spitfires
[Top] [All Lists]

Re: Fw: Two SU means twice the problems

To: "Reed Mideke" <rmideke@interbase.com>,
Subject: Re: Fw: Two SU means twice the problems
From: "James Carpenter" <james.carpenter@jccsystems.swinternet.co.uk>
Date: Wed, 7 Apr 1999 00:43:37 +0100
Thanks Joe and Reed,

Finished the work with the silver solder, results are good.  Gives me a fair
indication of what a rebushing and new spindles would do.  Anyway did some
tests after fitting, you said it was probably too rich on higher revs so
putting my high flow filters on would lean it out.

Air filters                            Tune               Cars MAX happy
speed
Chrome Wire high flow    Normal ish    58
Chrome Wire high flow    Slightly rich 62
Standard                           Normal ish     72

As you can see that putting these chrome air filters on really makes a
difference for the worse, they really lean out the mixture.  Having said
that if the needle were changed to suit the filters the power increases
would be very good.

Anyway the car does 31MPG UK thats 25US, 100 miles costs me £9 in petrol.
Still cheaper than public transport.  Thats even with my unleaded
conversion, consisting of checking the dwell angle, ingition timing and
valve clearance, and a have one ear out to adjust the valves as soon as I
here the slightest "fluff".  You never know the batch that my cylinder head
came from might be immune to seat recession.


Still there are some problems.

I now cruse at 60MPH, but I do get a hot smell!  And when cruseing, if I
keep my foot steady the car tends to do what it wants, accelerating a bit,
decelerating steady, in quite a fast but subtly cycle.  You here it in the
engine note and well as in you back so its not the wind. Wasn't looking at
the vacuum meter at that time, (must swap it with the oil so that the
passenger can keep an eye on it for me).

Since driving at these speeds I have noticed a wisp of smoke from the
exhaust when starting, it needs a head job at some point (when the valves
go).

I have noticed that the front piston falls slower than the back, (roller
bearing dash pots) when everything is the same on them.  I'll maybe try
using the old non roller bearing dash pots see what difference it makes.
Maybe swapping the dampness may even them out?

I need an overdrive, well I need to overhaul the spare gearbox and J type,
then find a shorter prop, (keeping the old box and prop etc for spares).
Unfortunately meditation with a pint of beer, picturing it done dosent work.



<Prev in Thread] Current Thread [Next in Thread>