US2733695A - goodridge - Google Patents

Description

Feb. 7, 1956 M. GOODRIDGE TWO-STAGE MANIFOLD AND CARBURETOR Fil ed Feb. 21, 1955 FIG.|.

INVENTOR. LAURENC E M. GOODRI DGE ATTORNEY prohibitive.

United States Patent TWO STAGE MANIFOLD'AND CARBURETOR Laurence M. Goodridge, Clayton, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application February 21, 1955, Serial No. 489,711

7 Claims. (Cl. 12s-s2) This invention relates to internal combustion piston engines having cylinders arranged in parallel rows and, more particularly, to an induction system for this type of engine providing dual manifolds for multi-barrel, multistage carburetion.

The most prevalent form of engines of the type above referred to is the V 8, which is fast becoming the standard in the motor car field. This invention will be described and illustrated as applied to this specific form, although it obviously canbe adapted to most, if not all, known engines of this general type, regardless of the number of cylinders.

At the present time, the motor car manufacturers are extremely power conscious, and each year engine performance 'must be'improved in order to meet the claims of competition. This improvement must be accomplished without basic engine changes, since this cost would be Thus, each succeeding model has made changes in the induction system, because this is regarded as the source of greatest possible gain in engine output. It is well understood in the'artthat better engine breathing characteristics yield better volumetric efficiency and higher torque, and'cooler temperature of the charge increases the mechanical octane rating of the engine to permit an increase in compression ratio.

Of course, all of these benefits could be obtained with individual carburetors for each cylinder, but this presents such obvious technical difiiculties that up to now it has been avoided.

A brief description of V-8 engines and present induction systems applied thereto is included here solely to form a background to better explain the advantages and objects of the present invention.

A V-8 engine has a cylinder block with opposite banks of cylinders, four in-each bank, inclined with respect to one another at 90degrees. Looking down at the top of such anengine, one of the banks of cylinders is slightly ahead of the other. This offset relation between the two banks is sufiicient to permit connecting rods of opposite cylinders to be journaled side by side on the same crank pin of the crankshaft. The four crank pins of the crankshaft are displaced, so that the end throws of thecrankshaft journaling connecting rods one and two and seven and eight, respectively, are exactly opposite. Likewise, the crank pins journaling connecting rods three and four and five and six are opposite but displaced 90 degrees with respect to the end cranks.

. The cylinders are numbered, generally, from front to back, with the odd numbered cylinders 13--5-7 in the bank oifset forwardly. Cylinders 24-6 8 are in the bank oifset rearwardly.

Looking at the front of the engine, if the odd bank is on the right and the even on the left, then certain of the pistons will be in a position to fire each 90 degrees. Forexample, starting at the top dead center for number 1 cylinder, in the first position both 1 and 6 will be at at top dead center. Ninety degrees later, 5 and 8 will be 1 2,733,695 Patented Feb. 7, 1956 2 at top dead center. Ninety degrees later, 4 and 7 will be at top dead center, and ninety degrees later 2 and 3 will be at top dead center. With the above piston positions it is possible, by changing camshaft design for valve timing and ignition, to obtain several firing orders of the cylinders. There are three such systems employed. The one used by the greatest number of car manufacturers fires one cylinder in one bank, two cylinders in the other, one in the first, and then repeates on the second revolution, such as 1--=84-36-5-7'--2. The other two systems employed fire one cylinder in one bank and one in the other alternately, or one in one bank, one in the other, and two in the first bank, and then repeat for the second revolution of the crankshaft.

The reason for the adoption of such firing orders will become apparent from the following discussion relating to induction systems now generally employed. These systems are now standardized, and in alldual manifolds each contains passages interconnecting the two end cylinders in one bank and the two inner cylinders in the opposite bank, with an intake centrally located on top of the engine. Although the firing orders used may seem dissimilar when compared, actually these dissimilarities are primarily due to different systems of engine cylinder numbering. Without exception, firing orders are selected so that intake strokes in the respective manifolds are spaced degrees.

Up until now, improvements in the induction system have been confined to increasing the number of intakes in the dual manifolds and applying, first, dual carburetors, and thenfour-barrel, multi-stage carburetors. One manufacturer has gone so far as to apply two four-barrel carburetors. No attempt 'has been made to improve the manifolding itself so as to obtain the equivalent of individual carburetion, although two four-barrel carburetors of the multi-stage type seems to offer this possibility.

