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PollyMobiles Rebuild
- Thread starter pollyp
- Start date
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pollyp
Club Member
no news bout the engine tday.
making the wheel spacers I marked the distance
n cut em off with the grinder
but then i realised i forgot to consider the thickness of the existing brake discs which means the front hubs already spaced 8mm by the pulsar discs (...yep just tested and the bbs wheels just fits the hubs with the pulsar discs on) but its the thinner rear discs that'll need spacing abit.
i'm not sure how thick the rear discs are at the hub? (prob 5mm? does anyone know?)
but if i fit the 8mm spacers on top of the rear discs it will push the BBS wheels too far off the hub centre so the alloy may not may fully centred or supported and relying purely on the studs :/
I could instead buy another pair of thinner spacers but will make all this cutting abit pointless really
think this is another expensive mistake of mine from forgetting bout the existing discs in my measurements and buying/cutting extra discs unnecessarily
if its just 2mm I could maybe just trim the edge of the hub centre to make em fit?
making the wheel spacers I marked the distance
n cut em off with the grinder
but then i realised i forgot to consider the thickness of the existing brake discs which means the front hubs already spaced 8mm by the pulsar discs (...yep just tested and the bbs wheels just fits the hubs with the pulsar discs on) but its the thinner rear discs that'll need spacing abit.
i'm not sure how thick the rear discs are at the hub? (prob 5mm? does anyone know?)
but if i fit the 8mm spacers on top of the rear discs it will push the BBS wheels too far off the hub centre so the alloy may not may fully centred or supported and relying purely on the studs :/
I could instead buy another pair of thinner spacers but will make all this cutting abit pointless really
think this is another expensive mistake of mine from forgetting bout the existing discs in my measurements and buying/cutting extra discs unnecessarily
if its just 2mm I could maybe just trim the edge of the hub centre to make em fit?
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OP
OP
pollyp
Club Member
while I'm having a quick break heres a quick update
cost was:
*honing the cylinders = £30
*fitting new rings = £25
*degreasing/clean block, re-notch girdle cage & reassemble engine with new rings = £70
*regrind crankshaft, bigends & chain journals 0.25 oversized = £90
old bearing shells & rings to be stored
new machined engine
nice of them to clean up the block & girdle spotless
ooh clean girdle, like that
removed girdle. odd hole feature in the lower shell
checking the stamped # on the rods are facing the correct way as last time
crank removed. main bearing shell oil inlet ports are all in line
grinded crank
bigend caps with new shells
but in the smooth surface spotted a defect, been knocked?
pistons removed
spotted a major issue in #1 upper main shell. the secondary hole in the shell is not aligned to allow some of the oil to the lower timing chain oiler jet which could lead to chain failure needs redrilling by machinist tomorrow. another part to custom mod and signs that these shells are almost certainly not meant for this engine.
new main shells
cost was:
*honing the cylinders = £30
*fitting new rings = £25
*degreasing/clean block, re-notch girdle cage & reassemble engine with new rings = £70
*regrind crankshaft, bigends & chain journals 0.25 oversized = £90
old bearing shells & rings to be stored
new machined engine
nice of them to clean up the block & girdle spotless
ooh clean girdle, like that
removed girdle. odd hole feature in the lower shell
checking the stamped # on the rods are facing the correct way as last time
crank removed. main bearing shell oil inlet ports are all in line
grinded crank
bigend caps with new shells
but in the smooth surface spotted a defect, been knocked?
pistons removed
spotted a major issue in #1 upper main shell. the secondary hole in the shell is not aligned to allow some of the oil to the lower timing chain oiler jet which could lead to chain failure
needs redrilling by machinist tomorrow. another part to custom mod and signs that these shells are almost certainly not meant for this engine.
new main shells
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OP
OP
pollyp
Club Member
re-notched n cleaned girdle cage
the notched appear to have been grinded roughly by hand
the #1 main bearing upper shells has a tiny nick
with the pistons out i noticed some of the Alu flaking off the bottom of the cyl from the repeated honing to reveal what must be the 1mm steel liner insert?
honing marks of cyl#1
cyl#2
cyl#3
cyl#4
the notched appear to have been grinded roughly by hand
the #1 main bearing upper shells has a tiny nick
with the pistons out i noticed some of the Alu flaking off the bottom of the cyl from the repeated honing to reveal what must be the 1mm steel liner insert?
honing marks of cyl#1
cyl#2
cyl#3
cyl#4
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OP
OP
pollyp
Club Member
yea MA10 bearings
OP
OP
pollyp
Club Member
as the bore gauge pin is depressed more (tighter the bore) the higher the dial reads.
here I calibrated the bore gauge by setting the micrometer to precisely 72mm, placing it over the bore gauge and as I roll it around to find the highest reading, I zero the dial to that high point.
when reading the gauge I subtract that value from the calibrated 72mm to give me the actual diameter.
