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In reality, the crank steel really doesn't matter much, assuming that it is a=
n adequate alloy to harden properly for the section thickness.
What really matters is increasing the resistance to fatigue failure, which i=
s where nitriding or tuftriding come in. It is vitally important to set up a=
residual compressive stress level at the radiused surfaces to prevent crack=
formation. The increased wear resistance helps too.
The 1300 lasts longer because of the shorter stroke. The longer stroke real=
ly puts a lot of stress on the crank. The harmonics don't help either.
Sent from my iPhone
> On Sep 9, 2016, at 4:43 PM, "don@dcphotos.com" <don@dcphotos.com> wrote:
>=20
> Just when I think I found the answer=E2=80=A6
>=20
> Unfortunately BLMC compounded this by downgrading the steel used for the c=
rank from EN40B to the far inferior EN16U.
>=20
> I find this:
>=20
> Triumph NEVER ever fitted a EN40B crankshaft to their engines.
>=20
> The Mk3/1500 Spitfire and TR cranks were always made from EN16T.
>=20
>=20
> AND THIS:
>=20
>=20
> The story that different materials were used for the Spitfire crankshaft s=
eems to be something of an urban myth - there is a widespread belief that ea=
rly Spitfire engines used a crank made from EN40 steel as standard, and late=
r ones used the cheaper, inferior EN16. I don't know where this story origin=
ated, but I reckon that someone has confused the Triumph 1300 engine with th=
e BLMC Mini Cooper 'S' 1300 engine, which did use a crank made from EN40, up=
to around 1968. After that, even the Cooper 'S' used EN16 for the cranks, w=
hich were generally tuftrided to improve durability. To the best of my knowl=
edge, all Triumph engines used EN16, it's just that the small crank 1300 eng=
ine had a lighter crank and lighter conrods - that's why it doesn't self-des=
truct like the 1500. If you still believe the Mk3 Spit had an EN40 crank, ju=
st remember that exactly same crank (Stanpart 307422) was used in the Herald=
13/60 saloon/sedan, and most of the Herald 1200 engines. Those models were p=
roduced in larger numbers than the Spitfire, had only a single carb, and wer=
e about 10BHP down on the Spit Mk2 and Mk3. Why would Triumph use a better m=
aterial than absolutely necessary for a low powered saloon car?
>=20
>=20
> Don
>=20
> DON COUCH PHOTOGRAPHY
> (512)-680-3540
>=20
> _______________________________________________
> fot@autox.team.net
>=20
> http://www.fot-racing.com
>=20
> 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/chasgee22@gm=
ail.com
>=20
>=20
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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><div>In reality, the crank steel really doe=
sn't matter much, assuming that it is an adequate alloy to harden properly f=
or the section thickness.</div><div id=3D"AppleMailSignature"><br></div><div=
id=3D"AppleMailSignature">What really matters is increasing the resistance t=
o fatigue failure, which is where nitriding or tuftriding come in. It i=
s vitally important to set up a residual compressive stress level at the rad=
iused surfaces to prevent crack formation. The increased wear resistan=
ce helps too.</div><div id=3D"AppleMailSignature"><br></div><div id=3D"Apple=
MailSignature">The 1300 lasts longer because of the shorter stroke. Th=
e longer stroke really puts a lot of stress on the crank. The harmonic=
s don't help either.<br><br>Sent from my iPhone</div><div><br>On Sep 9, 2016=
, at 4:43 PM, "<a href=3D"mailto:don@dcphotos.com";>don@dcphotos.com</a>" <=
;<a href=3D"mailto:don@dcphotos.com";>don@dcphotos.com</a>> wrote:<br><br>=
</div><blockquote type=3D"cite"><div><meta http-equiv=3D"Content-Type" conte=
nt=3D"text/html charset=3Dutf-8"><p style=3D"border: 0px; margin: 5px 0px 20=
px; padding: 0px; font-size: 14px; font-family: 'Droid Sans', sans-serif; li=
ne-height: 22px;" class=3D""><b class=3D"">Just when I think I found the ans=
wer=E2=80=A6</b></p><p style=3D"border: 0px; margin: 5px 0px 20px; padding: 0=
px; font-size: 13px; font-family: 'Droid Sans', sans-serif; line-height: 22p=
x; color: rgb(102, 102, 102);" class=3D""><span style=3D"color: rgb(93, 93, 9=
3); background-color: rgb(255, 255, 255);" class=3D"">Unfortunately BLMC com=
pounded this by downgrading the steel used for the crank from EN40B to the f=
ar inferior EN16U.</span></p><div style=3D"font-size: 14px;" class=3D""><b c=
lass=3D"">I find this:</b></div><div style=3D"font-size: 14px;" class=3D""><=
