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.

[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

[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

[Andrew H.]

Yesterday we were lucky to have our friend Neil (red jersey) come along to double-flare our brake lines. He is a retired A-Grade mechanic of 40 years experience who has done this job a thousand times, so we are now confident that they have been done properly and will be reliable. Working conditions are difficult at present with wind and cold rain outside. We work in two sheds neither of which are very warm or weatherproof and they are separated by a muddy track. Roll on summer!!!

[maple_leaf_eh]

Originally Posted by Andrew H.

... Working conditions are difficult at present with wind and cold rain outside. We work in two sheds neither of which are very warm or weatherproof and they are separated by a muddy track. Roll on summer!!!

And this is why Lucifer seems to be a preoccupation with the Hammond Barn gang. Sometimes making the workshop fit to work in is half the day.

[Andrew H.]

Today I cut a new stencil for the truck out of clear plastic sheet, scaling it off the photo. The designation T9 shows that "Te Aroha III" was the 9th Truck in T patrol of the LRDG. The letters T9 are white or desert-yellow on a matt black square and they are placed on the front RHS mudguard, the tailgate and both sides of the tray. I know you can buy ready-made stencils but I enjoy cutting them myself with a craft knife (especially inside by the heater on a miserable day like today!). I have already made stencils for the truck number "L4618825" which appears on both sides of the bonnet, and "INSPECTED" which is on the front bumper. I could not cut out the centre of the "9" in the T9 stencil without leaving a big hole, so I will have to spray it on like that and then tidy it up with a small brush afterwards. Onwards and upwards.

[Andrew H.]

On reflection, I think the outline of my number "9" is a bit top-heavy and may need re-drawing, as we like to be as historically accurate as possible. My mates are suggesting that T2 would be more appropriate for "Te Aroha III" as the truck was re-numbered T2 for the Barce raid in which the LRDG destroyed thirteen enemy planes on Barce airfield and damaged many others. Nearly all of the trucks in T patrol (including "Te Aroha III") were destroyed by retaliatory enemy fighter attacks, as they scurried back to base after the raid.

[Igor Shadrin]

Hi Andrew,
Highly appreciated with your lovely project, and dreaming of my own...
Mind bringing my opinion...
The lower part of the "9" character at your drawings seems to be a bit different:

[Andrew H.]

Thanks Igor,
Yes I agree with you and I have made a new drawing, which I think is more accurate. However, we may decide to use T2 instead - not sure yet.

[Igor Shadrin]

Andrew, I also tried to correct it. It's not that perfect, but maybe it will help. Also attached the 1/35 kit decals scan.

[Mike Kelly]

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!

[Dinty]

That looks very smart indeed, looking forward to the next installment cheers Dennis

[Ilian Filipov]

Originally Posted by Andrew H.

... and "INSPECTED" which is on the front bumper.

Hi Andrew,
Yep, the front bumper was the usual place for this stencil on LRDG Chevies (where present), but the one who painted it on T9/L4618825/Te Aroha III apparently was in disagreement with the rules. Note on her the "INSPECTED" stencil is on the right fender, facing forwards, starts approximately behind the marker light and runs to the bonnet sides diagonally behind the headlight fairing, ending under the net/canvas/sandmats front bracket.
HTH
Cheers!

[Andrew H.]

Hi Ilian,
That's news to me! I will have another look at my photos. Or maybe you can refer me to the relevant photo?
Andrew

[Andrew H.]

Hey I have just noticed it. Well spotted Ilian !! I have never seen "inspected" placed there before, on any LRDG truck. We will have to change ours for historical accuracy.

[Ilian Filipov]

Hi Andrew,
The only picture showing some of those non-standard markings on T9 is well known to you, it is from the IWM collection, Catalogue number E 12348, this one:
http://media.iwm.org.uk/iwm/mediaLib...at=photographs
The place of the "INSPECTED" stencil is well visible if you know what to look for. The font is typical for this stencil, something like that:
http://www.fonts101.com/fonts/view/U...305/GI_Stencil
Also note that Te Aroha III has no census number stenciled on the front bumper, just a small "V" in the center, below the hole for the hand crank.
Have here a picture you may also like. Sorry but I can't recall from where it came. Some T-patrol vehicles in line, Te Aroha III in front, her name is very well visible. Behind her are T1/L4618820/Tirau II and T4/L4618942/Te Paki.



HTH
Cheers!

[Andrew H.]

Thanks Ilian,
Yes your first link shows the photo I looked at to find the correct stencil position after you mentioned it. Its not very clear so I attach a sketch showing where I think it is meant to go. I have certainly never seen it like that on any other LRDG truck. Do you have the book "Kiwi Scorpions"? It has many good photos, although few of them are clear enough to see any really fine detail.