I measured each cylinder at 12clock, 1.5clock, 3clock & 4.5clock to check for ovality and at TDC, MDC, BDC to check for tapering
cyl#1 at TDC, MDC, BDC measures
cyl#2 TDC, MDC, BDC measures
cyl#3 TDC, MDC, BDC measures
cyl#4 TDC, MDC, BDC measures
measuring the forged pistons with a micrometer
the diameter at the base of the skirt 13mm from the bottom is what we need to calculate the piston to bore gap, each piston reads a consistant 71.4mm dia
when calculating the gap at the 12clock thrust face of the cylinders we get:
cyl1 = 0.026mm
cyl2 = 0.026mm
cyl3 = 0.024mm
cyl4 = 0.025mm
seems awfully tight? considering JE recommended a clearance of least 0.004" (0.1016mm)
dunno if that means (bore dia - piston dia) or (1/2 x (bore dia - piston dia))?
smooth grinded crank
so, got alot to talk to the machinist about tomorrow morning
here I calibrated the bore gauge by setting the micrometer to precisely 72mm, placing it over the bore gauge and as I roll it around to find the highest reading, I zero the dial to that high point.
when reading the gauge I subtract that value from the calibrated 72mm to give me the actual diameter.
I measured each cylinder at 12clock, 1.5clock, 3clock & 4.5clock to check for ovality and at TDC, MDC, BDC to check for tapering
cyl#1 at TDC, MDC, BDC measures
cyl#2 TDC, MDC, BDC measures
cyl#3 TDC, MDC, BDC measures
cyl#4 TDC, MDC, BDC measures
measuring the forged pistons with a micrometer
the diameter at the base of the skirt 13mm from the bottom is what we need to calculate the piston to bore gap, each piston reads a consistant 71.4mm dia
when calculating the gap at the 12clock thrust face of the cylinders we get:
cyl1 = 0.026mm
cyl2 = 0.026mm
cyl3 = 0.024mm
cyl4 = 0.025mm
seems awfully tight? considering JE recommended a clearance of least 0.004" (0.1016mm)
dunno if that means (bore dia - piston dia) or (1/2 x (bore dia - piston dia))?
smooth grinded crank
so, got alot to talk to the machinist about tomorrow morning
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OP
OP
pollyp
Club Member
k just watched this vid bout how to measure piston to wall clearance and seems you just simply subtract the piston dia from the bore dia without dividing in 2
so the clearance are actually:
cyl1 = 0.052 - 0.058mm
cyl2 = 0.050 - 0.052mm
cyl3 = 0.048 - 0.050mm
cyl4 = 0.050 - 0.055mm
its still half the value of the recommended min clearance?
so the clearance are actually:
cyl1 = 0.052 - 0.058mm
cyl2 = 0.050 - 0.052mm
cyl3 = 0.048 - 0.050mm
cyl4 = 0.050 - 0.055mm
its still half the value of the recommended min clearance?
OP
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pollyp
Club Member
machinist says he was basing all the honing on the ring end gaps till its at the min 0.005" gap for turbo/nitro spec. he thinks the manufacturer generally tends to overspec the recommended bore size. he's honed abit off the bore and if it didn't seize or scuff majorly when i last ran it in its tighter form, then it may be fine now.
the defected bearing shells he'll polish out and will drill the new hole in the shell for the timing chain oiler.
won't be done till monday so another 2days lost progress in the proj. could measure the crank and mod the girdle cage in the meantime.
ordered another timing cover o-ring for tues since the original ones missing when the guy was cleaning the block, but I should replace em anyway.
the defected bearing shells he'll polish out and will drill the new hole in the shell for the timing chain oiler.
won't be done till monday so another 2days lost progress in the proj. could measure the crank and mod the girdle cage in the meantime.
ordered another timing cover o-ring for tues since the original ones missing when the guy was cleaning the block, but I should replace em anyway.