' The present invention is directed to an improvement in a manifold system to obtain all the advantages of individual carburetion by the use of two multi-stage,"four-barrel type carburetors, and thereby eliminate the necessity of heat to aid in distribution of fuel through the manifold. In this inventioma dual manifold is used in which the individual system of passages connects the adjacent four cylindersat eachend of the V-8 engine. Each manifold mounts a fourbarrel, multi-stage carburetor with the barrels so arranged that each primary stage barrel operating singly will furnish the fuel mixture to a pair of intake ports in the engine in the low-speed range. 'When the secondary stage barrels come into operation, each-intake port will be served by both a primary and a secondary, and adjacent intake ports wil be directly supplied from twosecondaries and a primary'stage barrel.

The close relationship between the intake ports and the carburetorrneans short, straight passages communicating directly between the carburetor and the inlet port, so'that velocities through these passages will be substantially those at the intake port of the engine. This feature will contribute to good distribution throughout the low and medium range of engine speeds. At high engine speeds, all of theadvantages of individual carburetion are attained, since each intake port communicates directly with a primary and a secondary stage barrel of the carburetor, and any two adjacent intake ports communicate directly with a primary and two secondary stage barrels of the carburetor, so that adequate capacity is immediately available to supply the intake ports, and this will be true with regular or irregular firing order in each group of four cylinders.

The accompanying drawings illustrate a construction operating in accordance with the principles of the invention abovedescribed.

In the drawings,

Fig. 1 is a vertical section of a V-8 engine taken along a line extending through No. l and No. 2 cylinders.

Fig. 2 is a top plan view of an intake manifold with parts broken away to illustrate the internal construction. Fig. 3 is a side viewof the manifold in Fig. 2 with throttle bodies for carburetors'mounted thereon.

Fig. 4 is a top plan view of the throttle bodies shown in Fig. 3. p

The engine shown in Fig. 1 is a conventional V-8 type with cylinders arranged in parallel rows inclined 90 degrees with respect to one another. Looking at the front of the engine as illustrated in Figrl, the crankshaft rotates clockwise, and the cylinders in' the right bank are offset forwardly of those in the left bank. Those in the right bank will be referred to as one, three, fiveand seven. Those in the left bank will be referred to as two, four, six

and eight.

The cylinder block 10 is a single casting containing all of the cylinders. Fig. 1 shows the cylinder 1 in the right bank, and cylinder 2 in the left bank. The cylinder block 10 has a series of main bearings 11, only one of which is shown, which rotatably support the crankshaft 12. According to general practice, the crankshaft 12 has four separate crank throws, each having a journal or crank pin 13, one of which is shown in Fig. 1. Journaled on the crank pin 13 in side-by-side relation are a pair of connecting rods 21 and 22, which are, in turn, connected with pistons 23 and 24, respectively, reciprocating within the cylinders 1 and 2 during rotation of the crankshaft.

Mounted in suitable bearings between the cylinder banks is a camshaft 25 for operating the valves located in the cylinder heads. In this View, only two of the valves are shown, and both are intake valves.

The valve train for operating the valves includes tappets 26 and 27, which reciprocate push rods 28 and 29 extending to rocker arms 31 and 32 journaled on the rocker shafts 33 and 34. The opposite ends of the rocker arms contact the valve stems for operating the poppet valves 35 and 36. Valve springs 37 and 38 resiliently urge the valves 35 and 36 toward their respective seats.

Each bank of cylinders has a plurality of intake ports in this case, four in each bank. In Fig. l the intake port 41 controlled by the valve 35 supplies fuel mixture to cylinder 1. The intake port 42 controlled by the valve 36 supplies fuel mixture to cylinder 2. The intake ports, in turn, are supplied with fuel mixture through dual manifolds M, each of which has a separate carburetor.

The construction of the manifolds M illustrated in Figs. 2 and 3 is identical. The forward manifold has outlets 51, 53 and 52, 54 which connect directly with the intake ports in opposite banks of cylinders one to four. The rear manifold is provided with outlets 55 and 57 for cylinders three and five in the right bank, and 56 and for cylinders six and eight in the left bank. Mounting pads 61 and 62 each have four inlets, P'P' and S--S', which correspond in size and spacing with the four mixture conduits or barrels of multi-stage carburetors.

