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PollyMobiles Rebuild

Nice to see some progress Paul :)

Didn't realise people were so passionate about catch cans though. The modified scene doesn't help and, as a result, most of them are fitted for nothing more than engine bay bling. They also don't provide much in the way of vapour knockout and just move a potential issue from one place to another.
 
Low Rider said:
Nice to see some progress Paul :)

Didn't realise people were so passionate about catch cans though. The modified scene doesn't help and, as a result, most of them are fitted for nothing more than engine bay bling. They also don't provide much in the way of vapour knockout and just move a potential issue from one place to another.
Click to expand...
And others are fitted due to rally regs :)
Properly set up they do a good job too :)
 
7th June

went for another run.
cold cranking abit better without the soaked cylinders but initially cold idles too slow and barely builds enough oil pressure so would have to hold throttle at 2k till the damp oil clears then it cold idles ok.
cold crank enrichment needs leaning alot cos it starts at 9.6afr then rises slowly until the o2 is heated and then adjusts to 14.7

warm up through town and blast along the A road





check compression and its a good 11.2 11.7 12.1 11.3 bar at 273miles.
no signs of leaking.

more 4-6k rpm runs. it only briefly smokes slightly the moment I step on the throttle after a long deceleration vacuum (could it be inlet valve stem seal and also cause the lumpy cold starts? will need to video outside the exhaust to see if it poofs smoke on cold starts)



check compression at home at its 11.2 11.6 11.9 11.3 bar at 295miles.
its gradually building up (and exceeding the previous forged engine readings) as the miles rack up so tis good news

23110490.jpg


now that we've stopped her bleeding and her health is recovering really well after this upgraded heart transplant, I treated her with a luvely overdue TLC wash n clean after 6mths left in a garage

btw another thing I noticed last night is reduced vibrations. the stock engine used to vibrate the front grill n wings so much making an annoying buzz at idle (hence ziptied the grill n wings solid) but with this balanced crank/fly/clutch it no longer buzzes and is real smooth at high revs :)

and another thing, the exhaust at warm idle no longer randomly hiccup
 
8th June

with a clean car, it cold cranks ok with no smoke so inlet steam seals prob fine. warm it up then straight to blasting.

still faintly smokes under boost and oil leak is a tiny drip at high rpm



stopped to check compression straight after while hot and is improving.

whenever I pull the fuel pump fuse till it stalls and crank summore to make sure before pulling the plugs, then cyls are occasionally slightly oily.
but when I just stop the engine and pull the plug the cyl are dry?

vacuum still pulling loadsa oil in?

imag0747u.jpg


another run. noticed during deceleration a strange buzz at a certain rpm



I recall I had this similar issue before which was a loose timing cover bolt so looked there, nudging afew washers and yup the rear bolt washer was loose. tried to tighten the bolt but it was tight, so its actually too long and offered zero clamping force which might be the cause of the tiny leaks?

imag0749h.jpg


replaced it with a shorter bolt nearby, ah the front panel bolt

imag0750u.jpg


the front cover bolt was also the same long one so replaced that one too

imag0751m.jpg


checked the turbo inlet for any oily blowby from the catchcan and tis clean

imag0752u.jpg


so tightened the timing cover bolts n went for another run



abit better but still tiny tiny drips every so often

and again



done 350m now so time for an oil change. its all black n filthy. the rear corner of the engine near the PAS/water pump once again soaked with oil.
 
commence runs. still smokes under boost and tiny drips



the last run upto 400m going through another country



this is the compression history. tdays run from 114700m has been getting steadily higher as temps rise but the last run had a long cool down through town which might've caused the reduction in compression

13375161.jpg


not sure if this smokings gonna improve cos its been 400 hard miles and the wet cyl & smoke under boost is still there but tdays last 50m since I change the oil & filter, the dipstick is still full :)

we'll see at 1000m else I'll have to pull the pistons out n stretch those oil ring expanders
 
9th June

another day of breakin-in 100miles. slight smoke on boost and small oil leak still there



compression same as yesterday. brought up the revs and tis only with the sun behind me that I can see it smokes on boost.
smoking mainly happens initially for few secs (burning away the residue?) only during high boost after decelerating (high vacuum) from very high 5-6k revs.
when off-boost its clear, even at high rpm.

tried decelerating from 6k (incase the high vacuum is sucking oil into the cyl) then just lightly touch the throttle to resume combustion without boost and see if it burns any oily smoke..nope off-boost its still clear.

so something during the initial few secs of going full boost after a long deceleration is allowing a tiny bit of oil to burn in the cyl



driving back home



the last two compression readings from tday seem to have stabilized.
after disconnecting the catch can and tightening the timing cover bolts to stop the leakage, the dipstick has remained the same for the past 2days of reving

67830419.jpg


also got my endoscope back tday, lets see inside.

this is after switching the IGN off (cranking it without firing will prob make it oily, which I'll photo next)
cyl 1-4 all showing the same damp crusty coating with clean wet patches on the outer corners near the inlet. could this signal that it could be a faulty inlet stem seals even though they're new?

