--===============2381329588163207634==
boundary="----=_Part_194667_255012818.1574772865187"
------=_Part_194667_255012818.1574772865187
Content-Transfer-Encoding: quoted-printable
Bob and FOT,
I'm beginning to suspect a combination of a weak chain tensioner and an eng=
ine harmonic that may have caused it. Attached a pic of the play in the tim=
ing chain..about 1/2". Is that too much? If so, Ted, I'll be contacting you=
shortly. Chain is about two years old, maybe 6 weekend s of racing on it. =
New chain tensioner from Moss should be here today and I'm interested in se=
eing the difference in spring arch between the original single chain tensio=
ner and the new TR6 double chain tensioner. Stay tuned!
Mathieu=20
On Monday, November 25, 2019 Robert Lang <robertlangtr6@yahoo.com> wrote:
Hi - I've seen this before. Mostly on American V8's but the principle is t=
he same... It's almost always a loose chain or worn teeth on the crank gear=
. If the=C2=A0 crank gear has really sharp teeth, the gear is probably worn=
. Note that this is really easy to overlook. And I've had this problem with=
TR6 engines a couple of times. Especially if you sourced the inexpensive g=
ears. Seems like the hardening of the metal is wrong on some of the parts o=
ut there.
That said, the numbers look like you jumped more than one tooth. If the "ju=
mp" occurred on the crank end one tooth is about 17 degrees (360/21 teeth).=
Your mention of 150ish for your lobe center sound more like more than 34 d=
egrees or retard, the progression would be (roughly) 104 - good, 121 - not =
good, 138 - bad, 155 - really bad, etc. Note that I have seen engines run w=
ith more than 30 degrees of retard, but they ran very poorly!
I'd double check your crank gear for wear... actually, I'd just replace it =
along with the tensioner. Note that the current chain tensioners seem to be=
not as good as the OEM ones as the new ones wear fairly rapidly.
On the plus side, at least you didn't bend a valve in the process.
C ya,Bob Lang339-927-4489
On Sunday, November 24, 2019, 10:38:49 PM EST, Mathieu W. Huovinen via =
Fot <fot@autox.team.net> wrote: =20
=20
Fellas,
Sounds like we have the bearing cap strap issue resolved...who is up for an=
other mystery? Has anyone ever has their timing chain skip a tooth??
Final race on Saturday at the Turlkey Bowl this weekend at Summit Point. Tr=
iumph Spitfire..1296 engine. Double roller chain set. Car was running well =
all weekend, was out twice earlier that day. We leave false grid for the to=
set up for the first lap and I begin to accelerate. All of a sudden the ca=
r just dies and I coast off the track even before turn one. On the side of =
the track I couldn't start the car. In my mind I'm thinking my perrtonix di=
stributor just took a shit. Got towed in and all I'm thinking in pertronix.=
I swap in a points distributor and nothing. Perhaps my coil? Swap in a new=
coil. Nothing. Plugs perhaps? Swap in a good set of NGKs. Nothing. Not eve=
n a cough out of the engine. By this time I had run down the battery from t=
rying to start it so much. At this point I was jumping the racecar battery =
from my Tundra truck battery thinking perhaps a weak spark from a shot batt=
ery. Nothing. Was getting plenty of fuel because the plugs were wet. I even=
pulled and cleaned all the jets out of the Weber 45 DCOE just to make sure=
I was getting correct fuel. Fuel. Air. Spark. COMPRESSION. This next day (=
this morning) I did a compression test at the track. 80/70/70/70. What the =
heck? Thats not a blown head gasket..the cam HAS to be out of timing. I spe=
nt the majority of the 5 hour drive home trying to figure it out. Got home,=
car off trailer, straight to work. Pulled radiator, pulley, timing chain c=
over. No damage. Find TDC and put on my degree wheel. Pulled rockers and se=
t dial indicator on #1 intake. Tuned engine over to where cam sheet says wh=
ere #1 centerline is- 104 degrees after TDC while watching dial indicator. =
Went past 104 and dial was still climbing. Made it to to about 150ish degre=
es past TDC til indicator started to drop back down so I know I had went ri=
ght past the peak of the lobe. Pulled chain off carefully and rotated camsh=
aft until I found peak of lobe and moved crank back to 104 and set the chai=
n back on...about one tooth =C2=A0Put rockers back on and checked compressi=
on on #1. 160 PSI. That's as far as I got before my wife came down to yell =
art me. It was already 2130 at this point. More tomorrow as I put it back t=
ogether.=C2=A0
Thoughts? Ideas? Can the timing chain "float" at high revs? Thank-you in ad=
vance for any input!
