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--001a11452d14adb60d054278d385
I measured fuel flow at the tee feeding the carbs, and I got 2 quarts in 31
seconds or roughly 60 GPH. The pump is rated for 97 GPH,unregulated, so 60
seems reasonable and able to meet demand.
thanks
mike h
On Mon, Nov 28, 2016 at 10:59 PM, Kas Kastner <kaskastner@gmail.com> wrote:
> Duh!!! have your measured the flow of the pump to the carbs? Do you get
> 15 gallons per hour? You don't get fuel Mr. you do not get power.
>
> *Never be beaten by equipment.*
>
> On Mon, Nov 28, 2016 at 3:58 PM, Mike Harmuth <ofracer@gmail.com> wrote:
>
>> Thanks for the replies, here are the answers to some of the questions:
>>
>> Valve springs, - Dual springs with alloy retainers. The engine builder
>> tested and shimmed them to a uniform pressure but I don't know the number
>> off the top of my head. I'll ask him tomorrow
>>
>> Silver springs in the carbs, the lightest they make I believe. I have a
>> set of heaver ones (red I believe) that I can try. The pistons are filled ~
>> 3/4 of the way, up with SU branded oil and the dampers are in place.
>>
>> The fuel pump, Holley red, all the lines, micron filter before the pump
>> and the regulator were changed last winter because I didn't know how old
>> they were. I had the problem then as well, before and after the
>> replacement. I opened the cell up two weeks ago. The foam is in great
>> shape, the pickups and intake line look to be solid as well. The ATL cell
>> is 6 years old.
>>
>> Fuel pressure is measured by a gauge at the regulator 2 feet from the
>> carbs.
>>
>> I'm not sure that the problem isn't electrical but the car runs with a
>> alternator (confirmed working). The distributor was built with a profile to
>> match my engine by Jeff at Advanced Distributors. I've changed the points
>> (using his high speed set), rotor, cap, wires and capacitor over the
>> summer, just in case, but with no affect. Timing is steady, double row
>> timing chain.
>>
>> thanks for all the info.
>>
>> mike h
>>
>> On Mon, Nov 28, 2016 at 5:05 PM, Sam Halkias <atr6racer@hotmail.com>
>> wrote:
>>
>>> What are you running for valve springs? Sounds like valve float to me.
>>>
>>> Sam
>>>
>>> *Sent from my Verizon Wireless 4G LTE DROID*
>>>
>>>
>>> Mike Harmuth <ofracer@gmail.com> wrote:
>>>
>>> I'm tracking down a problem with the Spit race car (1296 Small Journal,
>>> 12;1 compression, APT TR74 cam 295 duration and 0.324 lob lift, head ported
>>> as per Kas's book). Rebuilt European SU HS4 carb setup with AAA needles
>>> (manifold and carbs checked for vacuum leaks), Advanced Distributor for
>>> spark (34 degrees at full, mechanical only, advance @ 3.5K RPM)
>>>
>>> The problem I have has followed me on two different short blocks, I can
>>> easily pull 7500RPM in 1st-3rd ( Close ratio TR7 gearing in a Spitfire
>>> case, 4th gear is 1;1, 4:11 locked diff ) gears. In 4th I'm struggling to
>>> get over 6K, no matter how long the straight. Just before the last race of
>>> the season, I installed an air fuel ratio gauge on the header (stahl) and
>>> found out I'm running (progressively) very lean (19:1) in 4th over 5K. At
>>> 2K I adjusted it rich, to 12;1 and it keeps in the 13.5- 14.5 range until I
>>> get over 5K when it really leans out. If I pull the choke to 1/2 full over
>>> 5K, I get a good ratio again, 13.5- 14%.
>>>
>>> To me that seemed like the carb pistons aren't pulling all the way up so
>>> I drilled and tapped the manifold to get a vacuum reading. It was steady
>>> but low at 6K, ~20 Inches but would jump to ~28 briefly as the revs dropped
>>> if I blipped the throttle. Under 6K, it was in the 15 inch range. Normal
>>> air filters are K&N with stub stacks but I get the same results with open
>>> carbs.
