I've read on this forum that cars with vaporizer carbs are less powerful. Is the difference really noticeable ?
I have a friend with a late-teens touring. He has complained that his car is really gutless. And after driving my car, he's convinced that something is amiss with his car. When comparing, I noticed that he has a late motor, with a vaporizer.
I speculated that the carb may be one of the reasons his car is so puny. Could this be the significant difference ?
Thanks,
Dick
If the vaporizer is working properly the car should perform well. I have been impressed with the set up if rebuilt right. You can have no vacuum leaks. KGB
Part of the problem is that the "improved" car is heavier and as a result I think not likely to perform as well as the earlier lighter cars. That said I had an NH on my '27 touring and switched to a vaporizer and wish I hadn't. Harder starting when cold and when you open the throttle it is slow to respond.
There could be other possibilities. What are the compression numbers on his cylinders compared to yours?
No idea what the compression numbers are. He has another engine that he's prepping to go into the car. I was just pointing out that he might transfer the low power to the new engine if he re-uses the vaporizer. That's why I ask the question on the forum.
The car is a late-teens, maybe 1917. Same body style as my 12. I would think their weights would be pretty similar.
Dick
You can put a diamond necklace on a pig and, it's still a pig! The T I drive the most has a vaporizer. After building that T, I was into that carb over a half dozen times in the first 2 weeks. I haven't been back into it in over 10 years now. It still runs good--I plan to take it to the MTFCI national tour next month. It would be interesting to see data from the same car with a G, an NH, and a Vaporizer being the only thing changed. Unfortunately, comparing 2 different cars there will probably be differences other than just the carbs.
Vaporizers were introduced during a time in our history when there were lax standards for making Gasoline. This resulted in lots of poor quality fuel especially bad in 1924 and lasted until mid 1927 when several states and then the Federal Government stepped in with standards (SAE) and inspections for the petroleum industries. This is why the Vaporizer use ended with Ford around 1928.
Finally Gasoline became a better quality that could be counted on and the Vaporizers were no longer needed.
Gutless performance of a Model T engine is not unusual, there are many possible factors involved, and it can be remedied. It could well be the fault of the vaporizer carb. The free-swinging air-gate behind the choke butterfly, for example, can be stuck in one position, and this definitely affects performance. No matter how beautifully restored it is on the outside, the insides of the vaporizer must be operating up to specs.
For a 26-27 Improved Car, I will put up with a lot of fussiness in the vaporizer just for a sense of authenticity and novelty. but in a late-teens, there's no question: Install an NH! They are cheap, simple, reliable, easy to restore and set up, they do not detract from the engine's performance, and they look correct on the car.
In my 27 tudor, I am thrilled to have a Kingston B-1 vaporizer. It's as exotic as a Model T carburetor can get without being an aftermarket unit. It would look strange on a late-teens car.
Jim
James is right on. I run the Vaporizer for authenticity and that is why I switched over from the NH that was on the car. I put up with it's issues but would never select it as the carburetor of choice on a car that did not originally come with one.
I have an original vaporizer on my 1927 Roadster. I think I may be one of the few people in the hobby who have not had trouble with it. It starts really well when cold. It's harder to start when warm, but I do get free starts at that time also. I will continue to keep it for now.
Vaporizers are real fussy. The first one I had started hard cold but gave a free start almost every time when warmed up. The second one started fairly well cold if you choked the devil out of it but was often hard to start warm. It had no power however. The one I have on the car now starts hot or cold about the same, not great but OK, but it runs well enough when you get it going. I'mm not sure I want to try for four at this point.
I've read on this forum that cars with vaporizer carbs are less powerful. Is the difference really noticeable ?
Think that statement is without real basis, we tested a bunch of T's on tour in MN on a Dyno, and look at the last entry on this tab list,
My T had NH carb, Z head, and Stipe cam, and still the Vaporizer carb T beat me in HP
Dan,
I think that the myth of the low power from a vaporizer may come from the tiny air intake. It looks as if your Ford has the intake volume of a lawn mower, and this can't possibly lead to big horses.
However, the visible intake is only the COLD air. It mixes with the concentrated, heated fuel/air stream in the mixing chamber. The real intake is probably superior to a NH.
But, the acceleration using a Ford/Holley vaporizer is poor, simply because the vapor has to travel through a long maze, and there's a resulting delay to vapor demand. On top of that, the quality of the cold-starting charge depends on a lack of wear and leakiness in the complicated choke scheme.
The Kingston B-1 vaporizer was designed with these deficiencies in mind, and both were taken down. The choke is superior to anything previously used on a Ford, and the car will reliably start from dead cold on the second turn of the crank. Raw gas is jetted directly into the mouth of the down-turned intake structure.
Acceleration was improved by minimizing the length of the vaporizing chamber and raising the bowl by 3 inches. (This modification works only on 26-27 cars with the gas tank under the cowl. A bowl extension was provided for installation on Fordor sedans. Near as I can tell, the factory didn't bother to take advantage of this feature, and seemed to install all of the Kingstons with the bowl extended down. I've got to do more research on this quirk.)
I don't have any dyno numbers, but I swear that my B-1 outperforms an NH.
Jim
Jim
Good info. Thanks
To me that bigger and better breathing exhaust manifold may help too at higher rpms for more HP?
Anyway, haven't ever used one, but someday......
Dan,
That's a gorgeous Ford/Holley vaporizer you've got there! Very, very nice.
Isn't it a shame that Ford insisted on using the old exhaust pipe? The exhaust has to go through speed-reducing curves to make it to the pipe. Ford finally came up with an excellent manifold/pipe configuration on the Model A engine of 1927 and managed to double the hp with the same-sized engine.
Jim
Been running vap on my 26 and 27 for years and they run just fine. Hill climbing ability is as good are better than others.
One of the nice things about the Vaporizer on my car is that it gives a beautiful very low, smooth idle. You can barely tell the call is running. If I leave the timing advanced slightly I can close down the throttle down all the way and it just sits there purring...
I would agree with all of you on the performance of a Holley vaporizer. It idles well, just as Randy described, it starts immediately when cold and sometimes a little tough to start when its warm. the acceleration was better with the Kingston vaporizer, but I could never get it to idle as low as the Holly and it always was very difficult to start when cold.
I have no doubt that the vaporizer is like any and all T carbs in one area. There are very well restored/maintained examples out there that function as well as when they were new. There are rusty/dusty non-functional examples. Then there are many, many in use that are in an in between state and functioning on a suboptimal level weather the owner knows it or not.