Baffled Mi Sump Vs Gti6 Sump And Extended Pickup?

[Anthony 1,003]

another engine I noticed that has piston located rods like the 1.9 MI16's is the LFY 1.8 16v, pretty much the same head as the RFS in principle, no oil spray bars in the head though, or windage tray, sump baffle of any sort, you don't hear of these engines rattling bottom ends

LFY's have a trapdoor baffled sump the same as GTi-6's etc (the sump itself is very similar to an alloy RFY one, but the casting for the oil temp sensor isn't drilled), and the gudgen pins are press-fit into the rods like 8v's are. It also has a high pressure and very high geared (thus flow) oil pump, which also has the chain cover as standard. No spray bars or windage tray though as you say.

[welshpug 1,661]

ah, mine was a very early LFY then, it had no baffle (steel sump!)

[brumster 135 1 Cars]

Ah this great old debate.

 

I reckon it's the pressure pixies. They've been laughing at our expense for years now.

[mmt 15]

Is there any reason why you would fit 8v rods in a mi engine over just getting a GTI-6 engine.

 

Is the retrofitting of 8 v rods in an mi engine better than the standard GTI-6 engine...given that the same sump guards/baffles/trays is fittet to both engines?

 

I wonder why we struggle to get the mi 16 engine not to surge if peugeot did all the work in the gti-6 engine. I figure it is easier to fit the gti-6 engine rather than costumising the mi16 internals.

 

Am I missing something here?

[James_m 0]

Mi16 is aluminium and gti 6 is iron blocked, so the advantage of mi16 is a weight saving

[Batfink 201]

Is there any reason why you would fit 8v rods in a mi engine over just getting a GTI-6 engine.

 

Is the retrofitting of 8 v rods in an mi engine better than the standard GTI-6 engine...given that the same sump guards/baffles/trays is fittet to both engines?

 

I wonder why we struggle to get the mi 16 engine not to surge if peugeot did all the work in the gti-6 engine. I figure it is easier to fit the gti-6 engine rather than costumising the mi16 internals.

 

Am I missing something here?

 

well the mi16 is lighter for one, the gti-6 has its improvements but it also has its drawbacks.

[mmt 15]

How much is the weight difference?

 

Is there any other drawbacks?

 

How much work is it to fit the 8 v rods into the mi pistons?

[Saveit 0]

Youll need someone who can do precise machine work in order to machine the small end of the conrods to suit the pistons as the piston is more narrow. Thats about it.

[DrSarty 90 1 Cars]

How much is the weight difference?

 

and the other questions.

 

As someone's mentioned before, this has been covered many times, i.e. the differences between the blocks, and this is turning into another debate going over old things.

 

Basically there is a 16kg difference, as the 2.0 Mi16 (or XU10J4 or S16) block, just like the XU10J4RS (or GTI6 or VTS) block is a bloody heavy lump of iron. It does enable you to overbore and avoid issues with liner protrusion which you can get on the XU9 alloy block.

 

The 1.9 Mi16 (or XU9J4) block is an alloy (wet liner) block that complete with its liners, is still 16kg less than the iron block.

 

Remember too that they have different bore x stroke ratios: XU9J4 = 83 x 88mm (1905cc) and XU10NN(NN) = 86 x 86mm (1998cc). Pistons, rods and crank are different.

 

On a related note: the EW10 & EW12 blocks are alloy too, with dry sleave liners, and are 23kg less than the XU10 even though it's 2.2L (EW12).

 

I suppose what I'm saying is we can't just say 'an Mi block' as there are 2 fundamentally different types.

 

Concerning the rods, I totally believe Martin (CR450 IIRC) and others that the rods are the main cause of the oil problem. I say this because they've done their research and experimented, but above all, through a process of comparison with the other engines, this appears to be the only culprit left.

 

Getting someone to machine 8v rods to suit the Mi XU9J4 pistons, PLUS adding the items the XU10 block has** will be IMO as good as you can get in a wet sump system for the XU9 Mi16 engine.

 

If you also added a drain tube from the head, you will have done everything you can, prior to dry-sumping.

