Idle quality on 200 inch six

JAGGUY

Active member
I picked up a 6 cyl Mustang a few weeks ago. First Falcon 6 I have owned in 20 years....
I have it running really well, but I can't get a really smooth idle yet. It idles OK, but shouldn't I be able to get "balance a nickle" on the air cleaner smooth from it?

Still using points, all ignition parts new, distributor rebuilt. Both Autolite 1100 carb and distributor are Load-o Matic style. Timed with a vacuum gauge and a light. Compression 160 straight across ... Carb clean and responds to the idle mix screw. No vacuum leaks.
Oh, automatic trans.

Balancer not new but TDC lines up with piston TDC and it doesn't wobble at all...

Kind of wondering if the motor mounts could be so old and hard that it is transmitting vibration to the rest of the car?

Or, does this old engine just not idle that smooth?
I have a '56 Jag with an inline six that will idle dead smooth @ 500 rpm all day long...

Thanks for your time and thoughts.

-greg
 
The motor mounts are worth a try, but I would think with an engine that is almost 50 years old and has a lot of unknown qualities (if it was rebuilt, quality of rebuild, etc) that it would be hard to expect to balance a nickel on the air cleaner.
If everything is running smoothly I'm not sure I would mess with it.
 
Asa's right. Unless you know the age of the internals of the engine, it's tough to say one thing or the other. Generally yes, they are pretty smooth engines at idle when dialed in. Motor mounts are a pretty easy culprit to fix, and if they are looking worn, worth replacing anyways.

On your jag, did you have the engine rebuilt?
 
You are both correct, the 200 has been apart but who knows how many times or what has been done! I will keep playing with it. Kind of fun playing with such a simple engine.

As far as the Jag goes, it was rebuilt in 1967 and hasn't been apart since. But it only has about 15k on the rebuild.....

This is what it looks like...

P2280001.jpg
 
"...a '56 Jag..."

Holly *^!+.
THAT wuz when the Brits were @ the top
of their game (Vincent motorbikes...).
Now U know Y I luv pic!

simple stuff like fuel filters (2 at least)
ign. parts (it's all pretty simple on these).
Keep talkin...
 
I'd like to know which end of the rainbow you found a Jag that didn't need reassembly since 1967.

My boss had one like that and it was a major repair at every stinkin' ride.

F***in' awesome.
 
ludwig":1ek2z2r4 said:
I'd like to know which end of the rainbow you found a Jag that didn't need reassembly since 1967.

My boss had one like that and it was a major repair at every stinkin' ride.

F***in' awesome.

That's too bad that you have that impression.
British cars, like any other vintage car are as good as the care they have received. Unfortunately after 10 or so years on the road people bought them because they were cheap and in need of deferred maintenance and repairs. Quality work on foreign cars has never been cheap so a lot of ham-fisted mechanics got them and made a lot of shortcuts in working on them. Then it's down hill from there.....

In the last 45 years I've owned 8 Jags, the newest was a '65. They were all as reliable as any Ford I have owned. Much more so than what Ford built in the 80's!
Actually with all the MG's, Healey's and Jags I have owned I've never really had any more issues with "the prince of darkness" Lucas electrical system than any other car I've owned.
The current Mustang I have has more electrical gremlins than any car I've owned!

Engine wise, the Jag DOHC six has to be one of the most reliable engines ever made, thus it was in production for over 40 years. It's also a very simple engine to work on so long as it's pre-emissions.

Anyway, the 140 above my Dad bought new in 1957. We restored it together in 1972 - 74.
He gave it to me just before he died and I suppose I'll have it the rest of my life too.

Ramble mode off ;-)
-greg
 
Very cool. Congratulations.

Boss had a ground up professional restoration. I don't know what more to say.
 
JAGGUY":2p52eb60 said:
ludwig":2p52eb60 said:
I'd like to know which end of the rainbow you found a Jag that didn't need reassembly since 1967.

My boss had one like that and it was a major repair at every stinkin' ride.

F***in' awesome.

That's too bad that you have that impression.
British cars, like any other vintage car are as good as the care they have received. Unfortunately after 10 or so years on the road people bought them because they were cheap and in need of deferred maintenance and repairs. Quality work on foreign cars has never been cheap so a lot of ham-fisted mechanics got them and made a lot of shortcuts in working on them. Then it's down hill from there.....

In the last 45 years I've owned 8 Jags, the newest was a '65. They were all as reliable as any Ford I have owned. Much more so than what Ford built in the 80's!
Actually with all the MG's, Healey's and Jags I have owned I've never really had any more issues with "the prince of darkness" Lucas electrical system than any other car I've owned.
The current Mustang I have has more electrical gremlins than any car I've owned!

Engine wise, the Jag DOHC six has to be one of the most reliable engines ever made, thus it was in production for over 40 years. It's also a very simple engine to work on so long as it's pre-emissions.

Anyway, the 140 above my Dad bought new in 1957. We restored it together in 1972 - 74.
He gave it to me just before he died and I suppose I'll have it the rest of my life too.