br class=3D""></div><p style=3D"border: 0px; margin: 5px 0px 20px; padding: 0=
px; font-size: 13px; font-family: 'Droid Sans', sans-serif; line-height: 22p=
x; color: rgb(102, 102, 102);" class=3D"">Triumph NEVER ever fitted a EN40B c=
rankshaft to their engines.</p><p style=3D"border: 0px; margin: 5px 0px 20px=
; padding: 0px; font-size: 13px; font-family: 'Droid Sans', sans-serif; line=
-height: 22px; color: rgb(102, 102, 102);" class=3D"">The Mk3/1500 Spitfire a=
nd TR cranks were always made from EN16T.</p><div class=3D""><br class=3D"">=
</div><div style=3D"font-size: 14px;" class=3D""><b class=3D"">AND THIS:</b>=
</div><div class=3D""><br class=3D""></div><div class=3D""><br class=3D""></=
div><div class=3D""><span style=3D"font-family: Arial, Helvetica, sans-serif=
; font-size: 14px; background-color: rgb(255, 255, 255);" class=3D"">The sto=
ry that different materials were used for the Spitfire crankshaft seems to b=
e something of an urban myth - there is a widespread belief that early Spitf=
ire engines used a crank made from EN40 steel as standard, and later ones us=
ed the cheaper, inferior EN16. I don't know where this story originated, but=
I reckon that someone has confused the Triumph 1300 engine with the BLMC Mi=
ni Cooper 'S' 1300 engine, which </span><i style=3D"font-family: Arial,=
Helvetica, sans-serif; font-size: 14px;" class=3D"">did</i><span style=3D"f=
ont-family: Arial, Helvetica, sans-serif; font-size: 14px; background-color:=
rgb(255, 255, 255);" class=3D""> use a crank made from EN40, up to aro=
und 1968. After that, even the Cooper 'S' used EN16 for the cranks, which we=
re generally tuftrided to improve durability. To the best of my knowledge, a=
ll Triumph engines used EN16, it's just that the small crank 1300 engine had=
a lighter crank and lighter conrods - that's why it doesn't self-destruct l=
ike the 1500. If you still believe the Mk3 Spit had an EN40 crank, just reme=
mber that </span><i style=3D"font-family: Arial, Helvetica, sans-serif;=
font-size: 14px;" class=3D"">exactly</i><span style=3D"font-family: Arial, H=
elvetica, sans-serif; font-size: 14px; background-color: rgb(255, 255, 255);=
" class=3D""> same crank (Stanpart 307422) was used in the Herald 13/60=
saloon/sedan, and most of the Herald 1200 engines. Those models were produc=
ed in larger numbers than the Spitfire, had only a single carb, and were abo=
ut 10BHP down on the Spit Mk2 and Mk3. Why would Triumph use a better materi=
al than absolutely necessary for a low powered saloon car?</span></div><div c=
lass=3D""><span style=3D"font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px; background-color: rgb(255, 255, 255);" class=3D""><br class=3D""></=
span></div><div class=3D""><span style=3D"font-family: Arial, Helvetica, san=
s-serif; font-size: 14px; background-color: rgb(255, 255, 255);" class=3D"">=
<br class=3D""></span></div><div class=3D""><span style=3D"font-family: Aria=
l, Helvetica, sans-serif; font-size: 14px; background-color: rgb(255, 255, 2=
55);" class=3D"">Don</span></div><div class=3D""><span style=3D"font-family:=
Arial, Helvetica, sans-serif; font-size: 14px; background-color: rgb(255, 2=
55, 255);" class=3D""><br class=3D""></span></div><div class=3D"">
<div class=3D"">DON COUCH PHOTOGRAPHY</div><div class=3D"">(512)-680-3540</d=
iv>
</div>
<br class=3D""></div></blockquote><blockquote type=3D"cite"><div><span>_____=
__________________________________________</span><br><span><a href=3D"mailto=
:fot@autox.team.net">fot@autox.team.net</a></span><br><span></span><br><span=
><a href=3D"http://www.fot-racing.com";>http://www.fot-racing.com</a></span><=
br><span></span><br><span>Donate: <a href=3D"http://www.team.net/donate.html=
">http://www.team.net/donate.html</a></span><br><span>Archive: <a href=3D"ht=
tp://www.team.net/archive">http://www.team.net/archive</a></span><br><span>Fo=
rums: <a href=3D"http://www.team.net/forums";>http://www.team.net/forums</a><=
/span><br><span>Unsubscribe/Manage: <a href=3D"http://autox.team.net/mailman=
/options/fot/chasgee22@gmail.com">http://autox.team.net/mailman/options/fot/=
chasgee22@gmail.com</a></span><br><span></span><br><span></span><br></div></=
blockquote></body></html>=
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_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Archive: http://www.team.net/archive
--===============4877098654349057737==--
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