Subject: Re: [Fot] TR6 camshaft "CB"

From: Chip Collingwood via Fot <[email-masked]>
Date: Mon, 8 May 2023 07:10:45 -0400

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Not certain about the cam "CB" designation. And the distributor drive being
off a tooth has nothing to do with cam timing. That is a relationship
between the cam and the crank set by how you install the cam sprocket. The
distributor drive only orients the proper position of the distributor so
that its body doesnt contact the block and prevent the "ignition timing"
from being set properly.
I believe there are 2 big issues with the cams/blanks. Most important is
always installing cam bearings as it will prevent any oil pressure loss due
to poor tolerance of original castings. And second is the oil pump for the
valve train is affected by rear cam bearing surface/cut. Evidently some
blanks are inadequate in comparison to the originals. I would source a good
original blank and have it cut to your specs.

On Mon, May 8, 2023, 1:50 AM Bob Kramer via Fot <[email-masked]> wrote:

> I am rebuilding an engine for a local club member and I just tore down the
> engine. It looks like someone rebuilt it but it did not run very long until
> it coked up the new pistons and valves. The camshaft installed looks to be
> from an unmarked new core and the only stamping on it is a capital CB on
> the back boss.  Has anyone seen this camshaft designation before? It was
> not timed correctly and the distributor drive was off by a tooth so I want
> to make sure I set him up with a car that will run correctly this time.
> I've heard that some of the blanks were not of a good quality so this is
> another worry.
>
> Bob Kramer
> _______________________________________________
> [email-masked]
>
> http://www.fot-racing.com
>
> Donate: http://www.team.net/donate.html
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>
>
>

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<div dir=3D"auto">Not certain about the cam &quot;CB&quot; designation. And=
 the distributor drive being off a tooth has nothing to do with cam timing.=
 That is a relationship between the cam and the crank set by how you instal=
l the cam sprocket. The distributor drive only orients the proper position =
of the distributor so that its body doesnt contact the block and prevent th=
e &quot;ignition timing&quot; from being set properly.<div dir=3D"auto">I b=
elieve there are 2 big issues with the cams/blanks. Most important is alway=
s installing cam bearings as it will prevent any oil pressure loss due to p=
oor tolerance of original castings. And second is the oil pump for the valv=
e train is affected by rear cam bearing surface/cut. Evidently some blanks =
are inadequate in comparison to the originals. I would source a good origin=
al blank and have it cut to your specs.</div><div dir=3D"auto"><br></div></=
div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On=
 Mon, May 8, 2023, 1:50 AM Bob Kramer via Fot &lt;<a href=3D"mailto:fot@aut=
ox.team.net">[email-masked]</a>&gt; wrote:<br></div><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex"><div dir=3D"ltr">I am rebuilding=C2=A0an engine for a local c=
lub member and I just tore down the engine. It looks like someone rebuilt i=
t but it did not run very long until it coked up the new pistons=C2=A0and v=
alves. The camshaft installed looks to be from an unmarked new core and the=
 only stamping on it is a capital CB on the back=C2=A0boss.=C2=A0 Has anyon=
e seen this camshaft designation before? It was not timed correctly and the=
 distributor drive was off by a tooth so I want to make=C2=A0sure I set him=
 up with a car that will run correctly this time. I&#39;ve heard that some =
of the blanks were not of a good quality so this is another worry.=C2=A0<di=
v><br clear=3D"all"><div><div dir=3D"ltr" data-smartmail=3D"gmail_signature=
"><div dir=3D"ltr">Bob Kramer</div></div></div></div></div>
_______________________________________________<br>
<a href=3D"mailto:[email-masked]" target=3D"_blank" rel=3D"noreferrer">=
[email-masked]</a><br>
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=3D"_blank">http://www.fot-racing.com</a><br>
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r>
<br>
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</blockquote></div>

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_______________________________________________
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From: Bob Kramer via Fot <[email-masked]>
Date: Mon, 8 May 2023 08:13:18 -0500

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Agreed. I based the cam timing being off by the position of the camshaft
gear. I assume that this is a stock grind and the slot in the front boss of
the new cam, the one that leaves a discoloration on the back of the gear
was off from the marks on the reused timing gear. And the distributor drive
was off position.

