1964 Hillman minx series v - Help my hillman minx not running to good

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Mon 2 Mar 2015 10:21
1964 Hillman minx series v - Help my hillman minx not running to good - dujjy1

Can anyone help?

My car isnt running too good, when driving the car seems to hesitate when hot, its as if its about to stall or out of fuel, then it clears and drives ok. I dont want to take things apart if its just an adjustment somewhere, can anyone advise me on what it might be.

Many thanks

Andy

Edited by dujjy1 on 02/03/2015 at 10:22

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Mon 2 Mar 2015 11:17
1964 Hillman minx series v - Help my hillman minx not running to good - Wackyracer

Have you done any elementary checks on it? Colour of spark plugs will give an indication of mixture. Checked points and condenser are good? and points adjusted correctly? Leads, cap, rotor arm all in good condition?

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Mon 2 Mar 2015 12:04
1964 Hillman minx series v - Help my hillman minx not running to good - Railroad.
There are lots of possibilities here so check one thing at a time. Check to make sure that there is a block gasket fitted between the carburettor and the inlet manifold. Its purpose is to act as a heat insulator, and if it's missing it could cause the fuel in the float chamber to vaporise and result in fuel starvation.

Also your engine was designed to run on four star fuel, which you cannot get anymore. Putting aside for a moment the fact that lead in fuel was an upper cylinder lubricant, classic car engines will run on 95RON unleaded, but they never run very well. Higher octane unleaded or use of an octane booster will give better running.
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Mon 2 Mar 2015 12:27
1964 Hillman minx series v - Help my hillman minx not running to good - skidpan

Also your engine was designed to run on four star fuel, which you cannot get anymore. Putting aside for a moment the fact that lead in fuel was an upper cylinder lubricant, classic car engines will run on 95RON unleaded, but they never run very well

Engines designed to run on old 4* will run well enough on unleaded providing the timing is adjusted or preferably the advance curve in the distributor is adjusted to suit the different fuel. Having said that the octane rating of 4* in the 60's was probably little better than the 95 octane unleaded so there is normally not that much to sort.

What does need sorting are the exhaust valve seats. Even with the best additives in the world you will still get the seats being eaten away which will lead to low compression and poor running. When I had a head done it cost about £100 but it was a onece and for all fix. No more worrying about additives or super unleaded. On soem engines it is necessary to replace the valves and guides but a specialist should be able to guide you on this. The Hilman Minx owners club will no doubt have a list of reputable traders.

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Mon 2 Mar 2015 12:46
1964 Hillman minx series v - Help my hillman minx not running to good - Railroad.
You talk rubbish. How many classic cars have you actually worked on? And how in depth is your knowledge of ignition and fuel systems? I've worked on hundreds, and I have never got an engine to idle nicely or perform properly on 95RON fuel. That's because they just don't. You can alter the mixture, play around with the float level, or do whatever you like, they just don't run well on fuel that's designed for modern petrol engines.

I'm not talking about ignition timing, or hardened valve seats. The best ignition timing on any engine is as advanced as you can get it without it pinking, regardless of the specific number of degrees BTDC your Haynes manual states.

You want your engine to run well, put good quality fuel in it.
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Mon 2 Mar 2015 13:31
1964 Hillman minx series v - Help my hillman minx not running to good - skidpan
You talk rubbish. How many classic cars have you actually worked on?

I have worked on many Ford Escorts plus several Caterham Sevens with engines that vary from the Fod X-Flow through to modern 16 valve engines.

And how in depth is your knowledge of ignition and fuel systems?

I have fitted mapped ignition to a x-flow and full throttle body management to a Zetec making some of the parts as necessary. I then mapped the ECU using a broadband Lambda.

I've worked on hundreds, and I have never got an engine to idle nicely or perform properly on 95RON fuel

That is not the fault of the fuel, there must have been other contributory issues.

The car/engine does not know what fuel is in it. If the engine is set up correctly for that fuel it will run fine. Lets remember that most fuel in the 60's was rubbish compared to what is sold today.

As an example the last x-flow I owned started life as a 1600 with 82 bhp. It was bored and stroked to a capacity of 1860 cc. The head was modified to full race spec and a Holbay rally spec cam fitted. The carbs were twin Weber 45 DCOE with 36mm chokes. The limiter was set at 8400 rpm. When leaded fuel became difficult to obtain I had hardened exhaust valve seats fitted and the ignition map was adjusted to prevent pinking when using 95 octane fuel. I could return to the original settings for track use with 98 octane fuel simply by swapping a couple of wires. Whatever fuel was used it ran exactly the same. I don't doubt it produced a few less bhp at peak when using 95 octane but on the road or track it was not noticable from the drivers seat. The engine is now in France doing trackdays.

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Mon 2 Mar 2015 13:45
1964 Hillman minx series v - Help my hillman minx not running to good - Railroad.
My apologies. I didn't correctly read the post above before replying.

It is true that older engines can run on unleaded fuel provided that the valve seats have been modified. If the seats are cut directly into the cylinder head, which many older engines were, then the lack of lead in the fuel will cause them to overheat and burn.
When I worked in a Vauxhall dealer in the 1980s we had to carry out hundreds unleaded conversions. Sounds complicated, but the recommendation was a simple adjustment to retard the ignition timing by 3 degrees back to 7 degrees BTDC. The cylinder heads on Vauxhall engines already had hardened valve seats.

