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PollyMobiles Rebuild

Enuo

Glorified Electrician
shall I work up the grade progressively? 15w40 semi - 20w50 semi
or fully synth
or you recommend sumthing? have no idea what the ideal oil is
Probably a more scientific way of doing it, just more expensive.
 
I'd dive straight into a thicker oil. You've established that 10w40 and 15w40 dont work. Mainly because there's no difference. Its the latter number that has the effect in your situation. It was bed in on 20w50? Use that ans if possible a fully synthetic it wont break down with increased temp :)
 
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pollyp

pollyp

Club Member
still got 4L of 20w50 mineral classic oil I used to break-in.
can I go from semi synth to the 20w50 mineral?
or can I flush the engine with the 20w50 mineral and then up to like a millers 20w50 fully synth?
 
Mineral oil is coarser and breaks down/fatigues with higher heat. You could use the mineral to flush it if you wish can't see it harming. Either way I'd definitely stick to fully synthetic after
 

Seb_

Give me some frogs.
Site Supporter
mind was thinking am I allowed/covered, what if? and before mentally answering thought ah fookit :p
sit in, seat was fixed so had to adapted position like when I once drove the oversized-kart ariel atom. what a privilege to experience such extreme experimental beast from the skunkworks of frankville:D

Good write up, remember me when Frank took me for a drive around his roundabout :D Screaming, smiling and feeling privileged !
 
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pollyp

pollyp

Club Member
been soo busy at work as usual hence the lack of updates but while the videos rendering, here's an update.

2013-09-22
checked tyres and the fronts are bout 5mm and rears 7mm but importantly they've worn the same amount all across the thread so the 2deg front camber and zero toe really helps to keep the wear pattern pretty even.

but the rear left has another damn screw/nail :rolleyes:

DSC08775.JPG
DSC08776.JPG


another screw & sealant fixed that:cool:

DSC08777.JPG


cos the fronts now down to 5mm and 7mm rear, I swapped them front to rear, tightened the wheels and went for a drive.


but few min later heard a knocking noise getting louder, huh wtf is the susp or brakes rubbing on wheel? ain't good so pulled over..damn the rear left nuts are loose, must've forgotten. so had to keep tightening em by fingers much as possible, drive few meters and repeat till I got home to retorque it :rolleyes:


so out I go once again, temps remaining at a stable 92c.

2013-09-23
went to BQ to get some castrol 15w40.

so drained the old 10w40, poured some fresh 10w40 to flush it, idle for few mins from cold to warm to run the fresh oil around the block, then drained that out and twas still dark. lotsa old muck left round the engine suppose.

filled with 15w40, went for a run then a blast and boo it's still the same dampness inside.

andy n andy, according to wiki the first number ahead of W is the cold start viscos and the 2nd number is the hot viscos?

went to halfords to see if there's any thick synthetics and nearest I found are some 5w50 synth (5w when cold maybe too thin for a very slack forged piston? ran it before with the new bore/used ring setup and made no difference to oily piston), and 10w60 mobil1 (hot grade tis prob as thick as it gets and tis fully synth too)

r0pr.jpg


you think that'll run in the cg13de ok with +10C thermo and slack pistons and ok'ish new bearings?
if this doesn't work then nothing else at all will
 
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andy n andy, according to wiki the first number ahead of W is the cold start viscos and the 2nd number is the hot viscos?

went to halfords to see if there's any thick synthetics and nearest I found are some 5w50 synth (5w when cold maybe too thin for a very slack forged piston? ran it before with the new bore/used ring setup and made no difference to oily piston), and 10w60 mobil1 (hot grade tis prob as thick as it gets and tis fully synth too)

r0pr.jpg


you think that'll run in the cg13de ok with +10C thermo and slack pistons and ok'ish new bearings?
if this doesn't work then nothing else at all will
That's correct :) but the oil doesn't change once warm its still there. Its an equal mix, for example 10w40, you'll have 1 parts 10sae with 1 part 15sae etc up to 40sae. The w refers to performance in colder ambient temperatures where oil thickens in the cold so you'll need thinner oil

I use the 50/50 with 0w50 so I pretty much have the whole oil range covered and the second part 10w40 magnetec so there's a concentration of the specified grade :)

You're having issues with 10sae oil and below its appearing to be too thin.
 
