Oil Pressure Solutions Mi16

[Mandic 0]

Aha, so You are saying that one shoud drill/cut a new opening in a block, so it would allow oil to flow freely into the sump and not just rebore (bigger hole) the existing drainage hole.

 

Cheers

 

Ziga

[Guest Cartooner]

Aha, so You are saying that one shoud drill/cut a new opening in a block, so it would allow oil to flow freely into the sump and not just rebore (bigger hole) the existing drainage hole.

 

Cheers

 

Ziga

Yep that's what I'm suggesting! I'm pretty convinced this will solve the problem with the lefthanders. Combine this with a baffled sump and a splashtray and You will also tackle the problem on righthanders and under braking.

[Mandic 0]

Hm, what about iron block, same design as ally or have they fix this problem, cos what You're saying is basicly the same thing as those french guys did, only it is "intergrated" in the engine. As people say iron block (S16, T16) is better against surge, so if one has access to iron block we can see if oil passages are in the same place as Mi's. But I agree with what You're saying, drilling a hole might help.

 

Cheers

 

Ziga

[Guest Cartooner]

Hm, what about iron block, same design as ally or have they fix this problem, cos what You're saying is basicly the same thing as those french guys did, only it is "intergrated" in the engine. As people say iron block (S16, T16) is better against surge, so if one has access to iron block we can see if oil passages are in the same place as Mi's. But I agree with what You're saying, drilling a hole might help.

 

Cheers

 

Ziga

I have no access to an iron block here. I am quit new to Peugeot and Mi16 engines. I have read a lot on many forums about this issue, but have never seen the solution of drilling a hole in the spot that I suggested.

I have a D6C block from a Citroen BX overhere and just dismantled it this week. I now have the oppurtunity to look at the head, the block and the oil passages for the first time, and this is what I came up with. It would be interesting to see what other more experienced Mi16 guys think of it. Still I am pretty confident this might just do the trick.

Remember that the oil that is in the head depends solely on gravity to get back to the sump again. It seems to me that the remaining oil in the sump that is pushed to the rightside of the sump by centrifugal forces can easily block a standing colom of oil on it's way down. The hole I suggest would not be blocked under these conditions.

[Mandic 0]

Yup, completely agree with You, just need a test bunny now

 

Cheers

 

Ziga

[petert 586]

Remember that the oil that is in the head depends solely on gravity to get back to the sump again. It seems to me that the remaining oil in the sump that is pushed to the rightside of the sump by centrifugal forces can easily block a standing colom of oil on it's way down. The hole I suggest would not be blocked under these conditions.

 

So why not externally drain the head down to the flywheel side of the sump?

[Mandic 0]

Cos it looks "cleaner" if done internally, IMO

 

Cheers

 

Ziga

[Guest Cartooner]

So why not externally drain the head down to the flywheel side of the sump?

 

Thought about that too, ofcourse. Two drainholes in the head on both sides, with plumbing in a V-shape that ends up as close to the oil-pickup as possible, aided by baffles, but under heavy braking conditions this would still leave You with a problem, because these drains are at the exhaustside and are positioned relatively high. Plus that it would give a lot of vulnerable plumbing. Since the flywheel-side oil passage seems to work well, I just thought it'd be nice to somehow copy that to the other side. I think a 10mm hole could do the trick. I'm just wondering if any of You can come up with a reason why not to do it this way. Could be so simple! Perhaps I'll just go ahead and drill it, but I will not be using it in flat-out race conditions so then we will never be sure if it works.

[Guest Cartooner]

Ok. well since nobody replied to 'my' solution to the oil-starvation problem, I decided just to go ahead and drill the extra hole to make an 'escape-route' for the oil to stream to the sump when the oil-passage on the frontside(distr.side) is blocked with a colom of oil. ( due to centrifugal forces that push the remaining oil in the sump into the chamber where the pump gear sits.

