valve seals, without head removal?

[Stace]

Can the valve seals be replaced without removing the head from the block?(DOHC)

I know it can be done once the cams are off, I guess my real question, is.. can the cams be removed without taking the timingchain cover off?

I read somewhere?? that Saturn has a tool for removing timing chain and sprokets from the cams with the chain cover on, so the cams can be replaced without removing the engine from the bay.

Is this just an alignment tool to hold the sprokets tight?

And once I pull my sprokets off the cams,..remove my cams, lifters and springs,.. I am assuming the seals come right out, like the haynes book says'

right? Does anyone understand or been thru this?

THe guy I bought this head(engine) from , said it was rebiult..the head, not the engine. I assume that would mean new seals,
It looks clean and tight, like a rebiult. But the engine it came on, spit all the oil out at full throttle, so the seals might not have been replaced..or replaced wrong, or the piston rings were shot.

if I put it on the new engine and find out that it has bad seals, I really dont want to have to rip the whole dam engine apart again!

[SupraCharged007]

yes. Make a fixture to hold the cam gears in place, take the cams out. attach an air line to the head via the spark plug holes. pressurize the cylinder you are working on. Remove the valve spring and then the seal. then just put everything back in reverse of removal


This is not easy. It's prolly much easier to just pull the head off if you dont have some specialised tools. like a valve spring compressor(not the big c-clamp style) and a fixture to hold the sprockets on good while you are working.

[TimT]

You'll also want to bring the piston up to top dead center before you remove the springs. An old school trick if you don't have an air compressor is to take some string and shove it down the spark plug hole when the piston is a few degrees before top dead center. When you cann't get any more string in the cylinder turn the crank a little to "pack" the string up tight against the combustion chamber. Change out the seals and just turn the crank in the opposite direction to release the presure on the string. Then just pull the string out and go to the next cylinder.

Peace
Tim

[ArghIGiveUp]

The string works better than the compressed air, let me tell you. About 1.5' of cheap 1/4" nylon works beautifully.

I managed to drop a valve once while using compressed air. That sucked a lot. Nothing ruins your day like knowing you have to come back to work the next day and tear a head off because you were retarded and managed to drop a valve.

[Stace]

So the fixure that hold the cam gears, holds them in place so I dont loose tension on the chain tensioner right?

And once I pull back the gears, wont they fall off the chain guides?

[SupraCharged007]

pretty much, but you dont move the gears any. You just attach the fixture, I think jeff has an example on his site some where .... http://www.differentracing.com. and it holds the gears in place so that you can remove the cams.