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Author Topic: broken GTR to working GTR....a rebuild thread  (Read 2067 times)

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« on: April 06, 2006, 10:00:38 PM »
hi

i hope to edit this with more pics and more info, i hope it may help others who have to do what i have just done and am about to do with the rebuild stage

hopefully this will be a start to finish engine removal, recon and refit, along the way i will try to do things as best i can with the cheapest parts i dare to fit...this is a budget build!!!

please be patient with the thread as i intend to edit this first episode and add the next stage next week?















hi

after buying a R32GTR the engine blew after 2 days on the way to the mechanics....i had a "det" noise and then lost a lot of compression on no:2 cylinder

i was fully aware of a tapping noise and i understand that this is a signature noise of detonation but this was soo loud i thought it was a gearbox mount..the car has a shortshifter on it but the seal had not been fitted allowing the noise to come from the gearbox area so even though i was on the way to a friends garage to have a look when it was on the lift i gave it about 3/4 throttle for a few secs and it dropped a cylinder

when i got to the garage we didnt bother checking the gearbox mounts lol but we did stand around shaking heads under the bonnet, we noticed that the fuel regulator hose had come away from the regulator.....this is a serious failure on a turbo car as the fuel regulator needs to increase the fuel pressure as boost rises, if it does not then the engine will run lean and detonation occurs

it may have been knocked off by one of us just before we noticed it so its not a definitive cause of this failure but its a good theory for the moment

upon checking the compression was 165-170psi across the board on the tester apart from no:2 which was 40psi down:apoke:

i havent the cash to pay for a rebuild and not many want to help on a project like this so i have done 99% of it own


heres a pic of the car in my back garden awaiting rebuild


another as the dismantle process starts...chassis looks nice and stiff (jacked up on passenger front only)


now for those that dont know me ive been fecking with cars for a long time now and in my previous cars i had honed down the engine strip down or removal process time to less than 3 hours but this car has a lot more stuff attached to it and after careful consideration it may prove easier to remove the engine and gearbox as a complete unit rather than remove the inlet and exhaust manifolds in the car!, and really i need to remove the cylinder head to find out what i need to replace

some of the nuts on the inlet side seem so far away from access it may be impossible with conventional spanners and sockets and the exhaust side isnt much better, the odd pre-rounded off bolt here and there always being in the most inacessable of areas.....

the clutch is a real nasty paddle type so maybe it makes sence to change it during this engine work period anyway eh (well thats my excuse lol)

heres the exhaust side with the heat shields, inlet pipes and other stuff removed



i dont intend this to be a quick rebuild...at the mo is about 10 degrees outside and ill be doing all of the work my myself this time so most of the heavy stuff may just have to wait until warmer weather, i have spent around 15 hours on the car and it feels like i have got no-where with it yet...





had some time off work this week to get this engine out, done 99% of it own my own and TBH that was prob the best way, dont normallly disagree with myself lol


as mentioned before its a *** of a car to work on but i tackled it like this

remove the inlet hoses from the bonnet area, remove rad and fan to get a bit of room to work in


the down pipe nuts, easier then they look to remove from under the car with a 14mm and extention

obviously it also needs to be disconnected from the cat also

i found a load of excess exhaust paste that had gone hard in the cat........now i know what that dam noise was lol



the clutch control arm needs to be removed on the pull type arrangement that i have on mine, you need to remove the slave cylinder and then prise a pin and circlip off from the end of the clutch arm inside the box, you gain acess through the hole the arm travels through

after the pin and circlip have been removed pull it away from the thrust bearing

the bottom bellhousing bolts are easy to get to but the top six bolts look almost impossible...if you remove the top and bottom driverside engine mount bolts and the bottom passenger side mount bolt you can jack the engine and then remove the driver side engine mount, the passenger side mount does not need to be removed to get the engine out of the bay

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #1 on: April 06, 2006, 10:01:37 PM »
when you drop the engine down onto the subframe you can get those bolts with a normal 14mm spanner from the bonnet side


the driveshafts are held in by circlips and in theory they just need a jolt and they will come free if you have removed the hub to allow movement, i couldnt do this on the driver side though even after about an hour of abuse, tried to release it from inside the diff housing to no avail so i split the shaft fromm the engine side joint, it didnt make engine removal any harder with it still attached



the passenger side has a very long driveshaft and it also needs to be unbolted from the engine before removal, the driveshaft castlenuts are a 36mm BTW

i left it to almost last to remove the power steering hoses..

the engine should come free as soon as you try to "wiggle" it off the input shaft, i didnt put a jack under the gearbox as it seemed very secuore by itself

once thats all done just lift the engine as much as you can whilst keeping an eye on any wires still attached, the higher the engine is at this point the easier it is to remove the knock sensors etc



sounds straightforward but that took me the best part of 20 hours in a typical english febuary 5 degree wether

hopefully i can have this stripped and rebuilt within a month!?

