Bubba's chevy conversion dist.

[BUBBAS IGNITION]

Originally Posted by Ol' Ron

The 11A is next!!!

The 11A could very well be the best distributor ever made (right up there with the chevy v8).
I thought i had covered every aspect of the 11A unit but got one in from a customer this morning that someone had bent the springs ( why i dont know) and the cam would stick mid range most of the time .
Would start good and then start bad was causing quite a problem.

Maybe we should write another thread on the very mis-understood vacuum brake on these and the helmets etc ??

What ya think...??????????

[Zaemo]

Yes, please.

Z

[Bill S]

Richard. Maybe you could post the degree strip.

[51 MERC-CT]

Originally Posted by Bill S

Richard. Maybe you could post the degree strip.

Sounds like a good idea but I suspect that with all the differences in the way printers and systems reproduce, the strip may not print out to exact scale.

[Richard in Florida]

Originally Posted by 51 MERC-CT

Sounds like a good idea but I suspect that with all the differences in the way printers and systems reproduce, the strip may not print out to exact scale.

I thought of that, so the scale pdf includes a reference line of specific length. You print once, measure that line, then adjust your printer accordingly until it's on the money.

[Richard in Florida]

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Originally Posted by Bill S

Richard. Maybe you could post the degree strip.

Crank pulleys come in different diameters and the diameter is critical to making the strip accurate.

I don't mind filling requests. Otherwise, the files would get lost in the shuffle.

[51 MERC-CT]

Originally Posted by Richard in Florida

I thought of that, so the scale pdf includes a reference line of specific length. You print once, measure that line, then adjust your printer accordingly until it's on the money.

Unfortunately most don't have the knowledge or ability to adjust their printers.
Perhaps a better way would to be provided with dia. of pulley then give measurement for 10 deg. increments.
For example 6'' dia. pulley = .523" per 10 deg.
So rather than printing it can be layed out.

Just a thought

[Barlea]

A 1/2" wide strip of paper can be wrapped around the pulley so that it overlaps and cut across the overlap. This will give an accurate circumference, fold it exactly in half for 180*, fold the end in to the crease for 90* and again for 45*. Next fold is 22.5* and if you have folded and creased carefully it will be at least good enough to work out the diameter for Richard's strip. ..B.

[34PKUP]

Originally Posted by Barlea

A 1/2" wide strip of paper can be wrapped around the pulley so that it overlaps and cut across the overlap. This will give an accurate circumference, fold it exactly in half for 180*, fold the end in to the crease for 90* and again for 45*. Next fold is 22.5* and if you have folded and creased carefully it will be at least good enough to work out the diameter for Richard's strip. ..B.

You don't have to figure any dia's. that way.
Just measure the length of the circumference and divide by 360 to give the length for 1deg. or divide by 36 to give the length of 10 deg. etc.etc.

[Richard in Florida]

Originally Posted by 34PKUP

You don't have to figure any dia's. that way.
Just measure the length of the circumference and divide by 360 to give the length for 1deg. or divide by 36 to give the length of 10 deg. etc.etc.

In actual fact, the number I need is indeed the circumference. I usually ask for the diameter because some guys know that number from their build days.

[Henry/Kokomo]

Anyone interested might want to check with Speedway Motors. They have "Timing Tapes", marked in degrees, for 6", 6-3/4", 7" and 8" diameter pulleys/balancers. They are marketed for Ch--y engines but will work nicely for any engine with the specified diameter pulleys or balancers. I modified the pulley on my 8ba to use one.

[Ol' Ron]

I agree with Jim the 11A is definately the best distributor available for the pre 49 engines. They get even better when converted to electronic. However I do thing the advance curve could be improved and that's one of my projects. It's quite simple:
Lighten the springs by grinding them down enough toge all the advance in by 2000.
and lengthen the advance slot to 28 degrees. Unfortunately thid depends on the vacuum brake doing it's job.
I discovered that my stock test engine has a broken area in the exhaust port under the front blind hole. Not sure how to fix this with the equipement I have and with out dissembling the engine. Today ewe installed the radiator and added water . After start up the drivers side exhaust looked like a fire hose.
This is very depressing and I will have to reevaluate my test schedule. Might have to go to the 280 now. I was hoping to have the truck running in a few weeks to work out all the bugs.

[34flathead]

great info here.
thanks.
rich

[trainguy]

Originally Posted by trainguy

Still in thy stone age,but have a battery opperated timing light.

Ordered a timing light with advance from Amazon almost ready to go.Richard,Ron and Bubba,THANKS ,Phil

[trainguy]

Just finished installing the Bubbas conversion.Set the inital timing on the dot with vac adv. plugged.Reved the engine has about 16 deg mech.Connected the vac.at idle dot moved about 8-9 deg.The engine idles better and has better throttle response.MISSION ACOMPLISHED. THanks for all the help. Phil

[Richard in Florida]

Originally Posted by trainguy

Set the inital timing on the dot with vac adv. plugged.Revved, the engine has about 16 deg mech.

With the vacuum disconnected and plugged again, try increasing the maximum mechanical to about 20. You'll get a little more oomph. And if your vacuum is adding 8 degrees, you're right in the ballpark.[/QUOTE]

[Ol' Ron]

Yes a new thread on adjusting the Vac brake and also fudging the max adv with the inital, which isn't that importanr. As long as it starts, who cares.

[36tbird]

OK, I need some help here because the statement, "If you get a digital timing light, you don't need a degree strip.", completely befuddles me.

I looked at an Innova demo on U-Tube, but it did not help me understand. If you do not have a tape or marking on the crank pulley, does the light only flash when the advance matches whatever you set in? What am I missing here?

[51 MERC-CT]

Originally Posted by 36tbird

OK, I need some help here because the statement, "If you get a digital timing light, you don't need a degree strip.", completely befuddles me.

I looked at an Innova demo on U-Tube, but it did not help me understand. If you do not have a tape or marking on the crank pulley, does the light only flash when the advance matches whatever you set in? What am I missing here?

It sort'a befuddled me too untill I got one and learned how to use it.
It's too complicated for me to fully explain here. (get one and learn)
Anyway, all you need is the T.D.C./timing mark on the pulley.
For example, if you want to advance timing 6 deg., with light aimed at timing mark and pointer, punch in 6 deg. to advance , the mark on pulley will move 6 deg., rotate dist. to bring timing mark and pointer back into alignment and lockdown. It's now 6 deg. advanced. No degree strip needed.
(probably clear as mud) This is example of one like I have--also a link to demo
https://www.youtube.com/watch?v=ViDA9IrkTtI

[36tbird]

Thanks, 51. I guess I do not understand how the darn thing gets its inputs.

When you said that you do not need a degree strip to set the timing that intrigued me because of what I'm doing. I put the late timing gear cover on a 59A to adapt a Chevy distributor to it. I took an 8BA crank pulley and cut off the timing bell. I reversed it and welded it to a 59A crank pulley. I used the crank key way as the reference for where to locate the timing dimple. I doubt that I have it exact so it will be just a starting reference point for TDC. This is why I thought this digital timing light could help me nail down the timing.

Seems like the cheaper light with the round dial to set the desired advance is all we need for this job, but I kinda like the red ones with the protective covers. Are the ones like you pictured pretty sturdy?