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PollyMobiles Rebuild
- Thread starter pollyp
- Start date
I just completed a track day at Goodwood in our 1962 3.8 lightweight e-type. The weather over the bank holiday was pretty cruddy and was chucking it down at points. We were running on a set of Avon ZZR semi-slicks and had more grip than those who opted for ordinary road tires, (not that we pushed too hard).according to this site the federal 595 rs-r seems to be the best all rounder and for just £85 each brand new
http://www.tyrereviews.co.uk/Tyre-Type/Passenger-Car-Summer-Trackday-and-Competition-Tyres/
seems tempting as last resort if no r888 comes up
Quick shot of the run past the start/finish into Madgwick
Many people span off and collected a fair bit of grass and mud, including a caterham who's driver and passenger both got a face fulls lol. Thankfully no bent cars or people, just mildly dented pride. So many people came off in fact, (3 in one session), that any more would have resulted in a 2nd driver briefing.
Despite being told that if you off at Goodwood there is a high likelyhood that you will die, (a friend offed on Lavant straight back in 2009 and earned 6 weeks in hospital), people still seemed to take risks. In fact said Caterham driver did a 180 and went back to pull Mike from the burning wreck. Lavant straight has barely a meter between the straight and tire wall and at 120mph that's quite humbling
One plank of a Ferrari driver managed the joke of gravel trapping the car on the first corner out of the pits.......seriously?! Only those on semis seemed to stay on track, it seems as though road tyres may have been a tad to hard and lacked compliance on the day.Still a very good tire despite a lot of water on the track and so they get my rating
Anyway, another tire available in 195/50/R15. Sadly I haven't found any available prices online though......probably safe to say they may be more than the 595's.
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pollyp
Club Member
ooh luvly jaaaag
just need something abit grippier and durable than the t1r in the back to resolve the understeer. not too much or else it'll be a hand full going backwards into the barriers.
will only be used for dry/int conditions and in wets i'll use the t1r all round
seems no one sells the zzr
yea some ppl are abit too eager n ambitious driving beyond their own and the cars abilities rather than learning/sensing prograssively the ever changing conditions with finesse
just need something abit grippier and durable than the t1r in the back to resolve the understeer. not too much or else it'll be a hand full going backwards into the barriers.
will only be used for dry/int conditions and in wets i'll use the t1r all round
seems no one sells the zzr
yea some ppl are abit too eager n ambitious driving beyond their own and the cars abilities rather than learning/sensing prograssively the ever changing conditions with finesse
I cannot understand it personally, there were only a handful of cars there worth less than £50k and the majority were worth £100k+ including the E. Given the driver's briefing, which spared all the sugar, I was utterly bewildered at the amount of red flags and a few blacks that I saw being given. Even more so that only 2 weeks prior a 30year old female driver died there after hitting the pit wall in a Caterham. You need nothing short of 100% concentration and balls of steel to drive at speed there.ooh luvly jaaaag
just need something abit grippier and durable than the t1r in the back to resolve the understeer. not too much or else it'll be a hand full going backwards into the barriers.
will only be used for dry/int conditions and in wets i'll use the t1r all round
seems no one sells the zzr
yea some ppl are abit too eager n ambitious driving beyond their own and the cars abilities rather than learning/sensing prograssively the ever changing conditions with finesse
I'll ask the old man where he bought the ZZR's from just for information sake.
Just read up the blog, shame to see you're having oil control problems again. I am assuming you didn't start with new ring packs?
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pollyp
Club Member
either the cars of that value are like pocket money to the persons vast bank account to afford to be that wreckless or they're mad
most of the engines the same except for the remachined block, new genuine HG, new front & rear crank seals.
cousin said the rings hardly appeared to have worn in cos the last block had such a massive gap that it didn't seal properly.
hope for the best with the stem seals and prepare for the worst if its the oil rings
Polly on my last sprint the two class winners were running Kumho V70A track tyres
http://www.ebay.co.uk/itm/195-50-15...60090?pt=UK_Cars_Tyres_RL&hash=item2c62947f3a
The escort with them on had them in soft, i pressed my thumb into one and the thumb print stayed! very sticky & get a good review against the Toyo's in the dry
http://www.tyrereviews.co.uk/Article/Road-VS-Trackday-Tyres-Mega-Test.htm
http://www.ebay.co.uk/itm/195-50-15...60090?pt=UK_Cars_Tyres_RL&hash=item2c62947f3a
The escort with them on had them in soft, i pressed my thumb into one and the thumb print stayed!