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pollyp

pollyp

Club Member
I'll give it a shot tonight anyway n see if the warm 60 grade changes anything.

not sure bout mixing oil grades n brands n conflicting additives, just want a simple buy one bottle and be done with.
wonder why don't they just ready mix everything together like mixing every cleaning product in the house with toothpaste, mouthwash, oven cleaner, degreaser, etcetc and hope its a powerful universal cleaner lol. ain't cheap either.

weekend I'll swap back to stock exhaust and we'll finally see if this engine has a future at all
 
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pollyp

pollyp

Club Member
this is cutting edge cocking about :p
increasing oil thickness is literally the only last thing I could do now short of a complete unfeasible expensive rebuild or bin it.

suppose when I swap back to stock, even if the pistons only slightly oily, I'll pop it through some emissions machine (local garage or my cousins) to see if the oil burning is actually enough to fail the mot
 
this is cutting edge cocking about :p
increasing oil thickness is literally the only last thing I could do now short of a complete unfeasible expensive rebuild or bin it.

suppose when I swap back to stock, even if the pistons only slightly oily, I'll pop it through some emissions machine (local garage or my cousins) to see if the oil burning is actually enough to fail the mot

Register your car over here mate instead :p im sure there would be problems with insurance etc with you being across unfortunately
 
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pollyp

pollyp

Club Member
Register your car over here mate instead :p im sure there would be problems with insurance etc with you being across unfortunately

if only I could move n live over there :p

I think worse case scenario if the engine fails emissions is to SORN the car for another few months and use moms cars for work, scrap the old engines, sell the forged engine, buy another stock 1.3 to rebuild and plonk it in, resume mot
 
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pollyp

pollyp

Club Member
turbo micra as trackcar & buy second stock daily micra :
pro - cheaper running costs, reliable daily
con - don't have nor can I store a trailer/a-bar to transport the track car, additional parking fee outside house, slow daily car, daily stock micra would prob require a rebuild too and adds rebuild cost, lost house space, forged engine not guaranteed to last in its current oily state.

rebuild forged piston engine by specialist :
pro - either more likely to work n pass emissions or get advice that combining daily with track with a forged engine ain't realistic
con - really no economic point, waste money, waste time, waste alot more money for little return

scrap forged piston engine & fit stock engine :
pro - certain to work n pass mot, reliable n cheap repair
con - time, find inspect and buy spare engine, refitting the windage tray setup, wasted time effort money of the forged engine.
 
I would strongly suggest a track day. Really push the engine. And see if that's the issue. What type are the pistons made of? 4032? 2618?
 
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pollyp

pollyp

Club Member
don't think that'll resolve the issue with MOT coming soon cos engines hardly stressed under normal use.
think they're 2618
 

Low Rider

Poindexter
Founding Member
Moderator
Club Member
P*ssing in the wind honestly. The difference in viscosity between a 40 and 50 oil isn't much, you're talking 5cst based on average grade values. A heavy classic grade like 20w70 may make a dent but it's sadly only a bandaid to a larger underlying issue :, (

It's bite the bullet and get an engine builder time surely?
 

r-reg-sr

-------
Site Supporter
you was having more fun out the stock engine,this ones dodgy from the start i recon,other wise they'd have used it themself ??? maybe maybe not.
 
P*ssing in the wind honestly. The difference in viscosity between a 40 and 50 oil isn't much, you're talking 5cst based on average grade values
Neither is the gap between rods n shells, ring gaps n piston to bore clearance but any small increase should be accountable
 
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pollyp

pollyp

Club Member
It'll give you a definitive answer at least :)

Indeed would be nice to quickly find if the trackday heat would resolve the oily piston, which would then mean that these are only for racing and not the roads which'll mean it doesn't have a future.

