40 replies to this topic

[PACINO]

Yes... I know it's a topic already talked, and I myself was clear about it, but after reading one and the other, I'm already starting to doubt.
On Monday I leave the car in a new garage. We must correct the things that were unfavorable in the M.O.T. but above all solve the overheating.
by steps:
- Adjust the mixture as it is still a little high.
- Set up the electronic distributor. After rereading several threads, I'm doubting. The correct is to put cylinder number 1 at "top dead center" or 10° before top dead center?
I think I know the rest; Vacuum tube disconnected. Engine at 1500rpm. Rotate the distributor until the mark on the crankshaft pulley coincides with the first line on the scale on the timing cover.

Thanks in advance!

[68+86auto]

As long as the engine starts you don't need to do the first stuff you mention about rotating the engine to TDC or 10 degrees. That's only if the distributor is being reinstalled to get a basic setting to start it.

Using a basic timing light you use the marks as you've described but it is NOT the first mark that you want. You need to work out how many degrees you need and work out which point that is on the scale. If you have a "dial back" or "advance" timing light then you set it to the desired degrees and then line up the pulley and scale to the first mark.

Once you've done the timing at 1500rpm, then do it at higher and lower rpms to verify that the advance is working correctly.

[PACINO]

"You need to work out how many degrees you need and work out which point that is on the scale".

Thank you very much friend. You're very kind like always.
But then, the question is;How many degrees should I set this engine (1310cc) to then calculate it on the scale?


Cheers
Luis

[Ethel]

My Guess would be around 7-8 degrees at 1000rpm (no vac). That's the 3rd "peak". The scale is 2 degrees from peak to valley.

 

It is a guess if the engine's modified - main factors are fuel grade & compression ratio. Cams with longer valve opening lower the effective compression ratio at lower RPM.

[PACINO]

Thank you very much Ethel. You've been one of the few brave people who have dared to answer.

This Forum reminds me more and more of the Spanish classic Mini Forum. 16 years ago you would go in there any Friday afternoon there could be 30 or 40 people interacting, people would chime in with their answers and it was very fun and you coul learn or teach to others. Today that place is DEAD. I hope the same thing doesn't happen here.

Regards !

[68+86auto]

Unfortunately there's no simple answer for what to set it at especially with a modified engine. Even with a factory spec engine and distributor the values can be quite different depending on manifold or ported vacuum and compression ratios etc. Without knowing the centrifugal and vacuum advance details of the specific distributor there's no way to say what you should set it at. Even then the distributor should be recurved to suit the engine based on dyno results, at a minimum a guess and modification on a distributor machine.

 

If it has manifold vacuum the timing may be close to TDC depending on the diaphragm.

[PACINO]

Thank you so much 68+86auto! The truth is that I believe that the distributor is already very, very close to the right point.The car starts very good, the idle speed does not exceed 1000rpm and it seems to accelerate well. The problem? The engine is just rebuilt to go out on the road and test it thoroughly.

When the weather is hot, the engine reaches 100 degrees very quickly. For that reason I want to regulate the gasoline mixture and leave the diszzy as good as possible. Once this is done, I'm going to fit these two items that have already arrived to me:

-Radiator two super core like the old rally Minis had. -Electric fan, so that if the temperature reaches 85 degrees with lot traffic in the city on a hot day. It automatically switches on to cool down.





Kind regards!
Luis

[68+86auto]

The timing can be far out and still run "fine" but generate heaps of heat. There's only one way to know what it's doing and that is to test it with a timing light throughout the RPM range. The best thing to do is to test the distributor on a distributor machine first so that an accurate test can be done. If that's not an option then you'll have to test it in the engine.

I've seen someone spend heaps of time and money on cooling system fixes at the recommendation of others. The problem ended up being what I'd said all along - a faulty distributor causing bad timing.

 

What is the model and specification code of the distributor?

[PACINO]

Hi 68+86auto! Thanks for your help. The car is now in the new garage to solve the problems to obtain the M.O.T. They'll try to know why it gets so hot when the car drives on hot days but I highly doubt they know how to adjust a distributor. (the thermostat 74º is new)

I use a 123Ignition without USB for 6 years. The car starts very well.

[68+86auto]

That distributor makes it easier to do the timing. It's not necessary to test the curve since it is known. What it does mean though from what I've read is that the curve will likely be poor if it's the one without an adjustable curve. What's the carb?

 

It shouldn't be necessary to run a 74 degree thermostat, 74 degrees was chosen for leaded fuels.

 

If you can get the emissions test result values it will help a lot with diagnostics. That means the CO and HC values but all four/five gasses would help.

Edited by 68+86auto, 07 August 2024 - 12:19 AM.

[PACINO]

Hi 68+86out! The carb is a S.u Twin Hs2. Yes, thermostat is the original 74º. Could you imagine to fit one opening in 82º . with this hot issue? The engine'd take more temperature before starting to cool. I think 82º or 88º is good for winter weather.

Cheers
Luis

[Earwax]

Hi PACINO

 

I had a 1310 with a CSI distributor ( preset one of 16 curves ) and i have played with that older version 123.   One version of the old 123 manual had asked to start setting at 10 degrees BTDC but i seem to recall static setting at 0 also .... sorry cannot remember which .... but I also recall my thinking that many of the 123 curves were too retarded  for 1275 ( and the CSI ones also). In the end the Group of 4 curves that i thought were best matched to the motor were the ones with 

 

Start at approx 10 degrees until before 2000rpm

         sharp advance to 20 - 24 degrees by 3000rpm

         and further advance until topping at 28- 30 degrees ( some were still slowly advancing up until 5000 rpm)

 

If you can POST the curves charts and others can have an opinion, but it important to check and know the current curve ( as per 68 auto advice)

 

I don't know MOT, but a lot of curves on mini dizzy are a bit too slow rising after 1300-1500rpm, and this may lead to unburnt fuel in that section of the curve.

 

and on that only slightly worked 1310 motor I could run twin HS4's - and could tune with a variety of needles including original 3s and finally 6s,  Also ran a single HS6 (bespoke needle) and even a DCOE with small chokes for a track day or two

 

It is important to know your curve

[68+86auto]

Hi 68+86out! The carb is a S.u Twin Hs2. Yes, thermostat is the original 74º. Could you imagine to fit one opening in 82º . with this hot issue? The engine'd take more temperature before starting to cool. I think 82º or 88º is good for winter weather.

Cheers
Luis

 

With a correctly functioning engine there should be no issue running a hotter thermostat, I run the hotter ones here in Australia. Anyway it's not likely your issue for now. You need to check the timing.

[GraemeC]

What’s the perceived advantage of running a hotter thermostat?

[sonscar]

I think that there is a lot of misconceptions about thermostats.If you are overheating then the thermostat value has no effect.Hotter thermostats were used in colder weather to help the engine run hotter before introducing the radiator.If you had masses of cooling which could reduce the water temperature below the stat value then it would have some effect,unlikely in a mini.The restriction value of the stat is more important.
This is my understanding and could easily be incorrect and I will embrace education if so.Steve..