1275 midget advance curve...

[liammonty]

Only you can make that decision... In my opinion, a rolling road session is priceless, and it gives the opportunity to get the carb set up and the needle profiled properly. It really is money well spent, and I payed considerably less than the figure Phil quoted, but my session was just to reprofile the carb needle. Tom Airey, near Phil, is excellent with A-Series engines, but isn’t cheap. I could have reprofiled the needle myself, but I would never really known if it was totally ‘right’ throughout the rev range. I’d already had my dizzy rebuilt by the Distributor Doctor with a curve suitable for my engine mods.

So, if you want to do a really good job, buy the dizzy AND a rolling road session!!!

[philthehill]

I quite agree that a rolling road is best but it is a question of cost and the above poster has already questioned the expense.
If you are prepared to spend some time road testing the car you can get near nigh the same result and sometimes even after the rolling road session adjustments have to be made to make real driving better.
There is nothing like driving the car to determine if the settings are right.
Phil

[BrianHawley]

Thanks all!

[Chipper]

Looking at the chart that mark posted above, it must have the wrong curve. I do have the original 25d side entry distributor that came with the 1275 engine. Perhaps I could use the springs and weights from this while utilising the rest of the accuspark 45d parts to get a 'normal' midget curve?

Good to hear you finally got the 1275/Type 9 conversion to work. I would certainly be inclined to give the original dizzy a whirl; I briefly fitted a cheap E-bay 'universal' 45D to my 1275cc Midget engine while I rebuilt the original 25D4, and it ran a bit 'flat' in comparison.

[philthehill]

Check that the distributer base plate is the correct one for the Midget otherwise the advance limit stop may not be correctly placed.
Early Midgets had the same 23D4 distributer as the Mini Cooper S and which did not have the vacuum advance.
https://www.moss-europe.co.uk/shop-by-m ... 500cc.html

[moggymaniac]

Thanks all.
Successfully installed the midget distributor and it seems to be a little flat lower down but then revs much better past 3000rpm. Have set to 13° BTDC as per manual, and will tweak as I drive. Didn't check the base plate but I will do when I get round to it! I'm going to see what the maximum advance is with the strobe when I get a chance.

On a separate note. I'd really like to know what cam I have without taking the engine out. Is this possible? I'm taking the timing cover off soon to clean out the oil separator, so will have access to the front of the cam. O wonder if it night be visibly stamped here ?

Yes...it's been a longer process than I thought to fit the type 9 and 1275, but all good fun! I'm enjoying the tweaking process now.

[Chipper]

Bear in mind, the original timing settings were intended for use with 4-star leaded fuel back in the day when they were new. Nowadays, it's best to more or less ignore the manual and adjust the distributor until it just doesn't pink (pre-detonate) when going up a hill or when accelerating in a high gear. This then gives you the optimum setting for modern day unleaded fuel.

[philthehill]

Non original cams are normally stamped with the cam type/number on the nose of the cam.
The standard 1275cc Midget cam is not marked.
Some non standard cams have been known to be inscribed with the details on the body/shaft of the cam between the lobes.
The standard Midget cam is nothing spectacular and is shared with the likes of the 1275cc Marina.
To remove the cam you will have to remove the engine and turn the engine upside down as the cam followers cannot be removed like the 948cc & 1098cc 'A' Series.
If you do take the cam out make sure that you do not loose the cam to oil pump spider adapter as they are near impossible to obtain.
If the cam has been changed the oil pump drive may have been changed to a slot drive which does not require the oil pump spider.

[moggymaniac]

Thanks for the info, Phil!

[IslipMinor]

turn the engine upside down

I have once used the 'clothes' peg method! I bought 8 telescopic magnets, and after removing the head and pushrods, slid a magnet down into each cam follower, lifted it up until it just touched the block and secured it with a clothes peg - repeat a further 7 times! The camshaft was a 'slot' drive version, so no concerns about losing the spider. I don't think I would have risked it with a spider drive cam - how would you know that everything was in the right position?

It worked, but I was resigned to removing the engine if anything went wrong.

If you have the timing cover off, then with a cam protractor, you could establish the current cam's timing, and from that get an idea of what it might be.

[philthehill]

The cloths peg method as described/shown in Vizard's book 'Tuning The 'A' Series' Camshaft Pt 2.
The magnets in that case were fixed to aluminium tubes. Vizard did it with the head in place.
I have to say - not a job for the inexperienced.

Whilst you can work out if you have the original 1275cc Midget camshaft or not, you really do need one if not two dial gauges as well as the cam protractor to compare the cam profile/specification with the 1275cc Midget camshaft profile/specification which is given in the Vizard book.

Below is a photo of checking the cam setting/cam profile.
Even with the engine out not an easy job.

[moggymaniac]

To come back to an old post...

fitting a 123 distributor solved running issues, and while it cost an arm and a leg it idles and drives so much better.

I have now got round to taking the timing chain cover off and can see the "nose" of the camshaft is marked with a 7. Can anyone shed any light on this? Would be nice to know what cam I have In the car without takin the engine and cam out.