DIY, DSII recurve kit???

okay, I know how to swap springs and weights, and adjust the vacuum canister...

a few questions about the DSII, I'm new to DSII and dont' know much about it.

is there an adjustable vacuum canister?
what's best for economy? ported vacuum or manifold vacuum? (probably ported from a 350cfm carb?)
which spring/weight kit can I get that will work?? and which springs?

if anyone knows about the DSII and it's best curve for our 200's let me know thanks!!

this is going in the mustang I have for sale.

Yes there are different canisters that are adjustable , they will have a hex shape ( Flats ) on them , I recommend Ported Vacuum for all Vac Advances , lots of opinions , BUT I been re-curving for 25+ years and have NEVER used Manifold as a source , whats the best curve , they are all different , no one fits all deal ( sorry ) the Mrg 925D is a spring kit I use ( among others )

I also have a sun distributor machine & have been recurving distributors for 45 years & depending whether to use ported or manifold vacuum depends on many engine componets mostly camshaft.
I use manifold vacuum if you get a higher idle speed & smoother idle mostly on engines with more camshaft duration.
Sometimes i only use a modified vacuum chamber for small amount of vacuum advance.
One can also adjust the range of vacuum with a hex wrench.
Normally an engine with a stock camshaft will work better with ported vacuum.
The canisters i usually use are a V-397 or a V-398. You can do a cross reference for those #'s for different manufacturers.
On certain engines i do not use any vacuum advance.
Every engine combination is different.
I you purchase a reman distributor from a parts house it defenitely needs to be re-curved. Also need to get a decent gear installed which is at least parkerized or better yet purchase one of my custom nitrided & parkerized gears.
Stock gears are 27 in hardness where mine are 40+ hardness on the rockwell C scale.
If interested see my ad in the small six parts on this forum.
I only have 2 left from the last batch.
I also have 1 crow cams gear from australia but i want $100.00 for that gem. PM me if interested.
MPG best of luck on your combination.

FalconSedanDelivery said:

Yes there are different canisters that are adjustable , they will have a hex shape ( Flats ) on them , I recommend Ported Vacuum for all Vac Advances , lots of opinions , BUT I been re-curving for 25+ years and have NEVER used Manifold as a source , whats the best curve , they are all different , no one fits all deal ( sorry ) the Mrg 925D is a spring kit I use ( among others )

Click to expand...

So how is the vac advanced adjusted? Turn the hex? Small screw inside the canister? Turning the canister/screw clock-wise increase or decreases the amount of advance?

Just trying to eliminate one step here...

tanx!

Clockwise causes it to come in quicker ( less vacuum ) and sometimes allows more advance ( depends on canister ) Counterclockwise does the opposite

You are not controlling the total vacuum mechanical advance but at what you are adjusting is when the vacuum is off & what vacuum it starts.
For example you can start vacuum advance at 3" & full advance @ 12 degrees.
Be careful cause different cans have a different range.
You need a handheld vacuum pump to check to make your final choice.
I know FSD likes ported advance, but your can make your own desision if using ported vacuum advance.
Remove the vacuum line to the chamber at idle & hook up your vacuum pump to the canister.
Gradually apply vacuum to the chamber. If the idle speeds up you want to use manifold vacuum to the chamber rather than ported advance.
You want to use a dial back timing light to see how many degrees it takes to increase the curb idle speed. If it helps consider manifold vacuum at idle if no change go back to ported.
Different chambers have different mechanical limits. You can also install a metal tab to limit total vacuum advance if necessary.

I use Ported because using manifold vac to smooth an idle will usually cause a bog when the throttle is floored , the vacuum drops , the ignition RETARDS , unless the mechanical can come in fast enough to offset that , a re curved dist that uses LOTS of initial 16-22 and limited total ( depending on many factors ) will outperform a non curved dist that is using manifold vac to band aid a smooth idle problem IMHO

What "tab" do you bend to limit total vac timing?

And I've always used ported vacuum exactly due to the retard issue when the throttle blade is open. I know that it works fo rsome guys, but I stay with ported.