[Ilian Filipov]

Hi Andrew,
Indeed, the IWM picture isn't much good, being too bright. But since the PhotoShop was invented such problems aren't problems anymore
The part of the photo of interest was enhanced a bit and I think it is more user-friendly yet:



Only this part enlarged:



How I see the place of the "INSPECTED" stencil, somewhat crude and approximate rendering but as close as I was able to do it:



Sorry for the pic, but there is no real Chevy 1533X2 in my garage, so I was forced to use my 1:76 model for this.

Regretfully I don't have the book "Kiwi Scorpions" but I know it is good one. I hope some day it will be within my reach and I also hope I'll find some new photos in it. BTW, I suspect the pic of the trio I've posted above is from this book.
Cheers!

[Andrew H.]

While we are talking about the historical accuracy of the LRDG stencils, I have recently found a pdf describing and explaining the change from T9 to T2 on the Te Aroha III truck (see attached). However I cannot remember where I found this information and therefore cannot quote the source.

At this stage we have more or less decided to adopt T9 as shown in post#175 above, as the basis for our truck.

[Ilian Filipov]

Hi Andrew,
Thanks for that, very interesting info. Must be cross-checked with other sources, though. For example I cannot agree the census number position "on the upper third of the right-hand side panels of the tailgate" was standard. Yes, on the upper third they were, but on R5 the W.D. number was in the middle, on S7 it was on the left, etc.
Cheers!

[Andrew H.]

Yesterday we attached the running boards. As we had only one front r/b bracket in very poor condition, we decided to make two new brackets from scratch (painted red in the photo). Another reason for making new front brackets is that the original "top hat" spacers welded to the under side of both running boards, were so badly rusted that they were un-usable. That created a 50mm gap between the running board and the original brackets, so we made our new front brackets 50mm higher. We then filled the gap on the rear r/b brackets with a wooden spacer. We have not yet bolted the LHS mudguard to the running board, but it looks like it will be a nice tight fit.

Purists will note from the photo that our mudguards do not have the correct curve at the front (near the bumper) for LRDG configuration. We may decide to fix this later, but right now it is not a high priority.

[Andrew H.]

Today we made and installed new sills for the running boards from 2mm sheet steel, made new floor boards from 20mm plywood (the original steel floor was toast) and bought four used radial tyres. The modern tyre specification equivalent to the original 10.5 x 16 inch tyres used by the LRDG is 265/75/R16 but strangely that outer diameter is too small compared to the tyres shown in the WWII photos. The second-hand tyres we bought are significantly larger at 315/75/R16 but much better-proportioned (see pic).They are worn but have enough tread for our purposes. We gave up looking for correct 10.5 x 16 sand-pattern tyres with highway speed capability, a long time ago. But we will have to remove that Yokohama brand name!

[Lang]

Andrew

Nice job.

I have a set of 11.00 - 16 NDT pretty worn but still legal and not too old if you want them free in Brisbane.

Regarding oil pressure. I took a 1945 Chev ute with Motto from Istanbul to Normandy and during the preparation was alarmed by low oil pressure. Changed gauges to eliminate error.

Once the vehicle got hot it would run at around 7psi if you let the revs drop say labouring up a hill it would go back to zero. Did the whole trip and it is still driving back here in Australia trotting along now at 5psi 10 years later with no problems.

I started a serious investigation on the 216 motor.

1. Factory recommended hot oil pressure for a new vehicle 13.5 lbs @ 2621 rpm ! I am sure this weird number is a result of the Owner's Manual Editors asking what oil pressure should the driver look for at 30mph and the engineers could not help themselves and converted it to engine rpm at that speed in the more technical specificatons.

2. GM did not want to put oil pressure gauges in the 216 military Chevrolets because people became alarmed but the Army insisted.

3. I have looked in numerous manuals for vehicles fitted with 216 motors and under oil pressure (if mentioned at all) the best I can find find is "indicating"

4. One source discussed the possibility that gauges reading double what they should were fitted to some vehicles to make people happy - great idea but true or not?

People get confused with 235 and Blue Flame motors that ran at normally expected oil pressures.

So, if your new engine sets off at 25 dead cold and drifts down to 12 or 14 hot you are on the money.

The oft repeated myth that 216 motors ruin the front big end because when going up hill the oil goes to the back and it does not get fed by the "splash" feed is just that - an old wive's tale. Many people believe "splash feed" means the cranks going into the oil in the sump each turn. If they did that the motor would shake itself to bits. The big ends are fed by small sprayer pipes directed on each journal, up, down or sideways all the journals receive the same oil. The mains get the benefit of direct gallery oiling from the huge pump pressure and, as Dave says above, a few drops manage to stagger to the top of the engine to oil the cam and rockers..

Lang