US1982596A

US1982596A - Multiple port charge forming and distributing manifold

Info

Publication number: US1982596A
Application number: US532151A
Authority: US
Inventors: Moore Arlington
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-04-23
Filing date: 1931-04-23
Publication date: 1934-11-27
Anticipated expiration: 1951-11-27

Description

' AQMOO'RE Nov. 2.7, 1934.

MULTIPLE PORT CHARGE FORMING AND DS'IRIBUTNG MANIFOLD Filed April 23. 1931 z'sheets-sneex 1 N iilllll m38 l mvENToR Arlznqlon Moore BY w C n I E L ATTORNEYS 'Nov'. 2,7, 1934.

Af MOQRE 1,982,596 MULTIPLE 'PORT CHARGE FORMING'AD DISTRIBUTING MANIFOLD Filed April 25, 1931 2v Sheets-Sheet 2 uw W1 f lNvl-:NToR Ar/z'nqon Moore APaternal Nov.27,1934 l .l 1,982,596

UNITED STATESPATENT OFFICE MULTIPLE PORT CHARGE FORMING AND DISTRIBUTING MANIFOLD Arlington Moore, New York,` N. Y. Application April 23, 1931, Serial No. 532,151

7 Claims. (Cl. 12S- 52) My invention relates to means for distributing maintain the charge in a homogeneous condition the charge materials to the cylinders of an iIlduring the travel thereof through the branch pasternal combustion engine, particularly eight-cylsages to the ports thereof.

inders-in-line engines, or engines of a greater Anotherobject of the invention is to provide *5 number of cylinders, and the same has for its a construction of the character specified in which 60 Object to provide a simple, compact, and eicient the passages thereof are formed toeiect equal construction which is capable of effecting subdistribution of the charge to the ports While mainstantially uniform distribution of the charge mataining the same in a homogeneous condition and y terials in a homogeneous condition to the cylincausing the sameto become or remain cool so as ders. not to reduce the volumetric efficiency. 65

Another object of the invention is to provide a Other objects Will in part be obvious and in construction of the character specified in Which part be pointed out hereinafter. the multiple ports thereof receive the charge ma- In the accompanying drawings:

, terials through a common conduit. Fig. 1 is a plan of one form of manifold con-` l5 Another object of the invention is to provide a struoted according to and embodying my said 70 construction of the character specified in which invention;

the passage thereof is disposed to positively de- Fig. 2 is a sectional elevation thereof on the fiect the charge materials into the first or inner line 2 2 of Fig. 1; port Without materially interfering with the pas- Fig. 3 is an enlarged end view thereof With sage of the charge to the remote port. the branch of the intake conduit removed; 75'

Another object of the invention is to provide a Fig. 4 is an enlarged section on the line 4-4 construction of the character specified in which of Fig. 2; the passage thereof is formed to distribute the Fig. 5 is an inverted plan of Fig. 4; and

` charge materials to either port Without undue de- Fig. 6 is a diagram illustrating the construcl ilection of the charge or other interference with tion of the intake conduit. 80 the passage thereof. The manifold embodying my said invention, as

Another object of the invention is to provide a shown, is particularly adapted for an eight cylconstruction of the character specified which deinder engine having four intake ports in the livers the charge materials substantially equally cylinder block, each to two cylinders, and six quantitatively and qualitatively to the several exhaust ports. The intake and exhaust yports are 85 ports. arranged in the same straight line. Four port Another object of the invention is to provide a manifolds, prior to the present invention, have construction of the character specified in Which not been favored for use in practice because of the passage thereof is formed to compensate for distributional defects therein, the dual manithe greater distance of travel of the charge in fold either with or Without dual carburetion be- 90 passing to the remote port. ing largely used. With dual carburetion it is Another object of the invention is to provide a diflicult to get the tWO CarburetOlS t0 Supply fuel construction of the character specified in which at the same rate, causing' roughness of engine the multiple ported branches thereof are formed perfOrmanee, While With Single CerburelJOIl the 40 separate or detachable from the entrance or cendual manifold comprises two sets of branches 95" tral portion thereof. of unequal length having communication with Another object of the invention is to provide a the riser in offset relation to each other, whichconstruction of the character specified in which is liable. to disturb the distribution because of the passage thereof is formed to distribute 01- turbulence or other causes. My inventionenables direct the charge to either port while allowing J611e use 0f a'fOuI DOI manifold OI uufOIm dis 100 drainage of fuel and maintaining adequate vetribution of the charge 'to the cylinders Without locity of the charge in its travel to the remote reliance upon the above expedients now resorted port. to in practice.

