Busted Valve, Help Needed!

[adam 32]

after rebuilding and replacing the turbo a valve has let go on the 'test run'

this was only at 10psi and under 5500rpm so not heavy conditions. at first it was a misfire so i changed coil packs, spark plugs and ignitor amps. nothing. ran a compression test, and it came up with 0 compression in cylinder 4. so it something to do with the valves

i pulled the rocker covers off and rotated the cams and all 4 lifters work fine so its not the valve springs. all looks fine from the top of the engine. so it must be a bent valve or something from the bottom... but does anyone else have any ideas? is there something ive missed in the diagnostic?

can anyone give me any advice with regard to pulling the head off to check from the bottom if a valve is stuffed. how much for a workshop to do this kind of job or any help is greatly appreciated. my budget is already stretched from the turbo job so i have little cash to play with

thanks in advance for any help, it is much appreciated

[adam 32]

anyone? im in the shitter this time...

[N I B]

It may have a lifter pumped up. see if you have any preload

on any or the valves,not common thou.

[adam 32]

steve; do you have an endoscope at your workshop? i want to check the valves before pulling the head off, just so i know what im looking at.

[Pva_Glue]

hhhmmm endoscope... I know vets have them but I dont think they will willing to lend you one... they cost as much as your engine... dang.

not a good news

I hear you can hire them...

[VSPECII]

do a cyl leakage test first not a comp test

determine whether it is in fact a inlet or exhaust valve or a slug prblem then go from there

[N I B]

Yes we have an endoscope but the valves are hard to see

but the pidton and bore is easy.

[adam 32]

cheers VSPECII im guessing any auto shop can do them...

steve; you dont reckon using an endoscope is going to help me identify the exact problem before i start pulling the head off then?

[GTS-t VSPEC]

Adam,

Give Steve a call, 9350 5444, and ask him, he won't be online till tonight otherwise. He might be kind and lend it to you.

See'ya:burnout:

[adam 32]

looks like it isnt going to be worth using... as someone has told me if im getting 0 compression the head has to be lifted

will start removing it this weekend

[MrMayhem]

strange its happened straight after a turbo swap.......

I got rb20 valves in stock, and pistons

[adam 32]

thanks, i will definately need valves, hopefully not pistons - how much you want per valve?

how could the 2 have been related? im writing it down as bad luck as i was only running the new turbo at 10psi... any thoughts, ideas?

[osc@r]

your just an an lucky barstad. there's no connection.. :-)

[VSPECII]

Originally posted by adam 32

thanks, i will definately need valves, hopefully not pistons - how much you want per valve?

how could the 2 have been related? im writing it down as bad luck as i was only running the new turbo at 10psi... any thoughts, ideas?

maybe a bolt or sumthing hard acidently fell into inlet side and bent valves

let us now what actually happened ie bent or burnt valves or holes in slugs

[osc@r]

Originally posted by MrMayhem

strange its happened straight after a turbo swap.......  

I got rb20 valves in stock, and pistons

Yeah u wanna eleviate on that

(mac)

anyone seen my 14 openender?

[osc@r]

i wondered why we were short a 12mm lock nut.... damm lucky it's not my car

[adam 32]

ok no more jokes

mr mayhem; how much you want for the valve/s? would you be able to give us any advice with regard to removing the head?

cheers

[MrMayhem]

never seen a rb20 burn a valve yet

vavles...... $10 ea

Removing the head, dont use alcohol.

Big job, if you choose to accept it yourself

elaboration, ever notice how on a rb twin cam how something could fall into teh exhaust manifold and land right on number 4, its teh most direct route..

A mate once found a micromachine in teh sump of a 253, might find that lock nut after all

[adam 32]

have you done it before?

how much work are we looking at? ie man hours? could you recommend a workshop to take it to if it is too big a job?

[MrMayhem]

yep several times

I dont know how fast you work but put a weekend aside

veale should be able to get your head gasket over.

if you do it yourself theres two 10mm headed bolts holding head to block on the rear two corners on the outside of the head.... dont forget em dont screw up for timing belt settup......

workshops ...... contraversial and political

theres two in bentley area id trust