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PollyMobiles Rebuild

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pollyp

pollyp

Club Member
thought it might be useful to share my knowledge of the mysterious restriction in Nistune for ppl like stani or frank or even Ed who have/use nistune.
prob help nistune users from screaming at their laptop "Why wont the O key work!" or "Why can't I lower the raw value!" like I did before :)
 

h701micra

Deactivated Account
It all helps
You'll have to do a full guide one day :rolleyes:
I personally haven't used nistune before but to know something like this can save hours in mapping
 

Stani1029

Club Member
Yeah paul the last time you gave me a brief description of the above helped alot. I made some data logs on cruise in 5th at 70mph and that gave me the point at which i wanted to remain closed loop
 
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pollyp

pollyp

Club Member
got my 8 new genuine stem seals :)

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compression is now a steady 11.6 11.9 12.2 11.7 bars after 1293m.
drained oil.
cover off, still shiny inside, no milkshake under cover but oil is quite dark

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while its hot, lets check the valve clearances.
(Too close, Close, Perfect, Loose, Too Loose)

INLET: 0.279 0.356 0.356 0.356 0.356 0.356 0.305 0.279
EX: 0.356 0.381 0.457 0.457 0.381 0.483 0.381 0.356

so cyl 1 & 4 had the lowest compression cos the valve clearances were too tight (valves kept open longer) so some air had leaked out.
once I correct these gaps I suspect the readings will shoot back up.

removed the timing chain cover and well there's ur problem :)
cos those 2 bolts were too long for the blind hole, it never pushed the plate onto the head during assembly to seal correctly (even the smear pattern is still there) so no wonder all the oil gushed out the gaping hole during high revs :rolleyes:

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OP
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pollyp

pollyp

Club Member
If your stuck for any cam shims let me know Paul have a good selection here!

luvely jubbly paul :)

I just bout measured n calculated the required shim thicknesses to reach the ideal clearances. inlet shims 2-6 staying as they are.

cxga.jpg


I've got a set of shims from two stock engines in the garage to check out in abit.

If I can't find the required shims, I'll txt you some thicknesses to check if u have em ;)
 
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pollyp

pollyp

Club Member
just removed 2 sets of shims from both spare engines, like a bunch of tokens coins :p
surely I'll find exactly the right shims in this lot

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OP
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pollyp

pollyp

Club Member
marked all 61 shims

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and assigned the correct shims to each bucket now :cool:

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replacing the stem seals tomorrow
 
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looking forward to the results of the new seals!!! i really do hope they are the problem. but iv gotta say, frank is nearly always right. hope he isnt this time eh!
 

Enuo

Glorified Electrician
You should never 100% rule out a fault without actually testing, or you can end up looking like a right muppet
Sincerely,
A Right Muppet
 

Low Rider

Poindexter
Founding Member
Moderator
Club Member
True, which will be Pauls basis for taking the stem seals approach instead of immediately pulling the engine apart. Worst case is he ends up with a better set of OEM seals instead of cheap knock-offs if it's another stripdown job.

All this certainly supports the consideration of a credible engine builder unless you are in the position to carry out no-frills re-builds at the drop of a hat.
 
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pollyp

pollyp

Club Member
looking forward to the results of the new seals!!! i really do hope they are the problem. but iv gotta say, frank is nearly always right. hope he isnt this time eh!

I hope it fixes it too. I was reading a guide on installing stem seals which advises placing a tube or tape over the valve stem collet groove cos else the sharp edge could damage the seal.

Last yr, I just pushed the seal down the stem and this might've wrecked it abit?