OP
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pollyp
Club Member
measured the crank journals
bore gauge can only read from 50mm so I'll have to measure the 3 outa 4 rod bigend bores with the less accurate digital calipers and they read
bigend1 = 39.7 = 0.01 clearance
bigend2 = 39.75 = 0.06 clearance
bigend3 = 39.76 = 0.07 clearance
#2-3 is kinda outa nissans clearance spec but the vernier calipers not that accurate anyway and nothing i can do bout the clearances so just gotta run it n see
bore gauge can only read from 50mm so I'll have to measure the 3 outa 4 rod bigend bores with the less accurate digital calipers and they read
bigend1 = 39.7 = 0.01 clearance
bigend2 = 39.75 = 0.06 clearance
bigend3 = 39.76 = 0.07 clearance
#2-3 is kinda outa nissans clearance spec but the vernier calipers not that accurate anyway and nothing i can do bout the clearances so just gotta run it n see
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OP
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pollyp
Club Member
after a whole evening of cutting n grinding, the forged engine girdle has been finely shaped. all the casting edges rounded n shaped n smoothed nicely
this recess feature in the casting has revealed a hole close to the edge of the windage tray port which would give oil a shortcut to surge back into the crankcase more easily during turning
I'd prefer to try n block it off securely somehow. obviously can't weld Alu here. ooh maybe i could weld an extra piece on the bottom edge of the side windage trays to cover the holes? won't be pretty.
or weld that piece onto part of the windage undertray? na it'll resrict the port.
or bolt a piece from inside the hole to block it?
or i could bodyfill all these recessed crater features to provide a smooth surface for the oil to flow on and the bolts holding the side windage trays will also be tapped into the bodyfiller to secure em more
or if i could buy a small enough door hinge, i could bolt the hinge onto the side of the port to act as a valve and so won't need to plug up that hole
this recess feature in the casting has revealed a hole close to the edge of the windage tray port which would give oil a shortcut to surge back into the crankcase more easily during turning
I'd prefer to try n block it off securely somehow. obviously can't weld Alu here. ooh maybe i could weld an extra piece on the bottom edge of the side windage trays to cover the holes? won't be pretty.
or weld that piece onto part of the windage undertray? na it'll resrict the port.
or bolt a piece from inside the hole to block it?
or i could bodyfill all these recessed crater features to provide a smooth surface for the oil to flow on and the bolts holding the side windage trays will also be tapped into the bodyfiller to secure em more
or if i could buy a small enough door hinge, i could bolt the hinge onto the side of the port to act as a valve and so won't need to plug up that hole
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OP
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pollyp
Club Member
door hinges were too big and so would've had to make my own thinner hinge and reweld em onto the windage tray which imho I cba so will leave and deal with it.
finally all bolted to the new girdle
slotted the crank on to double check it'll clear the scraper
test fit the windage trays
front needs a slight trim
finally all bolted to the new girdle
slotted the crank on to double check it'll clear the scraper
test fit the windage trays
front needs a slight trim
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OP
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pollyp
Club Member
tday i checked the ring endgaps. my feeler gauge doesn't have enough range so when measure the rings i only have say 0.127 0.152 0.176 etc but the results are:
cyl1 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl2 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl3 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl4 (top, 2nd, oil1, oil2) 0.152 0.152 0.152 0.152mm
very consistant and the oil rings no longer had any gaps round the sides when shining a light through but afew concerns.
the JE guidelines suggests the min ring gaps should be (top, 2nd, oil) 0.3573 0.393, 0.381mm
http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf
which seems to say the piston to bore is too tight and the ring gaps are way too tight?
also the 2nd ring gap should usually be abit bigger to allow trapped oil/gas between the top & 2nd rings to escape n reduce ring flutter but the gaps are the opposite way in my case.
i dunno which one to trust, this guideline sheet or my machinist?
abit of a dilema in my head.
i oiled all the rings, wrist pin, piston skirt, bores and slotted em in.
although the guides recommend a light coat on just the skirt and bores but then when you install the pistons the rings get coated in oil anyway? or maybe its to keep the top rings dry so they instantly bed in? meh
crank fitted
machinist told me a gr8 tip bout the main bolts.
i used to oil the threads and only under one side of the washer and i'd occasional get that creaking snappy bolt stutter as i torque it up which distrupted my sequences.
he suggests i apply grease to both sides of the washer and only a light drop of oil on the threads.
when i torqued the girdle cage main bolts it was soo smooth, fab. an the new anglular torque wrench made it alot easier to do
windage tray bolted on with locktight, wouldn't want it to loosen at any time. the front tray will need a hole cutting for the dipstick.
cyl1 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl2 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl3 (top, 2nd, oil1, oil2) 0.152 0.127 0.152 0.152mm
cyl4 (top, 2nd, oil1, oil2) 0.152 0.152 0.152 0.152mm
very consistant and the oil rings no longer had any gaps round the sides when shining a light through but afew concerns.
the JE guidelines suggests the min ring gaps should be (top, 2nd, oil) 0.3573 0.393, 0.381mm
http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf
which seems to say the piston to bore is too tight and the ring gaps are way too tight?
also the 2nd ring gap should usually be abit bigger to allow trapped oil/gas between the top & 2nd rings to escape n reduce ring flutter but the gaps are the opposite way in my case.
i dunno which one to trust, this guideline sheet or my machinist?
