Full engine rebuild

Antony

Ex. Club Member
hi guys,

as some of you know i am fully rebuilding a CG13DE from bare block with new Big end shells, new main bearing shells, new piston rings, new valve stem seals (thanks jowley) .5mm machined off the head, reconned oil pump, brand new water pump, very low mileage timing chain set, new engine seals, new core plugs, resealed and greased everything..





i have a question, once the pistons, rings and bearings are in, how difficult should the engine be to turn over by hand (no cylinder head) as i feel its a little stiff, but i think that might be the friction of the piston rings.... has anyone done a full rebuild before and if so ever come accross this before?

thanks guys!

p.s. i have asked this before but has anyone got a cylinder head locating dowel spare, i have tried using a piece of tube but its too thick and i cant ram it home without damaging the head?

thank you.. (Y)(Y)(Y)
 

Ed

Fusion Motorsport
MSC Founder
Official MSC Trader
If you measured everything accurately you'll be fine. (Including ring gaps and bearings) ONLY use a Nissan dowel, DO NOT use anything else. I.e. go to nissan and get a new pair.
 
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Antony

Antony

Ex. Club Member
thanks ed ill take the sump off again and double check everything but all my parts are to spec (nissan oe parts from Mr humphris)

rings are pre-gapped and bearings are to block and crank specs.. crank has less than 0.001mm wear.

so should be good, ill soon see when i get that dowel.

ill have a word with the guys at nissan. see if they can get me a pair.
 

frank

Club Member
ant, any tightness would concern me, i would back-off each crank journal one at a time, to see if it free-ed up :)
 
you will have a little resistence/tightness their think if the pistons are tight in the bore then theres going to be resistence when its moved as for dowels get 2 old head studs cut the tops off and use an hack saw to cut a grove in the top then wind in the block like a stud drop on head and screw them out with a screwdriver.
 
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Antony

Antony

Ex. Club Member
ant, any tightness would concern me, i would back-off each crank journal one at a time, to see if it free-ed up :)

hm, yeah, ill try that but with the pistons still attached and see if its still there, if it is still there ill know its just the rings.... ill drench it in fresh oil too..lol(Y)(Y)

you will have a little resistence/tightness their think if the pistons are tight in the bore then theres going to be resistence when its moved as for dowels get 2 old head studs cut the tops off and use an hack saw to cut a grove in the top then wind in the block like a stud drop on head and screw them out with a screwdriver.

that sounds like a sound idea, ill see how much nissan wants first. then ill try that.(Y)
 

Stani1029

Club Member
yeah ant, you should be able to turn the engine over. if not something has been tightened to much. are you following torque settings from the haynes manual and tightening sequences??? stani
 
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Antony

Antony

Ex. Club Member
yep, every nut and bolt has been tightened to the correct torque using a very very expensive 1/2"drive 36" long snap on torque wrench. all the main bearing bolts have been tightened by hand then tightened in sequence with a 1/2" ratchet untill i could feel a bite then torqued using the torque wrench....

im gonna have to pull it apart again arent i?
 

Stani1029

Club Member
yep, every nut and bolt has been tightened to the correct torque using a very very expensive 1/2"drive 36" long snap on torque wrench. all the main bearing bolts have been tightened by hand then tightened in sequence with a 1/2" ratchet untill i could feel a bite then torqued using the torque wrench....

im gonna have to pull it apart again arent i?

yeah possibly, is the head on?? also how are you trying to turn the engine over. i use the crank pulley bolt and it always turns over fine :blush: have you angle torqued them too???
 

pjg1979

THIS IS MY BOOMSTICK!
Sounds like a mission, someone one has too much time on their hands, lol.

Anyway how's it coming along Ant, have you been taking pics?
 
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Antony

Antony

Ex. Club Member
not yet, its in a bit of a state at the mo, (one white wing, front bumper in primer, stickers removed, loads of red over spray all over the windows ....dont ask.....and loads of dings and stuff. but ive got the battery relocated in the boot and im determained to get my new engine fitted before end of may.


i have the cylinder head off at the mo and no i havent angle tightened them as i dont own a guage.

ill strip her down again and have a butchers.
 

jowley

Ex. Club Member
you should be able to turn it with your hands crank pulley on(well depending on your streght and there should be a little resistance but not much and oil is needed on every moving part when rebuilding if ya need a hand i can pop up one day
 
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Antony

Antony

Ex. Club Member
i can turn it easily with the flywheel on up to where the pistons in 1 and 4 reach the top of the stroke then it gets realy stiff again and i have to give it a propper shuv. then as soon as they start to go down it gets easier and the same happens for 2 and 3.

the bores were cleaned with paraffin and wd40 on a clean rag (you can still see the standard swirl marks on them and there is no lip at the top) everything is coated in either tungsten grease, wd40 or 10w40 oil. nothing was dry fitted.

i would appreciate it no end if someone could pop over and take a butchers as i havent ever seen a new engine build. (the lowest mileage engine i have ever had was 68000miles.
 