No one local sells a stem seal tool so figure I'll buy a self-gripping nose pliers and mod it
 
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pollyp

pollyp

Club Member
so brought a long nose lock plier for £8.39 (better than £15-80 for a slide hammer seal puller)

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the jaws were abit too slack so I tried heating it, and smack the rivets with a hammer to crush it tighter. nope, has no effect or it all just binds. need more accurate adjustment of the pivot joints, so I grind the rivets out. squeeze the frame till the jaws fit snug

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and nut/bolts to tighten it accurately

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the jaws hold a stem seal like this, notice the flat parallel fingers only touch a tiny bit of the seal, it will slip off too easily

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using a grinding stone of similar size

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I grind a matching contour in the jaws to hold the seal more effectively

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grinded the excess edges off to clear the valve bucket hole

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rather than just squeeze, pull & wriggle the seal out and risk damaging the stem, I incorporate a sort of slide hammer effect by tethering a weight aligned with the pliers jaw opening. tried string initially but snaps easily so found a much stronger bicycle cable tied to a big hammer

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and this is the process

 
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Enuo

Glorified Electrician
It really wpuld be best to use a slide hammer, it's a lot more accurate than pliers or a mallet. Making one is a bit of a right of passage too...
 
This thread is absolutely awesome! Been following it for a while now, despite only just creating an account :rolleyes:. Hopefully one day I will be as competent at rebuilding and tuning Micra's as you, although I severely doubt it!

Keep up the good work and good luck!
 

h701micra

Deactivated Account
This thread is absolutely awesome! Been following it for a while now, despite only just creating an account :rolleyes:. Hopefully one day I will be as competent at rebuilding and tuning Micra's as you, although I severely doubt it!

Keep up the good work and good luck!
Just like paul you've got the msc behind you. My advice.. get an engine and strip it down. You'll learn alot and there's no time like the present
 
OP
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pollyp

pollyp

Club Member
It really wpuld be best to use a slide hammer, it's a lot more accurate than pliers or a mallet. Making one is a bit of a right of passage too...

would be nice but not worth the cost when the £8.50 DIY tool achieves the same result and rarely use it :)
 
OP
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pollyp

pollyp

Club Member
This thread is absolutely awesome! Been following it for a while now, despite only just creating an account :rolleyes:. Hopefully one day I will be as competent at rebuilding and tuning Micra's as you, although I severely doubt it!

Keep up the good work and good luck!

thank you for ur support Calum ;)
 
learn by reading and doing and getting stuck in. that's how I started off

I think I will buy a spare 1.3 block to work on. I am scared to mess around with the Super S I just bought because it is running flawlessly. It would be nice to have a block to work on where I don't need to worry about breaking it :rolleyes: It would be also be nice to see how the cams and stuff fit together and maybe rebuild the engine and clean everything. I'll post it up on my thread if I ever get round to it! Thanks for the suggestions :)
 
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pollyp

pollyp

Club Member
21st June

so inlet valve stem seals replaced, timing chain side & top cover resealed, valve clearances corrected and oil/filter changed.

she cold cranks abit rich but fine. small poof of smoke from the residue oil then idles clear initially.
BUT when I hold revs up (high vacuum) while its still cold it smokes alot, dammit.
and now whenever I apply any sort of throttle it smokes continously depending on amount of throttle.
very low or no smoke during coasting or idling.



pistons still half damp but dry compression with the corrected valve clearances are 11.8 11.7 12.0 12.0 bars at 1300 miles, perfect

so lets continue the hard runs to see if the wet cylinder & smoking on boost goes.
nope, she still friggin smokes continuously whenever on boost and pistons still damp/soaked so we eliminated that oil isn't entering via the inlet stem or pcv.
the only single cause will be the 2nd/oil rings :(



did a wet/dry test at 1315miles
dry 11.7 11.8 11.9 11.9 bars
wet 14.2 13.9 13.8 14.1 bars
pretty much perfect even compression after a hard hot run

continued the normal drive to see if the low revs affect the oily cylinders. one of the widebands copper heatsink fins fractured off at 1:04



pistons still half damp and smokes on boost. tried to point the front camera forwards under the car but it didn't record

continue blasting through the country. was running low on fuel at 20:00 so headed home, completely blinded by the low setting sun



dry compression after a gentle run was 11.3 11.3 11.8 11.6 bars

compression history at the mo shows the corrected shims made the compression very even & high when the pistons hot but slightly lower when its cooler after a cruise. see what happens later on

