--===============2250566299571018220==
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The lobe separation angle is 105=C2=B0 and valve timing is 57-83 inlet and =
87-53 exhaust. So I think it is 110=C2=B0 (inlet opens at 57=C2=B0 before T=
DC and outlet closes at 53=C2=B0 after TDC)=20
Marcel=20
Van: "John Styduhar" <johnstydo@gmail.com>=20
Aan: "Scott Janzen" <sjanzen@me.com>=20
Cc: "van mulders marcel" <van.mulders.marcel@telenet.be>, "fot" <fot@autox.=
team.net>=20
Verzonden: Zondag 3 mei 2020 02:38:14=20
Onderwerp: Re: [Fot] Valve overlap and compression test=20
I think Marcel is talking about the lobe separation angle (LSA). The Isky T=
R 777 cam I'm running has the same LSA. LSA is not effected by valve lash a=
djustment.=20
On Sat, May 2, 2020 at 5:36 PM Scott Janzen via Fot < [ mailto:fot@autox.te=
am.net | fot@autox.team.net ] > wrote:=20
Maercel, I=E2=80=99m puzzled. Are you referring to the lobe separation angl=
e, or to the overlap between the intake valve opening before TDC and the ex=
haust valve closing after TDC on the same revolution? Unless I=E2=80=99m re=
ading them wrong, I=E2=80=99ve looked at some pretty radical cam specs and =
the opening/closing overlap does not approach 110 degrees, more like 50 deg=
rees on a really aggressive cam, but the lobe separation angle is about 104=
degrees on the cam I have in the car and 107 on the cam I=E2=80=99m puttin=
g in another engine.=20
On May 2, 2020, at 4:30 PM, van.mulders.marcel--- via Fot < [ mailto:fot@au=
tox.team.net | fot@autox.team.net ] > wrote:=20
Hallo Chris,=20
of course the cylinderhead has to be repaired. I think the man who has put =
the big valves in it, has taken too much risks : the valve seats (the rings=
that are pressed into the cyl head) are small where they do meet, and mayb=
e the seats are distorted a bit because of this, but I don't know for sure,=
I will see when pulling the head. I know one cannot change the valve clear=
ance too much, but maybe 0.05mm more valve lash is ok and it will reduce th=
e valve overlap. I believe 110=C2=B0 overlap is a lot, even for a racecamsh=
aft. Any idea's someone about that? The compression test with increased val=
ve lash is much higher than with the recommended valve lash : I wonder if i=
t is making any sense at all to check the compression of a race engine with=
out increasing the valve lash : with the normal clearances, the inlet valve=
is closing when the piston has already travelled a lot upwards, hence the =
big difference between the compression test results with normal and with in=
creased valve lash. So I think, if you want to test the compression, you ha=
ve to increase the valve lash firstly(at least when the engine has a race c=
amshaft).=20
Marcel=20
Van: "fot" < [ mailto:fot@autox.team.net | fot@autox.team.net ] >=20
Aan: "fot" < [ mailto:fot@autox.team.net | fot@autox.team.net ] >=20
Verzonden: Zaterdag 2 mei 2020 21:29:59=20
Onderwerp: Re: [Fot] Valve overlap and compression test=20
Hello Marcel,=20
Your engine has leaking valves.=20
It won=E2=80=99t get better from changing measurement procedures.=20
Maybe the seat is rough, or the valves bent, or offset .=20
Something to make sure about.=20
Enlarging the valve leash could result in hammering everything dead in the =
valve train.=20
Cheers=20
Chris=20
Von: Fot < [ mailto:fot-bounces@autox.team.net | fot-bounces@autox.team.net=
] > Im Auftrag von van.mulders.marcel--- via Fot=20
Gesendet: Samstag, 2. Mai 2020 14:43=20
An: fot < [ mailto:fot@autox.team.net | fot@autox.team.net ] >=20
Betreff: [Fot] Valve overlap and compression test=20
A leaking test on my TR6 engine is showing a leaking exhaust valve on cyl n=