Unfortunately I don't have time for trackdays, they're very expensive at short notice, and won't have the time money effort to swap to stock engine to pass mot, then swap back to forged to further test on track, only to find it still leaks and have to swap back to stock anyway.

So this thicker oil test will determine the engines future
 
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pollyp

pollyp

Club Member
P*ssing in the wind honestly. The difference in viscosity between a 40 and 50 oil isn't much, you're talking 5cst based on average grade values. A heavy classic grade like 20w70 may make a dent but it's sadly only a bandaid to a larger underlying issue :, (

It's bite the bullet and get an engine builder time surely?

Aye its a lot of guessing. I have tried to rebuild everything that surrounds the pistons from the bore to rings to shells to the seals with no effect which leaves the piston as the only cause.

Letting a builder completely rebuild an engine to make forged pistons work on a 1.3 (new or used piston) is an absolute waste of my money n time since I spent thousands already when the cheaper stock engine will do fine.

Forged will give me no extra benefit vs stock engine cos I'm not after insane power and keeping it 160bhp anyway.

Bang per buck, if I can't fix the forged engine now, the stock engine is more affordable
 
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pollyp

pollyp

Club Member
What's the dimensions of the pistons Paul?

http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-92#post-624941

pistons are 71.375mm and bores 71.50mm (2.81")
piston to wall clearance 0.125mm (0.005")

JE guide says Sport Compact applic with bores 2.50 - 3.625" have min clearance of 0.003 - 0.0036"
forced induction and endurance applic may require additional 0.001 - 0.003" clearance
http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf
 
Trying to find you some wiggle room.. but you none really... have you looked at the pistons once theyre warm? Or took a temperature reading of them?
 
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pollyp

pollyp

Club Member
my front right indicator has been playing up recently.
coming to a turn, when I flick right indicator it flashes quickly like a blown bulb but then after awhile it reconnects and flashes normally or when I blip the throttle slightly or going over a bump or when I bash it with a hand.
then it got harder to reconnect over time till it stopped connecting and just flashes quickly.

took the hard to reach bulbs out and behold it was actually a blown RH filament.

DSC08778.JPG


when indicating right, the blown circuit flashes quickly as it should. but the engine vibration and suspension jolt eventually causes the flailing filament to briefly touch and join the circuit, this spark kinda welds the filament in place therefore almost appear as though it self repairs itself n continues slowly flashing till u stop indicating.

once the flashing stops and it cools down, the vibration n jolting loosens the temporary filament weld so that the next time I indicate it flashes quickly and the process repeats.

so got a new set in halfords and its fixed

DSC08779.JPG


also got a bottle of 10w60 mobil1 n filter.

first here's a capture of the cylinders after fitting the hotter thermo with 15w40


drained old 15w40, poured the last remaining 10w40/15w40 I had in to flush for few secs then drain that out and it looks almost golden clean now. new filter and poured 3L of 10w60 synthetic in and drove out.

few miles cruising down the motorway and in the country, remove the plugs that are still white looked in and oh FFS its even wetter :rolleyes:
thicker oil clearly hasn't worked, its actually worsened.

ok my theory is that those tiny tiny drain back oil holes in the pistons ain't letting the thick oil escape from the oil ring groove fast enough so instead it could be backing up and being forced up towards the cylinders. I think the final test is to go the other way and pour the thinnest oil in to see if that can drain away from the oil rings easy enough to prevent it being purged up into the chamber.

10w20? 0w20? 10w30?
 
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pollyp

pollyp

Club Member
Trying to find you some wiggle room.. but you none really... have you looked at the pistons once theyre warm? Or took a temperature reading of them?

