TTEC4842 - Automotive Engines

TTEC4842 - Automotive Engines -  practical

18/10/2011 tuesday

start = 1.00pm finsh = 4.30pm

                                                                   Engine Short Block

(Enigne short block)

first thing i started with the engine block was taking everything apart from the block pistons, conrods, crankshaft, ETC

Inspection of pistons

first thing i started with was Inspection of the piston, which i had no pistoon damage on all pistons , no scarfing, so the pistons were in good condition.

Then moved on by measuring the piston diameter, by using a micrometer. 

 

	1	2	3	4
piston	77.93mm	77.96mm	77.97mm	77.97mm
ok/fail	ok	ok	ok	ok

This showed me that the piston were all ok and dont need replacing.

Inspection of cylinder bore

First thing was to inspect the `bore of the block and there was no sign of damage or any scuffing.

then moved on by measuring the bores with a bore gauge at two positions top, , bottem.

Cylinder bore measurement.

		cylineder 1	cylinder2	cylinder 3	cylinder 4
1	first measurement ( direction x)	78.05 mm	78.051mm	78.051mm	78.051mm
	first measurement ( direction y)	78.05mm	78.051mm	78.051mm	78.051mm
3	third measurement (x)	78.05mm	78.05mm	78.05mm	78.05mm
	third measurement (y)	78.05mm	78.051mm	78.05mm	78.05mm
	amount of taper	0.0mm	0.0mm	0.00mm	0.00mm
	amount of ovality	0.0mm	0.001mm	0.0mm	0.0mm
	ok/fail	ok	ok	ok	ok

 this showed me that the cylinder bore measrement meet the specifications some which were 0.1 mm of but didnt matter

Piston clearance

		cylinder 1		cylinder 2	cylinder 3	cylinder 4
(a)	largest boren diameter	78.05mm	78.051mm		78.051mm	78.051mm
(b)	pistoon skirt diameter	77.93mm	77.96mm		77.97mm	77.97mm
	piston to cylinder clearance(a-b)	0.12mm	0.091mm		0.081mm	0.081mm
	ok/fail	ok	ok		ok	ok

 this showed me that all four pistons were in the manufactring specifications.

piston and rings

first thing was i did a visual check on the piston rings for any sign of damage, wear or breakage,.

four of the rings were in good condition, so they dont need replacing.

checking piston ring side clearance

then moved on by checking the clearance of the piston rings using a feeler gauge between the ring and the ring groove.

	ring side clearance
	specification  0.030mm-0.065mm
1	0.051mm ok
2	0.051mm ok
3	0.051mm ok
4	0.051mm ok

 this showed us that the rings clearance is good and it meet the specification. if the rings have any excessive side clearance. if by if the lands wear our or the rings wear out aswell.

checking piston ring end gap

first thing was i put the ring into the cylinder bore, then push the ring down the bore, using the piston to keep it square, until the ring is in the least worn part of the bore. then i checked the ring end gap with a feeler gauge.

	top ring end clearance
	specification  0.15mm  - 0.30mm
cylinder 1	.229mm  ok
cylinder 2	.229mm  ok
cylinder 3	.229mm  ok
cylinder 4	.229mm  ok

The pistons rings didnt require any replacement and they were in the manufactring specifications

Inspecting connecting rods

first thing was is to inspect the rods for any bend twist or any misaligment. i checked my rods is by using the tool called hydrulic rod straightening press.

	bend	twist
1	2.95mm	.508mm
2	1.09mm	.254mm
3	.813mm	.505mm

in this task we couldnt use our rods we used different rods and couldnt get the manufacturing specifications.

Inspecting the crankshaft
main journal specification

diameter = 0.05mm

taper limit = 0.05mm

ovality= 0.05mm

In this task was to measure the main journal using a micrometer to check for (A) which is across and (B) down.

	1	2		3	4	5
diamater A1	49.49mm		49.46mm	49.45mm	49.45mm	49.45mm
diameter B1	49.96mm		49.45mm	49.44mm	49.40mm	49.45mm
diameter A2	49.94mm		49.43mm	49.46mm	49.46mm	49.45mm
diameter B2	49.93mm		49.45mm	49.45mm	49.45mm	49.46mm
ovality A minus B	0.04mm		0.01mm	0.01mm	0.05mm	0.00mm
largest diameter  A1 or B1	A1		A1	A1	A1	A1,B1
smallest diameter A2 or B2	B2		A2	B2	B2	A2
taper  A1 minus A2	0.00mm		0.03mm	0.01mm	0.01mm	0.001mm
STD diameter	49.956mm		49.956mm	49.956mm	49.956mm	49.956mm
smallest diameter (from A or B )	49.94mm		49.43mm	49.45mm	49.45mm	49.45mm
wear			0.506mm	0.506mm	0.506mm	0.506mm

The undersize was 0.50mm that mean main journals were in the manufactring specification.