o 1 (48% on the gauge of the device) and a leaking inlet valve on cyl no 2 =
(75%). Compression on cyl no1 is 9.5 bar and on cyl 2 it is 8 bar. The comp=
ression on the other cylinders is between 12 and 13.5 bar. This is with a r=
ace cam with a valve overlap of 110=C2=B0 (320-F grind). Because of the hig=
h overlap, the piston has risen a lot before the inlet valve is closed, so =
I did the compression test again, but with a valve lash of 2.5mm/0.1" : com=
pression went from 9.5 bar to 14.5 on cyl no 1 and from 8 bar to 15 on cyl =
no 2. With this valve lash, the compression on the other cylinders went up =
to 16 - 18.5 bar. Of course, when the engine is running at high rpm, a lot =
of valve overlap is necessary for best cylinder filling, but I wonder if 11=
0=C2=B0 isn't too much?? The recommended valve lash is 0.40mm/0.016" when t=
he rocker ratio is 1.45(0.43mm/ with my 1.55 roller rockers). Would it be r=
isky to set the valve lash at some 0.05mm/0.002" higher?=20
PS : is it common practice to set the valve lash at a couple of mm to perfo=
rm a compression test, because it seems that the valve lash has a lot of in=
fluence on the result when testing a race camshaft?=20
Marcel=20
_______________________________________________=20
[ mailto:fot@autox.team.net | fot@autox.team.net ]=20
[ http://www.fot-racing.com/ | http://www.fot-racing.com ]=20
]=20
Archive: [ http://autox.team.net/archive | http://autox.team.net/archive ] =
[ http://www.team.net/pipermail/fot | http://www.team.net/pipermail/fot ]=
=20
.marcel@telenet.be | http://autox.team.net/mailman/options/fot/van.mulders.=
marcel@telenet.be ]=20
_______________________________________________=20
[ mailto:fot@autox.team.net | fot@autox.team.net ]=20
[ http://www.fot-racing.com/ | http://www.fot-racing.com ]=20
]=20
Archive: [ http://autox.team.net/archive | http://autox.team.net/archive ] =
[ http://www.team.net/pipermail/fot | http://www.team.net/pipermail/fot ]=
=20
com | http://autox.team.net/mailman/options/fot/sjanzen@me.com ]=20
_______________________________________________=20
[ mailto:fot@autox.team.net | fot@autox.team.net ]=20
[ http://www.fot-racing.com/ | http://www.fot-racing.com ]=20
]=20
Archive: [ http://autox.team.net/archive | http://autox.team.net/archive ] =
[ http://www.team.net/pipermail/fotUnsubscribe/Manage | http://www.team.net=
/pipermail/fot
o@gmail.com | http://autox.team.net/mailman/options/fot/johnstydo@gmail.com=
]=20
--=_1f56dacb-4369-43bf-9148-af6a80f9d197
Content-Transfer-Encoding: quoted-printable
<html><body><div style=3D"font-family: Verdana, Arial, Helvetica, sans-seri=
f; font-size: 10pt; color: #000000"><div>The lobe separation angle is 105=
=C2=B0 and valve timing is 57-83 inlet and 87-53 exhaust. So I think it is&=
nbsp; 110=C2=B0 (inlet opens at 57=C2=B0 before TDC and outlet closes at 53=
=C2=B0 after TDC)</div><div>Marcel</div><div><br></div><hr id=3D"zwchr" dat=
a-marker=3D"__DIVIDER__"><div data-marker=3D"__HEADERS__"><b>Van: </b>"John=
Styduhar" <johnstydo@gmail.com><br><b>Aan: </b>"Scott Janzen" <sj=
anzen@me.com><br><b>Cc: </b>"van mulders marcel" <van.mulders.marcel@=
telenet.be>, "fot" <fot@autox.team.net><br><b>Verzonden: </b>Zonda=
g 3 mei 2020 02:38:14<br><b>Onderwerp: </b>Re: [Fot] Valve overlap and comp=
ression test<br></div><div><br></div><div data-marker=3D"__QUOTED_TEXT__"><=
div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-size:small">I th=
ink Marcel is talking about the lobe separation angle (LSA). The Isky=
TR 777 cam I'm running has the same LSA. LSA is not effected by valv=
e lash adjustment.</div><div class=3D"gmail_default" style=3D"font-size:sma=
ll"><br></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=
