AC Owners Club Forum

AC Owners Club Forum => Vintage, PVT & 2 Litre Forum => Topic started by: Big col on July 11, 2020, 23:01:51

Title: Cold running advice
Post by: Big col on July 11, 2020, 23:01:51

Hello Folks,
I am seeking advice on warming up the engine to running temperature.
I have recently had my engine rebuilt and rebuilt the carburettors. I decided to fit a later distributor that I had refurbished by the Distributor Doctor. The reason was to try and eliminate the need for the advance/retard operation.
I am currently having difficulty in getting the car to idle until it has warmed up. If I keep the throttle depressed and the revs on then it will warm up nicely. However no matter what I do with the choke I can’t get the engine to keep running unless  I use the throttle. The hand throttle is not connected at present.
The obvious questions are, do I need to connect the hand throttle and is that why the cars originally have one.
Is the car in need of a hand advance/retard to aid cold running.
Is the timing best advanced or retarded for slow running.
The car start with ease and runs really well when it reaches running temperature.

Title: Re: Cold running advice
Post by: GSouthee on July 13, 2020, 13:05:58

Hi Colin

Is the choke the thermo one or manual, if manual, the choke should open the throttle a small amount until warm and you return the choke.

Gary

Title: Re: Cold running advice
Post by: Big col on July 13, 2020, 21:11:48

It’s a manual choke. 1935 SU - HF 1 1/8 inch, (I think but I don’t have the info to hand just now). The original linkages for throttle, choke and hand throttle were reworked with the hand throttle being emitted. That is the reason for asking, has the hand throttle foolishly been forgotten when in fact it is required and needs reapplying. To the best of my knowledge the choke doesn’t open the throttle at present. You may have answered the question Gary.

Title: Re: Cold running advice
Post by: administrator on July 14, 2020, 08:59:34

I don't have a choke fitted to mine.  The starting procedure is to flood the carbs on the tickler pins, retard the ignition (manual advance/retard), start and advance the ignition as soon as it has fired.  What was the choke knob is set up as a hand throttle so I can set a 'fast idle' as it warms up and then slacken it off when it is warm.  The idle will not be good unless the carbs are balanced using an air flow meter.

Title: Re: Cold running advice
Post by: GSouthee on July 14, 2020, 12:37:50

Hi Colin

The su are simple to set up using the hose to ear technique, just listen to the hiss and aim for smooth idle, once warmed up of course.

G

Title: Re: Cold running advice
Post by: Big col on July 14, 2020, 22:12:21

Thank you Admin. That has helped to confirm my train of thought. I will reinstate the hand throttle.
As regards tuning the carbs, yes straight forward. I have a very useful SU manual which I picked up a number of years ago in my Daimler days. It lists the various types and how to strip, refurbish, rebuild and set up single or multiple mountings. If anyone needs this sort of information though it can be easily found on the web.
Thanks again, a hand throttle is another for the to do list.

Title: Re: Cold running advice
Post by: galfredus on August 17, 2020, 21:16:02

Hello Big Col,
On an unrelated matter...are you keeping your manual distributor? I need one for my car. If you would be up for selling it, please let me know.

Title: Re: Cold running advice
Post by: Big col on August 17, 2020, 22:35:21

I would like to retain it for now. That said let me have a look in my bits box. I collected a few bits and bobs but can’t just remember what.

Title: Re: Cold running advice
Post by: Big col on August 18, 2020, 20:51:12

GalFredus, I do apologise but I have not had chance to look today. I will try tomorrow afternoon or Thursday morning.

Title: Re: Cold running advice
Post by: Big col on August 20, 2020, 09:54:30

GalFredus, I have sent a message via the forum.