Each manifold has star-shaped internal passages in the shape or arrangement of a quadrilateral. The passage 64 connects outlets 51 and 52. The passage 65 connects outlets 52 and 54. Passage 66 connects outlets 53 and 54, and a fourth passage 67 connects outlets 51 and 53. These passages are formed between the outside walls and a star-shaped partition 68. One of the four inlets Pas shown in each of the mounting pads 61 and 62 communicates directly with each of the passages 64 to 67 approximately midway of its length.

Mounting pads 61 and 62 have vertical studs 70 and 71 for attachment of a carburetor on each mounting pad. The particular type of four-barrel carburetor contemplated is one such as shown in the co-pending application of James F. Armstrong, Serial No. 418,049, filed March 23, 1954. This particular carburetor, when modified by substitution of the throttle body such as disclosed and 4 described hereinafter, can readily be adapted to use with these manifolds.

Fig. 3 illustrates two throttle bodies 74 and 75 secured to the manifolds M.- A primary throttle shaft 76 extends through each throttle body 74 and 75 for operating the primary throttles P in each carburetor. A lever 77 secured to one end of the shaft 76 is provided for connection with the usual manual control.

The secondary throttles S in each throttle body are controlled by the throttle shafts 78 and 79 and operated by suction motors 80 and 81, all in a manner completely disclosed in the said Armstrong application. As shown in Fig. 3, the secondary throttle shafts extend through the throttle body above the primary throttle shaft 76. The primary throttle shaft mounts two primary throttles P in the throttle body 74, and two in the throttle body 75, so that all of the throttles P will open simultaneously and in synchronism. The secondary throttle shaft 78 mounts two secondary throttles S which will be operated in unison by the suction motor 80. Likewise, the secondary throttle shaft79 mounts two secondary throttles S, which will be operated simultaneously by the suction motor 81. Throttle shafts 78 and 79 may be interconnected for purposes of synchronization, if desired.

The alternate arrangement of primary and secondary throttles in this invention differs from the usual side-byside arrangement of primaries and secondaries in conventional four-barrel carburetors. There is no reason, however, why a carburetor such as shown by the Armstrong application, when provided with a throttle body of this design, would not be suitable for the purpose of this invention. Possibly some other slight changes would be necessary such as the relocation of the choke valve in that carburetor. Of course, other types of carburetors could be applied, if desired, such as a dual and two singles.

Each of the dual manifolds is completely independent, as is shown in the drawings, but it is contemplated that small balance holes may be provided between the two, if desired. These balance passages could readily be located between the outlets 53 and 55, 54 and 56.

During operation of the engine, fuel mixture will be supplied through the primary mixture conduits or valves of the carburetor intermediate the length of passages 64 and 66 in one manifold, and the corresponding position in the passages in the other. Thus, when the engine is operating on the primaries alone, fuel distribution to each intake port will be through short, direct passages of a capacity preferably matched to each carburetor barrel. When the secondary throttles are open and operating in connection with the primaries, fuel will be supplied to each of the intake ports by short, direct passages, preferably matched in size to the secondary barrels of the carburetor. The supply'of fuel from the primary inlets P to the primary passages and the secondary inlets S to the secondary passages of the manifold give two-stage manifolding combined with two-stage carburetion. In addition, each group of four cylinders is continuously connected in a closed circuit. This closed circuit would negative the effect of pulsations in the flow .on feul distribution because each pulsation would damp itself in a closed circuit, and would amount to a mere momentary change of pressure throughout the whole circuit, so that no reverse flow would occur. A pressure change of this kind would, therefore, have no effect on the directional flow of gases to the outlets of the manifold.

The short, direct passages from each of the primaries and each of the secondaries will communicate directly with the carburetor, so that velocities throughthe carburetor barrels and the intake manifolds will be substantially identical with the high velocitiesdue to pulsations at the intake ports of the engine. The short, direct passages are such as to negative the effect of any accumulation of fuel on the manifold walls, and these two features acting together eliminate the necessity for heat ing except for de-icing purposes. 2

Another feature of this particular manifold arrangement is that each intake port communicates directly with a primary carburetor barrel and a secondary carburetor barrel, and, furthermore, each adjacent pair of intake ports communicates directly with three barrels of the carburetor. Where the firing orders are such as above described in this application, there will be a certain overlapping of intake strokes in the cylinders supplied by each manifold. Thus, in the front manifold the mixture will be simultaneously flowing from outlets 5453 and then 5251, since cylinders 4--3 and 2-l fire in sequence. In the back manifold, mixture will be simultaneously flowing through outlets 56-55 and 55 57, since cylinders 6, 5 and 7 fire sequentially. Under ordinaiy conditions, it would be disadvantageous to interconnect these cylinders in the same manifold because the sequential firing means overlapping intake strokes where one cylinder tends to rob the other of fuel. This cannot take place, however, because, as pointed out, in each instance, each pair of intakes is connected directly with three barrels of the carburetor, so that there will be more than an adequate supply of fuel for both cylinders.