abit of a dilema in my head.
i oiled all the rings, wrist pin, piston skirt, bores and slotted em in.
although the guides recommend a light coat on just the skirt and bores but then when you install the pistons the rings get coated in oil anyway? or maybe its to keep the top rings dry so they instantly bed in? meh
crank fitted
machinist told me a gr8 tip bout the main bolts.
i used to oil the threads and only under one side of the washer and i'd occasional get that creaking snappy bolt stutter as i torque it up which distrupted my sequences.
he suggests i apply grease to both sides of the washer and only a light drop of oil on the threads.
when i torqued the girdle cage main bolts it was soo smooth, fab. an the new anglular torque wrench made it alot easier to do
windage tray bolted on with locktight, wouldn't want it to loosen at any time. the front tray will need a hole cutting for the dipstick.
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Roughly speaking the resultant reduction in ring end gap looks to be pretty close to the difference between recommended bore and machined bore sizes. I also concur on the 1st and 2nd ring gaps as you have stated them, 2nd ring gaps are usually bigger for the stated reason.
Typically one can go by a rough 0.001" clearance per inch or bore size, so 0.0030" for the CG10/CG13 absolute minimum, plus a little extra for boosted/nitrous or high output engines will land you pretty close to 0.004". FYI, we're aiming for 0.0035" on our engine. Yes a little different but it gives you something to go by on a high output N/A engine as a comparison.
Since your engine is sitting around the 0.0020" range currently, it does seem a tad tight and things such as scuffing and end gap clearances perhaps need some additional consideration. Doing this lot again, I am sure, would really be bad juju!
OP
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pollyp
Club Member
ok my schedules getting abit desperate here.
i feel abit uncomfortable that the clearances i measured are well below JE's min.
personally it's better to have an engine thats too loose and may not seal properly than an engine way too tight and could seize and trash the entire project.
i need to phone my machinist and confirm my measurements with his records. if the bores are indeed underbored i need to know WHY? and whether i can actually trackday it without risking seizing.
i will also phone sabastian at JE to double check the clearances are acceptable (prob not) but if not, i will need to have the bores IMMEDIATELY rebored abit larger to 71.5mm to increase the end gap to above 0.35mm, which may take another week and if I can't build it & bed it all in by Sept I might not make the show((
so the dilema is either
-carry on reassembly to get it finished on time hoping it goes well but risk seizing the engine (especially when on track) and risk wrecking the £500 pistons and £100 rings and everything else and worst case not make JAE anyway!
-get it rebored to spec (possibly risking bore ovality), prevent the risk of seizure, risk having the same burning oil issue & fail mot emission issue if the gaps too large, delay back the rebuild and risk wasting this yrs £20 JAE ticket?
it would be economically logical to get it machined larger to spec and missed out a £20 jae ticket which will save £1000s of engine work in the long term
i feel abit uncomfortable that the clearances i measured are well below JE's min.
personally it's better to have an engine thats too loose and may not seal properly than an engine way too tight and could seize and trash the entire project.
i need to phone my machinist and confirm my measurements with his records. if the bores are indeed underbored i need to know WHY? and whether i can actually trackday it without risking seizing.
i will also phone sabastian at JE to double check the clearances are acceptable (prob not) but if not, i will need to have the bores IMMEDIATELY rebored abit larger to 71.5mm to increase the end gap to above 0.35mm, which may take another week and if I can't build it & bed it all in by Sept I might not make the show
((so the dilema is either
-carry on reassembly to get it finished on time hoping it goes well but risk seizing the engine (especially when on track) and risk wrecking the £500 pistons and £100 rings and everything else and worst case not make JAE anyway!
-get it rebored to spec (possibly risking bore ovality), prevent the risk of seizure, risk having the same burning oil issue & fail mot emission issue if the gaps too large, delay back the rebuild and risk wasting this yrs £20 JAE ticket?
it would be economically logical to get it machined larger to spec and missed out a £20 jae ticket which will save £1000s of engine work in the long term
OP
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pollyp
Club Member
i dunno if this is really the correct maths but using Circumference = Pi x dia
the current bores are 71.452 dia, ring endgaps bout 0.152mm and circumference of 224.4730783mm
if the bores were machined to the specced 71.5mm, the circumference is in theory 224.6237847mm so endgaps could be 0.302796448mm?
the current bores are 71.452 dia, ring endgaps bout 0.152mm and circumference of 224.4730783mm
if the bores were machined to the specced 71.5mm, the circumference is in theory 224.6237847mm so endgaps could be 0.302796448mm?