 

**Windage tray; more capacity; extended pick-up etc. Also note that PeterT started a thread recently about some specific ideas he has about the best sump to modify, and how to do the trap-doored baffle plate.

Edited April 11, 2010 by DrSarty

[SPGTi 2]

Just a quick addition to the discussion.

 

Has anyone looked at changing to solid lifters in the Mi16 head and fitting an oil restrictor for the flow to the head (as it shouldn't need as much oil now -- ???) ? To see how this effects surge ?

I am also pretty convinced that all the XU10rs extra baffling helps (especially the chain baffle and windage tray) as hot oil being whipped up by an open chain and the crank will be pretty well aerated and this must effect the amount of oil that can get to the shells. I am also of the opinion that the comment of overfilling an Mi16 (to compensate for oil held in the head) would aggrevate the effect and not help it as you would have more oil closer to the crank.

 

I think that the main problem here is that I am sure that lots of things contribute to the surge problems and it is difficult to find the main culprit. I know the rod theory is building a lot of support but lots of other engines use a piston located design, Mercedes for one. Also Nicks engine had a good rebuild job done on it and there are also other "anti surge" items installed. So even though the engine now doesn't surge, as a number of things were changed at the same time, can it be concluded catergorically that the changing of the rods stopped the surge ? Personally I think it would be very interesting to run a "surging" engine with just new shells to see the effect, and then new shells + 8v rods.

 

Anyway I am sure the debate will carry on, just my ramblings as I am bored in a German hotel room.

 

 

Steve

[DrSarty 90 1 Cars]

Personally I think it would be very interesting to run a "surging" engine with just new shells to see the effect, and then new shells + 8v rods.

 

I gather you'll pay for this test?

 

I have that engine from you Steve which could be the standard, (well) rebuilt comparison versus another XU9J4 I will build with 8v rods. All other oil surge avoidance fittings (aka PeterT's stuff) will be the same on both.

Edited April 11, 2010 by DrSarty

[brumster 135 1 Cars]

What bemuses me about this topic every time it comes up is that everyone comes up with theories (or well proven ideas) on what causes the problem, and yet I managed to run a standard 1900 mi16 engine (albeit with performance mods, but none related to the problem - ARP bolts, set of cams, throttle bodies) on a tarmac competition car and never once saw the problem. The ONLY significant thing I can offer is that when it was rebuilt it was fully cleaned up, new genuine oil pump, tin sump and a PTS sump baffle (PTS; not a Constella 'pattern' part, should it make any difference). I'd see low (<25psi) pressure at low revs into hairpins, for example, but certainly never saw a problem on high speed, sustained long corners - and that's running moulded slicks so 'pretty grippy'. And remember that's low - not zero - it never fully starved; I have a telltale on my pressure gauge to verify and it was about 18psi.

 

I'm with Steve, I think there are many contributing factors and if you get an engine that's detrimental in more than one area then that's the engine that's going to cry enough. Maybe they all suffer the piston-located issue but provided the rest of the engine is in good condition, it's not a problem - but find one more that's got another weak area and it worsens the problem?

 

I've never suggested I have the solution; just that I am happy to prove that you can have an engine that's reliable without resorting to anything more than a good rebuild (if needed) and a bit o' baffling. I'll leave the choice of proper oil and cooling out of the equation for now.

Edited April 11, 2010 by brumster

[DrSarty 90 1 Cars]

I don't disagree with your comments Brum.

 

I argued (shock!) in yet another thread about this, that I couldn't imagine Peugeot would make an engine that on the public road would have these surge/starvation problems.

 

Every man and his dog said how they'd experienced it though.

 

But on the other hand, others didn't.

 

The point I'm making is that I totally, 100% agree that a really well (re)built engine, will have far less possibilities of encountering this problem, perhaps like you, none at all. But whilst the engine is apart, doesn't it make sense to do all you can to ensure you don't ruin your day with spun shells or worse?

