New Solution For Mi16 Oil Surge

[Owain1602 0]

is there no way of improving the oilways in the head returning to the sump? or creating some spray for the bottom end bearings? i've just got an MI head the other week for a 1600 MI project i might get time to start this decade, i'll have to have a carefull look at it i think.

Does the same problem occur for an MI head on a 1600 bottom end with mix/match pistons, cranks and rods does anyone know?

[nick 3]

Me and Martin are working on a 16v/8v hybrid type thing at the moment, so watch this space.....

 

my engine has turned into a bit of a Guinea pig (without the fur and s*it everywhere!)

 

Nick

[crf450 0 1 Cars]

I don't subscribe to the school of thought that the Mi's surge problems has anything to do with drainage inefficiencies in the head, surely if we're saying that oils is collecting in the head and is being fed quicker than it can drain back the head would fill with oil to the point it was full and would be forced back under pressure.

This would obviously be combated by putting whatever oil is held in the head extra in the sump.

I think the problem is simply down to the Mi having spay bars and piston located con rods which allow a massive amount of leakage around the journal.So as Nick said, we are putting 8valve rods in his Mi and doing away with the spay bars.

[labrat 0]

<quote Rally Slag>

this might sound silly but what about putting like 0.5-1 litre extra of oil in the engine, mayby not so good for a road car as it needs to be reliable, but round the track wouldnt that do that trick?

</quote Rally Slag>

 

That's what we tried ... made no difference

[saveloy 8]

I don't subscribe to the school of thought that the Mi's surge problems has anything to do with drainage inefficiencies in the head, surely if we're saying that oils is collecting in the head and is being fed quicker than it can drain back the head would fill with oil to the point it was full and would be forced back under pressure.

This would obviously be combated by putting whatever oil is held in the head extra in the sump.

I think the problem is simply down to the Mi having spay bars and piston located con rods which allow a massive amount of leakage around the journal.So as Nick said, we are putting 8valve rods in his Mi and doing away with the spay bars.

 

 

I'm not saying you are wrong. But, if that is so, why do Richard Longman race engines run return pipes from head to block?

Is it not possible to use a higher capacity pump to test the theory? I know the room is limited.

[KRISKARRERA 2 1 Cars]

Do you guys who get oil surge on track also get it on the road?

[James_R 3]

So as Nick said, we are putting 8valve rods in his Mi and doing away with the spay bars.

 

I stripped down an Mi used for autocross racing which has the above done, had spun big end 3 very impressively, although I can't commnet on how much oil was in it etc.. but I'd assume it was up to the level etc..

 

Do you guys who get oil surge on track also get it on the road?

 

Yes I get it on long left handers like th eM11/A14 interchange can get the stop light on easily, but tend ot lift off and slide the back out and things return to normal pretty quick, but that's doing a fair amount more than the speed limit

[sam1312 0]

When you do fit a proper oil pressure guage you'll just see how much it moves around

 

 

i done that today and the original guage is 3 seconds slower to react to the michanical guage, and yes mile the guage is all over the place when i took it for a spin in the lanes

[Bally 4]

yup, you need to fit a proper gauge and see how much it moves around, its scary actually. I never even push my Mi16 in corners anymore.

[saveloy 8]

Christ! Reading through this thread, plus remembering past threads on the subject, what a pain in the arse.

An Mi wouldn't last 3 minutes in my hands. If the little red light kept flickering at me, I'd want to torch the bloody thing.

How an earth does anyone actually enjoy their 205's, when you have to drive like Dino in the bends?

[welshpug 1,622]

How an earth does anyone actually enjoy their 205's, when you have to drive like Dino in the bends?

 

 

 

8 valves....

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

runs away

[veloce200 3]

My old standard Mi lump (one that Doug now has) exceeded 8000rpm on a downshift when I was trying to slow the car after the brakes failed, and that didn't gain any additional rod-shaped ventilation holes in the block...

 

I once owned a Fiat Strada 105TC - Fiat TC engine - prob the toughest 4 cylinder motor ever made. Once shifted into 1st from 60 mph in second ( I did want 3rd but the gearbox was s*ite!). I calculated it pulled 11500rpm. Only damage - couple of bent valves - still ran on all 4 cylinders though. Damn tough engine!

But seriously though pug engine it tough too. Every one I speak to say 8200 on 8v internals intermittent is fine.

[boombang 2]

At Anglesey in my 106 Gti I downshifted into first before the hairpin a bit early once. It bounced off the rev limiter and locked the wheels up for a short while - passenger said the RPM counter was up around 9k when he looked.

 

Just one of those things I didn't even think about and did by accident but the car was absolutely fine

[mfield 20]

Yes I get it on long left handers like th eM11/A14 interchange can get the stop light on easily, but tend ot lift off and slide the back out and things return to normal pretty quick, but that's doing a fair amount more than the speed limit

 

One of my favourite corners

[welshpug 1,622]

pretty strong these pug motors, I one stuck my mum's TD 405 into 3rd instead of 5th when I was already at 4500rpm and flat...