I've videoed the pistons with the scope and they appear the same oilyness hot or cold. not measured the piston tops with IR yet
 
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pollyp

pollyp

Club Member
Thicker oil has worsened it :eek:
I wouldn't suggest going too low. Maybe 0w30 as your lowest grade

do you think all these symptoms I'm having is similar to clogged oil ring drain back holes? stuck oil rings?
ie. as if these JE piston oil holes are too little too few?

ok I'll try 0w30 synthetic tomorrow
 

frank

Club Member
the different oil weights have done sweet F/A really paul, the oil control rings are the key factor imo, the consumption/smoke issues have only reduced when you increased the pressure of those rings really
 
do you think all these symptoms I'm having is similar to clogged oil ring drain back holes? stuck oil rings?
ie. as if these JE piston oil holes are too little too few?

ok I'll try 0w30 synthetic tomorrow
Could well be but you've had them all out recently and were clean. You could be right there could be a fault with the oil rings themselves.
You've had them out re-spec'd them and still getting the issue :/
Do they suggest a certain oil grade? I'd say oil grade is vital to such a fine a tolerance as this setup is
 
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pollyp

pollyp

Club Member
the different oil weights have done sweet F/A really paul, the oil control rings are the key factor imo, the consumption/smoke issues have only reduced when you increased the pressure of those rings really

the expanders are now twice as draggy as before and it's made little difference, still as oily as before, and thicker oil seems to make it worse so logical last step is to go thinner to help it drain through the holes away from the rings.

tbh ultimately if thinner oil doesn't work then it's game over.
can't make the oil expanders any harder without making it impossible to install the pistons.
maybe some more oil drain back holes can be drilled into the pistons to help drainage but too much work, money and no time for it.
I think these pistons have a design flaw and this engine would be uneconomical to resolve and is scrap tbh
 
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pollyp

pollyp

Club Member
Could well be but you've had them all out recently and were clean. You could be right there could be a fault with the oil rings themselves.
You've had them out re-spec'd them and still getting the issue :/
Do they suggest a certain oil grade? I'd say oil grade is vital to such a fine a tolerance as this setup is

I meant could the restrictive oil drain back hole design flaw show a similar symptom to stuck/clogged oil rings?

rings when fresh we're gapped perfectly.
after bed-in they've worn in slightly wider due to the smoothed larger bore but still within spec.

no mention of oil, temps etc etc on their sheet, just the clearances
 
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pollyp

pollyp

Club Member
ah crap just looked at me mot and it expires next week 3rd oct:eek:
not good. need to test this thin oil tomorrow then swap exhaust and hope to god it passes.
if not then I'm stuffed
 
I meant could the restrictive oil drain back hole design flaw show a similar symptom to stuck/clogged oil rings?

rings when fresh we're gapped perfectly.
after bed-in they've worn in slightly wider due to the smoothed larger bore but still within spec.

no mention of oil, temps etc etc on their sheet, just the clearances
Aye I'm with you on that one. Had a thought last night a thicker oil will have/need a higher pressure to move it around.
If the drain back holes are insufficient as you suggest then it will struggle more to return. So the thinner oil may be/ hopefully the answer

Hmm I'll see if I've got anything that's oil/temp related regarding forged pistons
 

frank

Club Member
the pistons have nothing to do with oil control tho, forged or stock, have your honing marks bedded in yet paul ?
and i bet you will still be within 200 ppm HC emissions paul :)
 
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pollyp

pollyp

Club Member
this morning videoed the state of the piston tops with the 10w60 synthetic oil. piston 1 is 40% dry but the other 3 are just wet:rolleyes:


video of the cold start with 10w60. very slight haze at startup from the oily piston


went to get some 0w30 castrol edge

DSC08781.JPG


stuff is like water compared to the honey-like 10w60.

on startup it runs slightly quieter and the turbo seems to be abit more responsive with the thin stuff (maybe placebo)

down motorway n plugs out, still white, look inside and OH GIMME A BREAK!
its slightly wetter WTF:mad: no point testing compression

just blasted down the road to try get some heat in, plugs out and still wet:confused:

well thats the unfortunate result. this stupid engine is bloody feckd GAME OVER, do not pass go, scrap.
so angry with kasandra now.