Octane is a fuel's resistance to flame. The higher the RON number the less easily it will ignite. Higher octane fuels tend to burn in a more controlled manner rather than as an explosion. This means you can run with the ignition timing slightly more advanced which in turn allows for smoother running, better throttle response, better fuel economy, a cleaner engine and more power.

One of the major drawbacks on conventional ignition systems with points and a condenser is that they are 'Constant Dwell'. This means that the period of time that the ignition coil is switched on/off never changes. This is the complete opposite of what we would ideally like. We would actually like the coil to be switched on for longer and off for less at higher engine speeds. Electronic ignition systems are variable dwell and allow for that. This gives a bigger fatter spark at all engine speeds. Ignition coil primary resistance is lower on electronic systems because they switch much faster.
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Mon 2 Mar 2015 14:02
1964 Hillman minx series v - Help my hillman minx not running to good - dieselnut

" This means that the period of time that the ignition coil is switched on/off never changes."

I think you mean that the ratio between the on/off period doesn't change.

The actual time for the coil to take in current for each spark varies depending on the revs.

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Mon 2 Mar 2015 15:03
1964 Hillman minx series v - Help my hillman minx not running to good - Railroad.
That's exactly what I mean. Thank you for the clarification.
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Mon 2 Mar 2015 15:15
1964 Hillman minx series v - Help my hillman minx not running to good - Quicksilver

I think this will be the old 1600cc engine? probably not the 1725cc.

If i remember well it has a Stromberg carburettor, (CD175?)?

Maybe a blocked jet or a punctured diaphram?

I would also check this.

Q.

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Mon 2 Mar 2015 15:55
1964 Hillman minx series v - Help my hillman minx not running to good - Robin the Technician

Hi,

My first suspicion would be the stromberg carb. They were notoriously bad at splitting the diaphragm inside. Once split the car would run like a bag of old nails. That would be my first place to look. Easy to change too.

Hope this helps

Robin the Technician - I fix, therefore I am

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Mon 2 Mar 2015 22:10
1964 Hillman minx series v - Help my hillman minx not running to good - hardway

I'd suggest you get a multi meter capeable of doing dewll readings and low voltage,

i.e 0-1 volt.

check the voltage frop across the points,

ought to be less than 0.200 V.

More than that means the points are probably shot.

then set up what would be the points gap useing the dwell function.

Older cars can have worn dizzy internals making setting the point by feeller gauge inaccurate.

and dont forget the fiber cam follower on the points heel.

Often as dry as a bone!

lube it.

Then I plug a vacuum gauge into the inlet manifold stub and check the vacuum when idling.

There's an awful lot that vacuum gauge reading can tell you about the way the engine is running from ignition timing to valve seat condition.

hell,I just realised I'm showing my age!

No code readers back then,just a wall sized Crypton machine with a 'scope

Basics!

Check your points voltage drop,

the ignition dwell angle and vac the inlet.

Once they're all sorted you can worry about fueling or H/T

You could probably buy a dewll meter for less than a tenner,

And vacuum gauges are pretty cheap too.

Not a lot of call for either these days.

Though I still dig mine out when something like yours comes in.

Nothing against today's mechanics but if they can't find the socket for the code reaer they're stumped!

And us older guys can ramble on a bit.

Sorry.

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Tue 3 Mar 2015 08:32
1964 Hillman minx series v - Help my hillman minx not running to good - dadbif

Set of plugs, new points, (set up using dwell meter), then check your ignition timing, new diaphragm for the carb and dont forget to top up the carburettor dashpot with some three in one oil (or thinner). Check idle mixture, anybody still got a colortune?

If that doesnt fix it then run a compression check, you may have some valve seats burnt out from using unleaded...

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Tue 3 Mar 2015 10:00
1964 Hillman minx series v - Help my hillman minx not running to good - MrEckerslikefromRamsbottom

And a Gunson Colortune, eh? Still got mine and nothing to use it on.

Back in the day, after much experimentation, I got a 1098cc Mini Clubman to run beautifully on unleaded by sawing the inlet manifold away from the exhaust, leaving the exhaust manifold in place and fitting a water-jacketed inlet manifold which was off, i think, a Metro, then routing the hoses to the heater through the inlet manifold. This gave a cooler inlet charge using an 1 1/2" SU. It ran well and the exhaust valves stayed clean - non of that grey hard crud caused by the lead. Problem was that I couldn't turn off the hot water to the heater!

Modern cars are no fun any more.

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Tue 3 Mar 2015 10:18
1964 Hillman minx series v - Help my hillman minx not running to good - Galaxy

Yes, I know what you mean. I've got a cupboard full of all that stuff, Gas Analyser, Colourtune, Dwell Meter, Compression Tester, Stroboscope, Vacuum Gauge, etc.

I don't suppose they'll ever be used again but I can't bear to dispose of them. All part of my motoring heritage, I guess you could say!

Edited by Galaxy on 03/03/2015 at 10:19

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