Another object of the invention is to provide a The manifold embodying my said invention inconstruction of the character specified in which cludes as features thereof the inventions shown, 105

the passage formation is supplemented in causing described 'and Claimed in my impending applicaequal or uniform distribution of the charge malJiOnS Serial N0- 513,804, filed Feb- 6 .1931. and terials to the cylinders by the application of ex- Serial No. 514,105, filed Feb. 7, 1931. The contraneous heat to the fuel component so as to effect Structions disclosed in said appliCaOuS, aS in 5 Substantially COmPlete Vaporization thereof and this, are adapted to vaporize the fuel component 110 and 22a.

enroute to the engine cylinders, to maintain adequate charge velocity for the stable entrainment of the fuel component without sacrice of Volumetric efficiency, to provide adequate facilities for drainage of the branches during initial operation and for vaporization of the fuel thus drained, to concentrate substantially the hottest portion of the intake conduit contiguous to thepoint` of subdivision or deflection of the charge stream into the branches for causing the vaporization of fuel particles discharged through or thrown out of the charge stream at said point enroute to the engine cylinders, and to render the thermal efficiency of said central heatedl portion substantially maximum to cause fuel vaporization at a rate to prevent accumulation of fuel in said heated portion and thermal decomposition of fuel to form tarry products liable to impair the thermalv eiiiciency of the heated portion.

The fuel vaporizing and charge distributing manifold embodying' mysaid invention is also adapted for use with carburetors or fuel supplying devices of various types such as with the apparatus disclosedv in my -copending application Serial No. 525,992, flied March 20, 1931 and while the construction is particularly adapted for distributing charge mixtures containing fuel -of high volatility, such as gasoline, charge mixtures containing less volatile fuels may be as eifectively distributed thereby in homogeneous admixtlne with the air.

In ordinary constructions the incoming charge picks up condensed fuel from the intake manifoldwalls. Thecondensation or loading up of fuel in the intake manifold usually takes place during periods of low speed operation. The accumulated or condensed fuelswept into the engine cylinders, especially when the throttle is opened wide, causes waste of fuel, oil dilution, non-uniform distribution with temporary overrichness of the mixture in certain of the cylinders, and other detrimental effects, resulting especially in roughness of engine operation. While various expedients have been resorted to in order to obviate these defects, none of them has proved very successful.

In my invention I rely upon the suitable vapplication of heat to the intake conduit whereby the fuel component of the charge is completely vaporized and maintained homogenized enroute to the intake ports, and the maintenance of this condition is preferably supplemented or helped by providing branches of progressively decreasing cross-section such as disclosed as a feature of the intake manifolds of said applications Nos. 513,804 and V514,165 and of my application Ser. No. 234,417, filed November 19,` 1927,` thereby promoting uniform distribution to the intake ports with resulting smooth, powerful and economical engine operation.

Referring to the drawings, the intake manifold 10 (the form `illustrated being of the downdraft type) is preferably located above theexhaust manifold `12, being associated therewith for heating purposes. The charge mixture passes into the manifold through the central neck portion or descender 14 formed integrally with the exhaust manifold and into the branches 16 and 18 and out through the

ports

20 and 22 and 20a The branches 16 and 18 are preferably separately formed and are detachably connected to the central portion 14 as hereinafter more fully described.

With the form shown, neck 14 leads downwardly to communicate with the branches at substantially the middle of the manifold and immediately above the entrances to its branches, and at this point a distributing chamber 24 is provided from which the mixture is supplied to the manifold branches through

openings

26 and 28.