Bob Kramer

On Mon, May 8, 2023 at 6:10=E2=80=AFAM Chip Collingwood <chip@theukmotorspo=
rts.com>
wrote:

> Not certain about the cam "CB" designation. And the distributor drive
> being off a tooth has nothing to do with cam timing. That is a relationsh=
ip
> between the cam and the crank set by how you install the cam sprocket. Th=
e
> always installing cam bearings as it will prevent any oil pressure loss d=
ue
> to poor tolerance of original castings. And second is the oil pump for th=
e
> blanks are inadequate in comparison to the originals. I would source a go=
od
>> I am rebuilding an engine for a local club member and I just tore down
>> the engine. It looks like someone rebuilt it but it did not run very lon=
g
>> until it coked up the new pistons and valves. The camshaft installed loo=
ks
>> to be from an unmarked new core and the only stamping on it is a capital=
 CB
>> on the back boss.  Has anyone seen this camshaft designation before? It =
was
>> not timed correctly and the distributor drive was off by a tooth so I wa=
nt
>> Unsubscribe/Manage <http://www.team.net/pipermail/fotUnsubscribe/Manage>=
>> http://autox.team.net/mailman/options/fot/[email-masked]

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<div dir=3D"ltr">Agreed. I based the cam timing being off by the position o=
f the camshaft gear. I assume that this is a stock grind and the slot in th=
e front boss of the new cam, the one that leaves a discoloration on the bac=
k of the gear was off from the marks on the reused timing gear. And the dis=
tributor drive was off position.=C2=A0<div>=C2=A0<br clear=3D"all"><div><di=
v dir=3D"ltr" class=3D"gmail_signature" data-smartmail=3D"gmail_signature">=
<div dir=3D"ltr">Bob Kramer</div></div></div><br></div></div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Mon, May 8, 2023 =
at 6:10=E2=80=AFAM Chip Collingwood &lt;<a href=3D"mailto:chip@theukmotorsp=
orts.com">[email-masked]</a>&gt; wrote:<br></div><blockquote cla=
ss=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid =
rgb(204,204,204);padding-left:1ex"><div dir=3D"auto">Not certain about the =
cam &quot;CB&quot; designation. And the distributor drive being off a tooth=
 has nothing to do with cam timing. That is a relationship between the cam =
and the crank set by how you install the cam sprocket. The distributor driv=
e only orients the proper position of the distributor so that its body does=
nt contact the block and prevent the &quot;ignition timing&quot; from being=
 set properly.<div dir=3D"auto">I believe there are 2 big issues with the c=
ams/blanks. Most important is always installing cam bearings as it will pre=
vent any oil pressure loss due to poor tolerance of original castings. And =
second is the oil pump for the valve train is affected by rear cam bearing =
surface/cut. Evidently some blanks are inadequate in comparison to the orig=
inals. I would source a good original blank and have it cut to your specs.<=
/div><div dir=3D"auto"><br></div></div><br><div class=3D"gmail_quote"><div =
dir=3D"ltr" class=3D"gmail_attr">On Mon, May 8, 2023, 1:50 AM Bob Kramer vi=
a Fot &lt;<a href=3D"mailto:[email-masked]" target=3D"_blank">fot@autox=
.team.net</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding=
-left:1ex"><div dir=3D"ltr">I am rebuilding=C2=A0an engine for a local club=
 member and I just tore down the engine. It looks like someone rebuilt it b=
ut it did not run very long until it coked up the new pistons=C2=A0and valv=
es. The camshaft installed looks to be from an unmarked new core and the on=
ly stamping on it is a capital CB on the back=C2=A0boss.=C2=A0 Has anyone s=
een this camshaft designation before? It was not timed correctly and the di=
stributor drive was off by a tooth so I want to make=C2=A0sure I set him up=
 with a car that will run correctly this time. I&#39;ve heard that some of =
the blanks were not of a good quality so this is another worry.=C2=A0<div><=
br clear=3D"all"><div><div dir=3D"ltr"><div dir=3D"ltr">Bob Kramer</div></d=
iv></div></div></div>
_______________________________________________<br>
<a href=3D"mailto:[email-masked]" rel=3D"noreferrer" target=3D"_blank">=
[email-masked]</a><br>
<br>
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=3D"_blank">http://www.fot-racing.com</a><br>
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errer" target=3D"_blank">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://autox.team.net/archive" rel=3D"noreferrer norefe=
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">http://autox.team.net/mailman/options/fot/[email-masked]</a><b=
r>
<br>
<br>
</blockquote></div>
</blockquote></div>

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