very sticky & get a good review against the Toyo's in the dryhttp://www.tyrereviews.co.uk/Article/Road-VS-Trackday-Tyres-Mega-Test.htm
Did you noticed any difference?hmm the central beam has this rubber resonance damper to prevent it from resonating at certain frequencies. no need for that here
Is the damper adjustable, my mounts are all solid rubber, except the front one, so i have annoying vibrations in the cabin around 900-1000 rpm
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pollyp
Club Member
gasket set arrived
and the OHC tool
has fitting for large or small retainers
the arms would normally attach to the valve spring on a rocker valve setup but since the micra has floating buckets, it won't work as intended
so i'll have to remove one of em
and secure the other arm under the bucket casing like this
seals soaked
to push the new seals in i found a pen cap that had the right diameter
video of replacing the seal
to pull out the old seal i figured rather than grabbing with pliers and pulling it off freehand which could damage the stem or bucket housing when it slips, i could instead slowly pry the pliers outwards with some leverage like this
all 16 friggin stem seals replaced, cams back on
taken me 6hrs, my legs and especially lower back is agony from standing n bending over the engine all night :/
and the OHC tool
has fitting for large or small retainers
the arms would normally attach to the valve spring on a rocker valve setup but since the micra has floating buckets, it won't work as intended
so i'll have to remove one of em
and secure the other arm under the bucket casing like this
seals soaked
to push the new seals in i found a pen cap that had the right diameter
video of replacing the seal
to pull out the old seal i figured rather than grabbing with pliers and pulling it off freehand which could damage the stem or bucket housing when it slips, i could instead slowly pry the pliers outwards with some leverage like this
all 16 friggin stem seals replaced, cams back on
taken me 6hrs, my legs and especially lower back is agony from standing n bending over the engine all night :/
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pollyp
Club Member
nope
We really need you to let us know IMMEDIATELY you get done pleeze. Do you get nervous on startup? When I did my headgasket and timing belt, as it was something I had never done before, my hands were literally shaking!
when i took the old seal out, the rubber was black n hardened
should finish it all tonight, wait for sealant to dry then start her up late near midnight
triple XX
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pollyp
Club Member
got my 3rd x170 cam tday.
the ebay pic showed the 2gb sd card but to my surprise i opened her up to find a 8gb card already inside, wahey
chains on, covers sealed on, injectors n TB on
just waiting for sealant to dry enough and fit little bits n bobs and she's ready to start up
the ebay pic showed the 2gb sd card but to my surprise i opened her up to find a 8gb card already inside, wahey
chains on, covers sealed on, injectors n TB on
just waiting for sealant to dry enough and fit little bits n bobs and she's ready to start up
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pollyp
Club Member
didn't work
started her up and a big ploom of smoke comes out, prob the left over residue oil, then in this cold rainy night while engine and exhaust is still cold it steams abit.
when warmed up, its clear and when revving there's no smoke or steam at all although its dark.
after few miles i recheck the pistons and they're still friggin lightly oily FFS.
not sure if the rings are worn and keeps wetting the piston or if it takes alot of miles to burn away the residue oil.
woulda thought combustion would dry up the cylinders quickly if the leak had stopped but judging by the same sooty plugs and smear of oily piston, i fear the piston oil rings definately fecked.
this engines a friggin joke
cyl 1-4 after taking plugs out
freely cranking the engine pushes the pool outwards on cyl 1 & 4 here
try cold starting again tomorrow to see if the new stem seals make any difference at all
started her up and a big ploom of smoke comes out, prob the left over residue oil, then in this cold rainy night while engine and exhaust is still cold it steams abit.
when warmed up, its clear and when revving there's no smoke or steam at all although its dark.
after few miles i recheck the pistons and they're still friggin lightly oily FFS.
not sure if the rings are worn and keeps wetting the piston or if it takes alot of miles to burn away the residue oil.
woulda thought combustion would dry up the cylinders quickly if the leak had stopped but judging by the same sooty plugs and smear of oily piston, i fear the piston oil rings definately fecked.
this engines a friggin joke
cyl 1-4 after taking plugs out
freely cranking the engine pushes the pool outwards on cyl 1 & 4 here
try cold starting again tomorrow to see if the new stem seals make any difference at all
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pollyp
Club Member
started her this morning and dammit! it smokes the same
engines really p!ssin me off
now what.
