U.S. patent number 3,874,358 [Application Number 05/453,086] was granted by the patent office on 1975-04-01 for engine conversion system.
This patent grant is currently assigned to Crower Cams and Equipment Company. Invention is credited to Harry Bruce Crower.
United States Patent |
3,874,358 |
Crower |
April 1, 1975 |
ENGINE CONVERSION SYSTEM
Abstract
A system for deactivating half the cylinders of an internal
combustion engine to reduce its capacity, as in converting a V-8
engine to a V-4, to reduce fuel consumption and atmospheric
pollution and make the engine more economical to operate. The
pistons of the deactivated cylinders are replaced by piston
substitutes, which are equal in weight to the original pistons and
do not affect balance of the engine, the piston substitutes being
cut away to allow free air flow and avoid pumping action. Spark
plugs in the deactivated cylinders are replaced by dummy conductive
plugs, the valve push rods are removed and the tappets replaced by
fixed substitutes.
Inventors: |
Crower; Harry Bruce (Jamul,
CA) |
Assignee: |
Crower Cams and Equipment
Company (Chula Vista, CA)
|
Family
ID: |
23799151 |
Appl.
No.: |
05/453,086 |
Filed: |
March 20, 1974 |
Current U.S.
Class: |
123/198F;
123/DIG.1; 123/DIG.7; 123/1R; 123/192.2 |
Current CPC
Class: |
F02D
13/06 (20130101); F02B 75/22 (20130101); F02B
69/00 (20130101); F02B 2075/1832 (20130101); Y10S
123/01 (20130101); Y02T 10/12 (20130101); Y10S
123/07 (20130101) |
Current International
Class: |
F02B
75/22 (20060101); F02B 69/00 (20060101); F02D
13/06 (20060101); F02B 75/00 (20060101); F02B
75/18 (20060101); F02d 013/06 () |
Field of
Search: |
;123/198F,1,DIG.1,DIG.7,192B,192R,55UF,55UE,55U,52R ;92/59,72
;417/236 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Myhre; Charles J.
Assistant Examiner: Lazarus; Ira S.
Attorney, Agent or Firm: Brown & Martin
Claims
Having described my invention, I now claim:
1. In a multi-cylinder internal combustion engine, in which each
cylinder has a piston, a spark plug, valves and valve actuating
means, the improvement comprising:
piston substitutes replacing the pistons in alternate cylinders in
the firing order of the engine, each piston substitute having a
diametrical wrist pin receiving bore, an axially extending opening
therethrough, and being equal in weight to the respective replaced
pistons;
and the valve actuating means in the said alternate cylinders being
disconnected.
2. The structure of claim 1, wherein:
said piston substitute has a substantially cylindrical body with
axially extending cut away side portions.
3. The structure of claim 2, wherein:
said cut away portions are flat parallel sides.
4. The structure of claim 2, wherein:
said cylindrical body has a sliding clearance in the respective
cylinder to allow for expansion of the piston substitute.
5. The structure of claim 1, and including:
a dummy spark plug in each of the selected alternate cylinders, the
dummy spark plug being conductive and providing a direct electrical
connection to the engine ground.
6. The structure of claim 1, wherein:
the valve actuating means includes a push rod to each valve and a
cam actuated tappet connected to each push rod;
the improvement further comprising a fixed tappet plug replacing
each tappet and the associated push rod being removed.
7. The structure of claim 6, wherein:
the substitute piston has a substantially cylindrical body with
axially extending flat sides.
8. In a multi-cylinder internal combustion engine, in which each
cylinder has a piston, a spark plug, valves and valve actuating
means, the method of converting the engine to smaller capacity,
comprising:
removing the pistons from alternate cylinders in the firing order
of the engine, and installing in their place piston substitute
equal in weight to the removed pistons and with substantially
unrestricted openings therethrough;
and disconnecting the valve actuating means in the said alternate
cylinders.
9. The method of claim 8 and including the further step of;
replacing the spark plugs in the alternate cylinders with dummy
conductive plugs providing an ignition short circuit to ground.
10. The method of claim 8, wherein the valve actuating means
includes a push rod and a cam actuated tappet for actuating each
valve, and including the step of:
removing the push rod from each valve in the alternate cylinders
and replacing the associated tappets with fixed tappet plugs clear
of the actuating cam.
Description
BACKGROUND OF THE INVENTION
Various techniques have been tried to reduce power and improve
operating economy of an internal combustion engine. If certain of
the pistons and connecting rods are removed, considerable work is
involved in rebalancing the engine. If the pistons are left in
place and the fuel and ignition sources cut off, some means must be
provided to relieve compression, such as by leaving the exhaust
valves open, which creates problems in the exhaust flow. In most
instances, the modifications cause damage to the engine, or
otherwise prevents its return to normal fully operational
configuration.
SUMMARY OF THE INVENTION
The conversion system described herein is simple to install, does
not damage the engine, and can be removed at any time and the
engine returned to normal full capacity operation. The primary
element which makes the conversion practical is the replacement of
half the pistons with piston substitutes, which are equal in weight
to the original pistons and thus do not upset the balance of the
engine. The piston substitutes slide normally in the cylinders, but
are cut away at the sides and through the center to allow free
passage of air. This avoids any pumping or compression build-up in
the deactivated cylinders and provides for lubrication of the
cylinders and piston substitutes by crankcase oil.
Push rods to the valves of the deactivated cylinders are removed
and the tappets are replaced by fixed sutstitutes which do not
contact the cams, the existing valve springs keeping the valves
closed. To prevent damage to the ignition system, the deactivated
spark plugs are replaced by solid conductive dummy plugs, which
short the discharges through the engine ground.
