Engine Loom Pt. 2

Sometimes you work for hours but see very little visible progress at the end of it and that describes my weekend perfectly despite putting at least 12 man hours into the build.

As the LS engine has a sensor behind the starter motor I had to finish drilling the hole in the bulkhead to pass the wiring through for the ECU. A simple 35mm hole and the lots of careful/forcing of the wires to get them through the hole followed.

Once they were all in the engine bay and the cam sensor was connected it was time to move onto batter wires.

This included the battery positive, earth cable and AK loom to the starter motor and what become obvious very quickly is that I needed to make additional holes through the body (near where AK put their 1 inch hole). This was not easy as you have to kneel in the drivers seat area and crawl into the footwell then drill sideways on. This is a manoeuvre even a contortionist might struggle with and being a man of larger proportions made this even more difficult. Once complete it was easy enough to connect the wires as follows:

1) White AK loom wire to starter solenoid

2) Red AK loom wire to main starter connection

3) Red thick battery positive wire to starter main connection

4) Earth thick battery wire to engine block

Some of you may be asking why I haven't run a second battery wire from the alternator in this stage. This is because I am mounting my battery cut-off switch near the drivers side scuttle bars. The wires will therefore go:

Battery      >

                      Cut Off Switch   >  Starter Motor & Powered Accessories (e.g. ECU)

Alternator  > 

This design does two things; first if you have an accident and cut the power it will cut the engine. The standard AK design (where you put it on the negative) could allow the car to earth out (on another car for instance) and it would carry on running.

The second thing this does is that it addresses a problem I was advised about by Dave from Canems ECU who advised that in many of the car electrical issues he is asked to diagnose, the problem is typically a bad earth caused by these cut-off switches, whereas when they are on the positive feed the car seems to be much better.

This is also the reason I have run a main earth wire the length of the car to attach to the block as it will guarantee a good earth connection. The wire attaches to the block with a smaller wire also to the chassis to aid earth of anything that is attached to the chassis at the front of the car.

Once the starter motor was bolted into place it was time to move back to the top of the engine. It didn't take too long to connect all the sensors back into place following which what seemed like an age to clamp it all into place and loom conduit and tape where necessary to tidy it all up. As with anything a job can be done quickly but attention to detail makes all the difference in the end result.

I got lucky and the Edelbrock cover fitted perfectly with no fettling required - it's nice to have at least one easy bit of the build :-)

The last job I managed to achieve was running the breather pipes for the valve covers. The LS engine has enough breathers to connect them with a small 4 way adaptor to the air intake without using the AK inlets so I have just capped them off with rubber caps.

Like I said earlier - there's no much to show that can easily be pictured but here's a picture from the top of the engine.

There is still a few jobs left to do in the engine bay such as:

1) Make and fit a coil relocation bracket

2) Make and fit the HT leads

3) Extend the lamda sensor wires as my cable route means they are a little short

4) Attached the water pump hoses to the heater

5) Clamp the heater wires in place

6) Attached the steering column

7) Fit the bonnet

I have a couple of days off working coming up next week so hopefully I'll make good progress then.