Distributor curving for idjuts?

[shadango]

Just sitting here contemplating.......

My 318 is supposed to be stock as far as the short block aside from a dbl roller chain.

But it has j heads, a performer intake and a purple cam....low vac at idle, lots of roughness and a good deal of power up high in the rims but low torque down low.

When I first got the engine running,it had a 750 com Eddie carb......having issues with idle etc, and with the advice of folks here, I swapped in a 650.   I also ended up using a 2800 rpm stall converter.

At some point I swapped out the distributor that was in it for a stock off the shelf rebuild from autozone.

Wondering maybe in doing so I effectively tossed any recurring the previous owner of the engine may have done.

I had considered sending the distributor out to be curved, but I do not know the stats on the cam that they would need.

Is it worth tinkering with springs and such to try and get some low end?

Or just keeping working towards my dream of a small block strokes crate?

I never reps ringed a distributor before....

[Chryco Psycho]

IMO the Magic seems to be setting initial timing around 16*  at idle & using a 20* mechanical curve so usually you need to weld the slots to shorten the curve , using lighter springs  may just cause problems if they are too light causing them to advance at idle or close to it or cause detonation if it advances too quickly .
 I never run the vacuum advance

[Strawdawg]

IMO the Magic seems to be setting initial timing around 16*  at idle & using a 20* mechanical curve so usually you need to weld the slots to shorten the curve , using lighter springs  may just cause problems if they are too light causing them to advance at idle or close to it or cause detonation if it advances too quickly .
 I never run the vacuum advance

In my experience, if the car has less than 14 in/hg of vacuum at idle (and must about any performance cam will drop below that), then it becomes more hassle than it is worth to get the vacuum advance to work right and can make the car run worse.  Coincidentally, adding more initial advance can also cause problems with the vacuum advance so the simplest thing to do is disconnect it and plug the port on the carb.

Setting the initial advance to about 16 degs, using stock springs and weights, as Chryco suggests seems to be about the simplest and most fool proof method as long as you limit the mechanical advance to 18-20 degs as he said.

In other words, do it as he said 

[shadango]

In my experience, if the car has less than 14 in/hg of vacuum at idle (and must about any performance cam will drop below that), then it becomes more hassle than it is worth to get the vacuum advance to work right and can make the car run worse.  Coincidentally, adding more initial advance can also cause problems with the vacuum advance so the simplest thing to do is disconnect it and plug the port on the carb.

Setting the initial advance to about 16 degs, using stock springs and weights, as Chryco suggests seems to be about the simplest and most fool proof method as long as you limit the mechanical advance to 18-20 degs as he said.

In other words, do it as he said 

Yeah, that is pretty much what I have done - disconnected the vac advance (tried with and without and found all it seemed to do was jack up mu idle speed enough to be problematic).......didnt see any more power with or without anywhere along the rpm range.   I also did what Chryco said as far as initial timing.

Will double check my total advance -- pretty sure it was all in at around 36 or so.

[shadango]

IMO the Magic seems to be setting initial timing around 16*  at idle & using a 20* mechanical curve so usually you need to weld the slots to shorten the curve , using lighter springs  may just cause problems if they are too light causing them to advance at idle or close to it or cause detonation if it advances too quickly .
 I never run the vacuum advance

Thanks Chryco....I will do a search on "welding the slots".....

I did a search on springs and I guess you also have to change bushings when you do it?     I never realized that.....figured you could just swap out a spring or two and reinstall the distributor and test.

I just figured a few bucks for springs and my time would cost less than a $7,000 stroker....LOL (not the same results of course) and tide me over a bit longer. 

[Chryco Psycho]

So you will not gain much there
 You can swap springs easily , no bushings needed

[Bullitt-]

No expertise on my part but something I've gleaned from many posts and articles I've read is that cam dial-in can impact power in many ways. It sounds to me you might benefit from advancing the cam timing. CK this article & pay particular attention to the section called ADVANCE/RETARD.  http://www.lunatipower.com/Tech/Cams/CamSpecTerms.aspx

[Jamiez]

FBO systems sells a kit with plate for limiting advance and a variety of springs.  It also includes a tuning guide.  This might be useful if you do not want to permanently alter the slots on your distributor.

http://4secondsflat.com/Ignition.html

Item J685K or just J685 if you just want the disk.

Stock:

Plate installed:

Original slots reinstalled (note the plate showing through the slots):

[Chryco Psycho]

you can clearly see the slots in the plate that I have welded closed in the past , you can weld either end of the slots to limit the advance , I often weld the inner end of the slots . A chain saw file works well to open the slot back up if you limit it too much