As a pesonal preference I never change the slingers on the crankshaft
Slingers have a purpose , The add a bit of extrabeathig on an engine which considering it’s the same size as an XK , has a much smaller breather.
Slingers were use don for example Honda F1 engines.
The slinger IF properly set up generally don’t leak. while the engines make leak under the front and rear mains , the leaks are generallyf rom the alloy blocks under the bearing caps . Not well engineering, they have fine thread BSF bolts screwed into the alloy from the sump ; Better solution would have been studs with Whit thread at the top end in these four holes.
I block off these 4 holes on the top side as when you look at them, they have cup shaped depressions which collect oil and while you sleep it permeates down along the screw thread
There are also horizontal holes which serve no { useful purpose. I also block there off. And the area of seal between the sump face ad the alloys and block is quite small and one needs to be careful in this area.
The other issue is that Slingers set up will last virtually for ver { UNless someone lets te main bearings get so worn, that the crank moves down and touches them
But an acquaintance in another country made a similar casting to use a wave seal on the crank . : an improvement"BUT, these cars can often be left unused for periods and the seal stuck to the crank while in storage… So it was floor and gearbox out, flywheel off, to fix what wouldn’t have been an issue with the slinger I domodify the slig so the bolts can be inserted from inside the crank case , because with the engine on an engine stand it’s easier to put them in and the sump on before taking it off the stand [ and having to put it back
The main issue is the slingers need to be centred, A feeler gauge at the back and at the front , make a shallow taper tool to slip over the nose of the crank to hold the timing cover central while the bolts are tightened.
Attached pics should be fairly self explanatory.
Yes, the shells are different and the spiggots are in the opposite corners wrt the steel rod shells so they are not transferable unless you machine the rods.
Oh, that Dural rod is not a chunky one. The chunky ones came later and had a lot more metal all round.
Here is a pic I took many years ago with a film camera of a rod from a Mark IV a friend of mine was restoring.
I believe this is part C.1049 and is so marked on the side.
I noticed at the time that the oil tube and hole in the saddle are not centered.
The shell bearing that came out of this rod had a centered hole; it did not line up with the hole in the rod.
There was a small amount of overlap of the holes, perhaps 10 to 20 percent.
Unfortunately the picture of that shell failed to develop, but I think it was for the later C.2844 rods which had a centered oil hole.
It looked to me as though that engine had been running with the wrong bearings.
The effect of that would be oil starvation to the wrist pins.
Here is a C.2844 rod. There is a hole drilled through the center, and the bearing also has a centered hole.
XJ6 Rods don’t have the oil feed tube, They rely on splash to lubricate the gudgeon pin , However the inside of a MK 4/5/SS block is different to a twin cam block and the effective of splash would not neccesarily be the same . Apart from the rods being heavier.
What I’m really driving at, is this.
Did the bearing shell for the rod with the offset oil tube also have its oil hole offset from center, or was the hole in the center on these bearing shells?
Here’s a little more on this. This shows a chunky MkIV Dural rod C1050 and a steel C805 rod. A further factor is that the SS cars have a slightly different crank pin size 1.824" and the spiggots were in a strange position close to the clamp bolt. The shell in these photos is an SS shell. The MkIVs have 1.894" crank pins and have more normal spiggot positions as you can see on the C1050 rod but as I indicated previously they are incompatible with exchanging shells from Dural to steel rods. The big end bore sizes of SS and MkIV are all 2" and the small end bearing sizes are all 0.75"
Thanks much, Peter. That last picture with the bearing with off center hole clears up that mystery.
I am sure now that the Mark IV engine I saw had been running around for some time with the wrong rod bearings in it. It probably would have eventually suffered from wrist pin seizure and subsequently fatigue failure in the rods.
Note the offset oil holes, and the part number C.1144 and VP are stamped on the end. I think VP means Vandervell Products.
Overall width is 0.965 inches.
Hole diameter is .157 inches.
Center of hole is .564" to one side and .402" to the other side.
So it would appear that they used this bearing in both the C.1049 rod with offset oil tube, and the C.2844 rod with centered oil drilling, apparently hoping that there would be enough overlap on the holes to permit enough oil to pass to the wrist pins.
I begin to suspect that it was not enough, that the oil supply became insufficient at extreme operating conditions such as high speed cruising, leading to friction in the wrist pins, leading to fatigue flexure loading in the rods, and this may point to the cause of rod failures.
And the cranks that used early white metal faced bearings were a different material to later ones for copper lead bearings. Earlier cranks need to be Nitrided to use with bearings supplied for XK engines
I now this is a very old thread, but I never before acme across these problems:
I have a fellow club member with a recently discovered survivor a 2 1/2 Litre Mark V saloon sold new in Finland in March 1950.
Before he refills the engine with oil I would advise to check what sort of con rods he has. the engine number is H2024, mfg. date of the car is Feb. 6th 1950.
As always, all advice is welcome.
Cheers!
Ps. Yes, once it’s up and running, photos will follow…
From the SPCs it looks like there were 3 different rods used in the 2-1/2 Litre, of which all Mark Vs used the last one.
Since an oil tube is mentioned, I would guess that this is an aluminum rod, something like this.
Notice the tube inserted in the side.
The main concern I have is that the hole in the bearing shell should line up with the tube. This one is a little bit offset, and as such, the wrist pin may become oil starved at high sustained speed.
Hi Pekka,
If the rods in question are the same as used in the MkV, then I believe standard XK rods will suit as a replacement.- my rebuilder used steel MkVII Rods in my 3.5 rebuild.
Yes, that is true for the 3 1/2 Litre I have and that I have rebuilt. You can use any con rod set from 1949-1964 3.4 or 3.8, but NOT the later ones or from any 4.2 XK engine.
But this other chap that I am helping has a 2 1/2 Litre MKV with engine H2024 from very early 1950. Oddly enough the engine number on those Feb. 1950 LHD 2 1/2 Litre Mark V’s I know are much earlier than the 2 1/2 Litres I know from June 1949 up to November 1949. Yes, most Mark V’s were 3 1/2 Litre.
