external oil feed for no"s 1 and 2

[Lloydpiestate]

hi all,

a topic that has been on my mind for a long time now, external oil feed.

i use my mk2 pi every day, its fitted with a rebuilt 2000 lump at present, with a spin on filter and oil cooler, that has done about 20k miles, and is how it was when i brought it 4 years ago.

the engine is faultless day in and day out, and has fantastic oil pressure, 50- 55 at idle when hot and 65 -70 at higher revs, also when hot !!!

now most days i travel up and down caerphilly mountain, and its a steep ole thing, and i always keep an eye on the oil pressure gauge as i do so, as i cannot believe how much it moves in relation to whether you are going up or down the mountain !!!!!!!!

going up, the pressure can drop as low as 45 and you can hear the crank waining / knocking wanting oil, and going down with the auto box in 2nd and no throttle can rise to 80 - 85 !!!

so is there any more proof needed that our straight six engines need an external oil feed to at least numbers 1 & 2 !!!!!!!

easy enough to sort out an external feed if you have the spin on filter on your engine, SO the question is, does anyone do an external feed kit, ANYONE KNOW WHERE TO GET ONE FROM, as i dont have the time to make one from scratch at the mo ??

DAVE HARVEY, a nice little project for you to sort out for us perhaps

lloyd

[Clifford Pope]

If it's short of oil because of the incline I don't see how diverting oil to the rocker shaft will help - won't that just reduce still further the supply to the lower bearings?

If it is really true that there are roads in the UK whose gradient causes the oil level to drop below the pump intake, then I'd have thought it would be better to address that point directly.
The obvious solution would just be to put more oil in the sump.
More fundamentally, are there any baffles in the sump to prevent surge? I can't remember, but if not it might be a worthwhile modification.
Is it the correct oil pump? Aren't there two sizes of sump, the deeper one accommodating a longer pump intake? Or am I imagining that from some other car?

[Lloydpiestate]

hi clifford,

sorry, perhaps i didnt write my posting correctly / clearly, i ment an external oil feed to the crank no"s 1 & 2 via the allen key studs in the block.

and a good point on the sump, i need to check what one has been put on there and that it is a mk2 2000 and not a 2.5 nor a mk1 mk1 etc etc.

as for the pump, apart from the early mk1"s, i thought they were all the same ??

[Clifford Pope]

Sorry, I misread it. I jumped to the conclusion this was the usual valve gear bolt-on feed.

I still don't see though how tapping off more oil delivery AFTER the pump will overcome the apparent problem that it isn't getting enough oil because of extreme oil levels?

[Jonathan Lewis]

Hi Lloyd,

Just wondering whether a windage tray might perhaps prove a better solution than sump baffling - not sure whether anyone produces one for the TR5/6 engine?

I think the depth of the main part of the sump is the same across 2000 and 2.5 units, though the front bit (that over the suspension crossmember) was made deeper on the 2.5 to accommodate the larger throw on the crank. Oil pumps certainly changed during production but I believe that you're correct in saying that the final pattern is a 'one size fits all'.

I must admit that, with the normal oil pressures that you're quoting, I'm inclined to suspect that the issue might be simply one of the oil level being too low. Is the dipstick correct for the engine? Also, remember that if you've got an oil cooler fitted, the extra volume of the cooler and associated pipework can make a perceptible difference to the level of the oil in the sump once the engine is running; I tend to check oil level immediately after engine shut-down before the oil cooler circuit has any chance to drain back into the sump.

Regards,

Jonathan

[Jonathan Lewis]

Also, it would appear that with the final design of oil pump, there might be a need to check/adjust the fitted length of pick-up dependent on what sump is fitted:

http://www.triumphexp.com/phorum/read.php?13,827380 - post of 4th September 2008

Not something that I've come across before - or, indeed, ever found the need for - but could be worth checking. Seems to have addressed a similar issue of oil starvation on steep gradients for others, and certainly easier/cheaper than adding baffles/windage trays/external oil feeds, etc

Regards,

Jonathan

[TedTaylor]

Personally I am a little surprised at this problem with a standard engine, assuming it is in basically sound condition being used under normal road conditions - however with 'our' engines anything can happen ......

I would first of all go along with Jonathan's comments about oil level and would check the accuracy of the dipstick. Without doing an oil filter change drain the sump and refill with the approved quantity of oil for refill without a filter change and see where the level comes to. If not on the correct mark, i.e. too low, re-mark it and using that mark in future see if that cures the problem.

Then following on from Jonathan's comments about the oil pump pick up check that it is picking up from low down in the sump.

Finally remember that baffles are to stop surge under extreme braking, acceleration and cornering situations as found in racing or similar conditions. They are designed to allow oil levels to stabilise by having holes in them to allow oil to move around the sump under 'stable' conditions. Under the conditions you are describing I consider that a baffle would have minimal or no effect.

MUT

[Alec]

Hello Lloyd,

"so is there any more proof needed that our straight six engines need an external oil feed to at least numbers 1 & 2 !!!!!!!"

The reasoning behind that comment is that the original gallery is too small in capacity, but from memory it is about 5/8" in diameter, quite a reasonable size I would say. I too believe it is an oil level problem, although 45 psi is a reasonable oil pressure anyway. Normally I would say oil level does not affect oil pressure given it is not too low, i.e down to pick up level, but I have over the years found that my Triumph engines have shown lower oil pressure if the oil level is down below minimum.

Physically, making an external oil feed rail is quite simple and can be done with basic hydraulic pipe fittings and some hoses if you want to try it? I know Kas Kastener did a similar thing on his racing engines but I don't remember if they were successful.http://sideways-technologies.co.uk/foru ... ing-draft/.
I do seem to remember that it was as much to do with getting cooler oil to the bearings rather than a greater volume, especially as those lines look fairly small in diameter.

Alec

[CAR]

Having had the sump off on the pi quite recently (and a spare pi engine too) it is worth noting that the bottom of the sump ends up with a lot of sludge in the bottom.
Since cleaning all of this out I have found that the oil capacity, including the large Z48 spin on filter is around 5.6 litres, this is probably a litre more than before the sump cleaning! This is to the mark on the dipstick.
Is it possible that the oil capacity has been reduced significantly due to the above in your engine Lloyd?

Somebody once said to me that an oil pressure gauge is an excellent aid to monitoring your engine. But sometimes ignorance is bliss!

Colin

[Mike Stevens]

45PSI is still a reasonable pressure and I find it hard to believe that the angle of the engine when going up hill, even with 45PSI pressure would make any difference to the oil feed to the front 2 cylinders.

I'm pretty sure that the dipsticks for the 2000/2.5 engine are different, with the marks at different places. This can only be due to the oil levels being different (why else?), logically as the sump is deeper for the 2500? I've always assumed so, maybe due to the longer throw and not wanting the big ends to dip into the oil.

I fitted a new oil pump last year in the PI and the one it replaced was of a different design. The new one does need to have the filter length adjusted but I can't remember the figures from Chris. Maybe the heights were different for 2000/2.5.

Sump baffles are probably better if they are horizontal with holes for the oil to drain down. It will help to stop oil surge, but I'd have thought unnecessary on a road-going car. My suspicion would be the same as the others - low oil level! Check the dipstick! I can measure the one in the PI here if that helps.

Cheers,
Mike.