Stani1029

Club Member
so it is turning over then, see how you never angle torqued the bolts im guessing you gave it a bit more nM to make up for it?? if you did maybe it was too much i dont know....
 

superls

K10 Tuner
sounds like where the bores are worn to suit the old piston rings and right at the top and bottom its a bit tight as the new rings will be slightly bigger and wont be rounded on the corners etc, glcse busting the bores would have solved this and is a must when building an engine, it eliminaltes the problem your having and helps to 'true' up the bore if you use one of those hone things, also it roughs it up slightly helping the new rings bed in quicker., id advise taking them back out and honing the bores, if your doing it do it properly.
 
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Antony

Antony

Ex. Club Member
nope. been told by a few engine builders that you only hone the bores if the engine is well worn as the carbarundum that the stones are made from ruins the score marks on the bore and actualy makes it worse for bedding in rings as it can allow the edges of the score marks to break off..

my dad has built hundreds of engines over the years and has only ever used carbarundum stones once. and that engine had done over 150,000 miles on 50w garden oil.

i will have to take it apart. its no biggie. its only the sump and big end.
 

frank

Club Member
sounds like where the bores are worn to suit the old piston rings and right at the top and bottom its a bit tight as the new rings will be slightly bigger and wont be rounded on the corners etc, glcse busting the bores would have solved this and is a must when building an engine, it eliminaltes the problem your having and helps to 'true' up the bore if you use one of those hone things, also it roughs it up slightly helping the new rings bed in quicker., id advise taking them back out and honing the bores, if your doing it do it properly.

yeh, deffo on the honing, it also allows a film of oil to cling to the bore, to ensure ring seal, but it,s probably one or more of the journals that is "binding" imo
 

Retepetsir

King of Subsonic
nope. been told by a few engine builders that you only hone the bores if the engine is well worn as the carbarundum that the stones are made from ruins the score marks on the bore and actualy makes it worse for bedding in rings as it can allow the edges of the score marks to break off..

my dad has built hundreds of engines over the years and has only ever used carbarundum stones once. and that engine had done over 150,000 miles on 50w garden oil.

i will have to take it apart. its no biggie. its only the sump and big end.

Then get your dad to build it? :suspect:
 
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Antony

Antony

Ex. Club Member
nope. i followed nissans reccomendations for rebuilding the block and it said that as long as genuine parts are used and they are to the correct spec (block vs crank) then they shouldnt need testing.

gonna be a while before this is running though as i have nowhere to fit it and no tools at the mo and also its at my nans house and i dont wanna go there at the mo...
 
Did you oil all things before you mount it together? Also the pistons, pistonrings, big-ends....all? If you put all together without oil, it's obvious it turns heavy.

I just did a rebuild, as I placed CG10 pistons inside my CG13, including new rings and big-end shelves. To be honest, I thing if you took off 5mm from the head it's a bit too much....but perhaps the specs tell you it's ok.
I oiled all, and the engine ran fine by hand!

Did you already place the head? If you did at fitst don't place the spark plugs, as it will make it hard to turn the crankshaft.



Chrismo
 
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Antony

Antony

Ex. Club Member
its all put together using assembly grease and fresh oil. the cylinder head isnt on it yet its just bare crank with pistons and rods..
 
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Antony

Antony

Ex. Club Member
sorted, the main bearing shells had slipped... no biggie. took the crank out, regreased it all and slotted it all back in place (taking extra care of the tabs) and its all torqued up and ready to go.
 

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jim_bling

Ex. Club Member
looks great mate wish i knew what i was doing when building an engine as i dont even know how to do my cams and im scared to do them
 
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Antony

Antony

Ex. Club Member
maaah, think that will be a litte too much red, the tensioner is brand new and shiney though and i might wrinkle paint the sump black.... ehe, now what colour cam cover?..lol

and dan matey if you know of anyone with a cg10 98> flywheel and pulley let me know cos thats exactly what i need...


and as for building it kenny. just take everything apart and put it in labled bags / boxes then put the new stuff where the old stuff came out. make sure its greased / oiled and follow the torque settings in the haynes manual........ theres nothing to it anyway as mos of the nuts and bolts on a micra engine are inter-changeable (same length and thread) so its realy not that hard TBH.
 
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