Yes, your ring end gap would increase by bore x pi
OP
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pollyp
Club Member
well this is sh*?
the guy won't be in till monday
spoke to the lady and she mentioned he says he couldn't bore it out anymore without the risk of losing roundness and would've preferred if he'd had the original stock block with more meat to hone it to the required spec and keeping it round rather than trying to shave afew thou on an underbored cyl.
she'll try to contact him bout it and get back to me but i truely believe it won't get done in time if I decided the bore needs correcting, if it's even possible?
i don't have anymore spare blocks to start over again and tbh it's not worth my money to start over again spending more to machine another block
I'll still ring JE to double confirm its ok but I think in the end this is as close to spec as the blocks gonna be and i'll have to risk running it to get it ready in time, hoping it'll run and won't seize
this engine's nothing but cursed.
if it all goes tits up I'll have to spend more effort to rebuild the broken stock engine (prob blown HG from last trackday in april) and all before the MOT in Oct :/
this is not turning out well
the guy won't be in till monday
spoke to the lady and she mentioned he says he couldn't bore it out anymore without the risk of losing roundness and would've preferred if he'd had the original stock block with more meat to hone it to the required spec and keeping it round rather than trying to shave afew thou on an underbored cyl.
she'll try to contact him bout it and get back to me but i truely believe it won't get done in time if I decided the bore needs correcting, if it's even possible?
i don't have anymore spare blocks to start over again and tbh it's not worth my money to start over again spending more to machine another block
I'll still ring JE to double confirm its ok but I think in the end this is as close to spec as the blocks gonna be and i'll have to risk running it to get it ready in time, hoping it'll run and won't seize
this engine's nothing but cursed.
if it all goes tits up I'll have to spend more effort to rebuild the broken stock engine (prob blown HG from last trackday in april) and all before the MOT in Oct :/
this is not turning out well
OP
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pollyp
Club Member
hmm so options are
leave it,
bore it to 71.5 but lose roundness and not before next week,
get another block, karl offer one, and start all over again = ££ & afew weeks,
or regap the rings?
hmm regapping rings maybe the best option. does anyone have or know of a ring grinder?
leave it,
bore it to 71.5 but lose roundness and not before next week,
get another block, karl offer one, and start all over again = ££ & afew weeks,
or regap the rings?
hmm regapping rings maybe the best option. does anyone have or know of a ring grinder?
OP
OP
pollyp
Club Member
so hard to resist at such desperate times.I would try and resist the temptation in opting for the 'suck it and see method', it can prove quite costly not only with regards to money, but also time and ones hair follicles too
i wonder if it'll be alright to leave the piston clearance and try to correct the endgaps instead?
OP
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pollyp
Club Member
oh FFS as if it couldn't get any worse of, i just found that my job is in doubt
for past few months since the new company started in Jan the team and me mostly been working flat out on reduced min wage (to give more time) to create all these high end apple/android/web apps for businesses to market themselves and their products in the hope it'll all take off and when it starts to make profit we get paid our normal wage.
all my hard works been to create all these luvely apps and they're 100% ready to sell to clients now, only to find that the strategy didn't work and we've ran out of money and will be closing down next month #cries#
they say even if we got a client the running costs wouldn't be sustainable.
this completely ruins my life
a bad bad period right now
don't even know if i can make JAE
certainly can't afford trackdays anytime soon
for past few months since the new company started in Jan the team and me mostly been working flat out on reduced min wage (to give more time) to create all these high end apple/android/web apps for businesses to market themselves and their products in the hope it'll all take off and when it starts to make profit we get paid our normal wage.
all my hard works been to create all these luvely apps and they're 100% ready to sell to clients now, only to find that the strategy didn't work and we've ran out of money and will be closing down next month #cries#
they say even if we got a client the running costs wouldn't be sustainable.
this completely ruins my life
a bad bad period right now
don't even know if i can make JAE
certainly can't afford trackdays anytime soon
Sorry to read the above Polly & i hope if it did come to the worst you could find another job soon! This blog should stand as a C.V for your decication & skill alone!
Hang in there mate!
Hang in there mate!
OP
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pollyp
Club Member
thanks skinner.
with income cut off, i think my rough plan is:
1. continue trying to correct the engine clearance issue thats most cost effective n safest, and maybe risk missing JAE unfortunately
2. once polly2's back up n running TAKE A HOLIDAY!