Ramble mode off ;-)
-greg
Chuck, the former Marine that taught me wrenching let me cut my teeth on Jags, as well as other British and Italian exotics. I used to point to grease on my hat and say "there's a Rolls, Ferrari, this smudge is a Maseratti."
He had (I think) a '55 XK120. I have a picture somewhere.

I miss workin on 'em sometimes.
 
Last month I almost picked up a 64 Jag at a price that was too good. But alas, with everything going on at home, I can't justify another project right now as my mustang has come to a grinding halt due to lack of time as it is.

Beautiful car.
 
Anyway, back to the Ford six..... You'll see a marked improvement in idle quality if you improve the ignition. On every one of these engines I've worked on that still had points, I've noticed a tendency to give you an irregular misfire that translates into a shudder at idle. At higher speeds this probably still occurs randomly but it's masked by the rpm. With a better spark, this effect largely goes away and the idle will be noticeably smoother and you should see an improvement in power and economy.

Look into an electronic conversion. I think you'll be surprised.
 
I think that means one of about 4 choices:
* there's Petronix
/OR/
* DuraSpark I (or ) DuraSpark II

* the DUI (a 3rd) is kinda pricey but more complete (integrats more components)
and lastly (I believe) is the GM sm 2 pin module with the ford TFI

I have seen build threads on this and other sites (some include schematics) on each one of these choices. Each seems to have equally committed advocates. I'll try the dura spark - " DSII. " 8)

I may have much of that incorrect but got the conversation continued...
 
I've thought about changing over to electronic ignition but haven't done it yet. I really like the simplicity of points and don't drive enough to worry about needing to replace/adjust points very often.
Also I don't want to change the L-O-M carburetor to work with another distributor. So that would mean using a Pertronix which I have read some have had good luck with but more seem to say to stay away.....

I greatly appreciate the input

-greg
 
For my 2 bits, the electronic conversion is a great thing even if you don't drive it regularly. Just the ease of starting alone makes it worth it.
 
I used to have a '71 MGB - like everybody else, we traded it in for children....sigh...it was a good car, lots of fun...

LOTS of options for ignition upgrades, no need to get rid of the current carburetor!

You can:
* Keep the LOM carb and distributor and go to something like a Pertronix (Im leery of them as well) or an MSD box (mine made me a BIG fan of theirs, btw)
* Keep the LOM carb and swap to a Ford DS1 distributor that triggers either a GM HEI (standard 4-pin), a Ford DS box, an MSD, or just about any other electronic box. Just plug the carb's LOM port and run the distributor vacuum to the manifold.

Apart from getting away from points, the other BIG gain from getting rid of the LOM distributor is that the ignition curve on a "modern" dizzy is not only better than the LOM-type curve (you can get way more advance on the highway), it's way easier to modify.
 
per-form-ance! dude!
(economy, mods, starting, maintenance...)
8^0
 
Pertronix has given me no problem whatsoever. The car starts almost immediately and there is a noticeable increase in power because the spark is larger and more reliable. Mechanical ignition can have up to 15% misfires. No misfires with electronic. It burns all the gas. That is where the extra power comes from. If you go electronic, you will a have to set the idle back because it really runs well.
 
JAGGUY did you ever get your 200 too run any smother? I understand that you wanted to stay with points, they will work just fine for all stock car. Do you set your points with a tach / dwell meter? If not you will need too, then get it to run the smoothest that it can. This is the tuning order I have used for many years.

1. Set point dwell
2. Set timing for SoCal area I start at stock or 2 degrees advanced
3. Check or reset carb choke setting to factory spec. set cold idle rpm and then see if it opens fully when warmed up
4. Set idle high RPM speed (with choke linkage on high point index) to factory spec.
5. Set carb needle mixture to best RPM than lean it 1/2 turn
6. Reset Idle RPM. If you want on a used engine they can be set 50 to 75 rpm lower than a new tight engine.

When everything set correctly a warm engine will start without even touching the gas and very little cranking. Good luck
 
Hey bubba22349, thanks for asking.

I've have pretty much followed your list and it idles pretty good in gear. I bumped the hot idle to around 700 and it's a little smoother.

One thing I did was to side gap the plugs like in the old days and that smoothed it out some too.
However, a couple weeks ago the weather here got into the 80's and the old six really liked that. Idled smoother than it had before.

I do have to say the drive-ability on the road is really excellent, throttle response and acceleration are surprising for an old bomb with a six banger....And starts up instantly unless it's hot and has been sitting a short time. But even then it starts in a couple seconds if I hold the throttle half open.

-greg
 
Excellent glad you have some improvement, will toss a couple more things out. Have you checked the coil output? The coil wire to cap tower, spark should be a nice bright blue and be able to jump a 1/4 to 1/2 inch, same test on the plug wires. Have you looked inside the carb yet? On the hot restart a couple possible checks would be leaking economizer valve or it's gasket or a slightly high float level. Not as common but have had some carbs where they had pitted (from water damage) in fuel bowls (pin hole) allowing the fuel to leak out. Though it sounds like you have the tune very close, good luck
 
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