Engine cylinder cooling jacket
A coolant jacket for an engine cylinder bank having longitudinally aligned cylinders includes upper, lower and side walls defining two inlet flow galleries extending along the intake and exhaust sides of the cylinder bank and communicating with the upper ends of the cylinders. Two outlet flow galleries extend along the intake and exhaust sides of the cylinders and communicate with the lower ends of the cylinders and pairs of side flow slots extend between the upper and lower galleries and around the intake and exhaust sides of each of the cylinders. The side flow slots are separated along longitudinal edges from the slots of adjacent cylinders. Preferably, cooling fins extend into the flow galleries, forming pockets at the ends of the flow slots, the fins being impacted by coolant flow directed into the pockets to improve cooling of siamesed portions of the cylinders. Additional features are disclosed.
1. A cooling jacket for an internal combustion engine having a cylinder bank including a plurality of longitudinally aligned cylinders centered on spaced parallel axes and having upper and lower ends, the cooling jacket comprising:
upper and lower jacket walls extending outward from the upper and lower ends of the cylinders and intake and exhaust side jacket walls between the upper and lower walls and enclosing opposite charge inlet and exhaust outlet sides of the cylinders;
the walls defining two inlet flow galleries extending along the intake and exhaust sides of the cylinder bank and communicating with the upper ends of the cylinders, two outlet flow galleries extending along the intake and exhaust sides of the cylinders and communicating with the lower ends of the cylinders, and pairs of side flow slots extending between the upper and lower galleries and around the intake and exhaust sides of each of the cylinders; the side flow slots being separated along longitudinal edges from the slots of adjacent cylinders;
whereby cooling fluid introduced to the top of the cylinders through the inlet flow galleries is divided and directed down through the side flow slots of the several cylinders and collected into the outlet flow galleries for discharge to a heat exchanger.
2. A cooling jacket as in claim 1 wherein the intake side galleries and the exhaust side galleries are separated so that the intake side galleries communicate only with intake side flow slots and the exhaust side galleries communicate only with exhaust side flow slots to separately distribute cooling fluid to intake and exhaust sides of the cylinders.
3. A cooling jacket as in claim 1 wherein the longitudinally aligned cylinders of the cylinder bank have siamesed portions between each of adjacent pairs of cylinders and include a cooling fin between the adjacent cylinders and extending laterally between longitudinally adjacent side flow slots to transmit heat from the siamesed portions to the coolant in the adjacent flow slots.
4. A cooling jacket as in claim 3 wherein the cooling fins extend into the flow galleries, forming pockets at the ends of the flow slots the fins being impacted by coolant flow directed into the pockets to improve cooling of the siamesed portions of the cylinders.
5. A cooling jacket as in claim 4 wherein the galleries extend along laterally outer edges of the cylinders forming inwardly curved portions between the cylinders which direct coolant from the flow galleries toward the fins between the cylinders to further assist cooling, spaces outward of the fins allowing coolant to flow past outer ends of the fins to cool subsequent cylinders connected with the galleries.
6. A cooling jacket as in claim 1 wherein the inlet flow galleries have decreasing flow areas from a first cylinder at inlet ends of the galleries to a last cylinder at distal ends of the galleries and the outlet flow galleries have increasing flow areas from the first to the last cylinder to aid in distributing coolant flow equally to the cylinders.