carbking
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Posts posted by carbking
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Yes.
Jon.
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One of the major problems often encountered (among many) with the Marvel carburetor is the swelling of the spacer block, preventing closure of the air valve. For proper idle, the air valve MUST be capable of complete closure.
To check this, the carburetor needs to be removed from the engine. With the carburetor removed, one should be able to manually open the airvalve, and when released, the air valve should SNAP closed.
If the air valve does not fit tight against the throttle body, the cause generally is the spacer block. This block is made of a poor quality zinc alloy, that swells with age. There is a finite clearance specified between the lower edge of the air valve, and the spacer block; but the swelling of the spacer block will eliminate this clearance and actually force the air valve open. This prevents idle air from passing through the idle venturi to pull sufficient mixture from the idle jet to give proper adjustment.
If this condition is present, it may generally be alleviated by placing a piece of 400 grit emory cloth on a piece of glass, and "sanding" the flat surface of the spacer block. The spacer block is retained in the body by two flat head screws, which must be removed to remove the spacer block.
Jon.
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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Greetings. I was just looking in my manual and it states my car uses 84 motor, 93 research. What does this mean? I have a 215 ci with 2v 9:1. Since I use the lowest octane, could i maybe benefit from going with a little higher octane? I am going to try it but wanted to get some feedback from you learned folks first. Thanks.
Keith </div></div>
"Motor" and "Research" are the two most common methods used to measure octane (a measure of the speed of burning of the fuel). Sometime after your manual was printed, octane ratings on the pump were changed to reflect the average of the Motor and Research methods [(R + M) / 2]. In your case, this would be [(84 + 93)/ 2] or 88.5 as posted on the pump. Rounding 88.5 to the next highest number would result in 89 octane.
It is easy to determine which octane to use. Simply begin with a tankful of an octane slightly higher than supposedly required, and check for "ping" or "detonation". If there is no ping, try the next tankful with 1/2 the same octane, and 1/2 the next lower grade. Continue doing this until your find an octane where ping is present, then revert to the lowest octane that does not ping.
To check for ping, find a relatively level primary road where you can cruise at 55 MPH or, assuming the legal limit is higher, slightly more. This level stretch should terminate with a medium grade to climb. When beginning the climb, GENTLY press the footfeet to gently increase speed. If your engine is going to ping it will do so under these conditions. Ping will sound like your engine suddenly has a handful of marbles trying to get out!
There is absolutely no benefit to using a higher octane than necessary to prevent ping (in fact, quite the opposite may be true)! When gasoline was still gasoline, there was 117,600 BTU of energy in a gallon of 87 octane, 117,600 BTU in a gallon of 89 octane, 117,600 BTU in a gallon of 91 octane.......you get the picture.
Now that deathanol is being added to gasoline as one means to raise the octane (and deathanol has less energy than gasoline) higher octane fuel MAY have less energy (less power and less mileage), and in fact MAY require an internal carburetor re-calibration.
Jon.
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Assuming that your SF-4 has the proper internal venturi for the Packard (there were 7 different sizes); the initial setting would be 1 full turn from lightly seated on the idle.
As far as the high speed adjustment is concerned, the recommended factory initial setting was 2 and 1/2 turns from lightly seated at sea level to 4000 feet, and if you are able to acquire gasoline this is still a good starting point. If you live in an area where "deathanol" is served, increase the diameter of the high speed adjustment my 0.005 inch, then try an initial adjustment of 2 and 1/2 turns from lightly seated.
The SF-4 is an excellent choice, again assuming you have the correct one, and should serve you well. Unfortunately, many of the so-called "automatic" carburetors of yesteryear do not have sufficient adjustments to deal well with modern fuel without modification. In its day, the Detroit Lubricator was an excellent carburetor; but to perform well with modern fuels needs a different air valve spring, a different main metering jet, and a different taper needle.
If you have more questions concerning the SF-4, feel free to call during normal telephone hours.
Jon.
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I did not remember this being a feature of the Chrysler, however it may have been.
Initial setting would be 2 and 1/2 turns out from lightly seated.
Jon.
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Idle mixture control screw 1 full turn from lightly seated; top of float 1/64 inch from top of lower casting when fuel valve is closed.
Jon.
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Two other issues to check:
Fuel filter and tank vent.
Jon.
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Measurement is between the top of float with float valve closed, and the casting. Fuel level will be lower.
Jon.
