25 replies to this topic

[ACDodd]

I don't agree with the suggestions here that the available curves don't suit the ASeries. Most are based on my own curves which I supplied many years ago.
Curve 6 is a good start for a road based a series with typical road cams.

Sometime due to slack in the engine timing chain etc the engine can be short on timing, curve A and d can be useful.

Timing is a easy. Simply disconnect th vacuum and set to 10°btdc at 900rpm. Reconnect the vacuum and drive. Fine tuning is best achieved on a dyno.

Ac

Edited by ACDodd, 07 July 2020 - 02:02 PM.

[DamoMini]

Hi Damomini, cheers man for the help! I'd like to ask you all a question. There is something that strikes me, and perhaps it may have some importance to get from the engine all its full potential and to leave the Distributor well adjusted.

When I disconnect the vacuum tube coming from the dizzy and entering the side of one of the carburettors, the idle does not rise, the engine does not accelerate, and there is no change or alteration. When I had mounted the Hif44, disconnecting that tube you felt an alteration or change. Now with Twin Hs2 nothing happens. I have both carburettors connected by a rubber tube.

Do you think this is ok?

On the HS carb I don’t think this is a problem because the vacuum port is behind the throttle plate and at idle there is no vacuum in this line. I have a single HS4 and when I disconnect this line there is no change to the idle, same as yours.

On the Hif44 I thought I read that the vacuum connection is on the manifold side which means a lot of vacuum at idle so when you disconnect air enters the manifold and the vac advance changes so the idle will change.

[PACINO]

Thanks to DamoMini and ACDodd! Anyone else who has Twin Hs2 on the 1275 A-series engine and would like to give their opinion when disconnecting the vacuum tube would be appreciated.

Regards, Luis

[PACINO]

What about this one? With advance. I think it seems enought for the Mini.

[Spider]

Thanks to DamoMini and ACDodd! Anyone else who has Twin Hs2 on the 1275 A-series engine and would like to give their opinion when disconnecting the vacuum tube would be appreciated.

Regards, Luis

 

The revs won't rise with a HS2 or HS4 when the Vacuum Advance tube is disconnected. Where that port is the Vacuum is essentially 'switched off' when at idle and comes on gradually as the throttle is opened.

The Port on the HIF Series (it seems most or all) is in a slightly different location and has full (or close to) Manifold Vacuum to it all the time.

[PACINO]

Thanks a lot Moke!!

And now one last question because I don't want to bore anyone unnecessarily. There is something I'm not clear. If we talk about adjusting the ignition to 10 degrees BEFORE top death center (BTDC) and taking into account that the Mini's rotor rotates 'anticlockwise' where should the mark go?

I understand it here:



Yes or not

[DamoMini]

The mini motor turns clockwise in the picture.

Turn the motor clockwise until you find the TDC mark on your flywheel (clutch side of the engine)

Now the notch on the pulley also shows where TDC is so place a mark on the timing cover that aligns with this.

Set your timing light to 10 degrees advance. At idle, if the mark on the pulley and the mark on the timing cover are lined up, you are at 10 degrees BTDC.

It’s normally easier than this but because you haven’t got a timing scale attached to the timing cover it takes a little more work.

[PACINO]

Thanks DamoMini! Surely it's my fault, because you explain yourself great, and I really appreciate your help. And although my car does not have that scale, if it did, where would it be 10 degrees before the top dead center, blue arrow or green arrow?



Regards, Luis

[DamoMini]

Green arrow.

[gazza82]

Reverse your red arrow to match the engine rotation, then that notch in the pulley (at 0 in picture) would be passing the pointers when the strobe fires ... ie BTDC or before top dead centre ...

[PACINO]

That's true. You're right. I've been checking a manual, and the crankshaft pulley rotates clockwise direction.


Now I understand everything. So, thank you very much to everyone, specially to DamoMini by his patience and for so clear explanations.

Regards, Luis