I've not taken a single proper holiday since the company first started back in Nov, i had afew days available but never took em cos i was the only 1 3D developer in the team doing all the critical hard work and wanted this company to take off so was just work work work and even more ridiculous unpaid overtime to hit deadlines only to now find out in the bitter end that the company failed to sustain, the apps are technically finished and I'm only paid the remaining last month with no reward or anything for all this effort and frankly i'm worn out. it was all just not worth it n saddens me
3. after a reasonable roadtrip I begin the tedeous job search with JSAllowance
4. trackdays are on my backburner for now till i get a secure income
OP
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pollyp
Club Member
karl was just talking to me bout offering a spare block he has for free and this just sparked another option in my head
which is to replace the stock engine HG that i blew in april, hope it was just the HG, fit it to the car and get up n running straight to JAE with no need for any long break-in.
the engine won't be pretty but i'll be more certain it'll run.
the forged engine meanwhile would take another backseat side project for another time.
when i call JE, if the block can be bored out to 71.5mm or filing the rings abit will suffice then fine.
if not then i could pickup karls spare block n girdle from JAE? and start all over, getting machinist to absolutely get it SPOT ON this time from a stock bore dia so it'll be round and by waiting till the bore is exactly ready before i fire up the rings, i'll save £160 worth of rings, £500 worth of pistons and £few of machining rather than seizing it all and lose the whole £1000+ lot of block, pistons, rings etc
which is to replace the stock engine HG that i blew in april, hope it was just the HG, fit it to the car and get up n running straight to JAE with no need for any long break-in.
the engine won't be pretty but i'll be more certain it'll run.
the forged engine meanwhile would take another backseat side project for another time.
when i call JE, if the block can be bored out to 71.5mm or filing the rings abit will suffice then fine.
if not then i could pickup karls spare block n girdle from JAE? and start all over, getting machinist to absolutely get it SPOT ON this time from a stock bore dia so it'll be round and by waiting till the bore is exactly ready before i fire up the rings, i'll save £160 worth of rings, £500 worth of pistons and £few of machining rather than seizing it all and lose the whole £1000+ lot of block, pistons, rings etc
OP
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pollyp
Club Member
i don't wanna do the same job twice (assemble the whole outa spec engine, fit everything, run, remove everything, check gaps to find it needs machining, machine, reassemble whole engine, fit everything, run & hope it works) not worth the wasted work, time n risk. better to get it as perfect as I can the first time before firing it up.
work smarter not harder.
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pollyp
Club Member
thats a good detail to point out, the endgap increasing as the rough bore & rings wear away a larger dia.
so i wonder, would the guideline recommended clearances be applicable to freshly machined bores that'll bed-in to a fraction larger dia?
or is that clearance for only once the rings bedded and fresh?
OP
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pollyp
Club Member
k status update
i called JE and sabastian agrees the clearances are much much too tight especially for my application and will need to enlarge the bore to match the piston-wall gap first and then gap the rings. i mentioned someone had a spare free block to start from scratch and he'd personally prefer doing that given the option.
then i called my cousin for 3rd opinion and he thinks yeah you should be able to machine the bore it out to that spec no prob, there's enough steel liner left, and his local specialist is an oldschool type engine builder and when they built the remachined spare block with the old used forged rings the clearances to their book were spot on.
i have a theory that the old rings were prob worn and filed a tad small so the bore ended up being machined too small to acheive the old ring endgaps. anyway these new proper spec JE rings are prob larger and meant for a 71.5mm bore hence abit tighter on the underbored cylinder.
anyway after few hrs of chatting we came to the concluding plan:
1- take head of stock engine and check the flatness with straight edge. if warped get it skimmed and/or block decked for few quid
2- rebuild up the stock engine and get it up running as a daily runner only
3- make it to jae
4- collect spare block from karl
5- take the forged engine bottom block end to my cousin to double check clearances properly
6- get the engine block rebored precisely this time by my cousins local engine builder to fit the pistons and correct the new ring endgaps
7- while I'm there with the turboed stock engine, I could hook it to my cousins emissions machine and take the time to fine-tweak the fueling map till the turbo will certainly pass MOT, this will mean
that every year instead of swapping back n forth to n/a to pass MOT I could just simply switch to a leaner emission friendly tweaked turbo map, saving alot of hassle n labour.
8- have a holiday trip
9- if machining the forged engine bore a fraction towards the min spec and keeping roundness wasn't working then I'll have to send over karls spare block and start fresh
10- I'll only be able to goto trackdays etc once forged engines rebuilt, fitted n running perfect and have a secure job
tonight swapped the windage tray over to the stock engine.
good thing i didn't continue building this forged engine cos when i took the rear tray off, to my shock i found one of the rubber hose i use to cover the piston rod end threads, when fitting the crank, had become trapped on one of the trays which would've been very bad and same as a surgeon leaving his tools inside the patient :/ woops
tomorrow buy a straight edge, take head off n check flatness
i called JE and sabastian agrees the clearances are much much too tight especially for my application and will need to enlarge the bore to match the piston-wall gap first and then gap the rings. i mentioned someone had a spare free block to start from scratch and he'd personally prefer doing that given the option.
