Changing valve springs with head on block

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Taz

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So ive been doing a little diggin on google/youtube and the general consensus is that it is possible to do the valve springs with the head on block in the car etc.
I need to do the springs/retainers upgrade but want to avoid taking the head off if possible. Aside from the obvious, and the tool required, are there any tips/anything to look out for before i attempt this? The only concern i have is keeping the valve in place.
A handy method ive watched is putting some bungy rope or something similar into the spark plug hole, and winding the cylinder up so its packed with said rope so the valve cant go anywhere. Then its simply changing them out. Never done valves before in a car so i have no idea if this is a good idea or there is a better way. Also being a 63t, is there anything else that i need to look out for specifically for this motor? looks like any other straight forward job albeit with 3/5ths of fuck all room, but looks straightfoward otherwise if the valve issue is sussed.
 
Taz said:
A handy method ive watched is putting some bungy rope or something similar into the spark plug hole, and winding the cylinder up so its packed with said rope so the valve cant go anywhere. Then its simply changing them out. Never done valves before in a car so i have no idea if this is a good idea or there is a better way. Also being a 63t, is there anything else that i need to look out for specifically for this motor? looks like any other straight forward job albeit with 3/5ths of fuck all room, but looks straightfoward otherwise if the valve issue is sussed.
Taz mate as an engine conditioner I would attempt it if it was the only option, But..... it is a hell of a lot easier to do it with the head off. I personally would remove the head primarily to make sure I have a MLS/Copper new head gasket in place. Also the STD valves bend easy, & the only way you will find out is after you start it. My 2c worth... remove the head.

Cheers
 
Im only really being a tightass here. i have receipts for new MLS but cracking the head would mean another headgasket, id be doing oversize valves while its off, and tbh ive had nothing but trouble with MLS gaskets and are not a fan of them so disturbing a sealing one and going through that again isnt too appealing to me. If its pretty dodgy to do them with head on though that is the opposite of what this engine build is about - being meticulous in every pain staking detail so might just bite the bullet
 
you can use the fittings from a leak down tester and pressurise the cylinder. care needs to be taken as its possible to overcome the pressure and the valves might drop anyway. they usually don't drop in the cylinder as the valves only move 10mm or so, so past that they generally get a bit sticky on the valve stem seal.
 
I think i might price up a few things before i decide. If im taking the head off it will be done so i wont be taking it off again unless something goes horribly wrong, so id be inclined to be doing valves, seals, springs retainers even porting would be on the cards so it gets done now (which means buying manifolds etc so id be up for 2k+)
 
It is possible and you can buy the tool to do it. I'd fill the cylinder with rope and also pressurise the cylinder with either a leak down kit or get a screw in compression tester, take the hose off, connect it to your compressor and use the regulator to control the pressure. Then button down the tool and away you. Patience is key.
 
Hi Taz, I've done them with the engine in the car before, it's a little painful painful but not overly problematic, also have the tools for it. I also vastly prefer taking the head off, and if you're going to do oversize valves etc then you'll also want to be redoing seats etc. Give me a yell if you need some help, my workshop is in Rocklea. The disadvantage of putting new springs in the head with it in the car is it's more difficult checking installed height for new springs. There's nothing wrong with proper quality MLS headgaskets btw, you just need to make sure the correct processes are done when installing one. I've reused them without dramas also.
 
I changed my steam seals on m rvr with a use of rope and spring compresor that I've modified to suit 4g63 setup.
Easy done if you take care. Once you compress spring you know if rope is holding the valve
I could take a picture of that compressor for you if you want.
 

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