Entrances

26 and 28 are of enlargedcross-secvtional areas as compared to the cross-sectional tion, as indicated at 32, has a curvature such that the charge, following the same, is positively deflected or directed intothe Iport 22-22a. The straight outer portion 34A of the manifold has a communicating junction with elbow portionSO at the outer bend 32 thereof as indicated at 36, said junction comprising a portion 38 merging with the straight portion 34 and the curving portion 30, which portion 38 has a reverse curve relative to curve 32, The outer or

remote port

20, 20a communicates with portion 34 .through the curving elbow portion 40 having a curvature at 42 of longer radius than the radius of the curve 32 to insure easier deflection of the charge through

port

20, 20a.

When an intake valve in communication with the port 22, 22e is opened, the intake valve communication with port 26, 2f)a then being closed, the charge is guided and deflected by the elbow portion 30 through said port 22, 22e, the curvature allowing an easy sweep of the charge through the port. The opening formed in the outer bend of the elbow 30 by the junction at 36 reduces the wall area of the elbow and hence the drag or friction on the charge as it sweeps through port 22, 22e. When an end cylinder is being filled, the charge entering the branch through

entrances

26 or 28 is deflected by the reverse curved portion 32-38 into the portion 34 located in off-set relation tothe axis of the

entrance

26 or 28 but parallel therewith. The deection however is substantially less than the deflection rof the charge through port 22, 22e, the curvatures also being such as to insure an easy sweep of the charge into the portion 34.

vThe branches 16 and 18 each preferably comprises anupper part 4 of substantially uniform cross-section, preferably semi circular, from the inner end thereof to the elbow 40 thereof, and preferably horizontal, and a lower part 46 at the base thereof merging intothe upper part44 and likewise extending from the inner end of the branch into the elbow 40 thereof and gradually decreasing in cross-sectional area or depth towards each elbow, the upper part 44 forming the major part of the branch and the` lower part 46 the lesser part. The lower portions 46 jointly with the upper portions 44 form passages providing the relatively

large entrances

26 and 28 and gradually decreasing in cross-sectional area to said elbowsy 40.

'Ihe desired inclination of the fioor of the intake conduit branch and the tapering thereof as a whole is obtained as illustrated in Fig. 6, representing successive cross-sections taken on the lines y, and e of Fig. V1. 'Ihe cross-section at the elbow 40 is a circle a: having a radius r. The

ports.

cross sections of the upper portion 44 from the elbow inwardlyare partialcircles 1c', x" having the same radius` r, the centers c of the several circles lying on the same horizontal line. The cross sections however are enlarged :pro-

`gressively towards the inner end, of the branch,

the lower portion 46 having'cross-sections conforming to partialv circles a, b, havingthe same radii r and described about `centers c', c. located vertically below the centers aand progressively increasing in distance therefrom, the' partial `circles a, b, merging `with the partialcircles xl, xl.

By progressively enlarging the general contour of the branch at the bottom, the branch is made to incline downwardly towards the center of the manifold at a substantialangle for drainage purposes, as indicatedv at d, Fig. 6. At the same time the branch passage varies in cross section as a whole at a rate `determined solely by the variations in cross section of, the relatively smaller lower portion 46, the rate of variation in cross section of the branch passage as a whole being less than the rate of variation in cross-section of the lower portion 46. The lower portions 46 therefore provide sunicient inclinations for drainage and effect relatively slight progressive restriction Aof the branches to cause acceleration ratio proportional to distance traveled by the charge materials to effect uniform delivery through all The Abranches 16 and 18 are cast as separate open ended units or members with flange portions 48 contiguous to their inner ends adapted to register or flt corresponding bosses or portions 50 formed on the central portion 14 and disposed about the entrances or

openings

26 and 28 therein. The branches are secured in position by means of the bolts 52 extending through the ilanges 48 into the bosses 50, gaskets 54 being interposed between the ilanges and the bosses for producing a tight joint. The gaskets 54 are preferably composed of a material thermally insulating the branches from the central portion 14. The exhaust manifold 12 is preferably of the type in which the exhaust gases are conducted from the cylinders towards the middle and out through a central outlet 56, the branches58 and 60 thereof having openings 62 adapted to register with the exhaust passages of the cylinder block.