 

still going strong 50k lated

[C_W 3 1 Cars]

I once put mine in 3rd (instead of 5th) at 115mph momentarily. Obivously over revving is different to oil surge though.

 

8500 track miles puts even mine to shame!! I didn't think anyone else kept the same one running for longer than me. But what he said doesn't make any sense to me; oil surge is a standard feature of the engine! And Silverstone is really bad for it.

[C_W 3 1 Cars]

I know of the guy in question, he's had 13 different installations so unless he's had some really bad luck I doubt it!

 

And I know of his driving too, so the second quote doesnt apply either

 

It would be good to find out for definite what exactly does happen, surely some oil level sensors could be placed in the areas concerned to see if oil really does collect/surge this badly.

 

You have to bear in mind that most of the Mi16 conversions have utilised well used engines and would be more prone to low oil pressure.

 

Oil surge doesn't have much to do with low oil pressure (through high mileage) though - whatever oil pressure the engine normally runs at, if it surges then you don't have any! Mine had 110k on the engine when I fitted it in 99/2000 with 55 trackdays, probably around 6-7000 track miles.

[veloce200 3]

Oil surge doesn't have much to do with low oil pressure (through high mileage) though - whatever oil pressure the engine normally runs at, if it surges then you don't have any! Mine had 110k on the engine when I fitted it in 99/2000 with 55 trackdays, probably around 6-7000 track miles.

 

55 track days ! mental! I've only done 1 and 2 test days

it's definitely the head on the MI that makes a bad design worse. the 8v gauge moves and I can get the light on under braking so there are inherrent problems with the pickup that the MI head problem makes worse. incidentally new M5 has electric scavenge pumps in the head - 4 of them!!

[crf450 0 1 Cars]

55 track days ! mental! I've only done 1 and 2 test days

it's definitely the head on the MI that makes a bad design worse. the 8v gauge moves and I can get the light on under braking so there are inherrent problems with the pickup that the MI head problem makes worse. incidentally new M5 has electric scavenge pumps in the head - 4 of them!!

Why are you so sure the problems down to the head? The head isn't the only fundamental differance between the Mi and the 8valve engine.

[veloce200 3]

Why are you so sure the problems down to the head? The head isn't the only fundamental differance between the Mi and the 8valve engine.

 

Because there are many other engines with oil cooled pistons that don't have the same problem. Nearly everyone on here acknowledges it's a head issue and thats why solid lifters help

[engine killer 5]

Because there are many other engines with oil cooled pistons that don't have the same problem. Nearly everyone on here acknowledges it's a head issue and thats why solid lifters help

 

the head design might be a problem, but a better design of sump can solve all the problem - only dry sump can or drive slowly. the well improved EW10 engine also suffers oil surge unless you are not driving fast enough on track. it is very much like driving a car in a very brake demanding track, someone said a stock brake is already enough but someone overcooked a 4pot after some hot laps.

[veloce200 3]

the head design might be a problem, but a better design of sump can solve all the problem - only dry sump can or drive slowly. the well improved EW10 engine also suffers oil surge unless you are not driving fast enough on track. it is very much like driving a car in a very brake demanding track, someone said a stock brake is already enough but someone overcooked a 4pot after some hot laps.

 

 

I think there might be an inversely proportional relationship there. If you are cooking your brakes you aren't cornering fast enough, if you've got surge problems you probably don't cook your brakes !

[Batfink 201]

the head design might be a problem, but a better design of sump can solve all the problem - only dry sump can or drive slowly. the well improved EW10 engine also suffers oil surge unless you are not driving fast enough on track. it is very much like driving a car in a very brake demanding track, someone said a stock brake is already enough but someone overcooked a 4pot after some hot laps.

 

solid lifters are the key if I remember what Sandy was saying. he knows a lot of pugs in motorsport that suffer no oil surge and do not have a dry sump.

 

I'm not convinced that a dry sump in itself cures the problem unless it is literally sucking the head of its oil. The dry sump means you have about 10 litres of oil in the system and the oil pickup never sucks air

 

It masks the issue rather than cures it and I do like the look of my dry sump kit lol The 405 mi16 Touring cars were not allowed to have dry sump kits and they do not blow up round corners and they corner faster than any of our cars

 

Pedantic I know!

[Rally Slag 0]

is it not possible to make the oil ways in the head bigger, I have nevet taken an MI lump appart so dont know what its like in there but its just a suggestion, if the oil ways are bigger, more oil can get down there

[Guest superpug]

Hi newbie to the fourum here but a may have a theory as to why some mi s suffer the oil serge and some escape it when rebuilding my suppercharged mi i also stripped my standard mi which was originaly out of a 4x4 version to use the crank and i noticed that the spacer between the oil pump and block was thicker and the chain longer thus lowering the pump further into the oil