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #2 on: April 06, 2006, 10:02:36 PM »
the strip down process is pretty normal really, i wont go into that as this guide is for the experianced mechanic (although a beginners guide to skyline engine overhaul process)

 

upon removal of the head the valves in cylinder two showed no signs of damage...i filled it with water but none seeped through (water may not be thin enough for some but its thin enough for 40psi drop i believe eh)

the head gaskett seemed ok too

upon removal of the piston it also seemed fine...as i started to clean it i saw det marks on the "flats" of the piston


 
cleaning a bit more on the ringlands gave a nasty surprise!!, a lump of no:2 ringland came off in my hand and i then saw two cracks in the ringland above it!


just sittting there waiting to jump out eh lol,the detonation couldnt break the top of the piston but the shockwave the detonation made traveled through the piston and cracked it where it was weakest

 

the others have tiny cracks here and there..wouldnt have thought they were cracks until i saw no:2 piston so if you are doing a rebuild yourself changing the pistons or having them xrayed would be a very good idea if you have any signs of detonation on the flats

 

so...a set of forged pistons is on the cards and this is where the skyline tuning parts prices come into play............you can easy pay 1200 for HKS pistons and near that price for most makes that uk tuners stock

some uk tuners charge 5000 for a basic rebuild compared to 700 for your average 6 cylinder engine


the prices of OE parts isnt too bad...50 for bearings, 260 for a slightly uprated clutch, gasket kit 140 so why the massive prices?

 
there seems to be a serious lack of infomation on the net (or anywhere else!) about the cars/engines, and from what ive read most rebuilds end in enginge failure even when done by some tuning companys...

http://www.gtr.co.uk/forum/upload/showthread.php?t=31170&highlight=engine+failure

 

in fact my engine had 6/6/05 on the sump and rocker indicating that the engine had just been replaced....i presume due to engine failure?....this engine only lasted a few hundred miles before it blew for one reason or another so the chances of this "poverty" rebuild going smoothly is low to nil maybe


so anyway..the first and longest job of the rebuild should be the clean down, if you take the bits off and get them as clean as possible before starting any engine work the whole rebuild will be a far less messy operation

heres the inlet and exhaust manifolds as they were



i just ave them a degrease with some gunk, jetted them off and then put them in a friends sandblaster



i done that to pretty much all of the parts i could as the engine was very corroded, even the turbos

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #3 on: April 06, 2006, 10:07:01 PM »
the strip down process is pretty normal really, i wont go into that as this guide is for the experianced mechanic (although a beginners guide to skyline engine overhaul process)

 

upon removal of the head the valves in cylinder two showed no signs of damage...i filled it with water but none seeped through (water may not be thin enough for some but its thin enough for 40psi drop i believe eh)

the head gaskett seemed ok too

upon removal of the piston it also seemed fine...as i started to clean it i saw det marks on the "flats" of the piston


 
cleaning a bit more on the ringlands gave a nasty surprise!!, a lump of no:2 ringland came off in my hand and i then saw two cracks in the ringland above it!


just sittting there waiting to jump out eh lol,the detonation couldnt break the top of the piston but the shockwave the detonation made traveled through the piston and cracked it where it was weakest

 

the others have tiny cracks here and there..wouldnt have thought they were cracks until i saw no:2 piston so if you are doing a rebuild yourself changing the pistons or having them xrayed would be a very good idea if you have any signs of detonation on the flats

 

so...a set of forged pistons is on the cards and this is where the skyline tuning parts prices come into play............you can easy pay 1200 for HKS pistons and near that price for most makes that uk tuners stock

some uk tuners charge 5000 for a basic rebuild compared to 700 for your average 6 cylinder engine


the prices of OE parts isnt too bad...50 for bearings, 260 for a slightly uprated clutch, gasket kit 140 so why the massive prices?

 
there seems to be a serious lack of infomation on the net (or anywhere else!) about the cars/engines, and from what ive read most rebuilds end in enginge failure even when done by some tuning companys...

http://www.gtr.co.uk/forum/upload/showthread.php?t=31170&highlight=engine+failure