I use the vacuum advance at idle not as a bandaid, cause i use 10 X 2 =20 + 18 initial =38 total with all the centrifigul in by 2500 on a stick shift & 2750 on an automatic. This is where i see if the idle can be helped & fuel miliage will improve cause of a little more advance at low load operation such as cruising at low speeds. The above is just a random example.The engine is a 204" with 10.5 compression with 195 cranking psi. I am not a trainee in this art.
Mugsy, you don't bend any tabs, try to pick a canister with the total vacuum you want or screw or braze a mechanical stop on the advance lever.
When i get a chance i will post a picture.
Without vacuum advance with a mechanical advance curve as above, you are loosing fuel miliage & driveability at low load operation on a street engine.
On a strip engine i would use a crankshaft trigger @ full advance if your operation is above 3000 rpms.
Your choice if after your mechanical advance + initial does not respond to vacuum advance. All depends on your combination.
Don't forget to check your distributor gear for wear.
I do sell a hardened gear to make your worn gear problems eliminated.
PM me if interested.

The advice of others will help. Been there, done that, and have the results to back it up.

Most guys here use lots of intial timing on the crank. I don't like that method, but I do run a heap of advance because I use the Ak Miller method of advancing the heck out of the inital crank timing, then back off 0.5" Hg of idle vac. I got 16 deg that way.

These links and my dial back tming light and engine analyser are the key tools.


http://1bad6t.com/Maverick/diagrams/DSSPECS.htmL

http://www.carbdford.com/viewtopic.php?t=5392
http://www.carbdford.com/viewtopic.php? ... highlight=

Find total vac advance requirement

Cam duration-----Idle speed expected------------------Advance
----270------------------600-800----------------------------10-12
----280------------------900-1000---------------------------12-14
----290------------------1000-1100-------------------------14-16
----300------------------1100-1200-------------------------16-18
----310+----------------1100-1400-------------------------18-20

Click to expand...

For our good 2-bbl Falcons down here, we'd limit inital advance, with 264, I'd use 9 degrees static, and 36 degrees total by 2800 rpm with 9:1 c/r,

8L slot = 16 degrees centrifugal advance = .358"
9L slot = 18 degrees centrifugal advance = .384"
10L slot = 20 degrees centrifugal advance = .410"
11L slot = 22 degrees centrifugal advance = .436"
12L slot = 24 degrees centrifugal advance = .462"
13L slot = 26 degrees centrifugal advance = .488"
14L slot = 28 degrees centrifugal advance = .514"

Click to expand...

For mine, I need and use ported vac , but emission set ups are something I use rather than dispense of, and at the moment, I use a locked Duraspark with Boss 302 style 16 degrees static, and 25 degress total at 2500 because I've planed my head 120 thou to get a 12.7:1 c/r. I can't afford to blow up my 87 octane engine, so I use sharp intial and very mild total advance, and positive stop and reprofiled arms, via a welded up 0.267" second slot on my 510L sleeve assembly.

The Ford Duraspark isn't as Manifold Absolute Pressure sensitive like a mapped EDIS, but its curve plotted is dynamic. The Duraspark 2 is a smart system, and if you map it like the Meqasquirt system, you'll see how it works.

Your choice, but i like a lot of initial + centrifugal to achieve what total you need.
On some combinations manifold vacuum advance is a nice addition to achieve a decent idle.
I sometimes limit the total vacuum advance depending on cranking compression.
I am referring to using 93 octane fuel if over 9.5 compression & of over 175# cranking compression.
My engine has 16" of vacuum at idle in drive on this mild combination.
All i hear is low vacuum at idle with a 264 or a 264-274 camshaft.
Get your initial & total centrifigul advance for full throttle operation & then use vacuum advance to help your idle & low rpm operation.
All the success is what vacuum chamber you use & the adjustments that are necessary.
The final results will be a clean idle & improved partial throttle operation.
Fuel miliage will improve. Remember all engine combinations are different as i & FSD state.