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here's the copper fin that broke off

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got new manifold gasket so I can remove the turbo n inspect the stems for oil leakage

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frank u think I'll be ok with resuming the normal driving till I use the last 3L of the 20w50 mineral oil then change over to my usual 10w40 gtx semi-synth, see if it still smokes and then take apart and stretch the oil rings till it drags +5kg and hopefully stops the oil leak?

dry compression is good and even but is 2bars below the wet test.
also cos the 2nd ring is like a secondary oil scraper above the main oil scraper, if both of them can't hold back the oil and compression is that far off the ideal wet test, maybe all the rings are actually fooked?

another thought is could it be a design fault such as insufficient drain holes for the oil rings?
 
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frank

Club Member
yes paul, you will literally be able to "feel" the rings scraping the bore when you get that expander tension right :) (i usually fit the pistons upside down, with just the oil control rings fitted)
we have been having problems on our kart engines too, the later honda engines have thinner oil control rings and are wearing out after 18 months look !
and i have to stretch the expander on the new rings to account for the bore wear :)

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frank

Club Member
Frank is it mainly the expander ring that needs stretched to get it right? So long as the rest are gapped to spec?
the oil control rings are very thin and weak stani, so its those little feet at the bottom/inside of the expander that do all the pushing :) if they are,nt forcing the 2 rings against the bore, then the rings dont make contact all around the bore

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yes paul, you will literally be able to "feel" the rings scraping the bore when you get that expander tension right :) (i usually fit the pistons upside down, with just the oil control rings fitted)
we have been having problems on our kart engines too, the later honda engines have thinner oil control rings and are wearing out after 18 months look !
and i have to stretch the expander on the new rings to account for the bore wear :)

View attachment 23601


:eek:
 
OP
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pollyp

pollyp

Club Member
blimey just 18mths, that's some serious wear rate.

suppose I'll have to plan afew weeks to rip the engine out and apart once again:rolleyes: just not now with work etc
 
pollyp congratulations.you have great knowledge and magical hands.i have read your threads and i have copied some of your mods with succees so far but...i have bought a set of ma10 acl main (crankhaft) bearings.and a set of ga13 conrod bearings.my engine is a cg13 1992 uk model.i have put the down end crankshaft bearings and i did a notch like yours in order to make them fit.the upper crankshaft bearings not allign 100 percent(about half mm off) with the oil passage of the block and furthermore my block has just one oil passage and not 2 like the one you show in the pics that you use ma bearings.is there something more to worry about or do?i have tighten and the crankshaft turns sweet no play or so...also i was told that ga13 conrod bearings fit the cg13.is it correct?thanks so much for your help
 
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pollyp

pollyp

Club Member
22nd June

since the camera phone can't capture my borescope screen properly, I managed to hook its video feed into my laptop to give u this footage.

with a cold engine lets look inside the cylinders and bores.



all the pistons are 1/2 damp,
bores ok, noticed a slight machining error. cyl3-4 has a horizontal groove like some dirt in the hone stones while the machine was briefly stationary.
slight vertical scoring on the exhaust sides.

inlet mani kinda dry. plugs just white.
yet this is the cold start every time. smokey start and struggles, then clears



compression after warmup is 11.2 11.5 11.9 11.7 bars
lets drive to the north york moors



exhaust seems clear most the time
 
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pollyp

pollyp

Club Member
lets have a blast through the luvely york moors, slight misty smoke on boost



driving back up towards redcar



through redcar. someone videoing and trying to grab my attention at 31:00 :rolleyes:



compression after all that was 11.7 11.7 11.9 11.7 bar and still 1/2 damp

I highly doubt this damp issue will go away on its own
 
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pollyp

pollyp

Club Member
23rd June

its been raining heavily tday and I've lost the plastic air filter shield so made one from kitchen foil :D