In the present embodiment of the invention the exhaust gas manifold branches are disposed in spaced relation to the intake branches, providing cooling air gaps 64 therebetween., which,as shown at Fig. 2, increases in Width towards the outer ends of the manifold.

The intake conduit 10 at the junction of the branches thereof opposite the neck 14 is provided with a wall `portion 66 extending downwardly into the exhaust passage coaxiallyk with and in spaced relation to the walls of the outlet 56, i. e., substantially at the point where the'two exhaust gas streams unite, which is substantially the hottest part of the exhaust gas. The upper end of the portion 66 opens into the intake manifold and the lower end thereof is closed by a dome shaped member or wall portion 68 in spaced relation thereto to form a substantially annular chamber '70 opposite the inlet 14 at the point of subdivision of the charge mixture stream but lying substantially beyond the path of travel thereof, the upper end of the dome preferably lying `entirely below the plane of the intake branches.

such as copper.

The portion 68 is preferably separate from the portion 66, the.v former preferably being composed of `a material 'of high heat conductivity, The 4interior 72 of the portion or member 68 is exposed to the hot exhaust gases, the member preferably having means formed to insure positive circulation of the hot exhaust gases therethrough.

This means in the present embodiment of the invention includes a `deflector or baie 74 forming an integral extension of the relatively massive lower portion '76 ywhich forms a heat reservoir integral with the dome 68 and lies Within the exhaust gas outlet 56. The batile 74 extends into the chamber 72, substantially bisecting the same and terminating short of the top thereof. This forms a return bend passage having an entrance,

78 through which a portion of the hot exhaust gases are bypassed from the outlet portion 56 and directed into contact with upper portion of the dome. The bypassed exhaust gasespass out directly toatmosphere through an outlet opening 80 at the opposite end of the return bend passage 72, thereby accelerating the circulation and keeping the dome heated to a maximum. The dome 68 may be knurled or roughened to transfer heat to the fuel at maximum rate and reduce film deposit. The member 68-76 is preferably threaded into the portion 66, as indicated at 82.

The exhaust manifold 12 is arranged to supply heat to the neck 14 of the intake manifoldby surrounding the neck with a jacket extension 84 of the exhaust manifold, which jacket is vented directly to atmosphere through outlet opening 86'at the upper end thereof to insure positive circulation of hot exhaust gases through the jacket 84. i i

The exhaust gases discharged through the outlet openings 80, and 86 are carried to a remote point through a common conduit 88. The conduit 88 at its upper end has a iiange 90 adapted to vengage the portion 92 about the outlet 86and to be secured thereto by yscrews 94. The conduit 83 vextends downwardly substantially parallel with the descender 14 and with the main exhaust discharge outlet 56. The exhaust gases discharged through outlet opening 80 are conducted through a transverse conduit or pipe 96 communieating with and connected to the pipe 88 at 98. The pipe 96 has a telescoping end portion 100 extending into the outlet opening 70, and a flange 102 for securing` the. same to the portion 56 by screws 104.

The neck 14 is terminated in a sharp angle, vas indicated at 106, to shed off any liquid fuel from the neck wall into the air stream.

The annularwell 70 between the walls 66 and 63 is subject on both sides to the most concentrated heat from the exhaust gases. Themassive metal member 76 of copper, catalytic alloys, or the like, serves as a thermal reservoir for uniform supply ofheat to the dome 68 by conduction.

An air bleed through passage 108 serves to supply air for scavenging fuel in Crucible 70 to facilitate the returning of the vapors into the intake during engine operation, or if liquid fuel should accumulate in the well 70 it can run out through said passage 108.

