Skip to main content

Firing order of IC engine

The order in which the ignition take place in various cylinders of a multi cylinder engine is called firing order. Every engine cylinder must fire once in every cycle. Three factors must be considered before deciding the firing order in IC engine. These are

Engine Vibrations:

 Load on the bearing should not be imbalanced due to firing order of cylinder so firing order should be kept in such an order that the load is equally distributed on bearings. The imbalance load on the two bearings would result in severe engine vibrations.

Engine cooling

The firing should be in such an order that the cooling system should work in an effective manner. The cooling position should not change its position with time otherwise the task of the cooling system becomes very difficult.

Development of back pressure

There should be sufficient time and space for the exhaust gases to travel in the exhaust pipe otherwise the danger of back flow will rise.
The commonly used firing orders for engines are:
Three cylinder inline engine: 1-3-2
Four cylinder inline engine: 1-2-4-3, 1-3-4-2
Six cylinder inline engine: 1-5-3-6-2-4, 1-5-4-6-2-3, 1-2-4-6-5-3, 1-2-3-6-5-4.

Comments

  1. Great! your blog is very interesting and informative because this blog contains meaningful content.
    If your are looking for these ev charging point operators in india. Our company provides the best services in India

    ReplyDelete

Post a Comment

If you have any doubts.Please let me know

Popular posts from this blog

Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators

Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as minor is along the  direction of maximum stress.

Shell Expansion Plan

It is a two dimensional drawing of a three dimensional surface of the ship’s hull form. This plan is very useful for the following information:It is used for marking the location of a hull Damage on this plan by identifying the strake number , letter and frame number so that the exact location of the damage and also suggested repairs are marked in a localised copy. The shell expansion can be used for finding areas of painting surfaces such as topside, boot topping and bottom areas by applying Simpsons rules directly.  In the shell expansion the vertical scale used is different from the horizontal scale and a suitable adjustment has to be made when calculating areas. This becomes useful in solving disputes concerning areas of preparation and painting. It gives information on the thickness of the original strake which is indicated by the number in the circle shown in the strake.  The quality of steel used is also shown by letters A,B,D E and AH, BH,DH, EH.