 

in fact my engine had 6/6/05 on the sump and rocker indicating that the engine had just been replaced....i presume due to engine failure?....this engine only lasted a few hundred miles before it blew for one reason or another so the chances of this "poverty" rebuild going smoothly is low to nil maybe


so anyway..the first and longest job of the rebuild should be the clean down, if you take the bits off and get them as clean as possible before starting any engine work the whole rebuild will be a far less messy operation

heres the inlet and exhaust manifolds as they were



i just ave them a degrease with some gunk, jetted them off and then put them in a friends sandblaster



i done that to pretty much all of the parts i could as the engine was very corroded, even the turbos

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #4 on: April 06, 2006, 10:08:31 PM »
the strip down process is pretty normal really, i wont go into that as this guide is for the experianced mechanic (although a beginners guide to skyline engine overhaul process)

 

upon removal of the head the valves in cylinder two showed no signs of damage...i filled it with water but none seeped through (water may not be thin enough for some but its thin enough for 40psi drop i believe eh)

the head gaskett seemed ok too

upon removal of the piston it also seemed fine...as i started to clean it i saw det marks on the "flats" of the piston


 
cleaning a bit more on the ringlands gave a nasty surprise!!, a lump of no:2 ringland came off in my hand and i then saw two cracks in the ringland above it!


just sittting there waiting to jump out eh lol,the detonation couldnt break the top of the piston but the shockwave the detonation made traveled through the piston and cracked it where it was weakest

 

the others have tiny cracks here and there..wouldnt have thought they were cracks until i saw no:2 piston so if you are doing a rebuild yourself changing the pistons or having them xrayed would be a very good idea if you have any signs of detonation on the flats

 

so...a set of forged pistons is on the cards and this is where the skyline tuning parts prices come into play............you can easy pay 1200 for HKS pistons and near that price for most makes that uk tuners stock

some uk tuners charge 5000 for a basic rebuild compared to 700 for your average 6 cylinder engine


the prices of OE parts isnt too bad...50 for bearings, 260 for a slightly uprated clutch, gasket kit 140 so why the massive prices?

 
there seems to be a serious lack of infomation on the net (or anywhere else!) about the cars/engines, and from what ive read most rebuilds end in enginge failure even when done by some tuning companys...

http://www.gtr.co.uk/forum/upload/showthread.php?t=31170&highlight=engine+failure

 

in fact my engine had 6/6/05 on the sump and rocker indicating that the engine had just been replaced....i presume due to engine failure?....this engine only lasted a few hundred miles before it blew for one reason or another so the chances of this "poverty" rebuild going smoothly is low to nil maybe


so anyway..the first and longest job of the rebuild should be the clean down, if you take the bits off and get them as clean as possible before starting any engine work the whole rebuild will be a far less messy operation

heres the inlet and exhaust manifolds as they were



i just ave them a degrease with some gunk, jetted them off and then put them in a friends sandblaster



i done that to pretty much all of the parts i could as the engine was very corroded, even the turbos......

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #5 on: April 06, 2006, 10:10:03 PM »
to clean the head i used oven cleaner as per instructions on the carbonised parts of the head and jetted off, i then used fine grade wet and dry (wet) followed by fine wire wool to get a polish...this isnt just done from a cleaning point of view, it makes sure there is no sharp edges/hotspots on the combustion surface and will reduce the chances of detonation in future, the flat part of the combustion face (the bits that stop the head part of the cylinder being round) should also be rounded off slightly to avoid det...the inlet side is more prone to det than the exhaust side

so before clean down we have something like this
 

combustion face, oven cleaner first then jetter should get something like this



 

same bit but rubbed with fine grade wet and dry (wet) for about 45mins..maybe less



 

same bit, polished with fine wire wool for about 30mins



i cleaned the mating surface in the same way...didnt take too much time doing this as i have not yet checked the volume of the combustion areas on the head so it may need a skim if its off but we will come to that shortly, make sure you use a straight edge on top of your cleaning medium to make sure you are removing any material in a uniform manner

doing this polishing is a long process but it really does have great results

 
now heres an exhaust port as stock


here is one with the bump removed
 

i used a dremmel with a sandpaper end, then wet and dry followed by wire wool

the inlet side just wanted smoothing off really




now we can check the volume of the cylinder part of the head, i used some perspex, some sealant and a 100ml syringe

you will need to drill two holes for each cylinder..one so you can fill the void with water and one to let the air escape

put perspex onto head, mark out two holes for each cylinder and then drill the holes

then apply sealant to the perspex/head and weight it down for 45mins or so, aftrer that fill a 100ml syringe up and fill each cylinder with water..


you may want to check for leaks as one of mine was letting by at the sparkplug which gave some very confusing results lol

remember to keep a record of the volumes...


i got 66ml accross the board so no problems there (34ml left in the syringe)