A construction has been described which will fulfill the objects of the invention above set forth, but it is contemplated that other structures will occur to those skilled in the art which are within the scope of the appended claims.

We claim:

1. The combination of an internal combustion piston engine of the type having cylinder intake ports arranged in parallel rows and a fuel induction system for said engine comprising star-shaped manifolds each having a plurality of outlets for connection with a group of adjacent engine intake ports located at the outer periphery of said star, and inlets for said manifolds centrally arranged with, and corresponding in number to, said outlets, each of said inlets being so disposed radially with respect to said outlets that each outlet is directly opposite two adjacent inlets.

2. The combination of an internal combustion piston engine of the type having cylinder intake ports arranged in parallel rows and a fuel induction system for said engine comprising star-shaped manifolds each having a plurality of outlets for connection with a group of adjacent engine intake ports located at the outer periphery of said star, and inlets for said manifolds centrally arranged with respect to and corresponding in number to said outlets, each of said inlets being so disposed radially with respect to said outlets that each outlet is directly opposite two adjacent inlets and each adjacent pair of outlets is in direct communication with more than two of said inlets.

3. The combination of an internal combustion piston engine of the V type having cylinder intake ports arranged in parallel rows and a fuel induction system for said engine comprising star-shaped manifolds each having a plurality of outlets for connection with a group of adjacent intake ports located at the outer periphery of said star, inlets for said manifolds centrally arranged with respect to and corresponding in number to said outlets, each of said inlets being so disposed radially with respect to said outlets that each outlet is directly opposite two adjacent inlets, and a multi-barrel, multi-stage carburetor for each of said star-shaped manifolds and primary and secondary mixture conduits in said carburetor directly connected to said two adjacent inlets.

4. The combination of an internal combustion piston engine of the V type having cylinder intake ports ar ranged in parallel rows and a fuel induction system for said engine comprising star-shaped manifolds each having a plurality of outlets for connection with a group of adjacent intake ports located at the outer periphery of said star, inlets for said manifolds centrally arranged with respect to and corresponding in number to said outlets, each of said inlets being so disposed radially with respect to said outlets that each outlet is directly opposite two adjacent inlets and each adjacent pair of outlets is in direct communication with more than two of said inlets, and a multi-barrel, multi-stage carburetor for each of said star-shaped manifolds with a plurality of primary and secondary mixture conduits arranged side by side in alternate relation in said carburetor and directly con nected to said manifolds with said primary and secondary mixture conduits communicating directly with each of said manifold inlets so that each primary is connected with one of said inlets located between two of said outlets.

S. A fuel induction system for a V type engine comprising a star-shaped manifold having a plurality of outlets for connection with a group of adjacent intake ports in the engine located at the outer periphery of said starshaped manifold, and inlets for said manifold centrally arranged with respect to and corresponding in number to said outlets, each of said inlets being so disposed radially with respect to said outlets that each outlet is directly opposite two adjacent inlets.

6. A fuel induction system for a V type engine comprising a star-shaped manifold having a plurality of outlets for connection with a group of adjacent engine intake ports located at the outer periphery of said starshaped manifold, and inlets for said manifold centrally arranged with respect to and corresponding in number with said outlets, each of said inlets being so disposed radially with respect to said outlets that each said outlet is directly opposite two adjacent inlets, and each adjacent pair of outlets is in direct communication with more than two of said inlets.

7. The combination of an internal combustion piston engine of the type having cylinder intake ports arranged in parallel rows and a fuel induction system for said engine comprising a manifold for opposite pairs of intake ports in each bank of cylinders, a plurality of outlets in said manifold for connection with said group of adjacent intake ports, a plurality of passages in said manifold directly interconnecting each adjacent pair of outlets and arranged in the shape of a quadrilateral, and inlet openings in said manifold centrally arranged with respect to said outlets and each disposed intermediate the length of one of said passages.

References (Jited in the file of this patent UNITED STATES PATENTS 1,365,564 Strickland Jan. 11, 1921 2,097,424 Kolimbat Nov. 9, 1937 FOREIGN PATENTS 515,410 Great Britain Feb. 28, 1938

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