Zenith or Tillotson

David R.

Senior Member
Working on a AA. As found it had a Tillotson in pretty good shape. Any pros or cons to running the aftermarket carb on a driver? Working on rebuilding an engine now
 
Rebuilt or new Zenith, another problem area solved.

I learned this the hard way!

Enjoy.
 
If the Tillotson was working good, spend your money on the cooling system, with a tight fresh motor your cooling system will be taxed
 
Rebuilt or new Zenith, another problem area solved.

I learned this the hard way!

Enjoy.

I bought a new Zenith... once. It ran so lean my plugs were white. Even after installing Renner's flowed jets it ran too lean.

Finally traced it to the throttle shaft. It was so loose an oversize shaft almost fit with no reaming. It was not even round (the hole, not the shaft). It was sucking so much air in thru the throttle shaft (downstream of the jets) there was no way I could richen it up enough.

Moral of this tail; If you buy a new Zenith, check it closely. New is not better.

Update: I see new Zeniths are "Temporarily out of stock" at all of the vendors. Perhaps I am not the only one that had issues?
 
Last edited:
Just installed another Zenith recently. Could never get one to idle like I liked and all had a decal gallop that I couldn't adjust out. Went thru a half dozen over the years.
Car had a Tillotson when we bought it. Acquired a few more over the years. Just installed the Tilly yesterday and glad I did. They run so much better.
I like Marvel, but, only have one. It works very well.
 
I have a '31 Slant windshield with the correct side bowl Zenith and it seemed to run OK as far as I was concerned. A friend came across some NOS Tillotsons and gave me one. It had never been installed on a car judging from the lack of marks on the casting where the bolts tighten down. I was surprised at how much better the car seemed to run compared to the old Zenith. Maybe it ran better since it was new, but I noticed the difference in the smoother idle and better throttle response.
 
The Tillotson is currently used on a lot of Model A motors and seems to be acceptable. Purists will tell you that you need a Zenith. The choice is yours. If it runs well with the Tillotson, go ahead and use it! As mentioned in one of the other answers, there is also a Marvel Schebler carb that is used by a good number of people.
 
It sounds like the Tillotson will get a good tune up and cleaning while the engine is at the machine shop. Thanks guys. I understand about new not being better. Been down that road. I learned along time ago not to turn in your core before you check out the ‘rebuilt’ parts. Got a rebuilt starter once in worse shape than my old one.
I also build flintlock rifles and had to make bushings for one new lock because it had so much slop in tumbler bearings and ended up making new springs to get it functioning properly.
 
I want a go truck for sure and don’t plan on winning any shows with it. I will keep the tilli at least for now.
 
I want a go truck for sure and don’t plan on winning any shows with it. I will keep the tilli at least for now.





Tilly's are good carburetors. They are know for warping the body, but, thats not hard to fix. Be careful when taking them apart, especially the drain plug and nozzle. The threads are fragile.
 
I run both and can't tell the difference when both carbs are set up and adjusted correctly. But I always check all surfaces for flatness.
 
Hey, no posts for Marvel carburetors? Every bit as good as a Zenith, Tillotson or maybe even better......
 
I prefer the Marvel carburetor more than the Tillotson . I always prefer the cast iron Zenith carburetor over any pot metal carburetor .
 
Back
Top