 

I suspect an outlay of less than £200, to include all of the 'cheap route' options (ext pickup, windage tray, modified 8v A/C sump, even the modified rods) to ensure that on extensive track work and competition cars, you've done what you can to protect it all bar dry-sumping your motor.

 

This £200, or even £250, is still less than a genuine PTS baffle system, so seems good value risk mitigation to me.

 

For a road car though, just a good rebuild makes sense.

 

People shouldn't get the impression IMO that these engines spin shells and starve at every opportunity, as I can't see how that could be the case unless something else was contributing. So I completely agree with you on that basis.

[brumster 135 1 Cars]

Aye, exactly. I guess chances are a lot of them are getting old now, and even rebuilt maybe some of them have had a less-than-extensive job done on them, and their age is just showing. Longman vouched for running their engine wet-sump on track use so clearly they have confidence in them, albeit with the baffling and new pump/etc. Engine rebuilds are not cheap, when done properly. I think I worked out the rebuild of mine, less all the performance add-ons, was approaching £900 (I'm not going to double-check it or work it out again!) - that's just gaskets, shells, rings, head skim + rebuild, oil pump, belts, etc etc - and all the labour free because I did the work

 

Like you say, if you're going to have it apart anyway, you might as well do things right the first time - but that's the same old story for anything, of course, isn't it

[Batfink 201]

Its hard to say. My rebuild Mi16 never had any issues. We are not in the privileged position to be running brand new engines to see how they worked when new to see whether they were as varied in quality straight from the factory floor

[welshpug 1,661]

so what makes the 2.0 MI16 go rattle when its bottom end is near as you can get it identical to an RFS?

 

is it just that they're all worn out?

[jackherer 543]

I fitted an Mi16 engine I got from a close friends BX 16v about ten years ago, unlike most Mi16s I knew the history of this one and it was actually low mileage, not just claimed low mileage. I put it in my 205 as is and drove it hard for over seven years, I swapped it into a better shell at one point and put a new timing belt and water pump on then overall did at least 40 or 50k including several track days. It did eventually start to rattle and lose oil pressure but it had over 100k miles on it by then and had been driven hard in three cars so it wasn't a surprise.

[mmt 15]

so what makes the 2.0 MI16 go rattle when its bottom end is near as you can get it identical to an RFS?

 

is it just that they're all worn out?

 

 

Does the 2.0 have crank guided pistons as the 8valve and the later xu10, 16 valve?

[James_m 0]

so what makes the 2.0 MI16 go rattle when its bottom end is near as you can get it identical to an RFS?

 

is it just that they're all worn out?

 

I've often wondered this myself, they do seem quite prone to bottom end faliure, even in cars that have been nowhere near a track...

 

I think the key to understanding the problem with the xu9j4 is comparing it with the xu10j4, would rule out the head drainage problem if anything. Anybody used one extensively on track? Petert maybe?

[Miles 331 1 Cars]

It's just one of those thing's, I've had all 1.9 Mi's, S16's and Gti6's, Some did around 70k before giving up the ghost (All engine's) and extreme's like my Dad's 6 has 260k on it and still does fine as most of you know

But the best engine I;ve found is the 1.6 for abuse, why is anyone's guess

[Jrod 7]

Just to update I've decided to stick with the Gti6 sump, extended pickup and am adding the windage tray.

 

We'll see how this setup gets on.

[Baz 421]

But the best engine I;ve found is the 1.6 for abuse, why is anyone's guess

 

The original, not stressed or changed in any way i guess, they just take a hammering, and then some, and still come back for more!

[petert 588]

But the best engine I;ve found is the 1.6 for abuse, why is anyone's guess

 

Here's a new conspiracy theory: the smaller journal diameter of the 1.6L crank leaks less oil past the the rod bearings.

[Baz 421]

Than even the 1.9?

 

I think you may have stated this earlier in the topic, but screwed if i know for sure and where in amonsgt those 10 pages!

[24seven 104]

This may sound a bit silly, but if I plan on giving the car some stick I overfill the oil by about 0.5l and get no noticeable drop in pressure on the gauge on a completely bog standard XU9j4.

Edited April 11, 2010 by 24seven