Mi16 Reliability

[Guest chrisw]

Hi, i'm new to the 205 scene, basically i swapped a drift spec 200sx S14a for a drift spec S13 and an Mi16 205. It's got a Longman built bottom end, Longman cams, Longman head, twin Dellortos etc etc

 

I keep getting told that these engines are bulletproof, is this true? Or should i not rev it to 8 grand anymore?

Edited October 23, 2009 by chrisw

[Anthony 1,000]

They're hardy enough in a straight line, and will rev without too much issue - if it is still running hydraulic tappets (not sure if Longmans swap to solids for their cams or not) then they can "pump up" at sustained high revs (7500+) though.

 

Round corners, if adequate oil control isn't employed, is another matter entirely - they suffer oil surge and spin big end shells with alarming regularity. A search will reveal all....

[Baz 421]

I wouldn't say 'bulletproof' but yes they're fairly sturdy dependant on a few factors of course. 8k isn't that much...

[hexhamstu 9]

revving them is fine, as said its long corners that kill them.

[S33GAV 0]

Personally I've never found a reliable mi16! MUST KEEP OIL TOPPED UP (is what I force myself to say 50 times just before I go to bed)

[Jrod 7]

My Mi is the only unreliable car I've ever owned!

[Guest chrisw]

So a baffled sump is the way forward then?

[Tom Fenton 1,525]

You need to do a bit of reading my friend, unfortunately there is a bit more to it than that, in short, baffles plus mods to oil pump and pickup.

[hexhamstu 9]

The sump from an xu10 engine is deeper and is baffled, this sump fitted with an extended oil pick up is the cheapest way to battle the dreaded oil surge effectively.

[dcc 855]

I think its only the xu10j4rs which has the baffled sump (well single windage tray - not exactly baffled ) found on gti6 and xsara vts engines.

 

If its a well built engine by longmans then I bet it feels quick as sh!t off a shovel!

[brumster 135 1 Cars]

Baffle and windage tray are not the same thing of course

 

I see the old mi16-oil-starvation-death-block discussion starting yet again. Chrisw, I took my standard bottom end (with the exception of ARP bolts) to 7.8k regularly. My new Longman lump, well, Sid said it would be good for 8.5k tops but if I kept it to 8 then that would maintain much better reliability. I've set the limiter to 8.25 and will try and keep it below 8, with brief bursts about when I really need it on stages. So assuming you're spec is correct, I would think 8 would be fairly safe as your maximum.

[petert 550]

I think its only the xu10j4rs which has the baffled sump (well single windage tray - not exactly baffled ) found on gti6 and xsara vts engines.

 

All alloy XU10 sumps are baffled. I did an oil capacity test last weekend. An XU10 sump, with my modified XU9 spacer plate and windage tray below, will take 7.3L of oil and just lap under the windage tray.

[Guest chrisw]

Thanks for the info guys.

If its a well built engine by longmans then I bet it feels quick as sh!t off a shovel!

Yeah it's pretty rapid, it's supposedly running 220bhp, but i'm getting it set up and rolling roaded soon.

Unfortunately i'm probably going to have sell it soon as i'll need the money to buy a family car, bloody wife and kids lol

[Guest chrisw]

Baffle and windage tray are not the same thing of course

 

I see the old mi16-oil-starvation-death-block discussion starting yet again. Chrisw, I took my standard bottom end (with the exception of ARP bolts) to 7.8k regularly. My new Longman lump, well, Sid said it would be good for 8.5k tops but if I kept it to 8 then that would maintain much better reliability. I've set the limiter to 8.25 and will try and keep it below 8, with brief bursts about when I really need it on stages. So assuming you're spec is correct, I would think 8 would be fairly safe as your maximum.

Great, i was told that it revs to 8k, but the power seems to start dropping off at 7.5k so for now i'll keep it around there.

[Baz 421]

If it has been built competently then it'll no doubt have some form of attempt of oil control in the sump i would've thought, even if at least an xu10 sump with trap door.

[Masekwm 2]

I need to get my head around which bolts to use as I intend to put the XU10 sump on the Mi whilst it's off the road.

[Jrod 7]

I've got a xu10 sump and extended pickup, still surges.

[Baz 421]

I've got a xu10 sump and extended pickup, still surges.

It's a crappy, abused, sludged up, never rebuilt (properly) engine that's probably always been run on crap oil then... Edited October 24, 2009 by Baz

[Jrod 7]

Its just been rebuilt.

[DrSarty 90 1 Cars]

Its just been rebuilt.

 

Well arguably not very well based on your recent issues!

 

I have the set up PeterT recommends, which is used on road and track cars with little to no issues. Many people have similar. My car's never had a problem and has been tracked at the 'Ring twice.

 

Ultimately dry sump systems exist for a reason, because there are limits to typical set-ups. But for a road car, that perhaps even goes to the track occasionally, I can see no issues with Mi reliability whatsoever. It's a great engine, well designed, which if maintained will run and run.

 

Only when you start to push things outside of spec - as with anything in life and as we naturally do as humans - do reliability issues creep in, or, you get catastrophic failures.

 

(See how I tried to drag this back on topic here? )

[Jrod 7]

I have no problems with surge on the road.

 

So what exactly could be badly built to cause oil surge...?

[taylorspug 7]

Not alot really, its more bad design than anything as we all know the oil doesnt drain properly from the head and the rods waste a great deal of oil too with the way they are located (as per Nicks thread), and no amount of good engine building is going to get rid of that!

[Galifrey 1]

Not alot really, its more bad design than anything as we all know the oil doesnt drain properly from the head and the rods waste a great deal of oil too with the way they are located (as per Nicks thread), and no amount of good engine building is going to get rid of that!

 

Surely fitting drains from the head to the sump could address some of these issues?

[DrSarty 90 1 Cars]

Surely fitting drains from the head to the sump could address some of these issues?

 

That's a modification Mark, rather than Dan's comment being just about following good standard engine building practices.

[Guest chrisw]

Right then, from what i understand from all that is....it's a well designed engine that needs improved oil flow and a baffled sump and should be quite reliable, but there are a few out there that haven't been looked after properly and are therefore pretty unreliable, correct?