then i called my cousin for 3rd opinion and he thinks yeah you should be able to machine the bore it out to that spec no prob, there's enough steel liner left, and his local specialist is an oldschool type engine builder and when they built the remachined spare block with the old used forged rings the clearances to their book were spot on.
i have a theory that the old rings were prob worn and filed a tad small so the bore ended up being machined too small to acheive the old ring endgaps. anyway these new proper spec JE rings are prob larger and meant for a 71.5mm bore hence abit tighter on the underbored cylinder.
anyway after few hrs of chatting we came to the concluding plan:
1- take head of stock engine and check the flatness with straight edge. if warped get it skimmed and/or block decked for few quid
2- rebuild up the stock engine and get it up running as a daily runner only
3- make it to jae
4- collect spare block from karl
5- take the forged engine bottom block end to my cousin to double check clearances properly
6- get the engine block rebored precisely this time by my cousins local engine builder to fit the pistons and correct the new ring endgaps
7- while I'm there with the turboed stock engine, I could hook it to my cousins emissions machine and take the time to fine-tweak the fueling map till the turbo will certainly pass MOT, this will mean
that every year instead of swapping back n forth to n/a to pass MOT I could just simply switch to a leaner emission friendly tweaked turbo map, saving alot of hassle n labour.
8- have a holiday trip
9- if machining the forged engine bore a fraction towards the min spec and keeping roundness wasn't working then I'll have to send over karls spare block and start fresh
10- I'll only be able to goto trackdays etc once forged engines rebuilt, fitted n running perfect and have a secure job
tonight swapped the windage tray over to the stock engine.
good thing i didn't continue building this forged engine cos when i took the rear tray off, to my shock i found one of the rubber hose i use to cover the piston rod end threads, when fitting the crank, had become trapped on one of the trays which would've been very bad and same as a surgeon leaving his tools inside the patient :/ woops
tomorrow buy a straight edge, take head off n check flatness
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pollyp
Club Member
quick update
head removed
cyl 1-4
#1 appears full of soggy crud
under the head
cyl head 1-4
#1 again some soggy mashy carbon under the cooler inlet valve
the integrity of this type of gasket is ok during removal. it bonds very strong to the surface but once you peeled it off it mostly stays intact with the gasket sheet, makes cleaning abit easier
yep here's the problem. cracked metal seal ring
looks to be an easy fix
scrap clean the surface, check its flat, bang in new HG (gonna use the cheapo composite type that came with the HG pack cos wanna reserve the better genuine one for the forged engine), slot in car and away it goes
head removed
cyl 1-4
#1 appears full of soggy crud
under the head
cyl head 1-4
#1 again some soggy mashy carbon under the cooler inlet valve
the integrity of this type of gasket is ok during removal. it bonds very strong to the surface but once you peeled it off it mostly stays intact with the gasket sheet, makes cleaning abit easier
yep here's the problem. cracked metal seal ring
looks to be an easy fix
scrap clean the surface, check its flat, bang in new HG (gonna use the cheapo composite type that came with the HG pack cos wanna reserve the better genuine one for the forged engine), slot in car and away it goes
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pollyp
Club Member
scraping the old gasket off I saw this guys youtube vids, subscribed cos he's made some really useful fascinating guides
so have afew cheapo razer blades to do this
head & deck cleaned. I got a corner square rule and used the thick straight edge to measure if its flat. yep very flat i couldn't even fit my thinnest feeler gauge through it.
no need to skim or deck it which saves alota time n money
cyl head 1-4 scraped clean
fitted the cheapo HG
so cheap it doesn't even have proper tight locating holes so position it bout right n just drop the head on
head torqued up
so have afew cheapo razer blades to do this
head & deck cleaned. I got a corner square rule and used the thick straight edge to measure if its flat. yep very flat i couldn't even fit my thinnest feeler gauge through it.
no need to skim or deck it which saves alota time n money
cyl head 1-4 scraped clean
fitted the cheapo HG
so cheap it doesn't even have proper tight locating holes so position it bout right n just drop the head on
head torqued up
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pollyp
Club Member
redesigned the windage undertray with a larger square profile, enlarged the port under cyl4 as deep as i can before it hits the sump and then matched the port size area to the other cyl ports. and then thought i could fit a vertical hinge valves to them to reduce surges. so now the ports are large enough for cold oil to flow out and the valves prevent back surges when cornering.
technically the design's gone back to windage tray design 5 lol
http://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-62#post-529363
technically the design's gone back to windage tray design 5 lol
http://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-62#post-529363
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pollyp
Club Member
engine top reassembled
new windage tray pieces all cut n drilled
made the first bend but ohh, bit of an issue making such tight short bends.
