Our LRDG Chev

[motto]

Andrew, the FLOW to the rockers is controlled by a restrictor which doubles as a connector nipple where the oil comes out of the side of the crank case. The rockers don't need much lubrication, they certainly don't need pressure, just the presence of oil is enough.
Engine oil PRESSURE is pretty much controlled by the distributor valve which creates a back pressure in the same manner as a relief valve.Of course engine wear also plays a part when the engine has been in service.
Oil tapped off from upstream of the distributor valve feeds the main bearings, camshaft bearings, timing gears and rockers.
Oil that passes through the valve supplies the sump manifold for lubrication of the big ends.
It sounds complicated but it isn't really.

David

[Andrew H.]

Thanks David, we will have another look at it tomorrow.

[Andrew H.]

Recently we have been working on the drive-shaft and universal joints. The original drive-shafts could not be used so we had to source some from a cannibalised hulk that we have access to. Yesterday we did a bit more work on the motor, tweaking the timing, carburetor and fuel pump and running it very briefly (still no radiator) to check that everything is working properly. Un-muffled, she makes a throaty roar at full tit!

We were very pleased to see that the drive-shafts are aligned properly and rotate smoothly and without any vibration. When we pressurised the brake-lines for the first time, we found several leaks at the junctions. Tightening them up did not fix the leaks. We think this might be because we only single-flared the pipe, as we don't have a double-flaring tool. Would anyone like to comment on single versus double-flaring the brake line pipe?

[Grant Bowker]

MB-F1 and MB-C2 both specify double flares for CMP trucks. So does the Ford shop manual for Conventional and Modified Conventional vehicles. I don't have access to the corresponding Chevrolet manual. With the use of double flares being so widely specified (up to current vehicles), I would assume your truck probably used them too. If this is correct, then the fittings and junction blocks would all be designed to match the thickness and profile of double flares and might very easily not seal properly on a single flare. My understanding is that double flaring also reduces the chances of the line cracking from the free end. Since single flares are cheaper to make, I think the manufacturers must see a benefit in using double flares that outweighs the added cost.

There are a variety of double flaring tools that vary widely in price and ease of making acceptable double flares. Nickel-copper and steel lines are generally easier to form than stainless steel. Among the cheapest I found on ebay was http://www.ebay.com/itm/Tubing-Doubl...610665&vxp=mtr
I did all-new lines for a C15A in stainless using this http://www.eastwood.com/professional...ring-tool.html without any spoiled flares. I had done some stainless flaring with a tool like the cheaper variant with mixed results and decided I would go with the Eastwood tool when doing the complete truck. I found it much less frustrating to use than the simple traditional (cheap) machine. One limitation is that it can only flare up to about 1-1/2" from an existing curve in the line. It may work better to plan your lines to flare and then bend if possible although this gets harder to do if the same applies at both ends of the line.

[Andrew H.]

Thanks Grant and Motto, so it would seem that double-flaring is the way to go.

[Lynn Eades]

Andrew, single flare is illegal in N.Z. for WOF / COF.
Many so called cheaper "double" flaring tools work o.k. with soft tubing(copper, also no longer legal) but not well, with brake tubing.
Now that you have samples remove your pipes to a brake shop and have them done properly.
I assume you have single circuit brakes? Even if you had a tandem circuit, you still want them the best you can.

[Andrew H.]

Thanks Lynn,
Well that settles it then. Brakes are too important to take short-cuts and in any case if single-flaring is illegal there is no option but to double-flare. Thanks everyone for putting us back on the straight and narrow! Its a good example of why this forum is such a great resource.
Andrew

[motto]

All components of conventional automotive braking systems to my knowledge are manufactured for use with double flared connections. There is no way that I would attempt to use single flare connections unless in an emergency in a remote area. I highly recommend that you procure double flared lines one way or another.
A few years ago I finally got around to replacing my old double flaring kit with which I probably achieved a 50% success rate with a modern Eastwood kit purchased online. It wasn't cheap but turns out an excellent job almost every time and I'm very glad I invested in it.

David

[Mike K]

Originally Posted by motto

All components of conventional automotive braking systems to my knowledge are manufactured for use with double flared connections. There is no way that I would attempt to use single flare connections unless in an emergency in a remote area. I highly recommend that you procure double flared lines one way or another.
A few years ago I finally got around to replacing my old double flaring kit with which I probably achieved a 50% success rate with a modern Eastwood kit purchased online. It wasn't cheap but turns out an excellent job almost every time and I'm very glad I invested in it.

David

I have the same tool, the guy in the red jumper is using - I got it at a REPCO store years ago . It is OK most of the time, but sometimes the flare just doesn't work out , it squashes the edges sideways .

Talking about single flares ..the various WW2 Morris Commercials I have , all have original copper brake pipes fitted and they have SINGLE FLARED ends. I was amazed when I saw this but all of them are the same .

[Andrew H.]

Yesterday our mate Neil finished double-flaring the brakes. It was very cold, with a smattering of snow on the nearby hills, so full marks to Neil for coming back to finish the job on such a miserable day. And best of all, when we added brake fluid and pressurised the system there are no longer any leaks! Then we spent some time trying to give the engine a sustained run, but there were persistent fuel line blockages. Also we have discovered a bad leak in the radiator that will have to be fixed. She started great with a throaty roar and then died after a few seconds, but it was long enough to see 20 psi showing on the oil guage. By the time we had the fuel line cleared it was time to call it a day and go home and recover by a warm fire with a stiff whisky.

You can see from the pics that Erics workshop is somewhat "cluttered" but he assures us he knows where everything is. Trouble is the other two members of the team ("Major Cockup" and "General Mayhem") don't, and we spend as much time looking for tools as we do actually working on the truck!

[Andrew H.]

Today we fitted the new (re-cored) radiator and went for a brief drive to see if everything is working properly. There was barely enough room to fit the radiator past the fan and we spent a lot of time trying to install it carefully without damaging it. Then we filled it with water and set off down the tanker track, only to find that it was leaking quite badly. After spending a small fortune on re-coring, we were very disappointed to find it leaking. We still do not have any 10.5 x 16 tyres or a proper petrol tank, so we rigged up a temporary petrol tank clamped to the front bumper. We also need a proper back for the seat. Plenty to keep us occupied in the weeks ahead!