 

 

As I found out it was easy to drill the hole. I use a 11,5 cm drill and drilled it under an angle of about 45 degr.

 

Now the oil can flow freely from the head to the sump even when the frontside outlet is blocked by standing oil. However.........there is one downside to this. As You can see on the picture there is actually a casting-gallery running from the exhaust-side of the block (just underneith the coolant outlet) to about halfway above the no.5 mainbearing. By drilling the hole you thus create a passage to the outside world. This passage is easily blocked with a plug made out of metalbond( don't know the exact brand but it is used by the engine(re)builders I talked with. There's no pressure involved, so this should be ok.

 

I think I have just solved the oil-starvation problem on my block in a cheap way.( or ruined the block alltogether if the plug doesn't hold.

[Batfink 201]

can you weld the plug up??

[Guest Cartooner]

Absolutely. Just make a dummy plug from clay. Copy it from aluminium. Plug it in and weld it. Be very carefull with the welding though. But I think the metalbond will hold since I cleaned it up thouroughly and there is no pressure involved.

[petert 586]

An interesting project. I'll be keen to see how it goes. Why not just drill and tap the hole 1/2" UNF and loctite in a bung?

[Batfink 201]

An interesting project. I'll be keen to see how it goes. Why not just drill and tap the hole 1/2" UNF and loctite in a bung?

 

lol good idea! guess you could even use an off the shelf sumpplug

[Mandic 0]

Good job Cartooner!

 

Good idea and I don't see why it souldn't work. Just hope You didn't decrease block's intergity. So when's Your engine gonna be ready to see if it really works?

 

Once again, good job.

 

Cheers

 

Ziga

[Guest Cartooner]

An interesting project. I'll be keen to see how it goes. Why not just drill and tap the hole 1/2" UNF and loctite in a bung?

 

I thought about that, but since the hole is square, You'd have to drill a large hole to do so and I guess there is not enough 'meat' for that. But judge for Yourself. Underneith You can see the exact location of the hole that has to be plugged.( allready plugged with bondo). If You have a block lying around You can check.

 

 

Welding is an option but the walls of the block are thin, so watch out!

 

Well, in theorie this hole might just do the trick but it'll be another month (lacking time and funds) or so at least, before this engine is ready.

 

Then when it runs I'll be driving roundabouts like a 'mary go round' to see what the oil pressure does. Luckily, we drive on the righthand-side overhere, so I will not have to drive head on into traffic.

[veloce200 3]

I thought about that, but since the hole is square, You'd have to drill a large hole to do so and I guess there is not enough 'meat' for that. But judge for Yourself. Underneith You can see the exact location of the hole that has to be plugged.( allready plugged with bondo). If You have a block lying around You can check.

Welding is an option but the walls of the block are thin, so watch out!

 

Well, in theorie this hole might just do the trick but it'll be another month (lacking time and funds) or so at least, before this engine is ready.

 

Then when it runs I'll be driving roundabouts like a 'mary go round' to see what the oil pressure does. Luckily, we drive on the righthand-side overhere, so I will not have to drive head on into traffic.

 

correct me if I'm wrong but on the 8v the pump pickup is such the right handers are the problem - you will be going anticlockwise round a roundabout which shouldn't cause as much surge? Anyway this is the case with my 8v and the baffle I made mainly prevents oil going up around right handers. Is the pickup also on the right hand side on the MI?

[Guest Cartooner]

correct me if I'm wrong but on the 8v the pump pickup is such the right handers are the problem - you will be going anticlockwise round a roundabout which shouldn't cause as much surge? Anyway this is the case with my 8v and the baffle I made mainly prevents oil going up around right handers. Is the pickup also on the right hand side on the MI?

 

Take a seat and read the full 17 pages please The oil problem with the Mi starts in the head and since the oil can't get back to the sump on lefthanders it piles up and no matter where the pick-up is, the oil will be in the head, oil gallery and right-hand corner of the sump and not available to the pick-up.