=3D"gmail_attr">On Sat, May 2, 2020 at 5:36 PM Scott Janzen via Fot <<a =
href=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=3D"nofollow noopen=
er noreferrer">fot@autox.team.net</a>> wrote:<br></div><blockquote class=
=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rg=
b( 204 , 204 , 204 );padding-left:1ex"><div>Maercel, I=E2=80=99m puzzled. A=
re you referring to the lobe separation angle, or to the overlap between th=
e intake valve opening before TDC and the exhaust valve closing after TDC o=
n the same revolution? Unless I=E2=80=99m reading them wrong, I=E2=80=
=99ve looked at some pretty radical cam specs and the opening/closing overl=
ap does not approach 110 degrees, more like 50 degrees on a really aggressi=
ve cam, but the lobe separation angle is about 104 degrees on the cam I hav=
e in the car and 107 on the cam I=E2=80=99m putting in another engine.<br><=
div><br><div>On May 2, 2020, at 4:30 PM, van.mulders.marcel--- via Fot <=
<a href=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=3D"nofollow noo=
pener noreferrer">fot@autox.team.net</a>> wrote:</div><br><div><div styl=
e=3D"font-style:normal;font-weight:normal;letter-spacing:normal;text-indent=
:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoratio=
n:none;font-family:'verdana' , 'arial' , 'helvetica' , sans-serif;font-size=
:10pt"><div>Hallo Chris,</div><div>of course the cylinderhead has to be rep=
aired. I think the man who has put the big valves in it, has taken too much=
risks : the valve seats (the rings that are pressed into the cyl head) are=
small where they do meet, and maybe the seats are distorted a bit because =
of this, but I don't know for sure, I will see when pulling the head. =
I know one cannot change the valve clearance too much, but maybe 0.05mm mo=
re valve lash is ok and it will reduce the valve overlap. I believe 110=C2=
=B0 overlap is a lot, even for a racecamshaft. Any idea's someone about tha=
t? The compression test with increased valve lash is much higher than with =
the recommended valve lash : I wonder if it is making any sense at all to c=
heck the compression of a race engine without increasing the valve lash : w=
ith the normal clearances, the inlet valve is closing when the piston=
has already travelled a lot upwards, hence the big difference between the =
compression test results with normal and with increased valve lash. So I th=
ink, if you want to test the compression, you have to increase the valve la=
sh firstly(at least when the engine has a race camshaft).</div><div>Marcel<=
/div><br><hr id=3D"gmail-m_487887638361507941zwchr"><div><b>Van: </b>"=
fot" <<a href=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=3D"nof=
ollow noopener noreferrer">fot@autox.team.net</a>><br><b>Aan: </b>"=
fot" <<a href=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=3D"nof=
ollow noopener noreferrer">fot@autox.team.net</a>><br><b>Verzonden: =
;</b>Zaterdag 2 mei 2020 21:29:59<br><b>Onderwerp: </b>Re: [Fot] Valve=
overlap and compression test<br></div><br><div><div><div style=3D"margin:0=
cm;font-size:11pt;font-family:'calibri' , sans-serif"><span lang=3D"DE">Hel=
lo Marcel,</span></div><p class=3D"MsoNormal" style=3D"margin:0cm;font-size=
:11pt;font-family:'calibri' , sans-serif"><span lang=3D"DE"> </span></=
p><div style=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans-seri=
f">Your engine has leaking valves.</div><div style=3D"margin:0cm;font-size:=
11pt;font-family:'calibri' , sans-serif">It won=E2=80=99t get better from c=
hanging measurement procedures.</div><div style=3D"margin:0cm;font-size:11p=
t;font-family:'calibri' , sans-serif">Maybe the seat is rough, or the valve=
