Car is a 56 sunliner, 292.  I have a '57-style distributor and edelbrock carb.  The car has always felt a bit sluggish in throttle response, and after reading on here, I bought a set of different advance springs (Mr Gasket, maybe #925D or similar?  Dont remember exactly)...with hopes that they might make the engine a little peppier.

Well, this past weekend I had the pass side of the engine opened up to replace an exhaust gasket (another question to be posted in a different thread) and I decided Id open up the dizzy to swap springs.  however, when i opened it up, i couldnt find any springs.  The breaker plate that the pertronix unit is mounted on moves freely with the vac advance removed, but i cant see any springs anywhere.  Are they under the breaker plate?  do i have a vac only advance distributor?  I didnt want to pull the dizzy out and find out i dont have springs.  If it is vac only, should i get one with vac and centrifugal advance?  If so, any recommendations?

Any thoughts are welcome!

Ron Grove

Wauconda, IL

I'm definately not the expert because my last memory of a 56 was in 1961 but I recently bought a restored 56 Vic and the first thing I did was purchase a 57-62 distributer to get rid of the loadmatic as I remember was a problem. I looked into the new one and saw the springs under the plate (thought about how ez my Chevies were to change) I also replaced the Holley 4000 with a WCFB small base from a 1952 Cadillac. The 56 has a different cap and rotor than the 57-up. 

To check out everything as I was timing it I disconnected the vacuum advance and watched the timing mark move to advance as I reved the engine proving the centrifugal weights. Then I connected the vacuum line and did it again to watch it take "all" of the advance vacuum and centrifugal. If I accelerate hard the vacuum falls off and just weights advance and it doesn't ping.  

The hardest thing was to cut up a stock air cleaner to work on the WCFB and to add an insulator under the carb to help with the heat.

Hope this helps.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

The advance springs are under the plate, Ron.



I would highly recommend taking the distributor to someone with a distributor tester. While having the correct springs might be part of the equation, the posts they attach to are adjustable (by bending) to achieve the appropriate advance curve.



A Ford or Motor's repair manual would have the advance specs. Likely a Chilton's manual would have the info, too.



I'm not sure on the '57 distributor, but on some applications there are two different springs for the centrifugal advance. Taking everything apart to clean and lubricate the pivots, can result in springs getting installed on different posts resulting in a different advance curve! Having the advance curve 'right' can make a tremendous difference in an engine's performance.



While you've got the distributor plate out, you'll be able to see if the plate is moving without any 'catches', needs cleaning, or lubricating...



Also, with a timing light, run the engine at a constant elevated engine rpm while watching the timing marks. IF at a constant rpm of ~2,000, the timing marks 'float', you likely have a worn timing chain... And that can affect your engine's performance, too.



Going at everything another way, check the engine's operation with a vacuum gauge. IF the vacuum gauge readings are low, you may have a vacuum leak that you need to find. -Intake manifold gasket, carburetor base gasket, vacuum hose leak...



Hope this helps...



Regards,




NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Before you go changing your springs do a little test.  First make sure you balencer is marked correctly, find absolute TDC, then take your timing light and with the engine running look where you initial timing is. (at idle) Then rev the engine and watch to see if it advances.  If you have an advace timing light all the better but you should see total (around 32 -36*) by 3000 rpm.  these are rough numbers but if all is working it pretty close.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

Oh! and as Mr. No shortcuts said the advance mech. is under the plate.

bla bla

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

Hi Guys, thanks for the responses!  I guess i should have clarified a little more in my earlier post:

Engine is about 10 years old/20k miles on a complete rebuild.  When rebuilt, timing chain, etc were all replaced with new.  Also the new distributor went in then, with pertronix.   Also, the damper was rebuilt/calibrated as well.

Originally when i got the car on the road after restoration it had the teapot and stock intake, with the '57 style distributor.  Then went to original blue thunder intake and edelbrock.  Have also messed with several holley carbs as well.  Through all of this, it has always just felt lazy.  Some of this is to be expected as it has a bigger cam with some overlap and a FOM, so i know that its never going to be super-crisp (In hindsight i may have picked a different cam, but im not about to pull the whole thing apart to change that).  At idle it consistently pulls around 12-13in hg, again less than stock due to cam overlap.  no vac leaks, etc.  Last time i hooked up a timing light (last summer) it held timing consistently, so i think the dizzy itself is ok. 

Also, the engine seems to like more base timing than what is recommended here...like up to about 20 degrees or so.  If i dial up the timing to that, it accelerates better, but my brain tells me not to run that much initial advance (exhaust is so loud i wouldnt be able to hear any pinging).  Ive chosen to run timing where my brain says it should be vs. what "feels" better.  That was part of the thought behind putting in the different springs, to allow advance to come in sooner.

Sounds like the springs are under the advance plate; im assuming i need to take off the one nut to start to pull it apart?  As long as i know the springs are in there (and i can get to them), ill likely pull the distributor out this weekend and replace the springs; i just didnt want to take it out and find out there werent any springs..

THANKS

Ron Grove

Wauconda, IL

If you haven't touched the distributor, then it can very well be contributing to the problem. Many of the reman units come with a real lazy curve that can provide a lot of advance. And if the cam is too big, there's not a whole lot you can do. If by chance you're trying to run economy gearing with a performance cam, it probably won't work out well either. What are the specs for the cam?


Lawrenceville, GA

Charlie, thanks for the reply. I dont remember cam specs, i can try to dig out the cam card over the weekend. At the time, the cam and car was discussed with john mummert, and its the one he recommended for a convt with a fom. It has a bit of a lumpy idle, but it isntanything too crazy. Not sure if he still offers it though.

I can get exact specs later tonight.

Ron Grove

Wauconda, IL

If it's what he suggested for a fom, then it's probably quite mild and I think should have much better than 13inhg at idle and the sluggishness should not be due to the cam. A bad state of tune can cause low vacuum. Did you actually check that the damper marks were lined up correctly with #1 at tdc when the engine was assembled? If not then there is still the chance that it is not dead on (mine shows about 2 degrees retarded when it is actually at 0) and the 20 degrees of initial where it feels best may actually be where it needs to be.

Another thing, Edelbrocks start at 500cfm. Maybe it's too much. Are the Holleys you tried smaller?



Lawrenceville, GA

Ron: A couple of things to consider. Unless you manually start off in Low, the car is leaving in 2nd gear. Also, from tests I've seen printed, my impression is that the Blue Thunder intake results in less bottom end torque than a "B" intake on smaller displacement engines, like 292s. It's better on power in the upper ranges but not down low. The "B" intake is hard to beat below 3500 RPM. Recent tests by Ted Eaton confirm that..

Paul