DSC08371.JPG
DSC08372.JPG
DSC08373.JPG
DSC08375.JPG


the bores look like this, still have their 60deg? crosshatch

imag0757co.jpg


but the frontal exhaust side of the bores (decelerations, compression, exhaust stroke) all have this heavy multiple vertical scoring mark (phone camera can't exactly capture what I see on the scope display)

imag0760w.jpg
imag0761l.jpg


the rear inlet side of the bore (during intake under boost and combustion stroke) looks better, only has 1 gentle score.

another test would be to unplug and cap the TB PCV pipe (incase the pcv can't seal properly against 10psi) so the crankcase breathes freely on its own with no interruptions, and see if it still smokes at high boost & rev
 
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Just to chuck another idea at you. With it only being on boost what about the turbo itself? Bearing seal? I know its a bit extreme but I'd rather say and you catch it early just incase
 
really need to hook a pressure gauge to the crankcase to see whats going on under boost tbh.

removing the turbo elbow to check if the turbo is smoking is abit of a task so I'll try the easy tests first.

have a theory that if the PCV was letting boost leak into the crank and the PCV/cover breather can only flow out so much gas before the restriction of the port builds pressure, that crankcase pressure at high boost/rev pushes up against the turbo drain pipe which is trying to drain oil away from the turbo core.

so the turbo oil feed is feeding pressurised oil into the cores bearings while crankcase pressure is backing up the oil drain at the other end, this oil has to go somewhere and the next easiest weakest link is the turbo seals out the turbine seal.

so next task is really to unplug the PCV n see it that improves high boost smoking.
 
i doubt if you are getting any compression blow-by with those healthy compression readings eh paul, just try a hose clamp on the pcv pipe :)
 
frank said:
i doubt if you are getting any compression blow-by with those healthy compression readings eh paul, just try a hose clamp on the pcv pipe :)
Click to expand...

yeah doesn't seem much blowby on the breathers. I just tried disconnecting & plugging up the pcv pipe as I'll mention in update below
 
h701micra said:
One way valve in the turbo oil feed. Not something I've ever tried... but an idea :confused:
Click to expand...

no point in the valve at oil feed IN cos its pressurised oil forced into the turbo. and having a check valve on the drain pipe also doesn't help cos if crankcase pressure is making the valve shut then that oil is still trapped n leak out the seals instead anyway
 
so this morning drove to work and still smoked tiny bit under boost



after work I unplugged the pcv and plugged the hose

imag0767c.jpg




still smokes under boost. after a blast, checked compression, tis alright.
without any vacuum clearing the crankcase, any blowby n oil/water vapours just go into the evian can and condensed to a lightly milky base

imag0768l.jpg


removed the pcv valve, opens n flows fine one way and when I blew into it very hard it just leaks a tiny amount.
left it off and did another run



nope still smokes the same amount under boost and only after high rev deceleration.
so its not crankcase pressure causing the high rev smoke.
the cyls still moist with oil.
compressions 11.1 11.4 11.7 11.2 bar
cyl 1/4 compression is stable but 2/3 fluctuating.

47366397.jpg


meanwhile the alternators bracket has fractured again ffs

imag0770o.jpg
imag0771w.jpg
imag0772b.jpg


unlikely to be turbo seal cos it doesn't smoke hot or cold under idle, cruising, low boost or deceleration. only under high boost for first few sec after a long deceleration.

the old worn turbo seals used to smoke during cold & warm idle.

only cause I can conclude is weak/leaking oil rings and/or inlet stem seals.
but all of the cyls show the same damp oily tops so I think it's most likely all 4 weak oil ring expanders.
 
I think I'd have to agree with the oil rings :) after a long deceleration to high boost that's where you'd have high engine load plus you've tried pretty much everything else :p
 
h701micra said:
I think I'd have to agree with the oil rings :) after a long deceleration to high boost that's where you'd have high engine load plus you've tried pretty much everything else :p
Click to expand...