The fuel, when gaseous injection is employed for blasting the same into and through theair stream inneck 14, is very thoroughly pulverized by reason of its greater velocity, and by reason of its resulting great surface lexposure to the air Vabsorbs heat therefrom very rapidly. Rapidity -of heatabsorption is of *utmostl importance because of the extremely short interval of time available and which lis longest with the slow charge travel during engine idling and shortest with the high speed charge travel encountered at'full power operation. Heavy fuel, when used, is capable of taking up more heat than on operation with lighter and more volatile fuels. The heat of the charge is thus reduced so as to favor lhaving high density charge productive. of good volumetric eniciency, and the fuel is in large part put into such condition-gasied and/or vaporized and/or in fogged or like highly divided state, that it is suspended inand carried along with the air stream without condensation or deposition on the conduit walls as 'the air stream branches or changes direction on its way to the engine cylinders.

. The stream of blasted fuel, or fuel carried by the air from an ordinary carburetor, usually contains some fuel portions or droplets heavy enough to continue their substantially straight line travel without material deflection with the moving air. Unless given a liberal application of heat, this fuel portion would wet and load up the walls of the intake manifold.

By changing the direction of the intake manifold passage in the neighborhood where the blasted or inertia impelled heavier fuel particles strike the conduit walls, I can carry the lighter fuel particles thoroughly suspended in the air stream towards the engine cylinders with the air stream, and by applying heat of the exhaust gases to the intake conduit walls, I am enabled to secure a selective application of heat to vaporize and suspend this fuel without undesirably heating the air of the charge.

The illustrated mode of securing such effect is by directing the fuel blast or fuel charge mixture downwardly in the intake manifold neck 14, which at the bottom branches to each side, while applying heat of exhaust gas without such neck by surrounding it with the exhaust gas chamber 84, thus providing a hot surrounding walladapted to be contracted by and apply heat to the heavy particles of fuel spreading to the outer region of the blast fuel stream, and by providing the hot cup or crucible '70 in line with the discharge end of the neck 14, where the convex heated portion 68 also radiates heat to the charge passing to the cylinders or is struck by and supplies vaporizing heat tothe'heavy fuel particles projected thereon to complete the vaporization.

Inasmuch as the exhaust gas from all the exhaust ports is directed into the vicinity of the crucible 70, the crucible is subjected to the maximum temperature available. The annular crucible is in Contact at both sides with the exhaust gas, and provides a doubly extended surf ace, compared to the surface of an ordinary `non-annular cup, for heating the projected fuel, the heating effect being augmented by the positive deflection of a portion of the exhaust gases into the interior of the dome 68. By disposing the convex dome 68 in the path of downwardly projected fuel, the impact of the fuel particles thereon cause the particles to be reflected therefrom or to be deflected without tending to conglomerate or accumulate thereon, as such particles would be likely to do if the surface were fiat, an extended downwardly curving surface beingprovided along which the fuel particles may gravitate until vaporized, thereby enhancingvaporization or fuel porizing effect is also assisted by theI provision of 4'a down-draft manifold in which the fuel particles arecaused to positively gravitate in the direction of air flow into the crucible and onto the dome, the incoming particles being subjected to air passing throughthe opening 108 and moving in the opposite direction.

The temperature available with my manifold, particularly at the higher speeds, are sufficient to cause the fuel particlesv to assume the spheroidal state, evidenced by the fact that the fuel does not form tarry or other solid precipitates within the crucible 50 and the vapor produced is substantially dry and less liable to condense.

Extraneous heat for vaporizing and homogenizing the fuel component is thus applied'in an efficient manner prior to the deflection of the charge into the branches, and during the downward travel thereof. The cross-sectional area of the neck 14 is preferably greater than the mean cross-sectional area of the branch to `retard the velocity of the charge during the vaporizing stage, and thev length of the neck 14 is such that substantially complete vaporization of the fuel component is effected by the several heating means 68 and 84 during the time interval of vertical travel of the charge, thereby forming a stable homogeneous mixture, the stability of which is enhanced because of the spheroidizing effect of the crucible 70. By applying prelimi-` nary heating or part of the heating to the neck 14 through jacket 84, localized wetting down of the vertical passage due to cold walls is also prevented, and washing down of deposited fuel into the branches to cause non-uniform distribution to the cylinders or other detrimental effects cannot occur.