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #6 on: April 06, 2006, 10:11:22 PM »
with the head now prepped and ready for lapping the parts have arrived to start the block

as mentioned previously the pistons were all either damaged or had suspected fractures on the ringlands...to replace these with stock items would cost 70 each from nissan but TBH they aint great pistons so i have gone with a larger bore with a set of JE forged items i bought from the american ebay site, worked out about 470 with shipping and customs tax

going 1mm oversize works out to be 2628cc (stock being 2568cc), this will not increase power by any noticable margin


the engine needs a good jetting out after any work like this, making sure no swarf has found a corner to hide in, all of the oilways and water ports blown through with the coreplugs removed for 30mins or so followed by some compressed air to dry it off is a must, dont want to allow any corrosion to get into the oilways, finish off with some WD40 on the oilports, journals and mating surfaces

i gave it a coat of silver high temp paint whilst it was outside and dry



moving on to the pistons....i weighed and bagged every piston and recorded the weight, i done the same with the pins and the rods with the old bearings removed

i found about 1 gram difference on the new JE's and about 4 gram on the rods, i am not going to balance the rods or pistons but i did do some basic blueprinting which is setting the heaviest piston with the lighest rod and so on

i took a record of the stock piston weight vs the new ones for no other reason than curisoty..


nice set of scales eh and perfect for this application....i got hold of this during the time i was made redundant from a closeing down sugar factory


the stock rods averaged out at about 640g IIRC

there are some sharp edges on the pistons that id prefer removed, i used some fine wet and dry to round off all of the sharp edges on the face of the piston, basicially its minimising the amount of hotspots which will go some way to deter detonation



i went with the recommended 4 thou bore clearance and ring clearances for "street car turbo/nitrous", the clearances have to be worked out by inch of bore, in this case its 87mm so thats 3.4 inches roughly, this does not apply to the oil control ring cluster though!

TBH i would prefer to see a more reasonable description of the application, there are too many variables on a turbo/nitrous engine to just throw it all into one part of the scale IMHO

on a previous engine i used the max clearance for turbo/nitrous on the bore and also on the rings........that was an engine that was designed to last ten thousand miles and no more so remember that if you want bigger cleances, lifespan will decrease at an unbelieveable rate the bigger your clearances are as they only allow good sealing of the rings at very high temps (which is what you would want on a 10 second drag car but this is a road car...)


so i have gone with a clearance of 17-18 thou on the top ring, 23 thou on the middle ring and the stock gapping on the oil ring which is ok provided its over 15 thou
the rings are file fit so its just a matter of filing gently on one side of the ring until you can fit the feeler guage through the gap in the ring with just a tiny bit of resistance when it is installed in the bore for your desired clearance

i always chase the ring up and down the bore clecking the clearance after i have finished filing the ring, if the clearance on your ring increases or discreases as you do this the bore has a "taper" to it

the JE pistons seem to have a lot of failures where the pin (or circlip) jumps ship and allows the gundgeon pin to slide out, there isnt any info supplied with the  piston set as to how to fit them but after looking at their site and speaking to people on forums the general method is to place the open ends into the groove facing away from the face of the piston and push in with your fingers, it shouldnt be hard to push them in if you are using the right technique...they just slide in real easy and hopefully make a nice click when they seat to let you know they are home, i still rotate them a few times just to make sure though as you really dont want to make a mistake here


although there was no crank failure on my engine i still wanted to get the crank checked over, it came back "all ok" but i had the jounals polished up whilst it was there

the bearings are a bit tricky on these engines...normally its just a case of ordering a new stock set but these are all graded

there is a beraring grade stamped into the sump face for each main bearing and another for the cranks mains jounals, these numbers are listed on the flywheel end of the crank



top-mains journals
bottom-rod journals

left to right nos 1-7/1-6

you add the numbers on the block to the numbers on the crank and thats the grade of bearing you need

same thing with the rods and the pistons (obviously the piston grade does not apply if you have a rebore)

also remember that cylinder 4 mains has the thrust bearing bit on it and you will need to mention that when you order

these bearing grades should still only be used as a guide, the bearings will still require checking with "plastigauge" if we are to be sure that clearances are correct and that the crank journals are not eliptical, it was given the "ok" by the rebore company but ill trust my own measurements only!, the crank is SO important you cant just take it for granted......double checking here will prevent the engine coming back out again in a few weeks time

after installing the mains bearings (prior to checking) we started to install the oil squirters..pretty cool items by all accounts and its a wonder why they are not fitted to all engines, they have an oilway and valve inside the bolt so make sure you fit the right ones in lol, the piston is also supplied with oil by the rod

one of mine had been damaged somehow, it wasnt until it was positioned along with the others that we noticed the bend...and then the crack on the shaft


cant be too careful eh:nonono:

i doubt it would have led to an immediate engine failure as the squirter is pressure dependant....if oil pressure drops under 3 bar (guess) the oil squirters are shut down, it may have led to failure at full throttle with lots of heat in the piston