I would've thought stem seals gave the symptoms of rough smoky startup and big smoke when resuming combustion under any throttle after a long high-vacuum deceleration.
but its prob not that cos it doesn't smoke upon cold cranking,
starts fine when warm with the same oily/damp pistons as cold,
doesn't smoke under light combustion after a long deceleration, only under high load combustion after a 5-6k rpm deceleration.
doesn't smoke as much if I decelerate from 4k and WOT, prob not enough vacuum.

if I decelerate from 6k (enough vacuum to begin sucking oil into cylinders) for only a short period down to 5k then resume WOT combustion, it only poofs a tiny amount of smoke compared to decelerating from 6k-4k. so more time decelerating under high rpm high vacuum = more oil sucked into the non-combusting chambers

when decelerating from 6k the boost gauge is at -25psi till it reaches 5k then goes to -27psi

not tried ALL options yet

last options would be either to:
  • unbolt turbo mani with oil feeds still hooked, rev engine and see if the ports smoking (rings) or turbo's leaking under oil pressure (turbo seals) but neighbours won't like that noise.
  • fit stock exhaust and see if it still smokes under WOT. lotsa work swapping bits. plus if the oil rings can't seal against this turbo now, it never will fix itself.
  • I'll play the waiting option, complete the 1000m break-in, change to normal 10w40 semi and see if it stops smoking under boost. or else it'll require a major job getting pistons out n increasing the oil ring tension.
 
make that bracket out of angle and lay weld beads down to add stiffness, then anneal it to take the brittleness out of it
 
Neighbours always have a reason to complain anyway its not like you'll be doing it for fun. Hopefully the turbo seals are good. If it was them they'd leak under high boost regardless of vacuum?
Stem seals like you said wouldn't just leak at high vac/load but they're easier to check than the rings. For some reason I already thought you had them crossed off
I'm hoping as much as you its not the rings but the events suggest it will be most likely
I'll keep watching to see how it goes after you complete break in. Be a different story by then at least you've solved the major smoke issue of the catch can
Have you thought of giving the rocker cover a second breather? Vented to atmosphere. Ive seen that a couple of times but its not clicked in my head until now
 
Quote : so something during the initial few secs of going full boost after a long deceleration is allowing a tiny bit of oil to burn in the cyl

What is the A/F Ratio like at this point ? If it is a bit rich for a moment, then it could be fuel washing the oil from the bores and burning this ?

To be honest burning a small amount of oil I wouldn't be too worried about personally.
 
Enuo said:
make that bracket out of angle and lay weld beads down to add stiffness, then anneal it to take the brittleness out of it
Click to expand...

I bent a straight bar slightly offset cos the alternator and the mounting faces are aligned but on opposite sides and was easier faster to bend a bar than an angle bar.

I've got a thick angle bar but again tis hard work to bend it offset or to cut a slot on one side/bend/weld up.

easiest and quickest way is prob to get 2 straight bars and weld em together offset.
wouldn't the heat of welding and cool down in air anneal the metal automatically?
I'll figure it out
 
h701micra said:
Neighbours always have a reason to complain anyway its not like you'll be doing it for fun. Hopefully the turbo seals are good. If it was them they'd leak under high boost regardless of vacuum?
Stem seals like you said wouldn't just leak at high vac/load but they're easier to check than the rings. For some reason I already thought you had them crossed off
I'm hoping as much as you its not the rings but the events suggest it will be most likely
I'll keep watching to see how it goes after you complete break in. Be a different story by then at least you've solved the major smoke issue of the catch can
Have you thought of giving the rocker cover a second breather? Vented to atmosphere. Ive seen that a couple of times but its not clicked in my head until now
Click to expand...

all 4 wet pistons since day one is a clear indicator that's where the smoking's coming from but where?, can only be inlet valves or oil rings.
youtube vids of turbo failures shows a constant thick smoke at most times.
my smoking is very faint n only under high loads after long high vacuum.

all 3 engine cover ports are now open and crankcase vapours will just hang round, hence the slow moving hot vapours allowed to condense into the evian bottle.
 
Not unless the whole bar glows red hot. Ideally wrap it in fiberglass or similar too to slow down cooling. Slower the cooling, larger the grains, less brittle the metal.
 
