As my camshaft oil pipe was leaking at one of the joints and I didn’t fancy trying to re-braze it I needed a new one. I didn’t fancy a fixed pipe one like the original since if the positions for the banjos are not exactly correct then they will be a struggle to get it on. Just how accurate are the ones you can buy? So I decided to go for a flexible pipe. Barratt has a two piece one ( part # C25619F) but why deal with one extra joint? Barratt also has a single piece one ( part # C25619U) but the price at $235 is more that double the two piece one. Moss Motors has a one piece one ( part #37-35533)for $90. I’m pretty new to E types but in my limited dealings with Moss and Barratt I think that Barratt has the better quality. But I ordered the Moss one because of the cost difference. Here is what it looks like compared to the original ( left hand side of photo):-
The banjo is much smaller in diameter , 0.680 ins compared with 0.790 and a little bit thinner, 0.323 compared with 0.387. However as you can see on the right hand side of the photo the original copper washer is much smaller in diameter than the banjo whereas on the Moss one the washer supplied is more or less the same diameter as the banjo. The copper washer for the Moss one is 0.045 ins thick whereas the original one is only about 0.015 before it is crushed. There is no way the Moss washer will crush given the limited amount of torque that can be used on the banjo bolt. When the banjo is fitted onto the hollow bolt with the appropriate washer the dimension to the oil hole centreline in the banjo from the face of the bolt is the same for both . 0.323/2+0.045 =0.206 for Moss and 0.387/2+0.013 = 0.206 (assuming a 0.002 crush). The disturbing, and astonishing, thing in both cases is that the distance from the bolt face to the centreline of oil hole in the bolt is only 0.140 so the two oil holes do not line up, indeed they are miles off. I cannot believe this but this is what my measurements indicate. It seems therefore that using the Moss part with the thin crushable washer might be the way to go.
So my questions to the forum are (a) has anyone used the Moss part successfully, (b) will the crushable washer work OK on the Moss part or (c) should I bite the bullet and buy the extravagantly priced Barratt one ?
The Moss parts does come from Goodrich which is a decent supplier of hydraulic hoses and there are some torque guide lines given:-
We stopped fitting these because their ID is smaller than the normal ones and they limit oil flow. As you have pointed out they are made of brake fittings.
We had a couple of customers complain about excessive top end noise which went away when we went back to the standard units.
It is a very simple process for anyone who can braze to fix your leak or in fact replace all of the piping with new pipe. If not just buy a new standard one.
I got the measurements of the bolt wrong because the ruler I was using was not marked correctly. The correct dimensions for the bolt are:-
Thanks for the information. I will set the part back to Moss and get a standard one probably from Barratt rather than Moss
Andrew, I am not keen on trying to braze my old camshaft oil feed since checking that it is leak proof after brazing means making up two fitting to seal the banjos that feed the camshafts and one fitting that can be connected to the lower banjo which can attach to an air supply.
Regarding the replacement rigid lines you can buy. They use the same smaller banjos which I don’t think is a concern but its a leap of faith that the pipes have the same OD and ID as the original. Have you had any experience with the two part flexible line that Barratt offer, Part number C25619F?
No sorry. You could find out what the tube they make it out of is and thereby find out the ID.
While a somewhat gross over-simplification, fluid flow in a hollow tube is proportional to the 4th power of the radius. So you only need to decrease the radius by 6% to halve the flow.
The tube that the rigid pipes are made of is probably of a standard imperial size and that is likely to be much the same now as it was in 1960.
OK thanks Andrew. Being engineer myself who deals with aero/hydrodynamics I would have thought that whoever designed this system made sure the pressure losses in this line are negligible compared with the restriction has to oil flows into the camshaft bearing so that flow rate is dictated by the bearings and not this line. But your experience does suggest that this is not the case
Stuart
It’s 3/16 OD, any steel or stainless steel 3/16 OD tubing will probably work just fine. You could consider brazing or silver soldiering the ends on new tubing.
I made one out of 3/16" brake line just for the process. I never used it.
I suspect the design meeting involved Nobby at the Usuals asking his brother in law Bert from the brake shop if he could “knock something up that looks like this but with flexible line”.
I ordered the expensive flexible pipe from SNG Barratt, part number C25619U but it had the same small bore as the less expensive version that Moss sells, part number 37-2553. The SNG part came with new banjo bolts and copper washers but the bolts were really thin walled. So I sent both parts back and bought the fixed pipe version from SNG , part number C25619, which is the same as the Moss version. The issue with the fixed pipe version is that it is not identical to the original one on the car and has to be judiciously bent to shape so the pipe did not kink and the three banjo bolts fitted into the end fittings without stressing the pipe which happens if the bending is not spot on. But I managed this and there are no leaks so far. I used the SNG crushable washer ,part Number C4146U/1, between the fittings and the engine block/cylinder head and the Jaguar knock off version , part number C4146*, between the banjo bolts and the fittings.
On refection I think the best way to proceed if you have a leaking joint on the original part is to re-braze it but you have to figure a way to pressure test it before you put it back on the car.
Thanks to all who offered suggestions
Stuart
This is truly one of those areas that is made of snake oil: the original oil pipe worked JUST FINE.
I know of two or three people on here who used the fancy “uprated” braided oil line and ended up with damage.
This is one point that Jaguar engineering cannot be improved upon, only screwed up.
I read somewhere recently that the original oil pipes are one of the most popular “salvage’ parts for guys who break Jags for parts.
I’m not sure if all the oil pipes were the same through the years, but it seems people are getting fed up with the aftermarket options.
You are correct Ben. The aftermarket rigid pipe I installed is not the same as the original one. The fittings on the ends are smaller in outer diameter than the original and they have a greater width than the original . Plus the length of the pipes from the junction up to the fittings into the cylinder head are longer than the original
But the diameter of the pipes are the same as the original which is probably what matters the most.
I agree that it would be best to get hold of an original one if you can but failing that you can make the aftermarket one fit. Just don’t but the flexible version since some say this restricts the oil flow
Stuart
I know there have been a number of comments about the reduced diameter and its large decrease in flow. However, I don’t believe that anyone has ever determined just how much flow into the cams is required. I would suspect Jaguar never knew either but used the available copper line at the time which means no one knows if the current braided lines are too small.
The oil flow rate to the camshafts should be controlled by the camshaft bearings just like the main and big end bearing flow rate are. I would have thought that the size of the camshaft pipes have no effect on the oil flow rate since these pipes should be massively oversized compared with the oil flow rate. So I think that the smaller diameter of the flexible pipes don’t matter at all since they are probably still well oversized… But Andrew Abowie said in his post:-
“We stopped fitting these flexible pipes because we had a couple of customers complain about excessive top end noise which went away when we went back to the standard units.”
This is the only evidence that I know of which suggests the size of the pipes does effect the oil flow rate.
Stuart
There’s lots of variability here which may account for the different outcomes. Some of the camshafts have drillings through the lobe tips which would increase the flow needs. Also, some versions of the camshafts are plugged at the front to prevent leakage, while others depend on the face of the sprocket to limit leakage.
Rolls them dice, and hope for snake eyes.
i’d like to see documentable, credible evidence of the engineering that went into the flexible pipes, as opposed to the engineering that went into the original design, that worked on hundreds of thousands of engines quite satisfactorially
That request applies to so many “upgrades”.
