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Timing Question
https://www.slantsix.org/forum/viewtopic.php?t=24913		 Page 1 of 1
Author:  Davey [ Fri Sep 14, 2007 4:23 pm ]
Post subject:  Timing Question
I believe my slant is a little retarded in time, and I think it'd start and run better if I advanced it a little. I have seen discussions in here about recurving a distributor, but am not up to it right now. If I just bumped the dizzy counter clockwise a couple of degrees, it would advance overall timing wouldn't it? I'm thinking I should be safe in doing this up until it just begins to ping, and then back it off a smidge. Does that plan soud OK? Davey
Author:  Aggressive Ted [ Sat Sep 15, 2007 1:17 pm ]
Post subject: 
Sounds like a plan, but I believe counter clockwise will reduce, clockwise will advance. I have mine at 20 degrees advance and it still doesn't ping! and am getting pretty good mileage for stop and go, town and about half of it freeway.

On the recurve it is pretty simple. I used a lighter spring than stock. For fun I am using the dreaded light drag racing spring that Summit lists (DCC-2932675) and Mr. Gasket sells at half the price (MRG-925B), and one heavy 1/8" longer looped spring from a big block distributor. I also rotated the spring peg on the stock 15R govenor to shorten the throw. The light spring comes in at 1500, which is nice because I have 2.76 gears. It has good initial punch and when I am cruising it stays advanced even though I am out of the throttle. In other words it coast more and doesn't immediately decelerate. It feels more like a sling shot when you get out of the throttle because the vacuum advance kicks in another 13 degrees.

Doctor Dodge has been coaching me on the recurve and I must say it is great if you want mileage. It is hard to be good though. It wants to rev and cruise at 70-75 mph. I am trying to keep it down to 2500 rpm and 60 mph. I can finally feel where the 1920 Holley is a little week. A 390 would probably fill that void right at 2000 rpm where it is working hard to get the weight moving.
Author:  68barracuda [ Sat Sep 15, 2007 8:55 pm ]
Post subject: 
OK insanley dumb question, but as a jnr. tuner maybe not

1 How do I recurve a distributor - (I picked up a ransdapt kit the otherday with 2 light springs - have not used them yet.

2 Why, and what is the influence?

Regards

Fanie
Author:  emsvitil [ Sat Sep 15, 2007 10:12 pm ]
Post subject: 
Quote:
OK insanley dumb question, but as a jnr. tuner maybe not

1 How do I recurve a distributor - (I picked up a ransdapt kit the otherday with 2 light springs - have not used them yet.

2 Why, and what is the influence?

Regards

Fanie

Here's the thread I started when I did it...........

http://www.slantsix.org/forum/viewtopic.php?t=13264
Author:  Aggressive Ted [ Sun Sep 16, 2007 4:35 pm ]
Post subject: 
Quote:
OK insanley dumb question, but as a jnr. tuner maybe not

1 How do I recurve a distributor - (I picked up a ransdapt kit the otherday with 2 light springs - have not used them yet.

2 Why, and what is the influence?
I will try to summarize.

First question: By replacing the advance springs, weights, modifing the govenor slots or vacuum cannister.

Second question: There are basically 3 different needs: mileage, racing and just keep it from pinging at the drop of a hat.

1. Mileage: The 1976 Feather Duster SL6 setup was able to get 30 miles per gallon. Wouldn't that be nice with today's prices. I drive 120 miles a day and every bit of fine tuning helps the mileage. I am at 23.3 to 24.5 miles per gallon at the moment. That is combined town, stop and go and freeway, about a (40/60) split. When I am done I hope to hit 28-30 miles per gallon.

2. Racing: You don't need 60 degrees of timing going down the race track. It will predetonate and eat plugs pistons, rings, etc. So folks will limit the advance from 15 to 30 degrees depending on their particular build.

3. Stock engines: When my 74 was stock it was the gutless wonder. It would ping with a load going up a steep grade. So it was necessary to reduce overall timing. That means add a stiffer spring or reduce the govenor slots and unscrew the vacuum canister a few turns....
Author:  68barracuda [ Tue Nov 20, 2007 1:36 pm ]
Post subject:  Update
Hey Ted followed your recipe it work like a charm slightly different ingredients

one of the light drag type transdapt spring, combinned with the std heavy long loop - this is on a electronic distributor

Same effect good lowend - read wheel chirping punch, (2.9 gears :cry: )
sling shot above 40 - it just goes like to use old Meat Loaf's song Like a Bat out Of Hell

Slight ping being observed - on part throttle - maybe vac is ading to much will dial it out slightly

The sound of this engine is phenominal - specially when the vac secondaries open up
Author:  SlantSixDan [ Tue Nov 20, 2007 1:47 pm ]
Post subject: 
Quote:
Sounds like a plan, but I believe counter clockwise will reduce, clockwise will advance.
No, other way round. Turn the distributor counterclockwise to advance, clockwise to retard.
Author:  68barracuda [ Tue Nov 20, 2007 1:57 pm ]
Post subject: 
Quote:
Quote:
Sounds like a plan, but I believe counter clockwise will reduce, clockwise will advance.
No, other way round. Turn the distributor counterclockwise to advance, clockwise to retard.
Ditto

listen to the man with the 10000 posts :bow:

Just razzing you Dan - with my playing around I started using a adjuster plate with longer slots - any idea where that come from? = allows more advance and retard adjustment :?:
Author:  Aggressive Ted [ Tue Nov 20, 2007 5:32 pm ]
Post subject:  Fine tuning the distributor recurve
Dan,

Well what can I say, I had a momentary brain lapse at the keyboard, but not at the car........

68barracuda,

In the past month I installed a red medium MOPAR spring instead of the light drag racing spring and left the long looped 400 big block spring. I was having a little too much fun. I need to conserve on the tires. It just dumps too quick for the P235 60 14" rear tires.

I rotated the end pin around so the medium MOPAR red spring has zero slop and it is punchier yet.! :D It has some extra midrange punch to go along with the initial hit. I think it may even be more fun to drive now.....

I also had to back off on the initial timing to 16 degrees from 20. 20 is fun and the mileage is better, but I was getting a slight surge when I backed off on the throttle at cruise. It also had a slight mis when I slowly revved it up in the yard. The 11R vacuum can was just over advancing a little too far. The odd thing was there was no audible ping.

So it is possible to sneak passed 60 degrees of timing with the electronic distributor with the 15R govenor and a 11R vacuum can with the long looped big block spring. :)

The fine tuning sure brings out some interesting results that I didn't think the engine had in it. I can hardly wait to try a 4 barrel!
Author:  68barracuda [ Tue Nov 20, 2007 10:59 pm ]
Post subject: 
Quote:
The fine tuning sure brings out some interesting results that I didn't think the engine had in it. I can hardly wait to try a 4 barrel!
Yup I am running a 465 4150 holley setup with the recommendations from the slant racing manual quite nice
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