The 1908 Holley carburetor ad below includes a chart for carb size depending on cylinder Bore. Does the number of cylinders matter (I would think it does)? In other words, if a carb works based on a 4 1/2 in bore size (chart below) does it matter if it's on a four or six cylinder engine?
I have a 1908 Holley carb with 1 1/4 (it actually measures 1 3/8) throat size, and our Model K has a 1 1/2 intake opening. Holley was listed as one of the Model K carb providers, along with Kingston and Buffalo.
Thanks for any advice,
Rob - I would think that a combination of bore size, stroke and number of cylinders,....in other words,....total displacement, would be a better guide for carburetor size than just the number of cylinders. I think this is a case of an advertising "guide" that is just basically aimed at selling carburetors to a public that is of more of a "horse-drawn" mentality than mechanical,.....just my opinion,....FWIW,.....harold
Well in those days most engines were low rpm, long stroke so in theory you could ballpark CFM requirements of an engine based on bore size.
I would think bore size and possibly stroke is all that would matter on a one two or four cylinder engine. On a four stroke engine only one piston is acting on the intake at a time, if four cylinders or less. A six cylinder would be different and a eight cylinder should be double a four. Just my thoughts ...
Check out Dykes and there is several paragraphs regarding carb throat size based on intake valve size. I had a 1909 Stoddard Dayton 50 hp and could never get the engine to produce real power. I replaced the original Stoddard/Rayfield with a larger throat carb based on Dykes. The car performed incredibly well.
The previous owner had totally rebuilt the motor, replaced all the valves and vale springs to try and improve the low power problem. He finally sold the car to me, after spending lots of money and effort and not making any improvement.
I recently provided a carb for a 1905 Darracq that wouldn't pull itself out of the parking lot. Bigger carb was all it needed. Just sent a company in Montgomery, Alabama a replacement carb for a 31 Dodge. The carb on it was half the size it needed. Donnie is right. Only one piston is taking in fuel at a time. Up to a six cylinder and with the slow engine speeds in 1908 that's all that's critical.
Look in the classifieds under 1908 carb.
Interesting. I guess that's what is on your N.
Very similar at a glance.
Thanks guys. I have a Holley with a 1908 patent date (same as seen in the ad) and I wonder if it is large enough for a Model K. The actual measurement is 1 3/8th, so I don't know if it's the 1 1/4 or 1 1/2 mentioned above. At some point I'll try it (needs work) and see,must looking for ideas.
Larry, we have an original Holley forum N, but it's an earlier style (1906 N). Currently I run a NH on the N, but Stan has rebuilt the original and I intend to try it at some point.
Maybe apples and oranges but my Zenith HP5A is supposedly 1 1/4 but I measure 1 3/8. I would suspect your Holley may also be considered 1 1/4.