OK, here's where I'm leaning based upon some logic, some guessing, and
some actual experience.
I know the following:
The engine at upper rpm's starts to miss and buck a little bit
preventing it from easily reaching redline.
The carbs were recently rebuilt, the spark plugs are good.
The engine will easily rev to upper rpm's when not under load - I'm
using this as evidence that spark is probably not my problem.
That leaves fuel, which is where I'm currently leaning. I also know
this:
The fuel tank has some internal rust and this will occasionally lead to
changing of the fuel filter. Knowing that there is rust coming from the
tank to the filter leads me to wonder what the condition of the fuel
lines themselves are?
So, I'm hypothesizing that I'm suffering from fuel starvation under
extreme load where the need for decent quantities of fuel is present. I
don't know this, but I hope to report back in the near future that I've
solved this issue. On a side note, this issue is not new, and didn't
give me any trouble when I went to the Summer Party, but it's annoying
when I really want to "get on it."
Cheers,
R. Ashford Little II
www.geocities.com/ralittle2
-----Original Message-----
From: Navarrette, Vance [mailto:vance.navarrette@intel.com]
Sent: Tuesday, September 02, 2003 11:21 AM
To: R. Ashford Little II; 6-Pack; Triumphs@autox. Net
Subject: RE: Engine RPM question
Ashford:
Your car is running out of something when under load
at high RPMs, air, fuel or exhaust capacity. I will ignore spark
because it revs freely in your driveway, so spark appears to
be working.
Check for clogged fuel filter, or restricted fuel lines and
correct the issue to alleviate the fuel issue. Also, make your
air filters are clean and in good shape.
If that checks out fine, you may have a dented or bent
exhaust pipe, or perhaps your muffler has rotted sufficiently that
it has collapsed internally. Excessive back pressure will prevent
your car from reaching high RPMs under load.
Lack of fuel is more likely than exhaust problems, so start
there.
Vance
-----Original Message-----
From: R. Ashford Little II [mailto:ralittle2@mindspring.com]
Sent: Tuesday, September 02, 2003 7:17 AM
To: 6-Pack; Triumphs@autox. Net
Subject: Engine RPM question
O:K, this has been bugging me for a while, so I'm going to throw it out
to the list. With a gear not engaged - revving in the driveway - my
engine will sing up to 6K or so, and easily. However, with a load on
the engine things are substantially different. The engine will rev to
around 5K in first, maybe a touch higher, to only 5k in 2nd, and will
not reach 5k in third or fourth. The engine will start to sputter or
miss at upper rpm's.
The condition of the engine is varied. The carbs are newly rebuilt, the
plugs are clean, the timing is accurate, and I use a Petronix so this
should alleviate distributor issues. The engine itself has good
compression, but is showing it age, and the head is definitely in need
of a going through.
So, any idea what's going on here? It's not that I want to continually
rev the engine, but I'm just trying to understand where my problem is
originating.
Thanks,
R. Ashford Little II
www.geocities.com/ralittle2
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