Not unless the whole bar glows red hot. Ideally wrap it in fiberglass or similar too to slow down cooling. Slower the cooling, larger the grains, less brittle the metal.
 
pollyp said:
all 4 wet pistons since day one is a clear indicator that's where the smoking's coming from but where?, can only be inlet valves or oil rings.
youtube vids of turbo failures shows a constant thick smoke at most times.
my smoking is very faint n only under high loads after long high vacuum.

all 3 engine cover ports are now open and crankcase vapours will just hang round, hence the slow moving hot vapours allowed to condense into the evian bottle.
Click to expand...
Have you thought of a simple vacuum draw through? It might help considerable getting rid of those gases?
Simple pipe from the front to the back of your bay with your crankcase pipework attached at an acute angle facing the rear? Extremely simple and effective. I've a drawing somewhere if it helps at all?

I think you can rule out the turbo seal. As you say 4 wet cylinders would suggest stem seals or rings
 
SuperUno said:
Quote : so something during the initial few secs of going full boost after a long deceleration is allowing a tiny bit of oil to burn in the cyl

What is the A/F Ratio like at this point ? If it is a bit rich for a moment, then it could be fuel washing the oil from the bores and burning this ?

To be honest burning a small amount of oil I wouldn't be too worried about personally.
Click to expand...

I'll need to review onboard cams to be sure but when I lift off at 6k rpm 70mph, gauges at 20.9afr open air (cut fuel) and -25psi vacuum.
at 5k goes -27psi vacuum and still 20.9afr cut fuel

at 4k rpm 50mph I smoothly reapply the throttle towards WOT and she goes roughly 13afr at 1/2 throttle point, then 11afr at WOT for initial fraction of sec, then 10.6afr throughout accelerating WOT from 4k-6k rpm.

you'll see in the exhaust shots that as I go WOT after a long deceleration I get a brief poof of blue smoke (burning away the collected residue oil)
then a quick black smoke as it goes to 10.6afr rich,
then runs clear from 5-6k rpm

tis only been 450m and its only during high rev WOT but maybe I'm worrying too much prematurely? and should just run it long term n see if it improves over the hundreds of miles? just thinking surely it shoulda stopped smoking by this amount of hard running?
 
h701micra said:
Have you thought of a simple vacuum draw through? It might help considerable getting rid of those gases?
Simple pipe from the front to the back of your bay with your crankcase pipework attached at an acute angle facing the rear? Extremely simple and effective. I've a drawing somewhere if it helps at all?

I think you can rule out the turbo seal. As you say 4 wet cylinders would suggest stem seals or rings
Click to expand...

or just reconnect the cover breather port straight back into the turbo inlet cos that'll be under a slight vacuum.

and yeah, stem seals or rings.

could the vertical scoring marks also be a contributor to the smoking under high boost only symptoms?
 
pollyp said:
tis only been 450m and its only during high rev WOT but maybe I'm worrying too much prematurely? and should just run it long term n see if it improves over the hundreds of miles? just thinking surely it shoulda stopped smoking by this amount of hard running?
Click to expand...

At 450m into a 1000m break in I'd say you've got a while yet before everything is fully settled.
If it was still smoking like a couple of weeks ago I'd be concerned. But a small bit of smoke at high boost and WOT.. I'd be happy with that at this stage
 
h701micra said:
At 450m into a 1000m break in I'd say you've got a while yet before everything is fully settled.
If it was still smoking like a couple of weeks ago I'd be concerned. But a small bit of smoke at high boost and WOT.. I'd be happy with that at this stage
Click to expand...

righteo I'll carry on.

the amount of fuel and oil I'm going through (21mpg during hard break-in and oil change per 400m) break-in ain't cheap :p
 
pollyp said:
or just reconnect the cover breather port straight back into the turbo inlet cos that'll be under a slight vacuum.

and yeah, stem seals or rings.

could the vertical scoring marks also be a contributor to the smoking under high boost only symptoms?
Click to expand...
Only just seen this.. yea the scoring marks are what lead me to say the rings earlier on

Yea reconnecting it back to the inler is the easiest way but your then sending the oil round into your cylinders again?
 
Enuo said:
Not unless the whole bar glows red hot. Ideally wrap it in fiberglass or similar too to slow down cooling. Slower the cooling, larger the grains, less brittle the metal.
Click to expand...

Not really important though if you just make it out of mild? it only really makes a difference if there is carbon in the steel as far as I know. Does look like a brittle failure though, what exactly did you make it from paul? something cast?
 
