Tricks for young (and old) players

I have often fallen into the trap of getting a few things right and then assuming I actually know what I am talking about, a case in point is a compression test I carried out on the Fulvia.
I bought the Fulvia while we were on the Tassie Tour in October, it never seemed to have much getup and go but as the previous owner had not driven it much I thought that it just needed an “Italian Tune” (aka a good thrashing). After returning from a trip to Falls Creek which I believe qualifies as the said thrashing I set about doing a compression test to prove the positive affects caning your engine, alas the numbers were not good, coming in between 40 and 80 psi which are the sort of numbers you may expect from a lawn mower.

This provided me with the excuse of buying more gauges of dubious accuracy from Ebay in the hope of a better result, but as I had to wait delivery I decided to do the cam timing which involved reading the manual many times then doing what I thought it meant, getting it wrong, going to bed and having a revelation at about 2am then getting it right the next morning. The new gauge arrives, and I get a similar result but now all about 100psi. so an improvement of sorts. It was suggested that the engine needed to be hot with the throttle wide open (HOT & WOT), so I duly did the test again with the same result, very perplexing.

The new gauge like the old gauge looked like this:

Then it was time for Revelation #2: The Fulvia engine is only 1300cc so each cylinder is about 325cc, the hose on the compression gauge is long and is a bit elastic so could I be losing something in the hose or is it just too small in diameter? Or probably a combination of both.

Next I used the same gauge but with a metal tube as per this picture:

Which meant I had to also make a remote starter switch as I now had to hold the gauge in place and turn the starter, the result? Cylinders now read between 150 and 165 psi. which is reasonable for a 47 year old engine.

In conclusion, paying less than $20 for a compression gauge may be asking for trouble. However the correct cam timing has transformed the car and it now likes to rev, very Fulvia, very satisfying.

Posted in S2 Fulvia Coupe | 4 Comments

The Good Oil on Castor or Caster Measurement

The Austin’s suspension is somewhat lower than standard so the castor angle probably needed a tweek but how to measure it?  Initially I thought I would use some flat surface on the axle or the stub axles but are those surfaces perpendicular to the king pins?

So, after a little Googling I found another use for the bevel box (Digital Level) and I think it would make a pretty good excuse to buy one if you have not already.

The jist of it is with the wheels straight ahead and sitting on a level surface, place the level on something vertical (it’s magnetic) as in the picture and zero it.  Turn the wheel 20° right and record the result then go back to straight ahead and go left 20° and record that number, in my case it was 1.3° for right and 1.2° for left so to calculate the castor it was 1.3 + 1.2 =2.5 then here is the magic part x 1.5 = 3.75°

Evidently, it’s important that the wheels are moved only 20° each way and that it’s related to the 1.5 that you multiply the result.  I will have to go ask a Maths teacher (Ian?) as my brain hurts when I try to do the trig.

20° lines drawn on the floor the White wedge is a piece of wood cut at 20° on the drop saw and used as a template

A7 chassis with one radius arm in place, I needed a 4° wedge to go under the spring to get the castor right then the radius rod needed some work to match.

Posted in Austin 7 Special | Leave a comment

Sevens Unite

My new year’s resolution of getting an Austin on the road by December is looking less likely as I didn’t realise the impact of cold weather on my productivity, never mind it will happen just not by December

The Special’s LWB A7 Chassis

All the chassis parts for the A7 Special have now arrived so the now rustless Chummy will take a breather.  There is a rolling chassis where before there was a pile junk, some would say I now have a rolling pile of junk.

There are three things on an Austin Seven that could be seen as drawbacks, low power, poor brakes and a tendency the fall over when cornered.  I like thousands before me are going to have a crack at eliminating most of these on the Special and lessen them on the Chummy.

Difference between original and flattened rear spring

First off, the rear quarter elliptics have been flattened this lowers the car but also stops the rear steering that comes with the spring’s effective length changing as you corner.  The front suspension also now sports a flattened spring, a bowed axle and separate shockers, all these changes (except the shocks) mess up the caster angle so I’m waiting for some lowered ends that will be attached to the radius rods that in turn may have to be shortened but before that I need to install the engine and gearbox to see what their weight does to the whole equation.

While I am waiting for that to happen I’m coming to grips with the brakes which had been converted to hydraulic in such a way that the chance of stopping would have been purely accidental.  Needless to say, they have been consigned to the ever-growing scrap heap and replacement late model “Semi Girling” mechanical units installed.  These improved brakes were supposed to cope with the later model Austin 7’s which were quite heavy so on the Special they should be good?  Better? We will see.

Any student of Bugatti or Lancia mechanical brakes will be bemused by the terrible geometry of the Austin brake system but given that it was only Herbert and his young offsider that designed the car in a very short time it is a remarkable job for it’s day, however given its long production run you would have thought that a little more “design” could have crept into the braking system over its life.

Corroded scrap from A7 brazed to a new strip brazed to another new strip

On another subject, I have been at many car shows and have often seen people demonstrating welding aluminium on old Coke cans and have always been tempted to buy the product but thought it was all down to the skill of the operator.  The chummy has some aluminium panel damage so I have bought some of these magic brazing rods from eBay, the stuff works because it melts at around 370° and Aluminium melts at around 600° so it can be done without blowing holes, they claim it’s stronger than the aluminium also you can do it with propane or Map gas.  The picture shows my first attempt so I will need some practice before the main gig.

Posted in Austin 7 Chummy, Austin 7 Special | 9 Comments