either rip out the piston and replace just the oil rings and reassemble but risking another failure or
spend another month and a fortune starting all over again- rip the whole engine apart once again, get the block rehoned, completely new set of rings this time, break-in again
rings - i think my bore is bout 72mm? looking at JE pro-seals site, i could either :
- order individual rings, only nearest size available is 73mm and regap them (risking the mis-shape prob all over again that frank showed)
http://www.jepistons.com/Products/J32874-02.8DCNF.aspx
- i order a whole new set of 72mm rings ($22 + p&p + tax custom) with a rehoned block (forgot if the ring thickness was 0.8 or 1mm).
http://www.jepistons.com/Products/XC7200.aspx
suppose their pricing of the ring sets are per piston so for 4 pistons its approx £30 + p&p + tax for the 73mm oil rings that need regapping or £57 + p&p + tax for the 72mm complete ring set
engines really p!ssin me off
now what.
either rip out the piston and replace just the oil rings and reassemble but risking another failure or
spend another month and a fortune starting all over again- rip the whole engine apart once again, get the block rehoned, completely new set of rings this time, break-in again
rings - i think my bore is bout 72mm? looking at JE pro-seals site, i could either :
- order individual rings, only nearest size available is 73mm and regap them (risking the mis-shape prob all over again that frank showed)
http://www.jepistons.com/Products/J32874-02.8DCNF.aspx
- i order a whole new set of 72mm rings ($22 + p&p + tax custom) with a rehoned block (forgot if the ring thickness was 0.8 or 1mm).
http://www.jepistons.com/Products/XC7200.aspx
suppose their pricing of the ring sets are per piston so for 4 pistons its approx £30 + p&p + tax for the 73mm oil rings that need regapping or £57 + p&p + tax for the 72mm complete ring set
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pollyp
Club Member
just so much work for nothing!
just teaches me to NEVER EVER reuse bad piston rings in a hope they could improve during break-in cos they never will.
complete ring set would prob be est £57 + £15 post + £20 tax = est £100
plus est £30 rehone, £80 genuine HG, £36 for 10L of 20w50, £12 for 3 oil filters, £126 for 3tanks of super unleaded during the break-in
overall its gonna cost another £384 and i just had my work salary reduced to near min wage for financial reason till we start making profit back which doesn't help
this engine almost seems to be not worth all this hassle at this moment.
easiest and cheapest alternative is to revert back to the stock engine, hopefully it just has a blow HG
just teaches me to NEVER EVER reuse bad piston rings in a hope they could improve during break-in cos they never will.
complete ring set would prob be est £57 + £15 post + £20 tax = est £100
plus est £30 rehone, £80 genuine HG, £36 for 10L of 20w50, £12 for 3 oil filters, £126 for 3tanks of super unleaded during the break-in
overall its gonna cost another £384
and i just had my work salary reduced to near min wage for financial reason till we start making profit back which doesn't helpthis engine almost seems to be not worth all this hassle at this moment.
easiest and cheapest alternative is to revert back to the stock engine, hopefully it just has a blow HG
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pollyp
Club Member
i would inevitably move to this forged engine anyway whether in future or now and has been taking long enough. since the engine is here with all the seals n bits are new and its just the damn rings that needs re-doing i may have to bite the bullet go all out and fix it now rather than later.
this is gonna hurt
this is gonna hurt
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pollyp
Club Member
just keep swimmin, just keep swimmin
i won't give up that easily, not after coming so far and near the finish.
have to push onwards through the hard times to get to the good stuff.
will just take more time, money and mistakes to get there.
through process of elimination i've pretty much replaced everything round the cylinder except for the rings so that must be the logical last straw of the puzzle
i won't give up that easily, not after coming so far and near the finish.
have to push onwards through the hard times to get to the good stuff.
will just take more time, money and mistakes to get there.
through process of elimination i've pretty much replaced everything round the cylinder except for the rings so that must be the logical last straw of the puzzle
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pollyp
Club Member
started her up again.
at 0:12 when cold cranking without any throttle it fails to get going with all that oil.
at 0:48 i clear the flooded engine
1:14 i try again with no throttle and same result
1:30 unflood
1:50 start with some throttle to get her going as she misfires and clear away the oil at 2:00
smoking badly, the rings have definately gone now
engine warmed up, i do a wet & dry test:
11.2 11.3 11.8 11.0 dry
12.1 12.3 12.8 12.2 wet
00.9 01.0 01.0 01.2 increase
i rang my local machinist bout rehoning the bores and its £20
well that's it then, back to square one.