I'll have to grind a lip section off the bender but don't wanna cause a racket this late in the night. so continue tomorrow
new windage tray pieces all cut n drilled
made the first bend but ohh, bit of an issue making such tight short bends.
I'll have to grind a lip section off the bender but don't wanna cause a racket this late in the night. so continue tomorrow
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pollyp
Club Member
hacksawed this section off, arms abit tired
i can bend the first short bits now
but oh, it hitting another section
so cut more thick sections off
now can finish bending the tray
but during bending i forgot that cyl3 is at a different angle and can't simply put it back in the sheet bender or vice
so improvised a jig from the metal i just cut off the sheet bender to correct the angles
i can bend the first short bits now
but oh, it hitting another section
so cut more thick sections off
now can finish bending the tray
but during bending i forgot that cyl3 is at a different angle and can't simply put it back in the sheet bender or vice
so improvised a jig from the metal i just cut off the sheet bender to correct the angles
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pollyp
Club Member
now to make the swing doors
clamp a section in the vice
to form the first edge for the pivot
to bend the edge over the pivot pin i used a gasket scraper which had the same thickness as the rod and extrude it through the vice opening
to complete the wrap we need a square flat corner such as the inside of a vice
using a flat punch to close the edge
and a flathead/chisel to tighten it closely around the pivot rod
eight doors made after alot of bashing
clamp a section in the vice
to form the first edge for the pivot
to bend the edge over the pivot pin i used a gasket scraper which had the same thickness as the rod and extrude it through the vice opening
to complete the wrap we need a square flat corner such as the inside of a vice
using a flat punch to close the edge
and a flathead/chisel to tighten it closely around the pivot rod
eight doors made after alot of bashing
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pollyp
Club Member
finished the other swing doors
cut out the section for the pickup support
drilled hole for the dipstick
and think thats pretty much the windage tray complete
off to day out in glasgow tomorrow but once back i wanna mount the windage tray & girdle back on the sump and test this final setup with water to confirm before finishing the engine
cut out the section for the pickup support
drilled hole for the dipstick
and think thats pretty much the windage tray complete
off to day out in glasgow tomorrow but once back i wanna mount the windage tray & girdle back on the sump and test this final setup with water to confirm before finishing the engine
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pollyp
Club Member
i couldn't wait to update with the test results but I believe it works brilliantly
so this morning i assembled the windage tray & pickup
mounted it on the sump filled with water and the first test was the long constant cornering by tilting the sump
compared to the previous designs, this new vertical trapdoor worked gr8 cos most of the surging fluid was seen outside the girdle cage area and only some of the fluid had time to get past the holes n gaps under each cylinder but the result is the fluid was shielded from the crank area for a longer period therefore I can drive round such long high G corners for longer period before the oil pool starts to hit the crank
next is to test against sudden high-G cornering by throwing it around laterally
and the result is it works fantastically
as the pool of fluid is forced across the sump so quickly, the force and pressure of the fluid trying to get past the vertical gates pushes em shut. plus the fluid didn't have enough time to seep through the gaps. so all the cylinders appeared completely dry and you could see the fluid was forced around the outside of the girdle cage instead
really happy bout that. now lets clean it up and finish building this engine
so this morning i assembled the windage tray & pickup
mounted it on the sump filled with water and the first test was the long constant cornering by tilting the sump
compared to the previous designs, this new vertical trapdoor worked gr8 cos most of the surging fluid was seen outside the girdle cage area and only some of the fluid had time to get past the holes n gaps under each cylinder but the result is the fluid was shielded from the crank area for a longer period therefore I can drive round such long high G corners for longer period before the oil pool starts to hit the crank
next is to test against sudden high-G cornering by throwing it around laterally
and the result is it works fantastically
as the pool of fluid is forced across the sump so quickly, the force and pressure of the fluid trying to get past the vertical gates pushes em shut. plus the fluid didn't have enough time to seep through the gaps. so all the cylinders appeared completely dry and you could see the fluid was forced around the outside of the girdle cage instead
really happy bout that. now lets clean it up and finish building this engine
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pollyp
Club Member
girdle & windage tray & pickup installed
sump fitted
fitted the oil filter, tilted the engine back and then syringed oil through the turbo oil feed hole to help prefill the lower oil galleries
fitted the stainless studs. some are cut too short but meh I'm gonna sort em soon
most of it sorted
clutch fitted
gearbox and engine cover tomorrow and then she's prob ready to be fitted
sump fitted
fitted the oil filter, tilted the engine back and then syringed oil through the turbo oil feed hole to help prefill the lower oil galleries
fitted the stainless studs. some are cut too short but meh I'm gonna sort em soon
most of it sorted
clutch fitted
gearbox and engine cover tomorrow and then she's prob ready to be fitted
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