The heating capacity of the dome 68 depends on the area of the surface thereof and on the flow of exhaust gas through the interior thereof. The diameter ofthe dome 68 is preferably made greater than the diameter of the passage through the neck 14 in alignment with said dome so that projected fuel particles passing from the neck 14 are sure to contact with said dome to complete the vaporization.

The application of extraneous heat substantially in the locality Where the fuel is introduced into the air in a highly comminuted or atomized state, and before such fuel condenses on the wall, facilitates vaporization, and the application of heat for vaporizing is accomplished here Without appreciably expanding the charge, because the heat absorption by the fuel is then high relative to the heating. The dome 68 has a high heat radiating capacity because of its thinness and composition but the heating action thereof does not appreciably affect the charge density because theidome lies substantially out of the path of travel of the charge and the heat absorption is high.

By the combined effect of the contact of the fuel particles upon these wallsurfaces, and the efficient application of heat thereto, thehomogeneous suspension of the fuel in the air is completed, without undue air heating and loss of volumetric efficiency through air heating Vand charge density reduction.

'Io maintain the homogeneous suspension of the fuel in the air so attained, I now keep the sectional area of the intake manifold branches, and, therefore, of the moving charge stream as low as practicable Without unduly restricting sof ,.inders through the branches 7g branches, thereby rendering lcharge How, thus keeping the charge moving rapidly and avoiding any slowing up or expansion of the charge material on its way to theengine cylinders, which would be productive of condensation, and I Valso preferably progressively in,- crease the charge velocity during such travel, asl by progressive'reduction of the cross-sectional area of the manifold branches from the common neck portion thereof to the engine cylinders.

The intake branches 16 and 18, being separated from the exhaust manifold 12 by gaps 64, are substantially entirely insulated from the exhaust manifold by the surrounding air, `or other cooling medium, so that no heating is'appliedto the charge in the branches after deflection of the charge thereinto, whereby a cool dense charge is caused to enter the cylinders in a homogeneous condition. The intake branches 16' and 18 because of their detachability can be and are preferably composed of a material of relatively high thermal conductivity, such as cast aluminum, capable of rapidly conducting away surplus heat to cause the charge to the interior walls of the manifold branches can be made much smoother than where cast iron is used, reducing skin friction tending to retard the 'i tion to the cylinders in substantially the proportions for which the carburetor or other fuel supplying device is economically set.`

The oors 46 taper from least at the outer ends of the intake manifold branches to largest depth ,iwhere they lead down into the annular well 70.

The decrease in section of the intake manifold speeds up the charge as it travels to the engine cylinders thereby opposing any tendency `of fuel particles to deposit on the walls.

By venting the annular well to the atmosphere at its bottom through passage 108 any liquid fuel which may run back from the branches and accumulate in well 70, as for example, at starting, or upon pumping in extra fuel for acceleration, will not simply boil or distill ofi, but can either run out through such vent, or, in case the intake depression is relatively high, be carried along upwardly as Vapor with air admitted through the opening 108.

That the hot wall surfaces are of sunicient area and mass to supply vaporizing heat to the relatively large quantity of liquid fuel blasted or otherwise projected thereagainst during full power operation insures plenty of heat being '.available when the same walls are used for communicating heat to the fuel when supplied in smaller quantities, even though the temperature of such walls is then lower. Owing to the heat available through the walls of the Crucible '70, yaporization of fuel is accomplished without the formation of tarry products liable to reduce the thermal efficiency thereof because of the insulating effects of such tarry formations.