 

On right-handers the oil can get back to the sump, but will be in de left-hand side (flywheel-side) of the sump squashed in the corner due to centrifugal forces. This will hapen on a 8V and an Mi in case of a slightly to low oil level. This is where a baffled sump will help correct the problem.

 

So....for right-hand corners on both 8v and 16v a baffled sump ( or oil-trap door) will help, because this is mainly caused by the fact that the oilpump and pick-up sit on the distr.side of the block. On the left-handcorners the 8V won't suffer, but the 16v will because..... a well read the 17 pages and the other billion topics

[Anton green 12 1 Cars]

I hopefully have a very simple problem, but unsure as yet!

I think it is could be caused by a faulty brown multiplug from what I have read, if one of you gents would be kind enough to tell me where to locate it I'll go check before I drive any further!

[veloce200 3]

Take a seat and read the full 17 pages please The oil problem with the Mi starts in the head and since the oil can't get back to the sump on lefthanders it piles up and no matter where the pick-up is, the oil will be in the head, oil gallery and right-hand corner of the sump and not available to the pick-up.

 

On right-handers the oil can get back to the sump, but will be in de left-hand side (flywheel-side) of the sump squashed in the corner due to centrifugal forces. This will hapen on a 8V and an Mi in case of a slightly to low oil level. This is where a baffled sump will help correct the problem.

 

So....for right-hand corners on both 8v and 16v a baffled sump ( or oil-trap door) will help, because this is mainly caused by the fact that the oilpump and pick-up sit on the distr.side of the block. On the left-handcorners the 8V won't suffer, but the 16v will because..... a well read the 17 pages and the other billion topics

 

sorry about that, being an 8v owner and very busy the 17 pages did seem a bit daunting, I knew it was something to do with the head - thankyou for making it clear and also making me realise my high output 8v budget build does have something over an MI16 !!

[rich_w 0]

sorry about that, being an 8v owner and very busy the 17 pages did seem a bit daunting, I knew it was something to do with the head - thankyou for making it clear and also making me realise my high output 8v budget build does have something over an MI16 !!

 

Not forgetting that the 8v has solid lifters, which if you converted an mi16 might help with oil surge issuses (I believe you have to reduce oil flow into the head).

[Guest Cartooner]

Just for the record: The pick-up of the oilpump is more or less in de middle of the sump by the way, but the problem remains the same, anyway.

[smckeown 1]

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?

 

Would it be a good idea to make a transparent cam cover so the oil drainage behaviour could be filmed in situ ?

[Phil 0]

Within 2 seconds the cam cover would be covered in oil and no longer transparent from oil flying around off the cam etc. Plus I guess the problem lies a bit lower down in the head than at the rocker cover.

[Guest Cartooner]

Well Smckeown, the part that You are quoting was my first guess. The shape of the drainage holes differs in the head and I do think the frontside hole would benefit from opening up as far as possible, to resemble the flywheelside hole.( porkchop shape). But since there is a coolant water passage near it there is not much that can be done I'm afraid.

 

What is very important is where the oil gallery ends. On the flywheel side it is just above the no.1 mainbearing cap. This hole will flow freely under most conditions. On the distr. side however the oilgallery ends up in a useless spot. Just above the oilpumpgear in a narrow space(Yellow dots ). I borrowed a pic from the Haynes manual to show You what I mean.( Red circle is the oilgallery )

 

 

The pumpchain slings the oil upwards towards the gallery also, which won't help flow(green) either. When under sustained lefthandcornering the distr. side of the sump is filled with oil( due to centrifugal forces) the oilpumpgear space gets filled with oil and the gallery will not flow any longer, which will fill the head up with oil, which will drain the sump from oil( Upto the point where the pick-up is set dry).

 

The hole I drilled will prevent this from happening. No need for perspex camcovers to prove it!( Would be nice though, but won't work I'm afraid ). This is the problem and I have the cure I think...........

[Batfink 201]

when will this engine be built up Cartooner