take the engine/box out, strip it back down to the core, rehoned, order complete new set of pro-seal rings from USA (check end gap and roundness), reassemble it all, fit engine/box, break-in 1000miles
at 0:12 when cold cranking without any throttle it fails to get going with all that oil.
at 0:48 i clear the flooded engine
1:14 i try again with no throttle and same result
1:30 unflood
1:50 start with some throttle to get her going as she misfires and clear away the oil at 2:00
smoking badly, the rings have definately gone now
engine warmed up, i do a wet & dry test:
11.2 11.3 11.8 11.0 dry
12.1 12.3 12.8 12.2 wet
00.9 01.0 01.0 01.2 increase
i rang my local machinist bout rehoning the bores and its £20
well that's it then, back to square one.
take the engine/box out, strip it back down to the core, rehoned, order complete new set of pro-seal rings from USA (check end gap and roundness), reassemble it all, fit engine/box, break-in 1000miles
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pollyp
Club Member
i'd personally try n get this shiny new engine fixed n up n running for next trackday soon.
taking this engine out, fitting the stock engine in, intentionally blowing it up, taking it back out, fitting the new engine and running it in seems a waste of time n effort n money, and getting insured on my moms car to get to work for a month while fixing this car each time is costing me. i'd rather try get straight to the crescendo and only when it dies do i then swap back to the stock block as a backup.
taking this engine out, fitting the stock engine in, intentionally blowing it up, taking it back out, fitting the new engine and running it in seems a waste of time n effort n money, and getting insured on my moms car to get to work for a month while fixing this car each time is costing me. i'd rather try get straight to the crescendo and only when it dies do i then swap back to the stock block as a backup.
Blimey, I thought a Genie was going to come out of your exhaust at 0:27
Shame to hear the engine is still exhibiting the same issues despite a new block. I have no details on those pistons but I'd imagine being a CG13DE that the pistons would likely be 71.5mm, (which is a typical overbore), easily checked however What will the block be re-honed to and will you still have good skirt clearances with a re-hone and be within range with respect to ring gaps?
Ring wise, if it's a JE piston then there should be a replacement ring pack available. Using the old rings given the issues was a bit of a gamble, which sadly didn't seem to pay off. I detest the re-use of rings, especially when something hasn't seated initially and especially when there's time and money invested in something. I doubt they will have much chance of seating well. Frank re-uses rings to good effect but they will likely be from used engines with little issue and probably have a good even wear on them, so with some careful work they can be and have been made to work.
I call 3rd time lucky on the next build
Shame to hear the engine is still exhibiting the same issues despite a new block. I have no details on those pistons but I'd imagine being a CG13DE that the pistons would likely be 71.5mm, (which is a typical overbore), easily checked however
What will the block be re-honed to and will you still have good skirt clearances with a re-hone and be within range with respect to ring gaps?Ring wise, if it's a JE piston then there should be a replacement ring pack available. Using the old rings given the issues was a bit of a gamble, which sadly didn't seem to pay off. I detest the re-use of rings, especially when something hasn't seated initially and especially when there's time and money invested in something. I doubt they will have much chance of seating well. Frank re-uses rings to good effect but they will likely be from used engines with little issue and probably have a good even wear on them, so with some careful work they can be and have been made to work.
I call 3rd time lucky on the next build
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pollyp
Club Member
rub the exhaust, make a wish (I wish this damn engine had worked)Blimey, I thought a Genie was going to come out of your exhaust at 0:27
Shame to hear the engine is still exhibiting the same issues despite a new block. I have no details on those pistons but I'd imagine being a CG13DE that the pistons would likely be 71.5mm, (which is a typical overbore), easily checked however
Ring wise, if it's a JE piston then there should be a replacement ring pack available. Using the old rings given the issues was a bit of a gamble, which sadly didn't seem to pay off. I detest the re-use of rings, especially when something hasn't seated initially and especially when there's time and money invested in something. I doubt they will have much chance of seating well. Frank re-uses rings to good effect but they will likely be from used engines with little issue and probably have a good even wear on them, so with some careful work they can be and have been made to work.