The charge so produced in passing to the cyl- 16 and 18 remains in a homogenized state, without substantial precipitation of fuel, due to the efficient Vaporizing and spheroidizing action imparted thereto prior to the entrance of the charge into the unnecessary the apbecome cool and dense,` or to maintain such charge in that condition. Byk the use `of a 1naterial,.such as cast aluminum;

By my invention, the application of heating t0` the charge is restricted to the central portionof the manifold, as the chargeftravels downwardly a somewhat retarded velocity. No heat 'is applied to the branches which are constructed to maintain the charge cool and also to maintain suiliciently high velocity thereof 'to retai'nfthe fuel in suspension. The neck orcentral portion slight variation in the ther- 14 of the intake manifold and the exhaust mani-` fold .12 'are formed integrally preferably of cast iron. `[The use of cast aluminum ispreferable for the branches because of its relatively'greater thermal conductivity and capability of being made smooth. The branches are therefore made detachable or separate from the cast iron portion to enable the utilization of such heterogeneous metals. Making the branches separate facilitates molding or casting of the parts and allows access to the interior thereof for machining the inner surface. Separate or detachable branches may be supplied in various shapes or sizes to enable iitting thereof to various types of engines and to engines of different characteristics, and this method of construction enables the particular branch to be adopted which suits the individual needs. The jointedA connection at the inner end of the branch also provides compensation for strains and stresses due to the heating and cooling of the manifold, this type of construction being less liable to crack than an integral construction. The aluminumbranches 16 and 18 are separated from the exhaust conduit by the air gaps 64 and are insulated from the heated portion by the gaskets 54. The result is that the charge in the branches becomes or remains cool and dense, obviating the danger of overheating the charge so as to impair the volumetric eiiiciency.

Having thus described my invention what I claim and desire to secure by Letters Patent is:

1. An intake manifold comprising a multiple ported conduit, a portion of said conduit including means for deilecting the charge into the inner port, and said conduit decreasing in crosssectional area towards the outer port.

2. An intake manifold comprising a multiple ported conduit including an elbow entrance portion for deilecting the charge to the contiguous port, and-forming a portion of the passage to the remote port, said conduit decreasing in crosssectional area towards the remote port.

3. An intake manifold comprising a branch having multiple ports, and including an elbow entrance portion for deflecting the charge to the inner port and an offset outer portion leading to 145v the more remote port and having a communicating junction with the outer bend of said elbow portion, said conduit decreasing in cross-sectional area along said elbow portion and outer portion towards the remote port.

Vi, An intake manifold comprising a branch lio having an entrance thereto at one end and a plurality of ports beyond said entrance at the saine side of said branch, the upper part of said branch forming a substantially horizontal partial passage of substantially uniform cross-sectional area and the lower part of said branch being inclined downwardly relative to the upper part from adjacent the 'outer port to the entrance and forming a partial passage of decreasing cross-sectional area in the direction of the outer end thereof, whereby to decrease the branch passage in crosssectional areaasa whole at a relatively lesser rate than the rate of decrease of the lower passage portion, the cross-sectional area of the branch at the inner port'being greater than that of said inner port.

5. An intake manifold comprising a multiple ported branch including an elbow entrance portion for deflecting the charge to the inner port and an outer portion having a communicating junction with said elbow portion at the outer bend thereof, the base of said branch being inclined downwardly substantially from the outer port to the entrance to the elbow portion.

6. An intake manifold comprising a branch having a plurality of ports disposedv longitudinally thereof in substantially a horizontal plane, said branch including an elbow `entrance portion for directing the charge to the inner port and 'an outer portion extending to the remote port and having a communicating junction with the elbow portion at the outer bend thereof in offset relation to the entrance to the elbow portion, the upper part of said branch including said portions being of substantially uniform cross-sectional area, and the lower part thereof being of progressively increasing depth towards the inner end thereof for draining the branch and producing a branch passage decreasing in cross-sectional area as a whole towards the outer port.

"7. An intake manifold comprising a multiple ported branch including an elbow entrance portion for deecting the charge towards the inner port, a portion having a communicating junction with the elbow portion at the outer bend thereof, and an elbow portion at the outer end of the second named portion leading to the outer port, said second named portion decreasing in cross-sectional area to said outer elbow portion, and said outer elbow portion having a greater radiusvof curvature than the inner elbow portion.

ARLINGTON MOORE.

yso