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David Hill wrote:
>
> Hi, Dave,
>
> Looks like this is what I wanted to know. Some cars apparently had an
> idle screw on each throttle body, which was threaded through the
> butterfly actuating arm to bear directly on the casting. Mine has just
> the long screws (called pushrods in the manuals). What was confusing me
> is in the manuals (factory PI, factory TR6, Haynes and Autobook). These
> say, 'Set the throttle stop screw well away from the lever on the
> throttle countershaft'. This seems pointless because the long pushrods
> would have to be set to give a readable airflow for balancing and then
> screwed back in to give a tickover. As far as I can see, it's a matter
> of raising the tickover with the throttle stop screw, balancing the
> airflows with he pushrods, backing of the stop screw then fine tuning
> the tickover with the air bleed screw.
>
> Many thanks for your help,
>
> Dave Hill
>
> dstauffa@csc.com wrote:
> >
> > Dave,
> >
> > I just when through this on my 19 70 TR6. I adjusted the main throttle
> > stop to give me about 1500 rpm. I then took a reading off of the first set
> > of intakes, recorded it and then read the second set. I have the early
> > setup and all I had to do was turn a long screw that is connected to the
> > throttles to get the same reading as the first set of intakes. I repeated
> > this for the third set of intakes. Once all readings were the same, I
> > secured the screws with the nuts on the ends. Pretty much what the Bentley
> > manual says.
> >
> > Is it these long screw that you don't have? They look to be an integral
> > part of the linkage. Maybe there is some difference between your car and
> > the TR6.
> >
> > Dave
> > San Diego, Ca
> > 1970 TR6 PI
> >
> > Hi, all,
> > I've just been playing with my PI again and a couple of queries spring
> > to mind.
> > I have an early system (no idle screws). To set it up, do you balance
> > the flow readings by holding the revs up with the main throttle stop
> > screw on the countershaft? The book says to balance each butterfly pair
> > with the idle screws but that's a bit tricky when you've got none.
> > Also, at 750 rpm, the engine is holding a slightly unsteady 16in. Hg
> > vacuum. Is this right? It's rather more than the 12in. mentioned in the
> > tech pages.
> > Yours, Puzzled of York (Dave Hill)
--------------FCB073918C02E98B943A3F58
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Message-ID: <3720DD99.325F8082@cwcom.net>
Date: Fri, 23 Apr 1999 21:52:42 +0100
From: David Hill <davhill@cwcom.net>
Organization: Psychomotor
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To: dstauffa@csc.com
CC: triumph, 2000 Register <2000-register@autox.team.net>
Subject: Re: Throttle and vac
References: <8825675C.00648A33.00@csc.com>
Hi, Dave,
Looks like this is what I wanted to know. Some cars apparently had an
idle screw on each throttle body, which was threaded through the
butterfly actuating arm to bear directly on the casting. Mine has just
the long screws (called pushrods in the manuals). What was confusing me
is in the manuals (factory PI, factory TR6, Haynes and Autobook). These
say, 'Set the throttle stop screw well away from the lever on the
throttle countershaft'. This seems pointless because the long pushrods
would have to be set to give a readable airflow for balancing and then
screwed back in to give a tickover. As far as I can see, it's a matter
of raising the tickover with the throttle stop screw, balancing the
airflows with he pushrods, backing of the stop screw then fine tuning
the tickover with the air bleed screw.
Many thanks for your help,
Dave Hill
dstauffa@csc.com wrote:
>
> Dave,
>
> I just when through this on my 19 70 TR6. I adjusted the main throttle
> stop to give me about 1500 rpm. I then took a reading off of the first set
> of intakes, recorded it and then read the second set. I have the early
> setup and all I had to do was turn a long screw that is connected to the
> throttles to get the same reading as the first set of intakes. I repeated
> this for the third set of intakes. Once all readings were the same, I
> secured the screws with the nuts on the ends. Pretty much what the Bentley
> manual says.
>
> Is it these long screw that you don't have? They look to be an integral
> part of the linkage. Maybe there is some difference between your car and
> the TR6.
>
> Dave
> San Diego, Ca
> 1970 TR6 PI
>
> Hi, all,
> I've just been playing with my PI again and a couple of queries spring
> to mind.
> I have an early system (no idle screws). To set it up, do you balance
> the flow readings by holding the revs up with the main throttle stop
> screw on the countershaft? The book says to balance each butterfly pair
> with the idle screws but that's a bit tricky when you've got none.
> Also, at 750 rpm, the engine is holding a slightly unsteady 16in. Hg
> vacuum. Is this right? It's rather more than the 12in. mentioned in the
> tech pages.
> Yours, Puzzled of York (Dave Hill)
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