Oil Pressure Solutions Mi16

[Guest birdii]

I have just been reading the new PPC mag and noticed a question about dry sumping, and apparantly they are going to do an article on the subject and how to dry sump your engine without spending a fortune!

One to look out for!

[sorrentoaddict 1]

quote C_W:

 

"It might be worth PM'ing martin(crf450) as I'm sure he's removing these spray bars as apparently they aren't essential (as far as I'm aware they are for piston cooling rather than extra lubrication anyway) - I think he also mentioned that you lose a bit of power from them too."

 

I think it should be clear to all of us that the MI pistons have a much lower tolerance to skirt distortion, therefore if they not at their proper crown temperature (which happens when your spray bar is blocked), they scuff the bores of the liners - cue the cylinder wear is not due to "lack of lubrication", CW, but exactly due to lack of piston cooling.

If you design the engine in such a way as not to rely on these spray bars, then they really might be omitted, thereby incressing power marginally and reducing the risk of them becoming blocked and wasting residual oil pressure.

 

and yes, C_W, there really are small oneway valves in the spraybars of your MI,

they are just very hard to spot visually.

 

apart from the expensive solutions of dry sumping or mechanical cam followers, the only really viable solution to the MI starvation problem is to fit an external oil drain pipe from the right rear part of the head down to the sump.

 

 

cheers

 

 

Alex

[C_W 3 1 Cars]

How can it be designed in a way to not need them?

[findlay 0]

the only really viable solution to the MI starvation problem is to fit an external oil drain pipe from the right rear part of the head down to the sump.

Alex,

 

I assume by that you mean the front of the engine (ie NOT the gearbox end).

 

Athough if you were going to go the the trouble of tapping a new, external, hole into the head it would be feasible and sensible to do one at both sides?

[B1ack_Mi16 67]

How can it be designed in a way to not need them?

That would probably be if the pistons are designed to not have spray-bars under them, they'll get hotter and will need to be able to expand more, hence they need to be slightly smaller when cold.

[nick 3]

quote C_W:

 

"It might be worth PM'ing martin(crf450) as I'm sure he's removing these spray bars as apparently they aren't essential (as far as I'm aware they are for piston cooling rather than extra lubrication anyway) - I think he also mentioned that you lose a bit of power from them too."

 

I think it should be clear to all of us that the MI pistons have a much lower tolerance to skirt distortion

 

Alex

What you have to remember though is Martins engine is far from std and I'm certain this has been taken into account with his choice of piston.

 

Nick

Edited October 7, 2004 by nick

[findlay 0]

Latest news...

 

Phoned Rab Elliot (phat206) last night as he has been tinkering with pugs since I was a mere twinkle in my father's eye.

 

His last experience with Mi16s was detonating the bottom end of one while running slicks at Anglesey.

 

Anyways having had a long chat with him he is looking to try to find out which of the XU engines has the 'trapdoor' baffled sump (one way hinged baffle) as fitted to the T16.

 

I will post my results tomorrow so we can all pillage the country's scrapyards for one of these sumps

[crf450 0 1 Cars]

Latest news...

 

Phoned Rab Elliot (phat206) last night as he has been tinkering with pugs since I was a mere twinkle in my father's eye.

 

His last experience with Mi16s was detonating the bottom end of one while running slicks at Anglesey.

 

Anyways having had a long chat with him he is looking to try to find out which of the XU engines has the 'trapdoor' baffled sump (one way hinged baffle) as fitted to the T16.

 

I will post my results tomorrow so we can all pillage the country's scrapyards for one of these sumps

The S16 has the double baffle set with trap door ,I've fitted this set up to a mi16'd 205 and it didn't solve any of the oil surge issues.

Cheers Martin

[C_W 3 1 Cars]

The S16 has a trap door baffle in the sump, but none of it works which is why this thread is 5 pages long!!!

 

1047 10 - Oil pump baffle (£1.72) XU10J4/RS

1047 17 - Sump windage tray? (about £9)

1047 15 - Baffle with trap door (think this only fits a steel sump though, but probably can be made to fit an alloy Mi16 sump.

 

I've got pretty much all 3 of those in mine and they help a little but not enough.

[findlay 0]

BOLLOCKS!!!

 

[Butler 0]

[Batfink 201]

surely the best solution (as most circuits run anticlockwise) is to move the oil pickup to the opposite side

[findlay 0]

What way do clocks turn in your house???

[C_W 3 1 Cars]

What way do clocks turn in your house???

 

Whichever direct a track is it won't help as the pickup sits in the centre of the sump anyway, most surge problems seems to be on left hand corners (for me anyway (anticlockwise)), but most ciruits tend to be clockwise so if you were to put it to one side of the sump you would compromise the other turns.

[GtiMad 1]

I have always wonderd why is in not possible to run more than one pickup? I know space is tight, but if you could run three from a moddified pump then this would surely help?

 

Or would the sucking up of air still screw it up for the other pickups?

[findlay 0]

The issue arises because the pump is essentially lazy and will draw from whichever pipe offers least resistance.

 

Say you operate 2 pickups, one at either side of the sump, fire the car into a corner, the oil rnus and covers one pickup the otherone is exposed, the pump will draw from the pickup which is in the air.

 

You'd need some compleg g-sensitice switch to operate it.