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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I saw that book when I was at Amazon looking up Roe's book. Bought them both. I'm glad to hear that his book is as good as it looked. Any ideas about buying internal parts for the Q-jet? Like if I need needles, or other parts? I've been buying cores for $5 - $10 so I'll have a parts inventory as I get this rig running like it should.
Thanks for the follow up
Steve </div></div>
With all due respect, read the book!!! Cliff has lots of parts available. Always nice to support the author!
Jon.
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Some other issues to remember:
Stand alone pressurized carburetors require sealing, plus a variable pressure fuel pump
Pressurized carburetors in an airbox require a variable pressure fuel pump.
Either of the above may (depending on the pressure) require adding baffles to the float(s) to prevent collapse.
A pull-through installation is easier.
Jon.
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If you drive the vehicle, consider:
A) vacuum systems did not last long in production after a reliable pressure pump was introduced.
as new fuels become more volatile, vacuum systems give more and more trouble.Jon.
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While the Doug Roe book mentioned is an excellent general reference on Rochester carburetors; a new book (within the last year) written by Cliff Ruggles "How to Rebuild and Modify Rochester Quadrajet Carburetors" is the best book that I have seen in 40 years on carburetor performance enhancements that may be done by someone with less than a full machine shop.
Jon.
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Dave - the 1946-1949 Triumph 18TR Roadster used Solex model 35 FAIE specification S-1381. The 1948-1949 2000 Roadster used Solex model B32 B10-4 specification R-265. These listings in a Solex manual printed in 1968 that covers back into the mid-1930's.
I concur with Ivan on the question of the Solex quality (or lack therof) if one plans to drive the vehicle.
Jon.
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Carter made many different of the the type BB-1 updraft carburetors; the first in 1931, so obviously not original to your 1928 Nash. However, the design is excellent, and assuming you have the proper sized unit for your Nash, should perform extremely well.
The top of the float, when the fuel valve is closed, should be 1/32 inch (0.8 mm)
The initial setting of the idle mixture control screw (top) is 1 full turn from lightly seated.
The initial setting of the high speed adjustment (bottom) is 2 and 1/2 turns from lightly seated.
While Carter did print a booklet on the carb, probably the least expensive procedure would be to visit a large library, and look in the reference section for the "Motors Truck Repair Manual" (green in color, not the blue car version). Chevrolet used various models of the BB-1 from about 1937 to 1963; and, with the exception of the high speed adjustment (not present in O.E. applications), the information should be correct.
The booklets are available, but UPS to the UK isn't inexpensive.
Jon.
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Does this vehicle have a vacuum advance unit on the distributor, and if so, have you checked it for leak and function?
Jon.
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If you have a rebuilding kit with two valves which differ in appearance, it is possible you have a universal kit with both a power (or economiser) valve and a distributor spark valve. Both have the same thread, but they differ in appearance.
If you don't know, you can tell one from the other as follows:
The power valve is normally in a position where you "push" the plunger to open the valve.
The spark valve is normally in a position where you must "pull" on the plunger to open the valve.
DO NOT interchange a spark valve for a power valve.
Jon.
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Depending on what you need:
1) Kurt Kelsey Pontiac Parts, in Iowa Falls, Iowa
2) The Antique Auto Parts Cellar, in South Weymouth, MA
Jon.
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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">How about the word RARE ? </div></div>
Cow poop on the subway is rare, doesn't mean it's worth anything.
<img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" /> </div></div>
Rarity depends on the highway, and its worth more than a liar's description. <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />
If I am buying, the first found lie cuts the price in half; the second and I go home making no offer.
Jon.
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As far as I am aware, K & D was used on 1916 and 1917 Maxwell passenger; 1917-1920 Maxwell trucks; and 1918 Moore. I have no records of any other use.
And you have just been looking in the wrong places! <img src="http://forums.aaca.org/images/graemlins/grin.gif" alt="" />
Maxwell models and carburetor information
Jon.
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Thanks. A little extra information. The carburetor is a "K and D" model "B" unit.
Jon.
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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The pump is in very good shape appears to have flat mating services so don't thik I will take the hammer and torch route. If you were going to send it out, who would you send it out to? </div></div>
The Antique Auto Parts Cellar in South Weymouth, MA is THE company when it comes to fuel pump kits, fuel pump parts, or fuel pump refurbishing.
We do not rebuild fuel pumps in our shop, but since we must deal with them when a pump with the wrong return spring creates way too much pressure on the carburetor; I have been forced to learn much about fuel pumps.
