Mancini vs Mr. Gasket distributor advance springs

Hi,

Has anyone on here tried both the Mancini and Mr. Gasket distributor advance springs? I was wondering if there is any difference in spring stiffness between the two.

https://www.manciniracing.com/disadweigspr.html

The car I am working on has what appears to be a Mopar Performance distributor.

https://drive.google.com/file/d/11wCWbwdOc88JX-NO2QipOSd-XHDh5A8M/view?usp=sharing

I have read to use one Mr. Gasket spring and one of the springs that comes with the distributor to get my total timing all-in at around 2500 rpm. Right now, it is all-in at about 3000 rpm.

I will call Mancini on Monday to see what they suggest.

Thank you in advance for the help.

Jon

Do yourself a favor and buy the springs and or plate from FBO .
http://www.4secondsflat.com/

Ron

some addit'l info

Can you please explain the table a little bit. Is it suggesting that my advance with the advance springs that come with a Mopar Performance distributor should provide all-in advance by 1100 rpm?

What is "point x" and what is "point y"?

That looks good, thank you. I will call them on Monday.

The Mopar Performance springs are the ones they sold to put in a distributor, they are really light. Removing the heavy spring and just using the stock light spring usually works good for a street car.

X is when the spring or spring combo starts advancing & y is when the particular spring or spring combo reaches full advance. EDIT I forget where I copied the chart from but yes it is sayin the MP combo would be all in at 1100

Is that chart in distributor degrees or crank degrees. If dist degrees, then crank degrees would be 2200 for the MP springs which is what I seem to remember from the old catalogs.

Our big blocks tend to like the advance all-in as quick as possible as long as it doesn't ping under load. Small blocks tend to be less picky. But you do not want the advance to begin until the RPM is above the idle. If it starts advancing while idling, you will be chasing the idle speed all the time, since the advance will be changing with engine speed especially when dropped in gear if an auto.

For a big block, I like to try for advance to start about 1,000RPM and be all-in by 1,500RPM. Then check to be sure that there is no spark knock under 2,500RPM. And the more overlap in the cam, the more advance they like in the idle. Most of my big blocks (and my current Hemi) have 25* to 28* advance at idle. Basically, all I can get before it starts kicking back against the starter.

thats what I was getting ready to comment on is that you dont want the springs to start advancing until several hundred RPM above the idle speed & someone said something about the center hole in the FBO plates to be to big possibly causing a problem (hanging up or inconsistent advance amt I would guess). I have several of em & I am going to check that out & maybe reduce the center hole ID but it is a good deal for the money.

Correct me if I'm wrong, but I thought the Mancini springs ARE FBO's?

crank

It may be a DC/MP vac advance distributor based on what I can see of the number.
If so, its already got a pretty good curve in it.
If you're dedicated drag racing, then the vac advance isn't needed and in that case, using a lighter primary spring may be an advantage. You'll then need to be sure there is enough initial tension so the advance is stable at idle speed. Leave the heavy spring installed. That's part of the secret of why the MP/DC distributor are better than most aftermarket.
A heavy secondary spring normally is used to slow down advance as the rpms get into better combustion above roughly 2000. But it also is used to offset electronic switching time (slew rate). see https://board.moparts.org/ubbthread...ry-unilite-timing-issue.html#Post2488504


If you're not dedicated drag racing, then work with the factory springs - especially if it is a DC/MP distributor. You can tweak the tension on the primary, and the engagement point on the second spring by turning the spring perch.

If the advance is really too long - say because a long duration cam is being used, then weld a tack on the inside of the slots. File it and you're done.
If its not a MP distributor, depending on the original application you may find a really long advance, like 30*. In which case, weld a tach and file it to length.

Hello,

Here is a link showing the springs that I received from FBO and the springs (on the right) that I removed from the distributor:

https://drive.google.com/file/d/13aksB4cg2LTe8dLoFCf8a0NVA5YyaMDq/view?usp=sharing

I doubt either of the springs that I removed are the original MP springs that came with the distributor.


Here is a link showing the distributor (Mopar Performance 3690432):

https://drive.google.com/file/d/13XMQZr0XITR9Z8WuE95IskTb2UIXYICV/view?usp=sharing


This link shows the slick FBO mechanical advance limiter plate. The plastic bushing fits loosely in the middle of the plate and is part of the distributor. However, I don't think the loose fit will be an issue; it isn't that loose.

https://drive.google.com/file/d/13KgiKgf7I70SbtqlKcs8OkzJ_0k_yXGj/view?usp=sharing


link with the plate and silver springs (med tension) installed in the distributor:

https://drive.google.com/file/d/13zQj6KBaYeNfBGMYxOSvTkMCBoWlIjUQ/view?usp=sharing


FBO recommended the following:
- initial 20 degrees
- mechanical advance 14 degrees
- 34 degrees total, all-in at 3000 rpm
- hook up vacuum advance canister for an additional 10 degrees at idle/light throttle (need to test to see how much it gives me)

I figure we will start with all-in at 3000rpm, which seems really slow to me. I'm thinking more like all-in at 2500 rpm.

The car is a '67 Plymouth Satellite, 440, auto, 440-EZ heads with Modman intake and two 600 Eddy's. The converter seems tight and appears to lock-up at around 2500 rpm. It has 4:10's. Cam is hyd FT with .532" lift and about 235 @ 50.

Yeah, with 4.10s, you will probably be able to be all-in much earlier than 3,000 without pinging. In fact, I would try all-in by 2,000.

The 2 springs in the Mopar kit are way too light to use together, I got almost full advance at idle when I used both. Used one MP spring and the FBO light one in there. Advance starts just off idle and all in at 1700. The slots I set to .350" wide (mine were made adjustable) and that gave 13 degrees. My 440 likes this combo with initial at 24. Similar to what was mentioned in a previous post.

I had a stiffer spring in it before and advanced started at about 1500 or so. Problem was off idle - normal driving (auto trans) there was a slight bog or stumble until that advance came in and then it would take off and run good. Seemed like a carb problem - like the squirter, but I couldn't find it. Redid the advance so it starts moving right off idle, and that fixed it.