I call 3rd time lucky on the next build
can't remember the bore of the remachined block, need to look back at blog notes.
remember me cousin saying that the blocks been bored to the rings min gap so even with a light hone it may still be within spec.
dunno what specifics to say to my machinist regards to honing other than take as little off as possible yet enough to promote break-in.
checking JE pro-seal website, i can only see the closest size being the set of 72mm rings of either 0.8 or 1mm thickness.
i should prob strip the block down,
get the bores honed lightly
measure the bore, piston & rings
then order the rings to suit the new bore
machine guy said the new rings should already be setup and won't need gapping?
it was my cousins advice that the rings seemed unworn and could be reused. guess i've learnt the lesson you mentioned above to never reuse em especially if they're bad from the start. what was i thinkin?
i suppose for a recon'ed engine there shouldn't normally be any oily piston this bad from the first crank yeah?
hmm when i take the rings out i'll have to check if i could've made the mistake of fitting em upside down
3rd time luck n wiser. it must work this time otherwise it'll all be a pointless waste
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pollyp
Club Member
oops the rings have finally broken now.
basically i ran cousin bout the issues and he suggests the last test to do to find if the rings are the cause is to let the crank breath freely by disconnecting the cam cover breather pipe, crank to cover breather and pcv pipe (plug the TB end to maintain inlet vacuum). this'll see if there's +ve crankcase pressure that could force the oil up past the rings during downstroke.
started her up and big ploom of smoke comes out as usual then runs better but in this cold rainy night i dunno if the mass of stuff coming out is smoke or heavy steam
and then as i was about to shut the bonnet n drive out she suddenly misfires running on 2-3 cyl, idle or reving.
i pull the plug ign cables individually to locate the misfire and #1 & #4 didn't make difference.
shut down and checked plugs. woops #1 and #4 plugs are wet
so i guess the rings were towards the point of failure and the -ve crankcase vacuum from the pcv valve was helping in keeping the oil away from reaching towards the chamber but once there's zero/+ve crank pressure from blowby, the poor rings fail and oil gets pushed into the chamber
well, i wonder what i'll be doing for the next few weeks
basically i ran cousin bout the issues and he suggests the last test to do to find if the rings are the cause is to let the crank breath freely by disconnecting the cam cover breather pipe, crank to cover breather and pcv pipe (plug the TB end to maintain inlet vacuum). this'll see if there's +ve crankcase pressure that could force the oil up past the rings during downstroke.
started her up and big ploom of smoke comes out as usual then runs better but in this cold rainy night i dunno if the mass of stuff coming out is smoke or heavy steam
and then as i was about to shut the bonnet n drive out she suddenly misfires running on 2-3 cyl, idle or reving.
i pull the plug ign cables individually to locate the misfire and #1 & #4 didn't make difference.
shut down and checked plugs. woops #1 and #4 plugs are wet
so i guess the rings were towards the point of failure and the -ve crankcase vacuum from the pcv valve was helping in keeping the oil away from reaching towards the chamber but once there's zero/+ve crank pressure from blowby, the poor rings fail and oil gets pushed into the chamber
well, i wonder what i'll be doing for the next few weeks
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pollyp
Club Member
thx for the support guys. I'll do the best i can
thought I'd brim the tank so next time i start with the new engine i won't have to stop.
purged the cylinders, cleaned the plugs, reconnected the hoses and started her up. heavy smoking till it clears later.
drained all fluids. sorted insurance to drive moms car another month. now the long process of rebuilding this engine repeats itself
thought I'd brim the tank so next time i start with the new engine i won't have to stop.
purged the cylinders, cleaned the plugs, reconnected the hoses and started her up. heavy smoking till it clears later.
drained all fluids. sorted insurance to drive moms car another month. now the long process of rebuilding this engine repeats itself
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pollyp
Club Member
i found some past measurements of the pistons back in post 1495 page 30.
the laser mark seems to suggests that this is a custom piston so i'm not sure what the actual measurements suppose to be nor what exact material grade its made from before i can judge what the clearances should be.
the piston had a job# 590755 but the dimensions abit unusual at 71.4mm at the widest piston skirt point, the 71 or 72mm piston rings they have listed may not work.
i think i should give em a call in US to track down all the info for this custom piston, what Alu grade it is and what min bore dia should be (to tell the machinist when deglazing) and if they have the appropriate ring size available or it'd have to be a set of custom sized/gapped rings.
the laser mark seems to suggests that this is a custom piston so i'm not sure what the actual measurements suppose to be nor what exact material grade its made from before i can judge what the clearances should be.
the piston had a job# 590755 but the dimensions abit unusual at 71.4mm at the widest piston skirt point, the 71 or 72mm piston rings they have listed may not work.
i think i should give em a call in US to track down all the info for this custom piston, what Alu grade it is and what min bore dia should be (to tell the machinist when deglazing) and if they have the appropriate ring size available or it'd have to be a set of custom sized/gapped rings.
