help on replacing valve springs

[sebstenator]

iv looked at some guides on the net but i cant seem to find much.
i was wondering if anyone knew how to replace valve springs without removing the heads.
iv read somewhere that you need an air compressor and put pressure in to the spark plug hole and so on. im just finding it a bit difficult.
any help would be appreciated.

[Not_An_Abba_Fan]

You can get a plug adapter with a valve on it. You screw it into the spark plug hole and pump air into the cylinder, this keeps the valve seated and stops it from dropping down when you remove the spring. A spring compressing tool that bolts to the rocker post is also needed. I have seen it done with a screw driver and ring spanner but if it slips you are in for some pain.

[VN_Luke]

this works on the v6 - not sure if it would work on the v8 as well (but I dont' see why not) i.e. the valves shouldn't be able to drop in if the cylinder is at TDC (ignore this post if they can)

- remove rocker covers and spark plugs
- pick a piston (work on one piston at a time)
- put a straw or something else nice and soft down the spark plug hole
- turn the engine by hand until the piston reaches the TDC (i.e the highest point it can, before it starts coming down again)
- compress spring, remove "valve retainery thinggies" with a magnet, try holding the valve up with your fingers so it doesn't drop, just in case (you can check by hand to see if it will drop in or not).. if it' doesn't well then you're laughing and just repeat procedure for the rest of em

[VN_Luke]

I have seen it done with a screw driver and ring spanner

A for effort!

[stocky]

does the v8 sit further back than a v6? when changing the springs on mine, the rear cylinders sucked trying to fit a compressor in there

[Blown V6 Hatch]

Bang on Stocky....Number 7 is a pain in the bum as it's right near the brake booster!

[stocky]

yeah i had the same problem with the v6. barely managed to fit the compressor in between the brake booster, and when i did, it wasnt very steady. could only imagine it being a lot harder on a v8

[sebstenator]

well iv got a compressor and a over head valve spring compressor so do you think using a magnet would be the best and easiest way to remove those little retainer lock thingies you where talking about? you are talking about the little half circle things on it right? lol.
would there be any other way of taking them out?

[stocky]

i didnt use a magnet. as the spring compressed, i just got them out with a small flat head screwdriver

[sebstenator]

i guess ill give it another shot. i did try with a small blade screw driver but still wasnt able to.

[VN_Luke]

magnet works a treat

specially those 'wand' style extendable ones.

you just poke the magnet at the top of the half circle thing, then it goes ZOOOOM right upwards and effortlessly onto the magnet (and doesn't go flying anywhere) ... of course you dont' want them to be wedged between the top of the valve and that plate... you want the top of the valve up, and the retainery plate and half circle jiggies down... then magnet action

[Morton]

To be completely honest, I don't know why so many people have issues losing their valves in the cylinders

The last time I removed valve springs from a set of heads, the valve stems had such a distinct burr on them, they wouldn't go through the heads when I TRIED to remove them I ended up attacking the valve stems with a die grinder just to try and drop them through the heads. Surely all old V6 motors must be getting to this point?

[stocky]

to stop valves dropping into my cylinders, i threaded some rope in through the spark plug hole until it filled it. valve wouldnt drop at all

[Blown V6 Hatch]

Generally, you give the retainer a bit of a tap with a hammer first to free it from the collets! Then it's just a matter of compressing the spring and pulling the collets out...

[centy]

Yes a tap is a must as with time oil and heat they can stick a bit to the valve stem.

[greenfoam]

Seen it done with a nut in the rocker stem and a ball joint fork pushing the spring down

[PaRaDoX]

Generally, you give the retainer a bit of a tap with a hammer first to free it from the collets! Then it's just a matter of compressing the spring and pulling the collets out...

this is the MOST important part of removing them.

you gently but firmly tap it until you see the collets/retainer start to rotate

i used a allen key/screw driver in the spark plug socket to prevent the valves from falling in and i removed my brake booster. was fairly easy to do on the car as the v8's arnt as wide as the v6's (well i dont think so anyway)
make sure u do the valve stem seals, even tho its a stupid little ring on the v8's but most of them are gone... the v8's rely on the valve guides not being worn

when replacing valve springs be careful in your spring choice, i had to purchase collets to give me 50thou more to prevent spring bind, if you stuff it up you can bash the lobes on your cam,

apparently holden went spastic on the v8's so the only way to be sure is to measure it with a inside micrometer, i think they'res 43mm 44mm or 45mm

this is something to keep in mind..