
Is this a Timing Cover Issue?
or
Is it a Front Diff Issue?
It’s definitely a space issue.
After drawing up the standard Rover SD1 style timing cover housing, I found that the oil pump was trying to occupy the same space as the front prop shaft and Sierra Front Diff UJ. NB. The UJ is intersecting not just the orange oil filter but the whole oil pump.
What are my options?
- Extend the wheelbase
- Move the gearbox back-wards
- Find a different front timing chain cover
- Angle the front differential down-wards at the back
- Use the thinner propshaft from the Sierra 2.9 xr4x4
My first thought was to replace the front cover with one from the interim Rover Serpentine Front Timing Chain cover. I knew that the oil pump was internal and driven off the crank shaft and not off the camshaft.
Now take a look at the Rover V8 Serpentine Timing Chain Front Cover:
The distance from centre of the crank is nearly 2cm less on the Serpentine Front Cover. The serpentine cover still has a distributor (disco), so it’ll work with the early tweaked JE Motors ECU I’ve acquired.
Into the bargain, the Serpentine cover has a better front seal than the SD1 and streets ahead of the P6 seal.
I’ll obviously have to draw it up, but so far, it is looking very promising. I’ll still need a remote oil filter but things are progressing forwards and not back as usual.
In the above shot, you can see that the front prop-shaft travels up hill, but the UJs are doing the same amount of angular adjustment.
In this shot the the rear, the UJ is barely out of line with the prop but the Sierra 4×4 Front Diff has been rotated making the front UJ do most of the work. (exaggerated for purpose of blog)
Moving the engine back-wards would also give more room
Doing all this, will allow the front UJ to occupy only the space where the oil filter is, not the oil pump. or timing chain cover.
Once I have my new Serpentine Front Cover drawn up, I’ll be able to see what combination of all of the above I’ll need to make.
Meanwhile, back to putting up more shelves in the workshop……