Setting ideal timing

[collins_dan]

Thanks for that information. I checked ignition timing this AM. At 1000 revs it was 14, 2000 = 21, 3000 = 31 and 4000 = 33. It was probably getting to 33 much lower than 4000, maybe 3300. If the L2 cams are supposed to be set at 102, instead of 110 for standard cams, would I reduce the static setting number by 8, making it 1, then add 1 to these numbers? It does seem to get to max advance very quickly compared to the numbers mentioned by Rohan and the manual. Thanks, Dan

[rgh0]

The cam maximum opening timing is determined primarily by cam duration with longer duration cams requiring a lower degrees after TDC max opening point. It does not relate to ignition timing in any systematic simple way.

Your ignition curve is advancing more rapidly than the original one which does not hurt as the standard curves are conservative as has been said previously. This may have been a deliberate modification or just stretched / weak / worn springs with age and use. Typical race twin cam ignition timing curves with high compression and long duration cams look something like your curve with maximum advance being achieved by the 3000 to 4000 rpm range and maximum advance around 28 to 33 degree depending on fuel and cam and head porting details so it may have been a deliberate mod when the L2 cams were installed and the emissions gear removed.

If you are not getting any pinging then it is probably OK as it is. The alternative is to put the car on a dyno to determine what the best advance curve is for your specific setup.

cheers
Rohan

[m750rider]

Dan

I am running sprint cams in a modified stage II head from Dave Bean. Your advance curve is very close to what I see on my car. I'd say you are dead on with ignition timing.

Bob

1969 S4 SE

[collins_dan]

Thanks all. Sounds like I need to look elsewhere. I think I will investigate the cartridge water pump and whether it is operating properly. Is there any kind of flow meter that can inserted into the cooling system to determine water flow? I drove the car yesterday and it was fine until I stopped at a light for 2 minutes, when the temperature climbed from 190F to 212F. Once moving it started to come back down. Thanks, Dan

[69S4]

On the Elan Factory website there is a pdf on testing water pump efficiency. It looks a bit involved but probably worth a look. Linky - http://www.elanfactory.com.au/technical_information.htm and scroll down

[saildrive2001]

Does anyone have detailed instructions on how to set the ingnition timing with a Petronix unit in a standard distributor. I know how to do it with the old points & a bulb but not with the Petronix. I want to get it close before I try to start the engine for the first time.

[UAB807F]

Does anyone have detailed instructions on how to set the ingnition timing with a Petronix unit in a standard distributor. I know how to do it with the old points & a bulb but not with the Petronix. I want to get it close before I try to start the engine for the first time.

I've got the Petronix set-up on mine. Although it's quite some time since I set it up I seem to remember all I did was to use a bulb just as you'd do with the points. I connected one lead to earth as usual, the other to the coil terminal that goes to the distributor. Turning the dizzy makes the light go on and off just as with points.

Brian

[UAB807F]

Thanks all. Sounds like I need to look elsewhere. I think I will investigate the cartridge water pump and whether it is operating properly. Is there any kind of flow meter that can inserted into the cooling system to determine water flow? I drove the car yesterday and it was fine until I stopped at a light for 2 minutes, when the temperature climbed from 190F to 212F. Once moving it started to come back down. Thanks, Dan

The standard pump is quite simple really, so unless it's worn with some movement at the pulley, or the fan belt is too slack, I can't think off hand how else it could become inefficient. When I replaced mine last winter it must have been at least 30yrs old and although the bearings were shot (the reason for changing) the impeller had virtually no significant corrosion on it.

But if you're looking elsewhere, how about the radiator ? If it works with airflow through it but not as soon as the airflow drops then it might be marginal; either external dirt reducing the efficiency or internal debris reducing the flow ?

If it is clear, then is it possible to either put in a higher efficiency core or a bigger radiator that simply gives you a greater volume of water in the system. The latter is very crude but a greater volume should mean a less volatile system and longer residence in the rad. for cooling & thus a lower exit temperature ?

Brian

[m750rider]

Dan

Are your fans coming on sitting in traffic once the temperature increases? They should be at those temperatures. Are they running the correct direction? Your description of the problem seems to indicate an air flow problem.

Have you closed off air passages around the radiator forcing air to go through the radiator instead of around it? Typical opening are under the radiator at the steering rack, above the radiator between it and the bonnet, and on both sides. Close these up - it will help.

It should be very easy to replace the water pump if it is a cartridge unit. I don't have one, still using the standard so I am just guessing, but that is the advantage of the cartridge pumps - you don't have to take the engine apart to repair them. Clearance between the impeller and housing is very important. Too much clearance and you lose capacity. Maybe the pump is not putting out as much flow as it should. I'd probably replace it with a new one.

I live in NC, and it can get pretty warm. I also drive in SC where 100 F is common. Even then, my car will run 87-90C except in traffic, it might get to 92 - 95C, but no higher. I do not run an electric fan, no need. I use the standard belt driven 4 blade fan.

However it used to run hotter and living here has made me work on it.

My keys to cooler running are:

1. Good condition water pump
2. Clean radiator, internal passages and external fins
3. Force all the airflow through the radiator by plugging bypasses

Regards

Bob

1969 S4 SE

[StressCraxx]

Hello Dan,

I agree with the others about air flow at low speeds. The later radiator is marginal at best even when new. The early metal blade fans were worthless and and heavy. The 8 blade plastic cortina fans are only slightly less worthless. They do not have enough extraction nor shrouding close to the rad to pull enough air through in traffic or sitting at the light.

The Stromberg Federal elans indeed ran hot to reduce HC and CO emissions.

I would recommend blocking off all of the areas between the radiator, bodywork and chassis. Particularly the chassis. The elan was originally furnished with some tar coated cardboard that sealed the bottom of the radiator from the chassis and ducted the air into the bottom of the rad.

Put a piece of 2" thick soft poly foam under the bonnet to seal the top rad tank to the bonnet.

Find the largest electric pusher fan you can fit with a thermostat control and set it to 80C at the top hose. Twink makes the most power at 170F/70C area.

If you dont like the electric fan, check out the Summit catalog and look at the plastic flex fans they sell.
http://www.summitracing.com/search/Brand/Flex-a-lite/Product-Line/Flex-a-lite-Nylon-Mechanical-Fans/?autoview=SKU

The 14" or 15" one should work depending on clearance and obstructions.

Space the plastic fan with spacers so it is about 3/4" from the rad core fins.

Drive and enjoy!

Best regards,
Dan Wise

[collins_dan]

Thanks for all the suggestions, unfortunately, I have implemented all of them to no avail. Larger radiator that is blocked all around... 2 electric fans... not running too lean or too advanced... My theory is the water pump is not installed correctly and therefore producing sub-optimal water flow, which is most apparent at idle. I plan to test the water flow using the methodology suggested on the Elan Factory website to confirm this, then remove radiator and pump to check its fit and overall performance (could also just be a bad one). I'll provide an update once I've conducted the test. Dan