Big end journals
big end journal specification

diameter = 39.94mm

taper limit = 39.94mm

ovality= 39.94mm

	1	2		3	4
diameter A1	40.70mm		40.70mm	40.70mm	47.70mm
diameter B1	40.94mm		4.94mm	40.93mm	40.94mm
diameter A2	40.93mm		40.94mm	40.94mm	40.93mm
diameter B2	40.94mm		40.94mm	40.94mm	40.93mm
ovality A minus B	0.24mm		0.24mm	0.23mm	0.24mm
largest diameter  A1 or B1	B1		B1	B1	B1
smallest diameter A2 or B2	A2		A2	B1	B1
taper  A1 minus A2	0.24mm		0.24mm	0.23mm	0.24mm
STD diameter	39.94mm		39.94mm	39.94mm	39.94mm
smallest diameter (from A or B )	40.93mm		40.94mm	40.93mm	40.94mm
wear	0.99mm		1mm	0.99mm	1mm

 This was a havey duty crank shaft , and the undersize 0.50mm this was in good condition and meet the specifications.

inspecting the crankshaft

crankshaft deflection specification. Runout 0.04mm ( 0.0016 in ) mm

first thing i put the crankshaft on the 'v' block to measure the crankshaft deflection. which i measured by using a dial test indicator (DTI)

The run out was 0.00mm there was no distortion.

inspecting the cylinder block

did a visual check on the block there was minear scuffing on the top.

The moved on by measuring the cylinder block face distortion in six places.

block face distortion specification   .05mm

6 of the test on the block face distortion were 0.00mm they were in the  distortion specification.

Inspection of timing gears, sprockets,chains,and belts.

camshaft gears or sprockets= there was no damage or wear on the camshaft

crank gear or sprockets= it was clean no wear or any sign of damage

idler gears or sprockets= the tensioners are nice and clean no sign of damage

this showed a good resultsn there was no damage or any wear on the timing belt.

inspect water pump

there was no sign or damage on the water pump, just needed new idle bearing replaced.

inspecting oil pump

the type of oil pump i was working on was a rotory pump. i did a visual check, the rotor pump looks in good condition no damage or any signs of scuffing.

checking clearance

	specification	actual
gear or lobe to housing	0.05mm	.004mm
gear backlash	0.05mm	.004mm
gear lobe to end plate	0.05mm	.004mm
gear to crescent	0.05mm

The oil pump is in good condition and its serviceable.

checking main bearing oil clearance

first thing i did was placed a strip of plasti-gauge across each main journal


Main bearing clearanceThen i installed the bearing and caps to torque specification 54-59 mm
Then i removed the caps and bearing and measured the widest part of the plasti-gauge

specification 0.024-0.042mm
	1	2	3	4	5
oil clearance (actual)	0.038mm	0.038mm	0.038mm	0.038mm	0.038mm
ok/fail	ok	ok	ok	ok	ok

The oil clearance were in the specifications.

 checking crankshaft end play, using The (DTI) first things i set the gauege to Zero and i pulled the crankshaft towards the DTI and i had reading of zero there was no end play on the crankshaft

checking crankshaft end play using the feeler gauge

specifications'0.08-0.242
End play 0.09

This showed that the crankshaft is in good condition and meet the specification

checking the big end bearing clearance

i used the same meathod for the main bearing by using a plasti-gauge across the connecting rod journal.

specification 0.024-0.042mm
	1	2	3	4
oil clearance (actual)	0.038mm	0.038mm	0.50mm	0.038mm
ok/fail	ok	ok	ok	ok

the big end bearing clearance also meet within the specification. i ensured that the crankshaft also should turn freely before doing the measurments.

checking the connection rod end play, using a feeler gauge.

specification -0.30mm
	1	2	3	4
con-rod-endplay (actual)	.559mm	.457mm	.457mm	.599mm
ok/fail	fail	fail	fail	fail

this showed me that my cond rods fail within the specifications because there was a big end play. this means they need to be replaced with a bigger once.

IN conclusion

the block i was working on was a haveay duty block which i worked on. the block was nice and clean looked in good condition. there was no damage on the pistons or the rings. the rods were nice and strait. there was couple of bolts missing on the block before i started working on it. but the block i worked on was nice and in very good condition.