The Ford Barn

Russell Reay · 05-19-2025, 04:59 PM

My Tillotson carb developed the warped casting right on schedule, so I switched to two Zenith carbs. I have cleaned and rebuilt both Zs following all the instructions and warnings on this forum, except the jets are not flow-tested. The car ran better with the Tilly and was certainly more fuel efficient. I used a long bastard file to flatten the top casting, and mistakenly created a divot. Is JB Weld gas resistant enough for me to apply it and resume the flattening exercise so I can resume using the Tilly?

Ruth · 05-19-2025, 07:30 PM

There are numerous different JB Weld products. You might try JB Weld "Gas Tank Weld" or equivalent. I have never used it.

rotorwrench · 05-19-2025, 08:24 PM

I had a manifold that had been brazed to fix a cracked flange on the inside where I couldn't see it. It warped my Tillotson every time I bolted it on. I finally replaced both manifolds and that fixed the warping problem. I was thinking that it was an inherent problem with those carbs but I was wrong.

nkaminar · 05-20-2025, 07:18 AM

The JB Weld that has the long cure should hold. Remove any oils by using carburetor cleaner or acetone or lacquer thinner.

Fullraceflathead · 05-20-2025, 11:05 AM

The tillotson carburetor is a much more efficient design than the zenith that's why you see better performance and better fuel mileage running the tillotson!!!

BlueSunoco · 05-20-2025, 04:21 PM

Sponsored Links (Register now to hide all advertisements)

I've got two professionally rebuilt Zenith Carbs. They perform well no complaints. One was from the late Jim Bullock.

BUT I went back to Tilly, the car runs a LOT better with it

You can pick them up on the cheap at swap meets. Russell, if I were you that would be my go-to solution. Tilly's are easy to rebuild. You don't have the rust issues. Grab a couple and use the top part of one of them on the carb you are running now.

Happy Model A-ing!

old31 · 05-24-2025, 06:46 AM

I have used jb many times on the carb bodies and then filed it flat with good luck.

Joe K · 05-24-2025, 08:37 AM

The best way to "level" the aluminum Tilly is to remove all the jets, lay sandpaper on the top of a table saw or other machined surface, and then "rub" the mating flange which will get "filed" on the high spots.

You may still be able to do this.

And - one should keep in mind - the bowl is "vented" and a seal surface on the edge is only there to prevent gasoline spillage on engine vibration.

Permatex No. 2 might be fine here - just to close the gap for driving.

Joe K

Ruth · 05-24-2025, 10:13 AM

Oops! Wrong thread.

05-19-2025, 04:59 PM	#1
Russell Reay Senior Member Join Date: May 2021 Location: NH/ VT Posts: 460	Tillotson top casting My Tillotson carb developed the warped casting right on schedule, so I switched to two Zenith carbs. I have cleaned and rebuilt both Zs following all the instructions and warnings on this forum, except the jets are not flow-tested. The car ran better with the Tilly and was certainly more fuel efficient. I used a long bastard file to flatten the top casting, and mistakenly created a divot. Is JB Weld gas resistant enough for me to apply it and resume the flattening exercise so I can resume using the Tilly?

05-19-2025, 07:30 PM	#2
Ruth Senior Member Join Date: May 2016 Location: Glide, Oregon Posts: 1,441	Re: Tillotson top casting There are numerous different JB Weld products. You might try JB Weld "Gas Tank Weld" or equivalent. I have never used it. __________________ Ruth "Sometimes you really DO need to read the whole thread"

05-19-2025, 08:24 PM	#3
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 17,410	Re: Tillotson top casting I had a manifold that had been brazed to fix a cracked flange on the inside where I couldn't see it. It warped my Tillotson every time I bolted it on. I finally replaced both manifolds and that fixed the warping problem. I was thinking that it was an inherent problem with those carbs but I was wrong.

05-20-2025, 07:18 AM	#4
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 5,869	Re: Tillotson top casting The JB Weld that has the long cure should hold. Remove any oils by using carburetor cleaner or acetone or lacquer thinner. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

05-20-2025, 11:05 AM	#5
Fullraceflathead Senior Member Join Date: May 2012 Location: Chillicothe, Missouri Posts: 1,684	Re: Tillotson top casting The tillotson carburetor is a much more efficient design than the zenith that's why you see better performance and better fuel mileage running the tillotson!!! __________________ "If I asked people what they wanted they would have said faster horses." -Henry Ford "Primitive technology is not a design flaw" 1928 Ford Model A Roadster Pickup 1930 Gordon Smith Air Compressor 1941 Willy's Pickup 1960 Thunderbird-For Sale 1964 Buick Riviera 2x4 425 1965 Pontiac GTO, 455 Super Duty 2004 Dodge Ram SRT-10, V-10 Viper 1977 Charger Jet Boat,460 Ford,Jacuzzi Jet Front Engine Nostalgia Dragster,Supercharged 296 "Fullrace Flathead" Ford Engine Build up on DVD ask

05-20-2025, 04:21 PM	#6
BlueSunoco Senior Member Join Date: Sep 2013 Location: Windy City Posts: 1,003	Re: Tillotson top casting Sponsored Links (Register now to hide all advertisements) I've got two professionally rebuilt Zenith Carbs. They perform well no complaints. One was from the late Jim Bullock. BUT I went back to Tilly, the car runs a LOT better with it You can pick them up on the cheap at swap meets. Russell, if I were you that would be my go-to solution. Tilly's are easy to rebuild. You don't have the rust issues. Grab a couple and use the top part of one of them on the carb you are running now. Happy Model A-ing!

05-24-2025, 06:46 AM	#7
old31 Senior Member Join Date: Jan 2016 Posts: 2,461	Re: Tillotson top casting I have used jb many times on the carb bodies and then filed it flat with good luck.

05-24-2025, 08:37 AM	#8
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,611	Re: Tillotson top casting The best way to "level" the aluminum Tilly is to remove all the jets, lay sandpaper on the top of a table saw or other machined surface, and then "rub" the mating flange which will get "filed" on the high spots. You may still be able to do this. And - one should keep in mind - the bowl is "vented" and a seal surface on the edge is only there to prevent gasoline spillage on engine vibration. Permatex No. 2 might be fine here - just to close the gap for driving. Joe K __________________ Shudda kept the horse.

05-24-2025, 10:13 AM	#9
Ruth Senior Member Join Date: May 2016 Location: Glide, Oregon Posts: 1,441	Re: Tillotson top casting Oops! Wrong thread. __________________ Ruth "Sometimes you really DO need to read the whole thread"