Saturday, 28 January 2012

Freeway run; check #2 plug

Test run 15km up the freeway and back again. Pulled number two plug to check it out...

Old Plug #2

Old Plug #2


New Plug #2
New Plug #2

Thursday, 26 January 2012

Engine Tuning

After concentrating hard on what was required for rego, now that the big Chev is road legal it was time to see what condition the engine was in.
The Australia Day holiday gave a prefect opportunity to spend some time on the Chev, so JtC made the trip north.

The day before (25/01/2012) I grabbed from Rare Spares a Dist Cap, Dist Rotor and points.
Plugs came out and generally looked pretty sooty so rich running or plugs too cold. Also, the colour change on the outside electrode was generally pretty close to the tip which shows retarded timing (pictures to come).

The spark plug leads (wires) read between ~ 12 and 15 thousand ohms and were cleaned with wax and grease remover and re-routed to tidy things up a bit.

Next was compression test, done on a cold engine...

Cylinder #1 ~ 160 psi dry
Cylinder #2 = 152 psi dry
Cylinder #3 = 160 psi dry
Cylinder #4 = 158 psi dry
Cylinder #5 = 110 psi dry/138 psi wet
Cylinder #6 = 156 psi dry
Cylinder #7 = 147 psi dry
Cylinder #8 = 108 psi dry/110 psi wet

...where wet is a test after squirting some oil down the spark plug hole.

#5 is reading low and ~ 30 psi increase with a squirt of oil seems to point to leakage past the rings.

#8 is also reading low and the fact there is almost no change with a squirt of oil seems to point to a burn valve.

New plugs (NGK B5ES) were gapped to 0.030" and put in. A new distributor cap (Bosch GD607) and rotor (Bosch DR65) went on also.

I picked up a new contactor set/points (Bosch GD143V) and condensor (DC10) as well, but it looks like the Impala has points with an integrated condensor (Bosch GD45 I believe). Might need to do a swap, though JtC reckons the existing points are in great nick.

Joe reset the dwell to 30 deg and gave it a short hit around the block; felt a bit doggy so advanced the timing (remember the plug reading earlier) and a second drive showed it goes a LOT better. Might cop more advance as it 'aint pinging yet.

Finally, Joe adjusted the reverse light switch so the reverse lights come on when the car is in reverse... as well as adjusting the Park/Neutral cut-out so the car starts in Neutral now.

Thanks Joe!