V/r,
Mathieu Huovinen_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
@yahoo.com
=20
------=_Part_194667_255012818.1574772865187
Content-Transfer-Encoding: quoted-printable
<p dir=3D"ltr">Bob and FOT,</p>
<p dir=3D"ltr">I'm beginning to suspect a combination of a weak chain tensi=
oner and an engine harmonic that may have caused it. Attached a pic of the =
play in the timing chain..about 1/2". Is that too much? If so, Ted, I'll be=
contacting you shortly. Chain is about two years old, maybe 6 weekend s of=
racing on it. New chain tensioner from Moss should be here today and I'm i=
nterested in seeing the difference in spring arch between the original sing=
le chain tensioner and the new TR6 double chain tensioner. Stay tuned!</p>
<p dir=3D"ltr">Mathieu </p>
</br></br><div class=3D"device_aol_et_org_dt_dd_quote"></div><hr style=3D"b=
order:0;height:1px;color:#999;background-color:#999;width:100%;margin:0 0 9=
px 0;padding:0;"></hr><span style=3D"font-size:14px; color:#999999;">On Mon=
day, November 25, 2019 Robert Lang <<span style=3D"color:#0000A0">rober=
tlangtr6@yahoo.com</span>> wrote:</span><br></br><div id=3D"yiv14603063=
54"><html><head></head><div><div class=3D"yiv1460306354ydpc7a6ebd8yahoo-sty=
le-wrap" style=3D"font-family:Helvetica Neue, Helvetica, Arial, sans-serif;=
font-size:13px;"><div></div>
<div dir=3D"ltr">Hi - I've seen this before. Mostly on American=
V8's but the principle is the same... It's almost always a loose c=
hain or worn teeth on the crank gear. If the=C2=A0 crank gear has really sh=
arp teeth, the gear is probably worn. Note that this is really easy to over=
look. And I've had this problem with TR6 engines a couple of times. Esp=
ecially if you sourced the inexpensive gears. Seems like the hardening of t=
he metal is wrong on some of the parts out there.<br clear=3D"none"></div><=
div dir=3D"ltr"><br clear=3D"none"></div><div dir=3D"ltr">That said, the nu=
mbers look like you jumped more than one tooth. If the "jump" occ=
urred on the crank end one tooth is about 17 degrees (360/21 teeth). Your m=
ention of 150ish for your lobe center sound more like more than 34 degrees =
or retard, the progression would be (roughly) 104 - good, 121 - not good, 1=
38 - bad, 155 - really bad, etc. Note that I have seen engines run with mor=
e than 30 degrees of retard, but they ran very poorly!</div><div dir=3D"ltr=
"><br clear=3D"none"></div><div dir=3D"ltr">I'd double check your crank=
gear for wear... actually, I'd just replace it along with the tensione=
r. Note that the current chain tensioners seem to be not as good as the OEM=
ones as the new ones wear fairly rapidly.</div><div dir=3D"ltr"><br clear=
=3D"none"></div><div dir=3D"ltr">On the plus side, at least you didn't =
bend a valve in the process.</div><div dir=3D"ltr"><br clear=3D"none"></div=
><div dir=3D"ltr">C ya,</div><div dir=3D"ltr">Bob Lang</div><div dir=3D"ltr=
">339-927-4489<br clear=3D"none"></div><div><br clear=3D"none"></div>
=20
</div><div class=3D"yiv1460306354ydpc2efc1c9yahoo_quoted" id=3D"yiv=
1460306354ydpc2efc1c9yahoo_quoted_5402201527">
<div style=3D"font-family:'Helvetica Neue', Helvetica, Arial, s=
ans-serif;font-size:13px;color:#26282a;">
=20
<div class=3D"yiv1460306354yqt1765380690" id=3D"yiv14603063=
54yqt19484"><div>
On Sunday, November 24, 2019, 10:38:49 PM EST, Mathieu =
W. Huovinen via Fot <fot@autox.team.net> wrote:
</div>
<div><br clear=3D"none"></div>
<div><br clear=3D"none"></div>
<div><div id=3D"yiv1460306354ydpc2efc1c9yiv0645507289">
<div style=3D"color:black;font-style:normal;font-weight:normal;font-stretch=
:normal;font-size:10pt;line-height:normal;font-family:arial;font-size-adjus=
t:none;">Fellas,
<div><br clear=3D"none">
</div>
<div>Sounds like we have the bearing cap strap issue resolved...who is up f=
or another mystery? Has anyone ever has their timing chain skip a tooth??</=
div>
<div><br clear=3D"none">
</div>