 

Trust me its something I have thought about too

[Guest Cartooner]

Oh well, this is a very old topic, but since this problem is still an issue with most of us I want to share my thoughts with You. From reading most of the topics concerning the oil starvation issue with Mi16 engines, I sincerely think that the problem lies within the head and not the sump. Why is it that most of the problems occur in long lefthanders. Well, the head of the Mi16 can contain a lot of oil. Anyone who has ever seen one would agree on that. There are only two drain holes. One at each end of the head. I haven't seen anybody mentioning the shape of those holes. The drain holes are positioned in such a way that they are in a sort of chamber with a ceiling. When this chamber is filled to the max on tilt conditions(corners) the triangular shape of the gearbox-side hole drains the oil far better than the circular shaped hole at the distr. side. Ever tried to empty a full canister of oil by just keeping it upside down? The circular hole only adds problems to this whilst the triangular shaped hole simply works better.( and is bigger, though the shape of the hole is key here!)

 

So, I herewith fully agree with Alex ( Sorrentoaddict) and suggest the extra oil drain hole on the distr. /exhaust side is the cheapest and the most ignored solution. It seems the french do this a lot.

 

Hasn't anybody tried this over here?

[Alastairh 47]

I've know of a couple of heads with this system been made into place, but not seen one working.

 

I know easy pugs new engine he is build has had this work carried out.

 

Alastair

[petert 554]

If you were dry sumping you'd scavenge from at least one of those points. There's no harm is drilling/tapping a hole there just to future proof yourself.

[findlay 0]

Al... I think you've slightly mistaken what cartooner is going on about. easypug has the head with the holes tapped into it for external drains back to the sump. Cartooner means actually opening out the poorly designed gallery that is at the pulley end of the engine within the head. The 2 factory drains are totally different shapes. One is kind of like a pork chop, the other simply round.

 

I've discussed this in other threads and if I'd have kept the Mi this is the first thing I'd have spent money on having done (long before I'd have gone for better bushes, braided lines, baffled sumps etc.). I had an exchange head lined up, a mate working in a head shop... then I sold the car Oh well.

 

From many long hours of discussions this seems to me to be the easiest and most cost effective way of trying to help the oil surge issues. Plus it gives you and excuse for a bit of porting, polishing and skimming while the head is off

[Guest Cartooner]

Well findlay it is actually only in the head where the restriction is. If You take a closer look at the block itself You will see that from there on the passage is the 'porkchop' shape again. So, it might help if the passage in the head is enlarged as close to the porkchop shape as possible. I think we are restricted here, because there is a waterpassage running near it. Removal of the freezeplug might show how far it can be opened up.

 

Now I have taken a closer look at the block and know how the oildrainpassages go down into the sump.Bear with me:

On the flywheel-side the passage in de head is better(full porkchop) but further down in the block it is actually worse than the front passage, which is porkchop shape alll the way down. But......the rear passage ends up facing the cilinder and my guess is that it benefits from the piston that is going up and down very near to it. Perhaps this is helping this passage to flow??????

 

The distribution-side passage just runs all the way down, not having the benefit of the piston. It might actually be possible to create an opening in this passage, similar to the one on the back, so this passage also benefits from the piston nearby.

 

I certainly think this is feasable. Any thoughts on this one guys?

Edited April 13, 2006 by Cartooner

[Guest Cartooner]

With pictures:

 

Pic 1 : Oil outlet flywheel passage, seen downwards towards the sump:

http://img136.imageshack.us/img136/7387/1000034large8vf.jpg

 

Pic 2 : oil outlet distribution passage, seen upwards from the sump:

 

http://img146.imageshack.us/img146/2488/1000036large0hj.jpg

 

Pic 3 : Suggested outlet for distribution passeage, seen upwards from the sump looking to the distribution side

http://img136.imageshack.us/img136/6484/1000044large2mv.jpg

 

???????????????????????Any thoughts?

 

Sorry first time with imageshack, so pics not to good!

Edited April 14, 2006 by cybernck

[Mandic 0]

Isn't the block the same as 8v's? So if this what You're saying is true, then 8v would suffer from oil surge just the same way Mi16 does...

 

Cheers

 

Ziga

Edited April 13, 2006 by Mandic

[Guest Cartooner]

Don't know about the underside of the block. I just have not got one here, so I can not compare, but the problem is initiated by the head, which holds a vast amount of oil! The 8 valve head does not hold that much oil, just drains the oil better and therefor does not create the problem, so the passages are not of an issue there. The 16 valve has the problem and in majority of cases it occurs in left hand corners of long duration. So the oil gets piled up on the right side of the head and that is when the level in the sump gets too low.

 

Why is it on left-handers? It must be due to the lack of drainage and I think the flywheel passage is helped by the movement of the piston nearby.

[Guest Cartooner]

In addition to these thoughts, I also think that, since the distr.side passage ends just above the pump gear there is not all that much space to fill up with oil. As the oil in the sump also tends to go to the distr. side of the sump( on long lefthanders), the oil just can not go anywhere and You might just end up with a pile of oil filling up the right side of the sump, the drainage gallery and the right side of the head. The new opening that I suggested ends up well above the level of the sump and would continue flowing and avoiding the pile up situation.

 

cheers!