>>>
>>> Am I correct in assuming that the vacuum is too low or is it that due to
>>> overlap with a performance cam? Any ideas on where to look to get the ratio
>>> "normal" at higher revs? Fuel pump is Holley Red, adjusted to 3 PSI at the
>>> engine compartment and steady through all revs.
>>>
>>> I have dyno time scheduled in a few weeks but I'd like to use that time
>>> to tune not debug things.
>>>
>>> thanks
>>> mike h
>>> 63 spitfire
>>>
>>
>>
>> _______________________________________________
>> 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/kaskastner@gmail.com
>>
>>
>>
>>
>
--001a11452d14adb60d054278d385
Content-Transfer-Encoding: quoted-printable
<div dir=3D"ltr"><div><div>I measured fuel flow at the tee feeding the carb=
s, and I got 2 quarts in 31 seconds or roughly 60 GPH. The pump is rated fo=
r 97 GPH,unregulated, so 60 seems reasonable and able to meet demand.<br><b=
r></div>thanks<br></div>mike h<br></div><div class=3D"gmail_extra"><br><div=
class=3D"gmail_quote">On Mon, Nov 28, 2016 at 10:59 PM, Kas Kastner <span =
dir=3D"ltr"><<a href=3D"mailto:kaskastner@gmail.com"; target=3D"_blank">k=
askastner@gmail.com</a>></span> wrote:<br><blockquote class=3D"gmail_quo=
te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"=
><div dir=3D"ltr">Duh!!! =C2=A0have your measured the flow of the pump to t=
he carbs? Do you get 15 gallons per hour? You don't get fuel Mr. you do=
not get power.</div><div class=3D"gmail_extra"><span class=3D""><br clear=
=3D"all"><div><div class=3D"m_5493796194784360336gmail_signature" data-smar=
tmail=3D"gmail_signature"><p><strong><font color=3D"#000099">Never be beate=
n by equipment.</font></strong></p></div></div>
<br></span><div class=3D"gmail_quote"><div><div class=3D"h5">On Mon, Nov 28=
, 2016 at 3:58 PM, Mike Harmuth <span dir=3D"ltr"><<a href=3D"mailto:ofr=
acer@gmail.com" target=3D"_blank">ofracer@gmail.com</a>></span> wrote:<b=
r></div></div><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;=
border-left:1px #ccc solid;padding-left:1ex"><div><div class=3D"h5"><div di=
r=3D"ltr"><div><div><div><div><div><div><div>Thanks for the replies, here a=
re the answers to some of the questions:<br><br></div>Valve springs, - Dual=
springs with alloy retainers. The engine builder tested and shimmed them t=
o a uniform pressure but I don't know the number off the top of my head=
. I'll ask him tomorrow<br><br></div>Silver springs in the carbs, the l=
ightest they make I believe. I have a set of heaver ones (red I believe) th=
at I can try. The pistons are filled ~ 3/4 of the way,=C2=A0 up with SU bra=
nded oil and the dampers are in place.<br><br></div>The fuel pump, Holley r=
ed, all the lines, micron filter before the pump and the regulator were cha=
nged last winter because I didn't know how old they were. I had the pro=
blem then as well, before and after the replacement. I opened the cell up t=
wo weeks ago. The foam is in great shape, the pickups and intake line look =
to be solid as well. The ATL cell is 6 years old.<br><br></div>Fuel pressur=
e is measured by a gauge at the regulator 2 feet from the carbs.<br><br></d=
iv>I'm not sure that the problem isn't electrical but the car runs =
with a alternator (confirmed working). The distributor was built with a pro=
file to match my engine by Jeff at Advanced Distributors. I've changed =
the points (using his high speed set), rotor, cap, wires and capacitor over=
the summer, just in case, but with no affect. Timing is steady, double row=
timing chain.<br><br></div>thanks for all the info.<br><br></div>mike h<br=
></div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Mon, No=
v 28, 2016 at 5:05 PM, Sam Halkias <span dir=3D"ltr"><<a href=3D"mailto:=
