Additional timing chain lubrication required?

westOz74P6B

westOz74P6B

Member
I was looking through a hard copy of something I had printed off a webpage, some chap rebuilding his SD1 3500 V8, I forget now the website from where I got it as I've had it for a while, but anyway, he goes on to explain the extra holes he had drilled towards the front of the valley through into the timing chain area to provide extra oiling of the chain drive (he had fitted a double chain drive setup). The photo he had shows the valley looking toward the front of the block and two arrows pointing to the holes he had drilled at the low point where the oil comes down from the front of the cylinder head. So I was wondering (as I am at the stage of fitting the valley gasket and manifold soon), if this would be a benificial mod, or is there enough oil as it is for lubrication of a roller chain and steel gear set up as I'm replacing the standard chain and camshaft gear.

Thanks in advance,
 
Hello Scott,

From my understanding, there is more than sufficient oil for the timing chain with the standard Rover V8 lubrication system, and that includes when a double row timing set and chain are used.

Where additional lubrication can be beneficial is onto the camshaft / distributor skew gears. This becomes especially so when one of two things happens.
(1) The oil pressure is increased by changing the pressure relief valve spring and substituting with a stiffer one, thus raising oil pressure.
(2) The engine is running at 5000rpm plus for long periods, such as in track events.

In these situations, without additional lubrication being directed onto the skew gears, failure is almost guaranteed, and in a very short space of time,...less than 5000 miles being typical. :shock:

One method to increase oil flow to these gears is to tap into one of the spare port threaded caps in the oil pump front cover, and then run a braided stainless steel line from there up to a point in the timing cover near the base of the distributor which will allow a direct oil stream onto the gears. There will of course be a reduction is overall oil pressure of a few psi by implementing such a system.

The standard Rover V8 lubrication of the skew gears is a combination of splash and oil being directed along the nose of the camshaft via the channel acommodating the woodruff key.

Ron.
 
I did this mod.

Will it improve things?? but wont do any harm. takes seconds to do.

Colin
 
thanks ron, arthuy, like you say ron, there is enough oil to take care of a roller chain, if the condition of the old chain and gears, fuel pump cam, dizzy drive gears are anything to go by, and seeing as I have heads and cam, tappets etc in place I don't think I will bother, maybe if I had a bare block, but I'm on my way to assembly so I'll leave that idea for another day. by the way arthuy can you remember what size drill you used and where it opened up on the chain side,

thanks
 
I will post this photo but dont know if it will last long, there seems to be a problem with my photos on certain forums.

If it doesn't appear send me a PM with your email address. or have a look at my photo album I will call it "oil holes"

If you look straight on they are just above the "Mickey Mouse" ears.....

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If I remember correctly looking from the inside of the block there is like little wells where the oil sits almost like tear ducts!!! Hard to describe but if you pour some oil around the area you should see where is sits.

I think you have to drill down at an angle. There should be stuff on the web or from the haynes book.

Colin
 
If I understand this mod correctly the oil released to the chain area is oil not under pressure that is anyway on its way back to sump? If this is the case then there is no harm at all in doing this mod. However if any proposed mod involves tapping into a pressurised area then great care and experience is required. There is every chance of diverting too much oil and starving the crucial cam followers and camshaft area of the engine with catatrophic results. There are mods out there which involve improving flow to the top end of the engine but I'd suggest anyone with limited experience of the V8 approach them with very great caution. What looks like a good idea for one area of the engine can upset the flows to other areas!

Chris
 
thanks, colin, chris, I noticed the wells on either side and mine were filled with a little sludge, so I suppose drilling the holes would keep this area flowing and free from sludge buildup, but like I said I'll leave this for now on my car but will have a look when I start a rebuild on the 3.5 from the spares car. like you say chris the oil is not under pressure but maybe crankcase pressure from the valley side may help blow it onto the timing chain (just a wild hypothetical) I'll see if i can locate the chaps website again, it was at least 4 years ago when i came across it.

Regards,
 
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