Fuel pressure is critical on modern (1950's and '60's) vehicles, but much more critical on those in the 1930's and 1940's; as the design pressure for virtually ALL pre-1950 carburetors is less than 5 pounds, and most 2 and 1/2 to 3 and 1/2.
Jon.
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The 1936 Packard would have used a Stromberg EE-23 carburetor. The EE-22 has a 4-bolt base, whereas the EE-23 has a three-bolt base. The confusing part is that the EE-23 uses an EE-22 bowl. The EE-23 would have EE-23 on the throttle body, and EE-22 on the bowl.
The 1401 and 1403 used different size carburetors (both are EE-23's). The 1401 carburetor is rare. The 1403 carburetor is almost non-existant. Using a 1401 carb on a 1403 will cause excessive fuel consumption, as the venturi is too small to support the 1403 engine.
The venturi size is cast on the side of the bowl (as a fraction). The 1401 would be 1 3/32, while the 1403 would be 1 3/16.
Jon.
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Bill (Buicksplus) - you type faster than I. <img src="http://forums.aaca.org/images/graemlins/wink.gif" alt="" />
Jon.
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Before throwing rocks at your rebuilding ability, try attaching a heavy duty jumper cable from the ground terminal of the battery to one of the starter attaching bolts.
Slow cranking is often due to a poor electrical ground,
Jon.
as new fuels become more volatile, vacuum systems give more and more trouble.
Vapor Locking
in Packard
Posted
"Vapor lock is a myth"??? <img src="http://forums.aaca.org/images/graemlins/shocked.gif" alt="" />
Making a statement such as the above, simply because one has never experienced vapor lock, is like me saying that hurricanes never exist! Well, I have never seen one in Missouri!!! <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />
Vapor lock most certainly does exist, normally inside the fuel pump, as that is where the largest concentration of heat (from the engine) contacts the fuel. While the fuel pump will still pump vapor, the effiency is greater reduced, and the supply to the carburetor is then interrupted.
Vapor lock may also occur, although less common due to pressure, in the fuel line between the fuel pump and the carburetor, if the fuel line is too close to the exhaust system. Vapor lock of this type will virtually only occur during idle conditions, when fuel demand is extremely low. Vapor lock under this condition will normally not cause stalling, unless the vapor condition spreads back to the fuel pump. As long as the fuel in the pump does not vaporize, the pump will eventually push the vapor through the carburetor. Vapor lock of this type will manifest itself as a very unstable idle, as the fuel level in the bowl will vary with incoming liquid/vapor. Use of an electric pump may not help this type of vapor lock.
Modern fuels are much more susceptible to vapor lock than gasoline from the 1960's and before.
Generally, the best defense against vapor lock is a "vapor return line", which would "T" from the main fuel line at the fuel pump or, better but obviously not original, at the carburetor. The vapor return line should be smaller than the fuel line, and goes back to and dumps into the fuel tank. As the vapor return line is smaller, there is more resistance to fuel flow, and the carburetor would then have first "dibs" on the fuel. Fuel not needed by the carburetor is shunted back to the tank; thus allowing the fuel pump to continue pumping.
This "fix" has the added benefit of maintaining a lower temperature of fuel delivered to the carburetor. Cooler fuel means marginally more power and fuel economy. The rule of thumb is that a 10 degree F. reduction in fuel temperature in the carburetor bowl is good for 1 percent increase in power and economy.
Electric pumps (my opinion) are fine if properly installed. This means wiring the pump with some safety device (normally an oil pressure switch); and either removing the original fuel pump completely, or leaving the original pump in place, but removing the "guts" and pipe the fuel internally straight through the pump. Electric pumps are "pusher" pumps, not suction pumps; and as such, must be mounted near the fuel tank for good results.
The biggest problem with electric pumps is the failure of the installer to understand pressures. ALL carburetors have design maximum pressure. MOST carburetors produced before circa 1955 have design pressures of LESS than 5 pounds, with a majority having a maximum of less than 4 pounds. Original gravity feed systems will generally have less than 1 pound. Too much pressure at the carburetor and fuel goes everywhere.
One other comment: a couple of posters have mentioned adding diesel to the fuel. "Skinned Knuckles" magazine did some testing on this issue a few years ago. I forget the exact percentage added; but knocking and pre-ignition was encountered prior to any noticable reduction in volatility. These were tests conducted by engineers specifically to determine if any benefit would occur. And while I do not have the equipment to scientifically duplicate this testing, experience gives me the exact same results. Again, others may have differing opinions. If it works for you, do it.
Jon.