atr6racer@hotmail.com" target=3D"_blank">atr6racer@hotmail.com</a>></spa=
n> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;b=
order-left:1px #ccc solid;padding-left:1ex">
<div>
<div>
<div>What are you running for valve springs? Sounds like valve float to me.=
</div>
<div><br>
</div>
<div>Sam</div>
<div><br>
</div>
<div><font style=3D"color:#333333"><i>Sent from my Verizon Wireless 4G LTE =
DROID</i></font></div>
</div><div><div class=3D"m_5493796194784360336h5"><div><div class=3D"m_5493=
796194784360336m_-9144502024920502084h5">
<br>
<br>
Mike Harmuth <<a href=3D"mailto:ofracer@gmail.com"; target=3D"_blank">ofr=
acer@gmail.com</a>> wrote:<br>
<br>
<div>
<div dir=3D"ltr">
<div>
<div>
<div>
<div>
<div>
<div>I'm tracking down a problem with the Spit race car (1296 Small Jou=
rnal, 12;1 compression, APT TR74 cam 295 duration and 0.324 lob lift, head =
ported as per Kas's book). Rebuilt European SU HS4 carb setup with AAA =
needles (manifold and carbs checked for
vacuum leaks), Advanced Distributor for spark (34 degrees at full, mechani=
cal only, advance @ 3.5K RPM)<br>
<br>
</div>
The problem I have has followed me on two different short blocks, I can eas=
ily pull 7500RPM in 1st-3rd ( Close ratio TR7 gearing in a Spitfire case, 4=
th gear is 1;1,=C2=A0 4:11 locked diff ) gears. In 4th I'm struggling t=
o get over 6K, no matter how long the straight.
Just before the last race of the season, I installed an air fuel ratio gau=
ge on the header (stahl) and found out I'm running (progressively)=C2=
=A0 very lean (19:1) in 4th over 5K. At 2K I adjusted it rich, to 12;1 and =
it keeps in the 13.5- 14.5 range until I get
over 5K when it really leans out. If I pull the choke to 1/2=C2=A0 full ov=
er 5K, I get a good ratio again, 13.5- 14%.
<br>
<br>
To me that seemed like the carb pistons aren't pulling all the way up s=
o I drilled and tapped the manifold to get a vacuum reading. It was steady =
but low at 6K, ~20 Inches but would jump to ~28 briefly as the revs dropped=
if I blipped the throttle. Under 6K,
it was in the 15 inch range. Normal air filters are K&N with stub stac=
ks but I get the same results with open carbs.<br>
<br>
</div>
Am I correct in assuming that the vacuum is too low or is it that due to ov=
erlap with a performance cam? Any ideas on where to look to get the ratio &=
quot;normal" at higher revs? Fuel pump is Holley Red, adjusted to 3 PS=
I at the engine compartment and steady through
all revs.<br>
<br>
</div>
I have dyno time scheduled in a few weeks but I'd like to use that time=
to tune not debug things.<br>
<br>
</div>
thanks<br>
</div>
mike h<br>
</div>
63 spitfire<br>
</div>
</div>
</div></div></div></div></div>
</blockquote></div><br></div>
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__________<br>
<a href=3D"mailto:fot@autox.team.net"; target=3D"_blank">fot@autox.team.net<=
/a><br>
<br>
<a href=3D"http://www.fot-racing.com"; rel=3D"noreferrer" target=3D"_blank">=
http://www.fot-racing.com</a><br>
<br>
et=3D"_blank">http://www.team.net/donate.htm<wbr>l</a><br>
Archive: <a href=3D"http://www.team.net/archive"; rel=3D"noreferrer" target=
=3D"_blank">http://www.team.net/archive</a><br>
Forums: <a href=3D"http://www.team.net/forums"; rel=3D"noreferrer" target=3D=
"_blank">http://www.team.net/forums</a><br></span>
skastner@gmail.com" rel=3D"noreferrer" target=3D"_blank">http://autox.team.=
net/mailman/<wbr>options/fot/kaskastner@gmail.c<wbr>om</a><br>
<br>
<br>
<br></blockquote></div><br></div>
</blockquote></div><br></div>
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_______________________________________________
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http://www.fot-racing.com
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