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pollyp
Club Member
that'll take more time, money n effort when i already have this stronger auto block i've spent months prepping.
i'm not sure its as simple as just honing the outer dia of the piston, its abit oval, there's also the inner ring grooves that would need machine down too cater for the thickness of the rings.
i believe JE does custom rings. i'm gonna try that route and not waste all that effort on the auto block.
i'm not sure its as simple as just honing the outer dia of the piston, its abit oval, there's also the inner ring grooves that would need machine down too cater for the thickness of the rings.
i believe JE does custom rings. i'm gonna try that route and not waste all that effort on the auto block.
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pollyp
Club Member
i will try my bestsorry to hear it
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pollyp
Club Member
sump removed n drained
taking the clutch & fly off
flywheel end of the clutch gradually wearing towards 50% coverage
PP side is near 100% coverage
flywheel barely worn in
removed all external bits
cams off
head off
top of cylinders 1-4. crusty layer of burnt oil on the exhaust ports
wet pistons 1-4
taking the clutch & fly off
flywheel end of the clutch gradually wearing towards 50% coverage
PP side is near 100% coverage
flywheel barely worn in
removed all external bits
cams off
head off
top of cylinders 1-4. crusty layer of burnt oil on the exhaust ports
wet pistons 1-4
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pollyp
Club Member
genuine HG perfectly intact
block face still lovely smooth, just needs a wipe
block is stripped
pistons n crank out. I noted the ring positions after removing the pistons:
piston 2 rings at 6oclock, 10oclock, 1oclock, 10oclock
piston 3 rings at 5oclock, 3oclock, 8oclock, 2oclock
piston 4 rings at 8oclock, 9oclock, 11oclock, 7oclock
deep honing marks still visible on the bores. i'm only able to measure the top of the bore with my digital caliper and its bout 71.35mm
taking the lower crank cage out i found an issue
the main bearing #1 appears to have been damaged with a debris or its pitted.
eek, looks like i may need to measure the crank clearance with plastigauge and order a new set of main bearings, god knows how much that'll be
i measured the pistons best i can and got this
still no reply from emailing JE tech dept
do they work at all over there?
block face still lovely smooth, just needs a wipe
block is stripped
pistons n crank out. I noted the ring positions after removing the pistons:
piston 2 rings at 6oclock, 10oclock, 1oclock, 10oclock
piston 3 rings at 5oclock, 3oclock, 8oclock, 2oclock
piston 4 rings at 8oclock, 9oclock, 11oclock, 7oclock
deep honing marks still visible on the bores. i'm only able to measure the top of the bore with my digital caliper and its bout 71.35mm
taking the lower crank cage out i found an issue
the main bearing #1 appears to have been damaged with a debris or its pitted.
eek, looks like i may need to measure the crank clearance with plastigauge and order a new set of main bearings, god knows how much that'll be
i measured the pistons best i can and got this
still no reply from emailing JE tech dept
do they work at all over there?
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pollyp
Club Member
according to JE's ring installation guide, if my pistons are grade 2618 non-silicon Alu alloy the Min piston to bore clearance would be 0.003" + 0.001" if turbo'ed, so from overall 0.1016mm (0.004")
http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf
the pistons from the wristpin area are 71.33mm and the top of the bore is 71.35 so i have a gap of bout 0.01mm (0.0004"), abit tight? or i didn't measure the bore correctly
a 4032 high silicon alloy would require a tighter overall clearance of 0.0813mm (0.0032")
http://www.jepistons.com/PDFs/TechCorner/SCPDrawings/piston_instrc2618.pdf
the pistons from the wristpin area are 71.33mm and the top of the bore is 71.35 so i have a gap of bout 0.01mm (0.0004"), abit tight? or i didn't measure the bore correctly
a 4032 high silicon alloy would require a tighter overall clearance of 0.0813mm (0.0032")
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pollyp
Club Member
k i'll use the feeler gauges tonight.
these forged pistons need least 4thou cos I think they expand more than cast alloy.
to replace the main bearings, is it like gapping the cam shims? measure the current clearance with plastigauge, measure the bearings thickness and then order the grade of main bearings from dealers till the estimated clearance will be at min spec?
these forged pistons need least 4thou cos I think they expand more than cast alloy.
to replace the main bearings, is it like gapping the cam shims? measure the current clearance with plastigauge, measure the bearings thickness and then order the grade of main bearings from dealers till the estimated clearance will be at min spec?