Noddie said:
Not really important though if you just make it out of mild? it only really makes a difference if there is carbon in the steel as far as I know. Does look like a brittle failure though, what exactly did you make it from paul? something cast?
Click to expand...
aye mild steel is low carbon eh ed :) the bracket is simply too thin for the job :)
and the scores in the bore are probably "pick-up" from the piston skirts eh paul
 
You'd be surprised how much of a difference it does make. Carbon being a factor depends on wether it is dentritic, austentic etc, but as it's low carbon it'll be mostly austentite, so it's the grain size that will be the important factor, which is controlled by heat treatment (e.g. annealing). If you want to get an idea just how much take a sewing needle and try to bend it. Then heat the bend red hot with a lighter, let it cool then try and bend it again. It'll be much softer, all because of the grain structure has been changed.
Edit: Was saying annealing to take stresses out, as welding causes non uniform heating which can induce internal stresses in the metal increasing the chances of a brittle failure mode.
 
h701micra said:
Only just seen this.. yea the scoring marks are what lead me to say the rings earlier on

Yea reconnecting it back to the inler is the easiest way but your then sending the oil round into your cylinders again?
Click to expand...

tis only a tiny amount, leaving it off for now
 
that red bracket piece was made from some piece of cast mild (yaknow the strip of thin steel on those tool chest that you padlock on front of the trays to lock em in)
yeah frank twas too thin n brittle so it fractured

so got some 20x10mm steel bar in BQ, blowtorched n bent n drilled this on the vice

DSC08376.JPG


much beefier and should do the job

DSC08378.JPG
 
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so recorded outside the exhaust during coldstart. cranking is lumpy but once clearing you can see its smoking blue, not a good sign.



when I blip the cold engine, can see some exhaust fumes blowby poof out the removed PCV hole.

on warm it idles n drives clear but again under boost it smokes and the cylinders are always either damp or oily. reconnected the pcv to purge the crankcase, it ain't causing the smoking so its fine.

dsc08379x.jpg


stuck the endoscope inside after a hot run and even though the center of the piston top is just damp, I can see the sides are wet and oil coming from down the bores.
tbh this can't be right at all? some part of the rings or pistons are seriously wrong. I don't think this'll improve.

thought I'd stop the break-in on/off driving style out of frustration and just try cruising off boost to see if that affects anything. nope other than a white plug (burnt oil) with black electrode, the cyl still oily damp ffs.

really dont fancy the job of ripping the head, sump, windage trays and pistons out to stretch the oil tension :/
 
12th June

went for another run driving through the country



changed the batteries and continued the runs.
some bloody idiot @17:15 almost causing a collision grr >;(



after all this low load runs, the compressions at a low 10.9 11.2 11.4 10.9 bar, cylinders still wet

tweaked the map to idle better and went for a hotter high rev run to heats things up



@14:09 there's a surprise backfire when lifted off from high rpm. can't see if its still smoking in the dim evening.
with hotter parts its at 11.1 11.3 11.8 11.3 bars so compression seems very temperature dependent, but still oily as always.

at this rate I can't see this oil issue ever improving at all imo, same as what happened before, and its prob also influencing the compression readings.

so debating whether to carry on driving towards 1000m n burn oil or rip it apart n stretch those oil expanders over the next few weeks.
 
I've been attempting to remove the o2 and tune the nistune parameters to run open loop and match the correct afr shown in the fuel map just like what I did with the stock engine but it's been a real headache tonight.
I try my best but I'm no tuner. alot of issues frustrating me.

first I try the original forged engine map and although its fine under boost, its way too rich at 11-12afr during high rev/low load and idle cos it was originally tuned with the O2 fitted to correct the 14.7 afr issue alot.

a tweaked version of the map ran pretty close.
14.7 at idle and wideband reading matching the light/med/hard load readings in gear at most rpm but the issue is it runs really rich 11-12afr during high rev/very light throttle (just before it begins to cut off fuel) or holding high rev in neutral (ie MOT fast idle emission testing type of revs) when it should be 14.7afr
during 1st gear very light throttle acceleration it leans 15-16afr as revs build, especially when its not upto temps yet.

balancing the injector multiplier & latency just complicates things. it's like the MAF VQ map isn't correct at the low end.

really wish the MAF & the VQ map was flow tested in the first place to ensure what it reads is real and that the fuel map would match the wideband to make tweaking easier but there's just so much parameters affecting one another.

think I'll just put the O2 back in to patch the low load error for now cos cba

throughout this tuning phase night its been under alot of cruising and idling, prob not good for break-in? even after 600m?
at home removed the plugs and seems 5-10% of the piston is dry. I dunno whether to believe that its truly drying under the low load session cos the wet/dry appearance of the piston has been very random.

I'm thinking fit the O2 back, carry on normal low boost/rpm driving and the heck with the on/off break-in method and see if she really dries out over the coming miles.
 

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