File or Heat Tilly?
 

Group,

Many past comments have stated that heating the Tillotson carb to remove warp is the best way to fix the problem.

I have a gap between the halves of the carburetor over the float bowl section. The various repair books state that you should not heat the carb to fix the warp, rather file the pieces to make them fit.

Why do the members seem to support the "heat" method, but the book writers don't ?

I have a "surface plate" that is my work bench and no milling machine and I'm not a machinist.

Marc

Re: File or Heat Tilly?
 

Anyone tried a quick run over with a belt sander?

Re: File or Heat Tilly?
 

It works well for me on the belt sander.

Re: File or Heat Tilly?
 

I think you would be better off laying some sandpaper on a very flat surface. I had a glass company cut and edge some heavy plate glass. Plate glass is ground and polished to an extremely flat surface. By placing some sandpaper on the glass, you can get a very nice flat surface on what ever you want to make flat, by moving the part back and forth. I have done this on goosenecks and water return pieces that bolt to the engine. You can tell when the parts surface is flat when the whole surface is shinny. It takes a little time, but it worked quite well.
Rusty Nelson

Re: File or Heat Tilly?
 

I would be careful with heat. Pot metal dissapears quickly if the heat gets out of control. I have always used a belt sander in situations like that, and also for dressing manifold surfaces. Be sure to wear a mask to reduce the chances of inhaling metal dust.

Re: File or Heat Tilly?
 

I bolt the carb together then put a large hose clamp around it to close the gap. Put in oven and warm,tighten hose clamp some more. Let cool. It works. Also have put one on a Unimat Hobbie lathe/mill
Someday I'm going to fix the 50 or so Tillotson carbs sitting here.

Re: File or Heat Tilly?
 

I have a Tillotson carb with some warping between the halves so I thought I'd try out the heat method to flatten it out. I'm a Zenith guy, so I figured I have nothing to lose if something goes wrong. I put the carb into my BBQ with C clamps for an hour, between 350° - 400° (it varied a little bit at first). I let it cool for 2 days, yes, I got busy and forgot it was in there until this morning, LOL. It worked great! When I have time I'm going to try it out on my Tudor.

Re: File or Heat Tilly?
 

Dan's pics show my process as well. Some sanding is sometimes necessary but usually the BBQ does the job.

Re: File or Heat Tilly?
 

I haven't tried it, but I wonder if a heat gun might work.

The other alternative here in inland Southern California would be to leave it out in the sun in the summer when its 100 to 110 degrees.

David Serrano

Re: File or Heat Tilly?
 

I'm in the filing camp. I've only done a handful, but, have had good success. I file at times and then sand on the piece of glass. I've not had any that I thought were 'badly' warped though.

Re: File or Heat Tilly?
 

To heat or to file? Wouldn’t that depend on HOW much of a warp? Why do they warp is my question? Would a thicker gasket work? More questions than answers, sorry :-(

Re: File or Heat Tilly?
 

Put me in the heat category.
It has worked very well for me.
If the warp is bad and you file off too much material it will throw off your float measurement.
One trick to remember is when you're done heating turn off the oven leave the carburetor in there too cool nice and slow.

Re: File or Heat Tilly?
 

It has been my experience that filing or (belt sander/scary) will remove precious material from an already delicate casting. heating at close to 450 deg. as stated above is the best place to begin. The Model A int/exh area gets very hot. 450 deg is actually a very low temperature but that is enough to do the job depending on the degree of warp/distortion. More heat and the housings may distort beyond recognition. Pot metal is zinc, mostly, soft, and inexpensive.
The combination any on of extreme heat and over torque causes the housings to warp between halves and at the intake junction. A thicker gasket is an aid to over torque.
A friend has five Model A's all equipped with Tillotsen carburetors and won't use anything else.

Re: File or Heat Tilly?
 

I really don’t understand the fixation some of us have with this carburetor?

It was a cheap replacement back in the day.

This is like putting lipstick on a pig. It’s still a pig.

Spend a little money and get a good new or rebuilt Zenith. Your car will run much better and one more problem will be taken care of. Some of us really don’t know how great a well maintained Model A engine can run. There like a fine clock if everything is right.

Re: File or Heat Tilly?
 

[QUOTE=WHN;1592084]I really don’t understand the fixation some of us have with this carburetor?

It was a cheap replacement back in the day.

This is like putting lipstick on a pig. It’s still a pig."


"A pig" seems a bit strong. "Cheap replacement" also strong, as the Tillotson XF was sold by Ford dealers as a service replacement. Could cheap been the reason Ford chose the Tillotson X design, or could it have been a more modern design winner? There were other choices. I would use the Tillotson X as a backup but prefer The B2 as an upgrade with a more period correct appearance. after all it is a Zenith. Good Luck: Fred A

Re: File or Heat Tilly?
 

I don't think anyone mentioned working the casting cold, That too works well without removing material or using heat. Thicker gaskets are the cause of warping IF they are more porus. And if the thicker gasket is hard,non-porus, it won't seal. When clamping the individual components hot or cold; clamp to a flat, rigid iron piece and not to the other half of the carb. because you only want one of the components to bend (straighten out). When clamping to the rigid plate, clamp on either side of warp and use shim under the high spot. When clamping both halves of the carb. body together there is no control over which half is going to move.

Re: File or Heat Tilly?
 

Its a better running carburetor by design.

Re: File or Heat Tilly?
 

Back in the day - I had a NOS Zenith 2 and a Brand new Tilly, Tilly for touring, Zenith for show...

Re: File or Heat Tilly?
 

I guess that I have to say that I now have a Zenith on the car but will soon be changing to a Marvel when the driving season begins. I have several Tillys Zeniths, and Marvels. I like the response of the Marvel the best but sometimes run the others for kicks. Surfaced many by sanding. Jack

Re: File or Heat Tilly?
 

I like the Tillotson carb. If it were not good, I don’t think Henry would have supported it at all as a replacement. That would just not be good business.
The casting process of the Zenith or any cast iron part is not simple and then it has to be machined to specs. The Tillotson uses a die-casting process where the die itself is made by machining to very accurate tolerances resulting in very little machining of the final parts. It is cheaper in cost once the mold is made, quicker production times and lighter but still strong enough. If the top warps by over-tightening the gasket, it can be fixed. I personally like the cold clamping method. But if the Zenith breaks off an ear from over-tightening it is hard to easily fix without it looking bad.
Although in our hobby there are a lot of things done because somebody else says it is good, in this case I think it is actually a good replacement carb.
The only thing they could have done better would have been to make the top a little thicker so it would not warp as easily.