s bent, or offset .</div><div style=3D"margin:0cm;font-size:11pt;font-famil=
y:'calibri' , sans-serif">Something to make sure about.</div><p class=3D"Ms=
oNormal" style=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans-se=
rif"> </p><div style=3D"margin:0cm;font-size:11pt;font-family:'calibri=
' , sans-serif">Enlarging the valve leash could result in hammering everyth=
ing dead in the valve train.</div><p class=3D"MsoNormal" style=3D"margin:0c=
m;font-size:11pt;font-family:'calibri' , sans-serif"> </p><div style=
=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans-serif">Cheers</d=
iv><div style=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans-ser=
if">Chris</div><p class=3D"MsoNormal" style=3D"margin:0cm;font-size:11pt;fo=
nt-family:'calibri' , sans-serif"> </p><div><div style=3D"border-style=
:solid none none;border-top-width:1pt;border-top-color:rgb( 225 , 225 , 225=
);padding:3pt 0cm 0cm"><div style=3D"margin:0cm;font-size:11pt;font-family=
:'calibri' , sans-serif"><b><span lang=3D"DE">Von:</span></b><span lang=3D"=
DE"> Fot <<a href=3D"mailto:fot-bounces@autox.team.net"; target=3D"_=
blank" rel=3D"nofollow noopener noreferrer">fot-bounces@autox.team.net</a>&=
gt; <b>Im Auftrag von </b>van.mulders.marcel--- via Fot<br><b>Ges=
endet:</b> Samstag, 2. Mai 2020 14:43<br><b>An:</b> fot <<a hr=
ef=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=3D"nofollow noopener=
noreferrer">fot@autox.team.net</a>><br><b>Betreff:</b> [Fot] Valve=
overlap and compression test</span></div></div></div><p class=3D"MsoNormal=
" style=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans-serif">&n=
bsp;</p><div><div><div style=3D"margin:0cm;font-size:11pt;font-family:'cali=
bri' , sans-serif"><span style=3D"font-size:10pt;font-family:'verdana' , sa=
ns-serif">A leaking test on my TR6 engine is showing a leaking exhaust valv=
e on cyl no 1 (48% on the gauge of the device) and a leaking inlet valve on=
cyl no 2 (75%). Compression on cyl no1 is 9.5 bar and on cyl 2 it is 8 bar=
. The compression on the other cylinders is between 12 and 13.5 bar. This i=
s with a race cam with a valve overlap of 110=C2=B0 (320-F grind). Because =
of the high overlap, the piston has risen a lot before the inlet valve is c=
losed, so I did the compression test again, but with a valve lash of 2.5mm/=
0.1" : compression went from 9.5 bar to 14.5 on cyl no 1 and from 8 bar to =
15 on cyl no 2. With this valve lash, the compression on the other cylinder=
s went up to 16 - 18.5 bar. Of course, when the engine is running at high r=
pm, a lot of valve overlap is necessary for best cylinder filling, but I wo=
nder if 110=C2=B0 isn't too much?? The recommended valve lash is 0.40mm/0.0=
16" when the rocker ratio is 1.45(0.43mm/ with my 1.55 roller rockers). Wou=
ld it be risky to set the valve lash at some 0.05mm/0.002" higher?</span></=
div></div><div><div style=3D"margin:0cm;font-size:11pt;font-family:'calibri=
' , sans-serif"><span style=3D"font-size:10pt;font-family:'verdana' , sans-=
serif">PS : is it common practice to set the valve lash at a couple of mm t=
o perform a compression test, because it seems that the valve lash has a lo=
t of influence on the result when testing a race camshaft?</span></div></di=
v><div><div style=3D"margin:0cm;font-size:11pt;font-family:'calibri' , sans=
-serif"><span style=3D"font-size:10pt;font-family:'verdana' , sans-serif">M=
arcel</span></div></div></div></div><br>___________________________________=
____________<br><a href=3D"mailto:fot@autox.team.net"; target=3D"_blank" rel=
=3D"nofollow noopener noreferrer">fot@autox.team.net</a><br><br><a href=3D"=
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