so NOW what do I do?
MOT is due on 8th oct
can guarantee this engine WILL NOT pass emissions with all that oily piston
gonna SORN the car but the next time she's back on the road it'll have to be for the MOT and has to pass emissions
I have tried every single thing to make these pistons work and failed and can no longer afford to try anything else nor is it ever guaranteed to work so it's useless to me now.

frank, its been running on mineral for 3-4k miles hard/gentle, 4-5k on semi and briefly on fully synth. It surely would've bedded in by now after all those miles.
throughout the entire process these forged pistons have never ever showed signs of drying up as the bores wear-in.
so it's either a fundamental flaw with the pistons or the bores were machined too coarse and retaining too much oil.

yes maybe we could run couple of thousands more hard miles on mineral to try bed the rings/bores abit more but I'm out of time and tbh would be a losing battle and just wasting my time n precious petrol money and lost faith in it.

basically calling it off, I've had it, give up, move on.

anyone got a spare 1.3?
 
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With the amount of time, money and effort that has gone into this project I feel I speak for everyone when I say how sorry and sad I am that this is how this chapter ends :'(
Sometimes, as hard as it is, the right decision can be to just cut your losses and walk away.
Paul, you are an inspiration to us all and your willingness to share your experiences and r&d with other members is to be admired.
Whichever direction this project now takes I hope you don't lose your mojo and you come back stronger than ever to keep us educated and entertained.
Good luck Paul and thank you, whatever happens :)

Sent from my HTC One S using Tapatalk 4
 
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pollyp

pollyp

Club Member
Dont give up. Take a break and come back another day :)

I'm not giving up on the car, course not, but I am giving up on the forged piston engine.
I've tried everything I can to resolve the oil issue but its never worked out at any point in time.
every single sign has been saying that forged pistons are not the way to go for my sorta application (mostly daily with occasional track) and requirements (reliability, MOT, reasonably low cost)

sometimes you just have to make a wise decision to call it a day when you input soo much exploring every reasonable r&d route within your budget, time, energy, resources but only to fail each time going nowhere with no change in result and no additional benefit to the other option (stock engine).

the only purpose for buying the forged piston engine was to discover if it could improve the turbo setups long term reliability for my application and the answer is NO.
yes someone with more experience, knowledge, skill, resources, patience, motivation, time & money to take up the challenge can possibly make it work but its something I can no longer sustain nor have any desire for.

I no longer have time to step back and reattempt at fixing this engine cos MOT expires next week and the next time she comes out of the garage will have to be able to pass it, which can only mean resort back to a stock engine.

don't see any more point in trying to disassemble n fix the forged engine for later on cos there's nothing more that I can economically do to fix it
 
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pollyp

pollyp

Club Member
With the amount of time, money and effort that has gone into this project I feel I speak for everyone when I say how sorry and sad I am that this is how this chapter ends :'(
Sometimes, as hard as it is, the right decision can be to just cut your losses and walk away.
Paul, you are an inspiration to us all and your willingness to share your experiences and r&d with other members is to be admired.
Whichever direction this project now takes I hope you don't lose your mojo and you come back stronger than ever to keep us educated and entertained.
Good luck Paul and thank you, whatever happens :)

Sent from my HTC One S using Tapatalk 4

thank you micrAde, indeed its a learning curve to know when to call it a day before it starts to burn ur money away fast.

so spent abit of resources asking does the forged piston improve reliability? -> answer nope -> k resort back to stock engine that did work -> and carry on

with my past documented history with the forged piston engine, I hope to help other ppl who's thinking of going the same route see and learn from my mistakes that it's not going to be easy or cheap.

well that was an expensive lesson ain't it :p
 
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pollyp

pollyp

Club Member
First of all, just Ade please Paul ;)

And second of all that sounds like marriage :( lol


Sent from my HTC One S using Tapatalk 4

righteo Ade;)

and lol yeah it does sound like I'm married to Kasandra who's a cash draining equivalent of Jaime from "The Bionic Woman" :D
tried to give her a stronger bionic heart but kept bleeding so its back to a normal working heart I suppose hehe :p
 
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