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also thought the pcv maybe too restrictive so I plumbed both the engine top breather and the crankcase breather into a bottle like this and plugged up the TB pcv pipe so now the crankcase breathes totally freely and lets see if this affects the damp piston

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so on cold start once again it smoke initially then clears abit



went for a drive through the country



pistons still half damp and here you see the crankcase port emits a high amount of water vapour from the blowby.
the top breather port only showing a drop of oil vapour.

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compression is a nice 11.8 11.8 12.0 12.0 bars

so I went home,



left it idling for awhile as I checked the base timing for baguette and then suddenly the exhaust plooms out thick oily smoke gassing the neighbours :mad:

this video only shows the first few secs while its misty but it began to rain and my neighbour distracted me requiring help with freeing a seized caliper guide pin on his clio.
after a min it began smoking so will try video that soon.



hold revs up and it still stays for awhile and maybe clears slightly.
let it idle with the slight mist, wait 30-60s and the mist turns to thick smoke WTF

at this point of the day I'm fuming with a migraine and just wanna give up screaming.

the symptoms kinda indicates stem seals as the vacuum during idle sucks enough oil to produce a thick smog but I just replaced the inlet seals :/

if it sucks that much oil in through the inlet stems to smoke that badly then I'd prob notice a big pool of oil in the pistons. so while its smoking, stop engine, pull plugs out and urm nope, pistons look exactly the same 1/2 damp as before.

so this oil burning maybe coming from after the chambers such as exhaust stem seals or the turbos turbine seal?

I think I remember baguette with the black SR turbo who posted a vid of his smoky turbo and when mine plooms smoke after prolonged idle, it looks just like his. so it might be a turbo issue which prob explains the smoke on full boost?

edit: just did a search and it was a footage of Martins super S black turbo that I saw smoking

lets do the easy process of elimination before labouring time on ripping the engine apart.

so I think the next task is to swap back to a SHTOCK exhaust to eliminate the turbo source.
if it stops smoking at WOT/prolonged idle then its a turbo issue (still prob won't solve the wet piston).
if all the exhaust stems appear wet then we replace those stem seals and try again.
if even the stock exhaust still smokes then its an internal oil ring issue and must begin the time consuming engine ripping.
 
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OP
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pollyp

pollyp

Club Member
Well this is puzzling. I tried to recreate the smoking by idling at least 15mins or just rev to the limiter (just get a rich black ploom) but she's behaving herself tday and not smoking :/

Pistons still 1/2 damp
 

Belly93

to turbo or new lump :/ hmmm
22nd June

since the camera phone can't capture my borescope screen properly, I managed to hook its video feed into my laptop to give u this footage.

with a cold engine lets look inside the cylinders and bores.



all the pistons are 1/2 damp,
bores ok, noticed a slight machining error. cyl3-4 has a horizontal groove like some dirt in the hone stones while the machine was briefly stationary.
slight vertical scoring on the exhaust sides.

inlet mani kinda dry. plugs just white.
yet this is the cold start every time. smokey start and struggles, then clears



compression after warmup is 11.2 11.5 11.9 11.7 bars
lets drive to the north york moors


exhaust seems clear most the time

is that a snap on borescope?
 
OP
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pollyp

pollyp

Club Member
indeed it is a snap on BK5500 inspection scope Belly and yes it's been totally invaluable for looking inside of anything including bores etc to identify/verify problems before committing time n effort taking it apart and I definitely recommend it. plus you can record the video out feed like me to share footage.

brought mine new on ebay for £200 which is a steal for what u get

found a listing here

http://www.ebay.co.uk/itm/Snap-On-B...iagnostic_Tools_Equipment&hash=item20d4791f54
 
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