Remove heads for valvespring change?
Thread Starter
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Remove heads for valvespring change?
Or should I leave them on? I really don't want to break that seal. On the other hand, if I need to do some height checking and shimming it would be better to have off...or would it? Any way to do all this with heads on the car?
Brett
BTW, I don't have a air compressor.
Brett
BTW, I don't have a air compressor.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
It depends on whether or not your changing camshafts. A taller lift cam may possibly require checking the valve guide to retainer clearances to avoid wiping out the lobes of the cam if the heads have never been previously subjected to a different cam. Best way, pull the heads and do it correctly if you want the new set up to last. There are many complaints in other threads that some camshafts wear out faster than others. The probable true reason is that they were never installed correctly.
Instructor
Joined: Jul 2003
Posts: 172
Likes: 0
From: Richmond Virginia
Valve springs
It is easier to do on the car, Are you replacing the springs with stock springs or?. However to do them on the car you will need an air compressor and a fitting to fit the spark plug hole. Plus a spring tool to push the retainer down. Without the compressor you will have to pull the heads.
Instructor
Joined: Dec 2002
Posts: 242
Likes: 0
From: Port Orchard Washington
Originally Posted by Brettmc
Or should I leave them on? I really don't want to break that seal. On the other hand, if I need to do some height checking and shimming it would be better to have off...or would it? Any way to do all this with heads on the car?
Brett
BTW, I don't have a air compressor.
Brett
BTW, I don't have a air compressor.
Good luck.
Thread Starter
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Originally Posted by Ironcross
It depends on whether or not your changing camshafts. A taller lift cam may possibly require checking the valve guide to retainer clearances to avoid wiping out the lobes of the cam if the heads have never been previously subjected to a different cam. Best way, pull the heads and do it correctly if you want the new set up to last. There are many complaints in other threads that some camshafts wear out faster than others. The probable true reason is that they were never installed correctly.
The only reason I don't want to take the heads off is the hassle of torqueing them back on. Why go thru that if it's not needed and if I can fit the springs with the heads on the car?
Brett
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
If you have a partner, you can just hold up each valve with a screwdriver through the spark plug hole. by the way, the lever-type spring compressor is wayyy better than the "arms and screw" type (sorry description)
Good luck
Edit: also, a magnet helps when removing the retainers
Good luck
Edit: also, a magnet helps when removing the retainers
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Originally Posted by Brettmc
That's the reason for the spring change, a cam swap. Going with a Comp XS274S or XS282S, both solids. Going to buy the complete cam kit so I'll have to install the springs, locks, seals, retainers from the kit.
The only reason I don't want to take the heads off is the hassle of torqueing them back on. Why go thru that if it's not needed and if I can fit the springs with the heads on the car?
Brett
The only reason I don't want to take the heads off is the hassle of torqueing them back on. Why go thru that if it's not needed and if I can fit the springs with the heads on the car?
Brett
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Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
If you still decide to do it in the car, this is how you use the rope to hold the valves:
Remove rocker arms and spark plugs. Bring the piston to about 30-45 degrees BTDC. Stuff as much clothesline or 3/8 rope in as you can into the plug hole. Then by hand, rotate the motor towards TDC until it stops. The rope will keep the valves from dropping into the cylinder. I also agree the lever type spring compressors are way easier to use. Just reverse the rotation to get the rope out. It helps to follow the firing order when using this method.
Joe
Remove rocker arms and spark plugs. Bring the piston to about 30-45 degrees BTDC. Stuff as much clothesline or 3/8 rope in as you can into the plug hole. Then by hand, rotate the motor towards TDC until it stops. The rope will keep the valves from dropping into the cylinder. I also agree the lever type spring compressors are way easier to use. Just reverse the rotation to get the rope out. It helps to follow the firing order when using this method.
Joe
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Originally Posted by tom102
It is easier to do on the car, Are you replacing the springs with stock springs or?. However to do them on the car you will need an air compressor and a fitting to fit the spark plug hole. Plus a spring tool to push the retainer down. Without the compressor you will have to pull the heads.
I have done them on and off the car and I find them easier to do on the car. If it is just a spring change and you have a compressor for holding up the valve then it is easy.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Originally Posted by Brettmc
How do I check the valvespring install height, coil bind, etc, with the heads on the car?
Brett
Brett