<div>Final race on Saturday at the Turlkey Bowl this weekend at Summit Poin=
t. Triumph Spitfire..1296 engine. Double roller chain set. Car was running =
well all weekend, was out twice earlier that day. We leave false grid for t=
he to set up for the first lap and I begin to accelerate. All of a sudden t=
he car just dies and I coast off the track even before turn one. On the sid=
e of the track I couldn't start the car. In my mind I'm thinking my=
perrtonix distributor just took a shit. Got towed in and all I'm think=
ing in pertronix. I swap in a points distributor and nothing. Perhaps my co=
il? Swap in a new coil. Nothing. Plugs perhaps? Swap in a good set of NGKs.=
Nothing. Not even a cough out of the engine. By this time I had run down t=
he battery from trying to start it so much. At this point I was jumping the=
racecar battery from my Tundra truck battery thinking perhaps a weak spark=
from a shot battery. Nothing. Was getting plenty of fuel because the plugs=
were wet. I even pulled and cleaned all the jets out of the Weber 45 DCOE =
just to make sure I was getting correct fuel. Fuel. Air. Spark. COMPRESSION=
. This next day (this morning) I did a compression test at the track. 80/70=
/70/70. What the heck? Thats not a blown head gasket..the cam HAS to be out=
of timing. I spent the majority of the 5 hour drive home trying to figure =
it out. Got home, car off trailer, straight to work. Pulled radiator, pulle=
y, timing chain cover. No damage. Find TDC and put on my degree wheel. Pull=
ed rockers and set dial indicator on #1 intake. Tuned engine over to where =
cam sheet says where #1 centerline is- 104 degrees after TDC while watching=
dial indicator. Went past 104 and dial was still climbing. Made it to to a=
bout 150ish degrees past TDC til indicator started to drop back down so I k=
now I had went right past the peak of the lobe. Pulled chain off carefully =
and rotated camshaft until I found peak of lobe and moved crank back to 104=
and set the chain back on...about one tooth =C2=A0Put rockers back on and =
checked compression on #1. 160 PSI. That's as far as I got before my wi=
fe came down to yell art me. It was already 2130 at this point. More tomorr=
ow as I put it back together.=C2=A0</div>
<div><br clear=3D"none">
</div>
<div>Thoughts? Ideas? Can the timing chain "float" at high revs? =
Thank-you in advance for any input!</div>
<div><br clear=3D"none">
</div>
<div>V/r,</div>
<div><br clear=3D"none">
</div>
<div>Mathieu Huovinen</div>
</div></div>_______________________________________________<br clear=3D"non=
e"><a rel=3D"nofollow" shape=3D"rect" ymailto=3D"mailto:fot@autox.team.net"=
target=3D"_blank" href=3D"mailto:fot@autox.team.net";>fot@autox.team.net</a=
><br clear=3D"none"><br clear=3D"none"><a rel=3D"nofollow" shape=3D"rect" t=
arget=3D"_blank" href=3D"http://www.fot-racing.com";>http://www.fot-racing.c=
om</a><br clear=3D"none"><br clear=3D"none">Donate: <a rel=3D"nofollow" sha=
pe=3D"rect" target=3D"_blank" href=3D"http://www.team.net/donate.html";>http=
://www.team.net/donate.html</a><br clear=3D"none">Archive: <a rel=3D"nofoll=
ow" shape=3D"rect" target=3D"_blank" href=3D"http://autox.team.net/archive =
">http://autox.team.net/archive </a><a rel=3D"nofollow" shape=3D"rect" targ=
et=3D"_blank" href=3D"http://www.team.net/pipermail/fot";>http://www.team.ne=
t/pipermail/fot</a><br clear=3D"none">Unsubscribe/Manage: <a rel=3D"nofollo=
w" shape=3D"rect" target=3D"_blank" href=3D"http://autox.team.net/mailman/o=
ptions/fot/robertlangtr6@yahoo.com">http://autox.team.net/mailman/options/f=
ot/robertlangtr6@yahoo.com</a><br clear=3D"none"><br clear=3D"none"><br cle=
ar=3D"none"></div></div>
</div>
</div></div></html></div>
------=_Part_194667_255012818.1574772865187--
--===============2381329588163207634==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Archive: http://autox.team.net/archive http://www.team.net/pipermail/fot
--===============2381329588163207634==--
|