Vacuum Advance On An L Head?

Would adding a vacuum advance to an L head help at all with performance? Especially with a better carb?

 

Did you ever try a progressive 2bbl carburetor?

 

Fuel economy and emissions might improve. Peaks won't change

 

I seriously doubt it. But you could try putting the intake valves in the head...

 

That I did. Forest Service 3A Weber carbs are progressive 2bbls.

 

I found a vacuum advance distributor for $75. Thought it might be worth a shot, but I'll save that money.

 

Weird I didn’t get notifications

I have a vacuum advance distributor but I haven’t done anything with it yet.

 

I didn't get notifications neither.

The vac advance distributor I had from a truck f-134 didn't impress me. It just rotated the whole distributor in the hole and I didn't care for that idea. Now a waterproof 4cyl bowtie hei with vac advance would solve all that.

 

I have a sbc distributor I’d like to try that with

 

Given the dismal economy of the original L134's in CJ's, I seriously doubt you could see a statistical significant difference in mileage. I'm not sure why Willys used the vacuum advance in the wagons/pickups/FC's but I doubt there was much advantage there either. Emissions? If that was a requirement, we wouldn't be driving any of these.

 

Our 134L from a 58-59 DJ-3A has had a Vacuum advance distributor since the 60's its from a 61 FC-150 and YES it does improve the driveablity of the Jeep As I have no knowledge of what the mileage would be without the advance to compare I can't say what it changed. But logic says if damn near everything uses a Vacuum advance there must be a reason. I currently have two IAT-4405 Distributors one will be set up with a Petronix unit (I will have to figure that out as there is no direct fit kit) the other will be conventional with points. I am also running a Weber DGV-5A on an Aluminum intake with a Tri Y design Header. Engine has not been started yet.

 

Engines will tolerate more advance under light loads, equating in added economy and performance. Since vacuum advances are load sensitive, they can provide added measured advance.