekend?  Lack of
> sponsorship and cash prizes mean that I must find the setup that maximize=
s
> the fun/cost ratio.
>
> Duncan
>
>
> > On Oct 31, 2015, at 1:34 PM, Larry Young <cartravel@pobox.com> wrote:
> >
> > That is an interesting article, but only speaks to one side of the
> issue.  I always say that you want to pick an intake duration for an RPM
> range that you're willing and able to turn. We all know what happens to a
> stock TR4 crank which sees >6,000 on a regular basis.  Some guys want a c=
am
> good beyond 7,000, but they are just not willing to push it that far.
> Nowadays I'm more of a street car guy, but still like to have power.  I
> don't believe the choices should be to do nothing or go all the way to ra=
ce
> specs.  From 1968 on Triumphs were severely detuned to pass emissions.
> Compression ratio and duration and hence cam overlap at TDC were reduced.
> For example, the early TR250/6 had 193 degrees duration (measured at
> 0.050), while the TR4 was about 215 and the early PI TR5/6 was 226. It
> seems crazy to rebuild a street car of this era to the original specs.
> Bumping the compression ratio by a point and increasing the duration to
> something like 210-215 will make the engine the way it would have been
> without emission restrictions.  I would not feel guilty about polluting t=
he
> planet, since most of these cars see few miles annually and most of the
> other pollution controls (e.g. ignition retard) probably quit working yea=
rs
> ago.
> > - Larry
> >
> > On 10/29/2015 7:25 AM, Duncan Charlton wrote:
> >> Cam specs and static CR are interactive.  This will give you a rundown
> if you are not already knowledgeable about this subject:
> >>
> >>
> http://www.crankshaftcoalition.com/wiki/Cam_and_compression_ratio_compati=
bility
> >>
> >> Duncan
> >> (Texas)
> >>
> >>
> >
> > _______________________________________________
> > fot@autox.team.net
> >
> > http://www.fot-racing.com
> >
> > Donate: http://www.team.net/donate.html
> > Archive: http://www.team.net/archive
> > Forums: http://www.team.net/forums
> > Unsubscribe/Manage:
> http://autox.team.net/mailman/options/fot/duncan.charlton54@gmail.com
> >
> >
>
> _______________________________________________
> fot@autox.team.net
>
> http://www.fot-racing.com
>
> Donate: http://www.team.net/donate.html
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/fot/mckearn2@gmail.com
>
>
>

