Restoration of Hull 731- Carrier, MG (Aust) Mortar Carrying

Darrin Wright · #1 02-08-13, 00:32

Here is the PCV set up on my engine, as depicted in my BGC manuals.
Lucky to have this as I think most people back then would have discarded additional stuff on an engine.
When reading the manual, I am not sure how this works in conjunction with the filter at the rear of the intake manifold and the sump breather/outlet.

I have also noticed that early engines did not have an oil filter, perhaps the PCV is a later engine item.
As I have an early BGC, the lack of an oil filter makes the routing of the oil lines at the LHR of engine a little bit easier. My engine also lacks the oil filter return bolt/fitting on the fuel pump mount to intake manifold.

Lynn Eades · #2 02-08-13, 02:24

Darrin, the normal sump vent on a car is sucked clear by the draft of air going under the car. This doesn't happen in a carrier because the engine is fully enclosed. The positive crank case ventilation is activated in a high manifold vacuum situation drawing the "blow by" fumes in the crank case into the inlet manifold. Clean air is drawn through the breather at the rear to replace the scavenged fumes. I imagine it was the poor filtration of this breather, as much as the air cleaner that caused such early engine wear in carriers in the north african desert campaign. Nigel Watsons book mentioned that The life of an engine was as low as 2 to 3 thousand miles. Trucks were probably not much better.
Thanks for the pictures.

Euan McDonald · #3 02-08-13, 02:44

Darrin and Lynn,
Referring to the carrier manual the early carriers with the 38-41 engine uses a different system to the one on Darrin’s engine (42 and on )

Lynn Eades · #4 02-08-13, 03:06

Euan, the first and last pictures are what I have tried to explain. The first picture is a standard set up, which can't really work when the whole engine is enclosed. It needs the road speed draught under the forward lower vent to draw the fumes out and away.
I believe the 1942 engine had no outlet vent at the bottom (as you were pointing out) If your engine doesn't have it, it should definately use a PCV system. If you have a PVC system, that vent could be blocked off.
Thanks for the pictures, they help a lot. I'll be looking for the wafer (adapter) for under the carb now)

Darrin Wright · #5 05-08-13, 10:47

Found the camera, so here are the pics from 123

Pics show the Right head on, accelerator linkage bolted to the head and my youngest tightening the exhaust manifolds.

Darrin Wright · #6 05-08-13, 11:22

The engine is all together, I have timed the distributor as best as possible using the tool.
With all the reference material that I have, I have found that they all describe timing of the distributor slightly differently using different tools and methods, this has and has not helped.
Timed stage 1 (right points) fairly good, did not have much success with stage 2 (left pints), so got it to where it is. Not sure how/if this will work. This may also indicate that I have something wrong inside the distributor.

After reading Lynn's post/info on oil flow in these engines, I blocked off the external holes at the LHR of the engine and checked that there was no internal plug. I also bought a hydraulic packing plug, with an in-hex drive slot, that has the same thread as the internal thread in the oil gallery- this will be cut/machined down later to divert the oil into the oil cooler (when fitted).

Filled the engine with a cheap 20-50W oil, and with crappy weather outside decided to use the Jeep as a slave, and attempt to start the engine.
After a little while had oil at the sender unit (and down the side of the engine), blanked this off and then primed the fuel pump and carby.
I think the battery is getting down in the Jeep, as the V8 would wind over for a little bit then I would have to stop and let the Jeep recharge.
Will have to get a pair of 12V batteries to assist.

Engine did not fire, so checked the distributor rotation & timing, checked that a spark was going to the correct lead and plug, also re-adjusted the points. Still did not fire.

Will have to think this over a bit more...moved on to other tasks in next post.

Darrin Wright · #7 05-08-13, 11:30

Moved on to adjusting the RH backing plate with my die grinder, enlarged the hole slightly so that the backing plate would fit over the actuator shaft in the mounting plate.
Fitted the backing plate and also fitted the LH brake drum as I managed to paint it earlier in the week when the weather was good.
Finished fitting the exhaust elbows into the hull floor, then moved on to the exhaust pipes (had these cut & bent by exhaust shop) and creating the Y section outlet.