Air pressure manifold for valve repair

Apparatus for use in repairing internal combustion engines by admitting air under pressure into selected cylinders of the engine comprises a manifold including an inlet fitting for connection to a source of compressed air, at least two primary outlet fittings on the manifold, two corresponding primary spark plug hole fittings, and primary hoses connecting the primary outlet fittings to corresponding ones of the hole fittings to provide at least two primary air circuits. The manifold also has at least one secondary air circuit comprising an outlet fitting including a normally closed check valve, at least one secondary spark plug hole fitting and a secondary hose connecting it to a nipple fitting which can interlock with and open the associated check valve. With four secondary circuits the apparatus can be used with a large variety of engines, including in-line 4 and 6 cylinder; 2, 6, or 8 cylinder V-type, and 4 and 6 cylinder opposed type.

BACKGROUND OF THE INVENTION 
This invention relates to the repair of overhead valve mechanisms for 
internal combustion engines. For many years it has been known that certain 
valve train repairs can be accomplished without removing the cylinder head 
or heads. Typically, broken or weak valve springs, or related parts, can 
be removed and replaced by removing the valve cover and whatever of the 
rocker arms as are necessary. Such repair operations are possible on both 
push-rod and overhead cam assemblies. 
With the more recent use of high speed, high compression engines, and with 
metalurgical and other quality improvements in overhead valve components, 
the parts that require interim repair or replacement are the valve stem 
seals or shields. These are intended to inhibit flow of lubricant along 
the valve stem, through the valve guides and into the cylinders. Wear or 
failure of these seals or shields can result in excessive lubricant 
consumption and/or fouling of the corresponding spark plugs or cylinders. 
Often, engines can be repaired for many additional miles (or hours) of 
efficient satisfactory service, merely by replacing the valve stem seals 
at relatively little expense. 
U.S. Pat. No. 1,898,720 of Feb. 21, 1933 illustrates and describes devices 
for admitting air into cylinders from which valve spring tension has been 
released. Typically this procedure has been accomplished one cylinder at a 
time. 
SUMMARY OF THE INVENTION 
The present invention provides a manifold member through which a selected 
plurality of cylinders, e.g. one bank of cylinders in opposed or V-type 
engines, can be pressurized simultaneously. According to the invention, 
one such manifold can be constructed for use with any of 3, 4 or 6 
cylinder in-line, 4, 6 or 8 cylinder opposed, or 4, 6 or 8 cylinder V-type 
engines. With in-line engines all cylinders can be pressurized, and with 
opposed or V-type engines one bank at a time can be pressurized. 
The manifold member is provided with an inlet fitting for connection to a 
source of compressed air, and such inlet fitting may optionally include a 
manually operable control valve. The manifold is fitted with at least two 
primary outlet fittings and two corresponding cylinder (spark plug hole) 
fittings, connected by suitable lengths of primary hose, making up primary 
air circuits. The member of primary fittings can be greater, but air flow 
is direct through these primary circuits to the cylinder, thus two primary 
fittings allows maximum flexibility in use of a given manifold. The 
manifold also is fitted with at least one (preferably two) secondary 
outlet fitting, corresponding secondary cylinder fittings, and 
corresponding secondary hoses, which make up secondary air supply 
circuits. 
The secondary circuits have quick disconnect fittings, preferably at the 
manifold, so they can be removed from the assemblage when not needed. 
These quick disconnect fittings include check valves, of conventional 
design, that close unless the secondary circuits are completed and used. 
Thus, by adding one or more secondary circuits the mechanic can quickly 
arrange the manifold assembly to correspond to the job confronting him. He 
can then pressurize simultaneously the number of cylinders he wants and 
quickly make the necessary repairs. 
The principal object of the invention, therefore, is to provide a manifold 
assembly for pressurizing multiple cylinder, comprising a manifold member 
with an inlet fitting, at least two primary air circuits outgoing from the 
manifold directly to cylinder fittings, and at least one secondary air 
circuit which also incorporates a normally closed check valve that allows 
air flow into and through the secondary circuit only when it is assembled 
to the manifold; and to provide such a manifold assembly which is easily 
and quickly adaptable for use in repairing a wide variety of engines. 
Other objects and advantages of the invention will be apparent from the 
following description, the accompanying drawings and the appended claims.

DESCRIPTION OF PREFERRED EMBODIMENT 
The head 10 of an engine includes a valve train gallery 12 which normally 
is fitted with a cover (not shown). Each cylinder has at least one intake 
valve IV and exhaust valve EV supported in guide tubes 14, and having a 
valve spring 15. The spring is seated against the head around the upper 
end of the guide tube and presses upward on a retainer ring 16 which is 
held to the valve stem by a spring clip 17, thereby urging the valve head 
to close against the corresponding port within the head, over the 
combustion chamber. The valves are opened in sequence by the usual rocker 
arms (not shown) which mount in the head in conventional fashion and are 
actuated by cams and/or push rods in known manner. These parts are omitted 
from FIG. 1, as if they were removed preparatory to working on the valve 
springs, etc. however it is assumed that the head 10 is still fitted to 
the engine block. 
Each valve is fitted with a seal 20, usually of a suitable inverted 
elastomer cup, which fits tightly to the valve stem and over the upper end 
of the guide tube 14. To replace these seals 20 and/or the valve springs 
15, the valve cover and rocker arms are removed, the spring is compressed 
to relieve pressure on the spring clip 17 which is then withdrawn, and the 
retainer ring, spring, and seal can be removed. 
To hold the valve seated, stem full up, during this operation it is 
customary to pressurize the engine cylinder with compressed air as 
explained in the aforementioned U.S. Pat. No. 1,898,720. However, in 
working on multi-cylinder engines, particularly replacing all the seals 
20, it is desirable to pressurize all the cylinders in one bank. 
The manifold assembly provided by this invention allows the mechanic to 
accomplish this pressurizing easily with a substantial variety of engines. 
The main manifold 25 has an inlet fitting 26, which may optionally include 
a control valve 28. The manifold has a plurality of primary outlet 
circuits 30, each of which includes an outlet fitting 32 on manifold 25, a 
flexible connecting tube 33 of suitable length, and a cylinder fitting 34 
adapted to be threaded, for example, into the spark plug opening of a 
selected cylinder. Each of the primary circuits is under pressure whenever 
air under pressure is supplied to the manifold. 
The manifold 20 also has one or more secondary circuits 35, each of which 
includes a manifold fitting 36 onto which a normally closed check valve 38 
is mounted, to block air flow from the manifold. These valves are of 
conventional type and are opened upon insertion of a snap-in nipple 
fitting 39 attached to one end of a flexible tube or hose 40 that has a 
cylinder fitting 34A, of the same type as fitting 34. The secondary 
circuit parts 39, 40, and 34A are supplied in numbers (usually four) and 
lengths as required. 
With the inlet fitting connected to a compressed air source if valve 28 is 
opened the primary circuits are pressurized. A desired number of secondary 
circuits are added by plugging into one or more valves 38, at which time 
each of those are available to be pressurized. Unless the assembly is 
being used with one bank of an opposed 4 or V-4 engine, at least one 
secondary circuit will be added. Thus, by having on the manifold 25 two 
primary fittings 32 and four secondary fittings 36, with check valves 38, 
the assembly is quickly readied for use with a large variety of engines. 
While the form of apparatus herein described constitutes a preferred 
embodiment of this invention, it is to be understood the invention is not 
limited to this precise form of apparatus, and that changes may be made 
therein without departing from the scope of the invention which is defined 
in the appended claims.