--001a1140f2ec95765705236e4a46
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>I can tell you that I already have a GT6 with a good =
flexible power band and good reliability. It lacks quickness=C2=A0however,=
=C2=A0due in part to the TR6 engine=C2=A0which is not highly tuned=C2=A0=C2=
=A0and I&#39;m sure the gearing could be better (3.27 rearend-Toyota T50 tr=
ans.)( Good for the highway.)=C2=A0My old car is pretty much=C2=A0to the po=
int where I don&#39;t want to do anything more to it=C2=A0so I want to move=
 on to another project.=C2=A0=C2=A0This time=C2=A0I want to build a car tha=
t snorts . I do however need to put it on and off the trailer and I&#39;m n=
ot thrilled about breaking parts with max. RPMs so I can&#39;t afford to go=
 all out.=C2=A0 I&#39;m looking for quickness through the gears and good ha=
ndling.=C2=A0</div><div>=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 P.J.=C2=A0</di=
v></div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Sat, O=
ct 31, 2015 at 3:43 PM, Duncan Charlton <span dir=3D"ltr">&lt;<a href=3D"ma=
ilto:duncan.charlton54@gmail.com" target=3D"_blank">duncan.charlton54@gmail=
.com</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">Larry=E2=80=99=
s comments make me wonder the precise intended purpose of the engine mentio=
ned by the original poster.=C2=A0 =E2=80=9CTrack days=E2=80=9D might mean d=
ifferent things to different people.=C2=A0 Does P. J. want a good flexible =
power band, or does he need an ultimate dyno horsepower figure?=C2=A0 Does =
the motor have the gear set to be able to take advantage of an engine with =
very little low-end torque? How high among his priorities is the ability to=
 be able to drive the car back on the trailer at the end of every track wee=
kend?=C2=A0 Lack of sponsorship and cash prizes mean that I must find the s=
etup that maximizes the fun/cost ratio.<br>
<br>
Duncan<br>
<br>
<br>
&gt; On Oct 31, 2015, at 1:34 PM, Larry Young &lt;<a href=3D"mailto:cartrav=
el@pobox.com">cartravel@pobox.com</a>&gt; wrote:<br>
&gt;<br>
&gt; That is an interesting article, but only speaks to one side of the iss=
ue.=C2=A0 I always say that you want to pick an intake duration for an RPM =
range that you&#39;re willing and able to turn. We all know what happens to=
 a stock TR4 crank which sees &gt;6,000 on a regular basis.=C2=A0 Some guys=
 want a cam good beyond 7,000, but they are just not willing to push it tha=
t far. Nowadays I&#39;m more of a street car guy, but still like to have po=
wer.=C2=A0 I don&#39;t believe the choices should be to do nothing or go al=
l the way to race specs.=C2=A0 From 1968 on Triumphs were severely detuned =
to pass emissions.=C2=A0 Compression ratio and duration and hence cam overl=
ap at TDC were reduced.=C2=A0 For example, the early TR250/6 had 193 degree=
s duration (measured at 0.050), while the TR4 was about 215 and the early P=
I TR5/6 was 226. It seems crazy to rebuild a street car of this era to the =
original specs.=C2=A0 Bumping the compression ratio by a point and increasi=
ng the duration to something like 210-215 will make the engine the way it w=
ould have been without emission restrictions.=C2=A0 I would not feel guilty=
 about polluting the planet, since most of these cars see few miles annuall=
y and most of the other pollution controls (e.g. ignition retard) probably =
quit working years ago.<br>
&gt; - Larry<br>
&gt;<br>
&gt; On 10/29/2015 7:25 AM, Duncan Charlton wrote:<br>
&gt;&gt; Cam specs and static CR are interactive.=C2=A0 This will give you =
a rundown if you are not already knowledgeable about this subject:<br>
&gt;&gt;<br>
&gt;&gt; <a href=3D"http://www.crankshaftcoalition.com/wiki/Cam_and_compres=
sion_ratio_compatibility" target=3D"_blank" rel=3D"noreferrer">http://www.c=
rankshaftcoalition.com/wiki/Cam_and_compression_ratio_compatibility</a><br>
&gt;&gt;<br>
&gt;&gt; Duncan<br>
&gt;&gt; (Texas)<br>
&gt;&gt;<br>
&gt;&gt;<br>
&gt;<br>
&gt; _______________________________________________<br>
&gt; <a href=3D"mailto:fot@autox.team.net";>fot@autox.team.net</a><br>
&gt;<br>
&gt; <a href=3D"http://www.fot-racing.com"; target=3D"_blank" rel=3D"norefer=
rer">http://www.fot-racing.com</a><br>
&gt;<br>
&gt; Donate: <a href=3D"http://www.team.net/donate.html"; target=3D"_blank" =
rel=3D"noreferrer">http://www.team.net/donate.html</a><br>
&gt; Archive: <a href=3D"http://www.team.net/archive"; target=3D"_blank" rel=
=3D"noreferrer">http://www.team.net/archive</a><br>
&gt; Forums: <a href=3D"http://www.team.net/forums"; target=3D"_blank" rel=
=3D"noreferrer">http://www.team.net/forums</a><br>
&gt; Unsubscribe/Manage: <a href=3D"http://autox.team.net/mailman/options/f=
ot/duncan.charlton54@gmail.com" target=3D"_blank" rel=3D"noreferrer">http:/=
/autox.team.net/mailman/options/fot/duncan.charlton54@gmail.com</a><br>
&gt;<br>
&gt;<br>
<br>
_______________________________________________<br>
<a href=3D"mailto:fot@autox.team.net";>fot@autox.team.net</a><br>
<br>
<a href=3D"http://www.fot-racing.com"; target=3D"_blank" rel=3D"noreferrer">=
http://www.fot-racing.com</a><br>
<br>
=3D"noreferrer">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://www.team.net/archive"; target=3D"_blank" rel=3D"n=
oreferrer">http://www.team.net/archive</a><br>
Forums: <a href=3D"http://www.team.net/forums"; target=3D"_blank" rel=3D"nor=
eferrer">http://www.team.net/forums</a><br>
kearn2@gmail.com" target=3D"_blank" rel=3D"noreferrer">http://autox.team.ne=
t/mailman/options/fot/mckearn2@gmail.com</a><br>
<br>
<br>
</blockquote></div><br></div>

--001a1140f2ec95765705236e4a46--

--===============0065384824979467585==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

_______________________________________________
fot@autox.team.net

http://www.fot-racing.com

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



--===============0065384824979467585==--

<Prev in Thread] Current Thread [Next in Thread>