Since the deactivated cylinders will not draw fuel and air, it is
not essential that the carburetor be modified. However, minor
adjustments may be made as necessary in the course of a tune-up on
the converted engine.
The primary object of this invention, therefore, is to provide a
new and improved engine conversion system for deactivating some
cylinders of an internal combustion engine.
Another object of this invention is to provide an engine conversion
system which requires a minimum of modification and can be removed
at any time to restore the engine to normal operation.
Another object of this invention is to provide an engine conversion
system utilizing piston substitutes which do not require
rebalancing of the engine.
A further object of this invention is to provide an engine
conversion system which does not require modification of the fuel
supply and ignition circuitry.
Other objects and many advantages of this invention will become
more apparent upon a reading of the following detailed description
and an examination of the drawings, wherein like reference numerals
designate like parts throughout and in which:
FIG. 1 is a transverse sectional view of two cylinders of a typical
V-8 engine, illustrating the differences between normal and
deactivated cylinders.
FIG. 2 is a diagram of an eight cylinder block, indicating the
order of the deactivated cylinders.
FIG. 3 is a partially sectioned view of a dummy spark plug.
FIG. 4 is a perspective view of a piston substitute.
FIG. 5 is a sectional view taken on line 5--5 of FIG. 4.
FIG. 6 is a side elevation view, partially cut away, of the piston
substitute.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 2, the engine block 10 contains eight cylinders in four
pairs, numbered consecutively 1 through 8. The conventional firing
order is 1 - 8 - 4 - 3 - 6 - 5 - 7 - 2 and every other cylinder is
deactivated in the conversion. Thus cylinders 1, 4, 6 and 7 are
unaffected, while cylinders 8, 3, 5 and 2 are modified, as
indicated by the flat sided piston substitutes 12 in those
cylinders. The converted engine operates as a V-4 on cylinders 1,
4, 6 and 7 in a fully balanced configuration.
A typical pair of cylinders, such as 4 and 3, is illustrated in
section in FIG. 1, the conventional cylinder 14 being on the left
and the converted cylinder 16 being on the right to clarify the
differences. In the conventional cylinder 14 is a piston 18 on a
connecting rod 20 coupled to crankshaft 22. Valve 24 is operated
through a rocker arm 26 by a push rod 28, which is actuated through
a tappet 30 by camshaft 32. The other valve, not shown, is
similarly operated and a spark plug 34 is suitably positioned.
In the converted cylinder 16, a piston substitute 12 is attached to
the existing connecting rod 36. The valve push rods are removed and
each tappet replaced by a tappet plug 38, which may be fixed in
place clear of camshaft 32 by any suitable means, such as a lock
screw or expanding portion, not shown. The valves 24 are held
closed by their existing springs 25 and the rocker arms 26 can be
left in place, since their push rods have been removed. A dummy
spark plug 40 replaces the conventional plug, the dummy being a
unitary element of metal for conductivity, to short the spark
discharge pulse to the engine block. The dummy spark plug,
illustrated in FIG. 3, may be of any suitable configuration, with a
threaded plug 42 to fit the existing socket and a connecting tip 44
to receive the conventional ignition harness connector.
The piston substitute 12 is generally of piston-like configuration,
with a cylindrical body 46, but has flat parallel sides 48
extending from top to bottom to provide large clearances between
the body and the cylinder wall. For some purposes it may be
desirable to obtain the side clearance by channels or grooves
instead of the simple flat sides. Body 46 also shows a large
axially extending core opening 50 completely through its depth. The
top and bottom faces 52 and 54 are flat, making it very simple to
manufacture the unit. A transverse wrist pin bore 56 extends
through the body to receive the existing wrist pin 58 on the
connecting rod 36. The piston substitute has a weight equal to that
of the piston it is replacing, in order to maintain the balance of
the engine. Precise balance can be obtained by drilling or cutting
material away from the body as required.
With the core opening 50 and flat sides 48 allowing substantially
unrestricted passage of air through and on both sides of the piston
substitute, there is negligible resistance to its movement and no
compression or air pumping action. No rings are necessary, merely a
free sliding fit with no play. As an example, the preferred
clearance between the cylindrical body portion and the cylinder
wall is on the order of 0.005 to 0.010 of an inch. Adequate
lubrication is obtained from oil thrown by the moving parts in the
crankcase.
In most V-8 engines it is not necessary to alter the carburetor for
the conversion. The intake manifold is usually divided for
alternate cylinders and the deactivated cylinders will not draw on
one side of the manifold. However, in a comprehensive tune-up it
may be desirable to adjust the idle mixture screws equally to avoid
hesitation above idle. Also, one of the accelerator pump outlet
parts may be blocked and a small bypass hole made in the pump
plunger to reduce the output. All conventional automotive service
procedures are followed in the conversion.
While the conversion is described as applied to a V-8 engine, it is
equally applicable to other multi-cylinder engines, such a V-6, or
V-12. It is not practical to so modify four cylinder or other small
engines, which are already economical in operation.
In vehicles tested the only appreciable effect on performance is in
acceleration, which has been found adequate for all normal driving.
Available top speed remains well above legal limits, since maximum
power is not normally used for cruising performance. Fuel economy
is greatly improved and, with proper tuning, can be almost doubled
compared to that of the original engine configuration. Atmospheric
pollution is also reduced and the useful life of associated
pollution control devices is prolonged.
One great advantage of the conversion is that the engine can be
returned to normal full capacity operation at any time, since no
permanent modifications are made to the basic engine.
Alternatively, for prolonged use at reduced capacity, the
conversion may be switched to the other set of alternate cylinders
for even distribution of wear.
* * * * *