Some of you may remember I had problems with the distributor that came on my 1923 Star C Touring with a w-4 engine. Aurthur Roberts was kind enough to sell me an Autolite distributor off a W-5 engine he had that was several years newer.

I sent the distributor off to a guy out in Califonia who specializes in remanufacturing Auto lite distributors. www.willysdistributors.com. $150 for a complete rebuild seems like a deal.

He is almost finished with my distributor but does not have all the info he needs for this distributor. He is asking me to find the timing curve for the mechanical advance. The distributor # is 7H IGB4010A. He says the 7H tells him this distributor was made in July of 1931.

Can anyone help me with the "timing curve" info he needs? If anyone has any printed info on this distributor, he would like to have a copy of that info just to add to his collection of information.

Thanks again to the group! I have almost completed the rebuild of the engine, drive train and steering thanks to all the help I have recieved here.

Tony

Do You own a car built by Durant? 1923 Star Touring

Tony:
In 1923 the original distributor was a manual advance.

I believe the distributor for the W5 was also a manual advance.

If the distributor you are using is a 1931 it must be for a 407 engine and the curve would be different than that of a 1923 4 cylinder. The distributor will work but not sure about the automatic advance .

Perhaps some of our more mechanical minded folk will be of assistance.

Do You own a car built by Durant? 1932 Frontenac

Actually, the timing curve for a manual advance distributor, as used on all Stars, is in your right hand. You just advanced or retarded the curve as conditions dictated!
Using an automatic advance distributor will require a trial and error selection of flyweight springs.
I have one of these automatic Auto Lite distributors on my '23 Star and it seems to operate nicely.

Do You own a car built by Durant? 1923 Star C touring, 1927 Star M coupe

I have gotten some additional information, or conflicting info, depending on how you want to look at it. I was told that the 7H designation means it was manufactured in 1927 and not 1931 and that the IGB 4010A was on the 1928 Durant M-2. Does this help in trying to find out the timing curve for this Autolite distributor? Or perhaps some one can verify that this distributor came off a Durant??

Don, since you are running an mechanical or automatic advance distributor in you Star, can you help me with what you found with your trial and error selection of flyweight springs? Can you suggest what I should tell the guy who is rebuilding mine?

Thanks
Tony

Do You own a car built by Durant? 1923 Star Touring

My best advice is to tell him to make it like a 1949 Willys. Otherwise, look at a WD Allis Chalmers tractor for reference. Today's gas shouldn't be a problem for pinging. Your redline rpm is probably about 2200 rpm. So full advance should occur before then. That should be about 30 deg. You want low advance for starting, maybe 5 deg. The curve rises fairly steeply at lower rpms and then bends. The knee might be around 1200 rpm, and 25 degrees. This is accomplished by the two springs having different loaded lengths and maybe different stiffness. At first only one spring is at work, after you get to the knee, both springs are holding onto the weights. Let us know how it feels to you. May take some trial and error.

[The more modern cars also used vacuum advance, which you get when the throttle is nearly closed and you have the engine manifold vacuum high. A sudden demand for gas, and the distributor vacuum goes down and it retards to reduce pinging. Pure centrifugal can't do that.]

Do You own a car built by Durant? yes

Tony, I didn't pick and chose the springs but just used what was in the distributor. I set the flywheel "0" mark just past top center (or slightly retarded)for #1, or front cylinder. Install the distributor, which is resting in retard position anyway, and in the #1 firing position. This will get the engine started and with a timing light you can speed up the engine and determine where the full advance mark is. If it is too much you can reset the retard mark a bit further retarded to bring the advance back a little bit. (Or you can install lighter springs to retard the advance mark and heaver springs to advance the advance mark. Slow the engine as slow as it will go and observe the retard setting. Never set the retard after top center position because it will cause kickback on starting.
Durant never published any info on timing curves so you will have to use such info from similar engines from other sources.

Have I confused you enough with all this?

Do You own a car built by Durant? 1923 Star C touring, 1927 Star M coupe