Extra cam lubrication - is this a good idea?

[Barkychoc]

Since my car has a worn cam I've been thinking how to get some additional lubrication to the lobes.

My thought is to fabricate an oil spray bar from a bit of brake pipe with oil outlet holes (small) drilled underneath where the black marks are on the tube below.

I have seen this arrangement on a number of ford engines though I guess it must be used elsewhere too.

Where the X is on the left side of the picture is the end of the oil gallery - so I would drill and tap that with an M10 x 1.0 brake pipe fitting then connect the pipe to it.

The right hand end of the bar would be blocked off - either just capped or I thought possibly through the valley wall at the front of the engine and fitted with a small valve to allow the pipe to be flushed through at service time to stop any sludge build up at the end (just open the valve and let the oil come out for a brief period).
(You can get small valves from model steam engine parts suppliers).

The downside that I can see is that it will affect the oil pressure - and I'm running pre serp which I guess won't help. Can anyone with more knowledge than me hazard a guess if this would be a serious drop?

The other maybe slightly wild tangent I had is to fit a solenoid valve so it only runs when the engine is cold and oil pressure is higher, but I think this is added complexity that you just don't need.

[350Matt]

This looks like a good idea in principle.
I wouldn't bother connecting the front of the pipe though the front cover I'd just crimp the end over to seal it and drill some 0.3mm holes to provide the jets.

Being as the rover is a high flow engine in any case the extra jets wouldn't effect the oil pressure by an amount you would notice.

I would take the time to fit some sort of fine mesh filter into the inlet of the pipe tho'
The Lee company products do some stuff that'd be suitable and they combine it with a tiny pressure valve as well so you could have it so it only worked over 2bar or something so allaying worries about low engine speed oil pressure.

I'd also support the pipe along its length as well with some small brackets.

[spitfire4v8]

You might like to do this yourself as there's nothing quite like the sense of achievement doing a mod you've created yourself, however I know raceproved were talking about a similar thing linked with their electric pre-oiling pump so the cam was lubricated (as well as the rest of the engine) prior to start-up. might be worth a call to see if they got anywhere with it?

[spend]

Personally, I think its the wrong approach There is plenty of oil from the rockers draining back down the valley - as well as the stuff coming out of the followers? Why would a pressure feed be necessary, surely just a sheet with holes that made all that oil drip where you wanted it would be better?

[Simon Says]

spend said:

Personally, I think its the wrong approach There is plenty of oil from the rockers draining back down the valley - as well as the stuff coming out of the followers? Why would a pressure feed be necessary, surely just a sheet with holes that made all that oil drip where you wanted it would be better?

Yes but but just how long does it take for that cold oil to start flowing from the bleeding follower and rocker gear is some distance away and we can only presume it decides to flow over the tappet and lobe face shortly after,surely oil jets shot onto the lobe/follower face would be instant soon as the oil light is out,and i dont need to remind you that most engine wear is when the engine is started from cold the oil jet thing seems like a good idea to me

[spend]

I think thats pure gobbledegook TD, biggest problem is even lube of the cam in use.. Just look at history of uneven cam wear, how would you correlate to that to lack of oil during starting?

[rev-erend]

Looks like a good idea ...

You might want to a bit of research on ACCUSUMP - this provides a reserve of oil for when oil starvarion occurs - like on start-up and also on hard track day cornering .. another solution..

[Simon Says]

spend said:

I think thats pure gobbledegook TD, biggest problem is even lube of the cam in use.. Just look at history of uneven cam wear, how would you correlate to that to lack of oil during starting?

Whatever

[Barkychoc]

spend said:

Personally, I think its the wrong approach There is plenty of oil from the rockers draining back down the valley - as well as the stuff coming out of the followers? Why would a pressure feed be necessary, surely just a sheet with holes that made all that oil drip where you wanted it would be better?

I do and don't agree with you Dave.

I think the lubrication for a Range Rover lolloping along at 2500 revs for most of its life is probably marginal at best with the oil eventually coming off the bottom of the followers after startup.
Add to the mix strong double valve springs, a peaky cam and the tendency to rev the nuts off the engine occasionally (technical term) and I don't think its any wonder we see worn cams.

I am seriously thinking of giving this a go - my engine is only a 3.9 litre lump anyway so if I screw it up it won't be the end of the world.
The initial plan is to plumb it in and see what happens when I drive the oil pump with a drill with the inlet manifold & valley gasket off.

Edited by Barkychoc on Thursday 14th May 18:29

[grahamw48]

Why not try it ?...if only Leonardo had put a laggy band on his helicopter.

[rev-erend]

Ohhh come on.

When Rover redesigned the front cover of the RV8 and also improved the oil pump - they had at least 4 YTS trainees who had never seen an engine before working on it ..

So the design is a good 'un

[CHGRIFF]

Out of interest which lobes suffer the most from premature wear, I've always understood the centre lobes are more prone. There also seems to be differing opinions of which cams wear better than others due to their manufacturing process, but I guess thats another story.

[Barkychoc]

OK thinking about this a bit further.

I feel I ought to use copper/nickel pipe rather than copper - whats the view?

It has been suggested above to use 0.3mm holes for the jets - does this sound about right?
It feels like a very small hole to me, left to it I probably would have gone to something like 0.6 but would that be too large? After all there will be 16 of them.

Will 3/16" pipe provide enough flow?

Any further suggestions positive or negative welcome.

[350Matt]

I'd agree with using Kunifer as its that bit stronger

See here for flow calcs over an orifice

http://www.theleeco.com/LEEWEB2.NSF/Engineering!Op...

[BrianMillar]

Barkychoc said:

I have seen this arrangement on a number of ford engines though I guess it must be used elsewhere too.

Beware: Make sure the oil pump can handle the extra throughput of oil.

I remember back in the days when I had a Mk3 Cortina (not sure I should have admitted to that). Ford recalled some of the 1.6 overhead cam engines to have the oil feed to the cam upgraded. I duly had this done to mine. 5000 miles later the engine needed new main bearings as they had been starved of oil. The oil pump couldn't maintain the oil flow to the mains beacuse of the bigger bore pipe to the cam.

[330p4]

Why not use a small electric pump & filter also be careful with the spray bar & support it well the ford pinto spray bars used to break off with vibration then the cam was knackered

[drlloyd]

Hi, When we have prepared these engines for performance use we polish the lifter valley and carefully remove the casting flash around the openings to the camshaft. This is really to enable the oil to drain back to the sump faster on higher revving engines although it also appears to improve the oil flow between the lifter bases and camshaft. We typically get 80-100,000 miles out of a moderate lift Rover v8 camshafts (eg Kent H218 etc. Hope this helps.

[Pupp]

Did this ever progress any further? Guess who has found a worn lobe this eve!

[Chassis 33]

For reference, BMW engines have oil drip bars in the cylinder heads, it might be worth finding a scrap M20 engine or such like to modify. If you've ever run the M20 engine with the rocker cover off you'd of noticed that the oil is a slow drip...drip...drip not a spray under "high" pressure.

However I question the necessity of such a system on an RV8, as has been noted theres is plenty of oil dropping down from the heads and the residue is more than enough to negate much of the wear during cold start, what is of more issue is engines that arent run for weeks on end, moisture mixed in with the oil can cause lobes to begin to rust and once the initial surface hardening is removed you may as well have a cam made from plasticine. The only solution is to use the car more often

Regards
Iain

[spend]

Try researching ZDDP, zinc additives, roller vs flat tappet cams and modern oil trends Gary. It's all been well written about in the US, where there are still a lot of flat tappet motors in use.