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #7 on: April 06, 2006, 10:12:53 PM »
the strip down process is pretty normal really, i wont go into that as this guide is for the experianced mechanic (although a beginners guide to skyline engine overhaul process)

 

upon removal of the head the valves in cylinder two showed no signs of damage...i filled it with water but none seeped through (water may not be thin enough for some but its thin enough for 40psi drop i believe eh)

the head gaskett seemed ok too

upon removal of the piston it also seemed fine...as i started to clean it i saw det marks on the "flats" of the piston


 
cleaning a bit more on the ringlands gave a nasty surprise!!, a lump of no:2 ringland came off in my hand and i then saw two cracks in the ringland above it!


just sittting there waiting to jump out eh lol,the detonation couldnt break the top of the piston but the shockwave the detonation made traveled through the piston and cracked it where it was weakest

 

the others have tiny cracks here and there..wouldnt have thought they were cracks until i saw no:2 piston so if you are doing a rebuild yourself changing the pistons or having them xrayed would be a very good idea if you have any signs of detonation on the flats

 

so...a set of forged pistons is on the cards and this is where the skyline tuning parts prices come into play............you can easy pay 1200 for HKS pistons and near that price for most makes that uk tuners stock

some uk tuners charge 5000 for a basic rebuild compared to 700 for your average 6 cylinder engine


the prices of OE parts isnt too bad...50 for bearings, 260 for a slightly uprated clutch, gasket kit 140 so why the massive prices?

 
there seems to be a serious lack of infomation on the net (or anywhere else!) about the cars/engines, and from what ive read most rebuilds end in enginge failure even when done by some tuning companys...

http://www.gtr.co.uk/forum/upload/showthread.php?t=31170&highlight=engine+failure

 

in fact my engine had 6/6/05 on the sump and rocker indicating that the engine had just been replaced....i presume due to engine failure?....this engine only lasted a few hundred miles before it blew for one reason or another so the chances of this "poverty" rebuild going smoothly is low to nil maybe


so anyway..the first and longest job of the rebuild should be the clean down, if you take the bits off and get them as clean as possible before starting any engine work the whole rebuild will be a far less messy operation

heres the inlet and exhaust manifolds as they were



i just ave them a degrease with some gunk, jetted them off and then put them in a friends sandblaster



i done that to pretty much all of the parts i could as the engine was very corroded, even the turbos

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #8 on: April 06, 2006, 10:24:07 PM »
when you drop the engine down onto the subframe you can get those bolts with a normal 14mm spanner from the bonnet side


the driveshafts are held in by circlips and in theory they just need a jolt and they will come free if you have removed the hub to allow movement, i couldnt do this on the driver side though even after about an hour of abuse, tried to release it from inside the diff housing to no avail so i split the shaft fromm the engine side joint, it didnt make engine removal any harder with it still attached



the passenger side has a very long driveshaft and it also needs to be unbolted from the engine before removal, the driveshaft castlenuts are a 36mm BTW

i left it to almost last to remove the power steering hoses..

the engine should come free as soon as you try to "wiggle" it off the input shaft, i didnt put a jack under the gearbox as it seemed very secuore by itself

once thats all done just lift the engine as much as you can whilst keeping an eye on any wires still attached, the higher the engine is at this point the easier it is to remove the knock sensors etc



sounds straightforward but that took me the best part of 20 hours in a typical english febuary 5 degree wether

hopefully i can have this stripped and rebuilt within a month!?

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #9 on: April 06, 2006, 10:57:00 PM »
Post?, post?

T.F.S.

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #10 on: April 07, 2006, 12:08:45 AM »
postpost??

GTS4GTR

  • Guest
broken GTR to working GTR....a rebuild thread
« Reply #11 on: April 11, 2006, 07:33:14 PM »
They are awsum side skirts.what are they? how much? and where ya get them from?
I stuffed my rb26 from detonation as well... a "mate" hooked up the boost controller wrong and so it was free boosting and i didnt really know til the clouds of white smoke weeks later...
But i got it rebuilt for $1700 which was an awsum deal for engine out, engine back in, 1 new piston and new rings, bearings were sweet and didnt need replacing.
I done the whole do it yourself thing i found that all the time and frustration isnt worth it