bottom end knock c20xe

[coombsey]

need help i brought a c20xe with the cambelt snapped, brought a new head slapped it on timed it up there was a knocking from bottom end stripped it down new rings new big end shells re built knocking still there took bottom pully off the woodriftkey was snapped off got new 1 timed it up again knocking still there any ideas

[Adam]

Crank journals damaged....?

[Benn]

is the crank damaged?
are the rods damaged?
oil pump?

[coombsey]

the rods were checked out by a mechanic said they were ok the knocking is only there when the plugs are in if i take the plugs out it stops

[Stuart]

did you get the crank inpsected when you blindly (and stupidly) replaced the bearings without fully understanding what you were doing......

The rods will be fine as its the crank that takes the brunt of the damage when the "bottom end goes" and ovalises the crank journals which will always cause knocking until you get it reground.

[rc]

i had this exact sinario, tho not from cambelt snap, from droppin a valve, had to get the crank big ends regroung and the mains reground, all 1mm undersized now and had to get a new conrod as the big-end end had ovalisedon on one too! sweet as a nut now!

[coombsey]

how much did you pay to have every thing reground? the people i brought it off said it snapped a belt 8 exhaust valves were bent and two guides were cracked if the crank is dammaged would'nt it show up in wear in the big end shells i was told it would'nt damage the crank they said the rods would bend or wreck first i only replaced the big end shells and piston rings

[Stuart]

they told you a load of old crap.

do you really think that clipping the valves will bend the rods? (come on think about it)
I'd get that engine stripped down and inspected at a reputable engine builders......
Or cut your losses and get a decentish XE from elsewhere..that hasnt dropped its guts

[coombsey]

not a mechanic so i wouldnt know what dammage that would do thats why im on here gettin advice????

[Stuart]

in all fairness we cant tell if your crank is shagged, and how shagged it maybe... you need to pull it out and take the whole thing to an enigineer then.

Its not going to be cheap.. you could always use this as a chance to learn how to rebuild a bottom end etc..
http://www.vauxhallsportforum.com/phpBB2/skyline-gtr32-rebuild-rb26dett-t654.html
ok its based on a RB26dett, BUT its an excellent rebuild guide.

[coombsey]

ok thx but if the crank is dammaged wouldnt it show in the big end shells??

[rc]

i stripped all down myself and took it to a local engine rebuilder which a machinein shop, i think it was about 50 or 60 quid to get all the journals reground then balenced, think theres 4 big end and 5 mains i think, normally they go 0.5mm at a time but mine had scored and distorted so bad they took 1.0mm off all of them. then had to order in 1.0m oversized shells all round, and they were same price as normal size 1s! hope that helps a bit!

[coombsey]

to have every thing ground down its 66 pound 60 that includeds the bearings do i have to take head off to remove crank?? dont really wanna again

[rc]

hmmm, i supose in theory u don't need to, you can just get all the pistons at half stroke down the bore then undo the big end bolts, then the main bearing bolts, unless theres anything someone else can think of? you'll have to take off your gearbox and clutch and such obvously!

[Will F]

Just buy a decent XE. There are millions of them available.
They take a lot of crap too, so the fact its like its, suggests that it has been given holy death.

Scrap it.

[coombsey]

someone told me it could be the input shaft?? and get the gear box reconed it will be perfect??

[Stuart]

hmmmmmmm

it would be cheaper to whip the sump off, get the cap for rod number 3 off and get that jornal checked for roundness than it would be to have a gearbox recon..... if the check says the crank isnt shagged then by all menas get the box reconned.

[coombsey]

took the big end caps off all no yellowness a man from an engine recon place is coming round some time this week

[Stuart]

i can garuntee that he will say your bottom end is naffed.... If a gearbox bloke came round he would say your gearbox is naffed....

get an honest person who has no money to gain from it to listen....

[coombsey]

thats probable the best advice any 1 could have gave
thx

[coombsey]

took cam belt off turned wheels not crank the knocking seems to be from gearbox??? what gear boxes fit the c20xe redtop?? its from a scrap yard and its got corsa 16v wrote on the side? where would i find the box number