200ci Duraspark & HEI - What initial Advance

[salty_monk]

My manual only lists a 144ci 6BTC or a 170ci as 8BTC.

What should I run on this engine? It's a 67 block with a 69 head I believe.

I realise some will depend on the individual engine, I do not know if it has a decked block or skimmed head. Just looking for a starting point.
At a guess 8BTC?

Also where do I pull vacuum from? Manifold I presume as the carb port will give me Venturi vacuum at high load/speed so too much advance...

Cheers,

Dan

 

[CZLN6]

Howdy Dan:

Standard trans- 6 degrees BTC.
Auto trans- 12 degrees BTC.

On the vacuum, the question is what carb & distributor are you using.
'67 and earlier Load-O-matic distributor requires an Autolte 1100 carb with a Spark Control Valve to send a specific vacuum signal to the distributor.

For a '68 & '69, this distributor uses both centrifugal and vacuum advance as requires a ported vacuum signal for proper distributor advance. This is also true of 66 & 67 Calif Emissions equiped engines.

So, What carb and distributor are you using?

Adios, David

 

[CoupeBoy]

So, What carb and distributor are you using?

David, the thread title says he is using a Duraspark distributor. I thought that all Duraspark distributors ran off manifold vacuum completely independent of which carburator was used?

-ron

 

[fordconvert]

6* should be safe to start. I read many people that are running in the 12* range. A lot depend on what the curve and total advance is in the dizzy. The rebuilts tend to be all over the map. Some of the GM ones can have as much as 20* in the vacuum. Not much quality control and a lot of one size fits all now days.

Most people (me included) get very good results from running off a manifold vacuum source. The SCV port (if you have one) does not tend to work well. If you have a typical 'ported' vacuum port they tend to be about the same as manifold at all positions but idle. Some of the cars had a thermal switch that would switch them between ported and manifold vac depending on coolant temp. More advance at idle tends to make for a smoother and cooler idle, less is better for emissions.

 

[flash_point01]

After considering the SCV issues you may or may not be having start with safe 6* then tune it using a vacuum gauge. Remember to disconnect the vacuum advance to the distributor and plug the line. Connect a vac guage to a manifold source and turn the dizzy to the highest steady vac reading and then back off 1-2 inhg then take a drive and see how that works. I have my 200 auto set at 14* Initial at 18ingh. After you set it take it for a test run and listen for ping. If you get any back off another degree or two.

 

[grocery getter]

manifold vacuum worked best for mine.
as for the advance, i've found there is no set number. after 40 years and a few rebuilds, these engines will respond different to the advance. I like to start at 10 degress and work from there.

flashpoint has a nice method 8)

 

[salty_monk]

I'm just about to bite the bullet & fit this. My current loadamatic setup is running at 8*. When I got the car it was running at 10* but seems happier at 8*.

I have a holley carb (single barrel) with the spark port but have also bought an Autolite 1100 which should also fit.

I have a port on the manifold for vacuum (currently runs the wipers, not that I ever need them here in Redondo Beach).

When you guys use manifold Vacuum, do you put any restrictors in? My thoughts were to get a T piece & T into the line that is there but try to get one with a small 1/8" or 1/4" take-off to run to the dizzy.

I've also just got a disk brake setup coming with a servo operated master cylinder, not sure if I'm going to run this yet, I may pick up a dual circuit master cylinder & just leave the servo/booster off.
If I do run the one with the Servo will this cause any issues again? Seems to be a lot of sources running off manifold vacuum, I don't want ignition problems when I hit the brakes or turn the wipers on for example.....

Cheers,

Dan

 

[Harte3]

flash_point01's method is a tried and true one that has been around for decades and is an excellent starting point. I used it for years until obtaining a timing light...should have saved my money...I hardly ever use the timing light.

 

[CZLN6]

Howdy Dan and All:

I'm confused. Do you have a Load-O-Matic distributor or a DS II?

THe numbers I listed are stock specs for a '65/'66 200. That's where I start tuning. I almost never end up there. I use a vacuum guage as well as a timing light to fine tune both initial advance, low speed air screw and curb idle.

If I read you right (?) you are currently using a Holley side bowl carb with a SCV and a Load-O-Matic distributor. Is that correct?

Which Holley 1 barrel are you using?

What Autolite did you buy?

Do you have a vacuum guage?

Do you have a timing light?

Flashpoint makes a good point in assessing a tuneup. Tuning at an idle is only part way there. Driving is the real test.

Zero us in on what you are currently working on. Then to the rest.

Adios, David

 

[fordconvert]

My car has a 3/8 steel line coming off the log that originally went to the transmission. It now has a t in it to go to the brake booster and the dizzy. Didnt notice any changes in performance with all the additions, if anything its better. Brake boosters dont consume much vacuum. Even if they did how often do you care if your timing changes while using the brakes? The brake booster should have a check valve in it. All that stuff may dampen things a bit but it seems to be working for me.

 

[salty_monk]

I currently have a Holley 1909 unit I believe http://www.carburetorfactory.com/expvw12.html on a 200Ci with a 67 5 bearing block & 69 head. Using a loadamatic dizzy with point.

I am about to switch to DSII & GM Module setup with an E coil.

I have bought a rebuilt 1100 off of a 250 that someone on here had running on a 200.

http://www.carburetorfactory.com/expvw06.html

By the way, anyone know what the thread size is for the screw in fuel filter? I think it's part number 15 in that exploded. I will try to take some pics later today of both carbs to post.

Dan

 

[salty_monk]

Carb pics.... First the Holley:






Then the Autolite:






Last pic shows the thread that I would like to know sizes on.

Thanks again,

Dan

 

[fordconvert]

I believe the fuel inlet is a 'regular' thread and seals with a washer. Many of them came with an adapter to adapt to the pipe thread of the filter which had a pipe nipple on it to go to the steel line.

 

[salty_monk]

Ok thanks, I'll take it to the hardware store & see what I can come up with for it

 

[salty_monk]

Well finished the install, apart from Vac advance, just plugged the metal line on the holley coming from the spark port for now....

Started off around 7* advance (about where it ended up when I first put it in) & took her for a test drive. Loads better than before with the loadamatic....

Came back checked idle was 600, set to 10*, wow, even better. I have no Vac gauge (guess I could get one) but a very clever timing light with RPM, voltage, Dial back etc on it.

Using the dial back facility I can see that the advance curve on the Duraspark is currently giving me about 32 degrees full advance all in at about 4k rpm.

Anyone think I can get away with running a little more initial? I'm guessing not without doing the switch out with the springs & bending the post to limit it a little.

By the way, what does Ping really sound like, I'm never sure on that one... How noticeable is it? People have told me it sounds like broken glass being poured down the heater vents??

Dan

 

[Harte3]

Ping, rattle,, knock, etc.,...usually on acceleration. Sounds something like a VW diesel Rabbit when it's really bad.

 

[JackFish]

If you really want to know, you can rotate the dizzy at idle until in pings.
A couple of seconds ought to ingrain the sound in your mind.

 

[salty_monk]

I don't have anything like that.... even with 90 something temps here today & regular gas (I am using a lead substitute though).

Maybe I'll think about trying 12 or 14 & taking it for a drive to see what happens but for right now I'm pretty happy with performance where i'm at.