replacing valve seals
Pro
Joined: Jun 2001
Posts: 520
Likes: 6
From: Elverson PA
Jim,
I have to do this too. I don't think it is that bad of a job. I don't have a step by step write up, but here are the basics. You just need the hose from a compression check guage that hooks to your air compressor. Some gauges have the same fitting as air tools. This will hold your valves up while you work on them. You also need a spring compressor that screws onto the heads to remove springs w/o pushing valves into the head. From there it should be cake, but I don't know yet b/c I have not done it. My car smokes on startup for a sec though, so I know I am due.
I just want to buy some roller rockers and springs before I go in there, but then I should upgrade the 3/8 studs to 7/16. Seems like everyone says the old 3/8 studs are just pressed in and pull out when you use good springs. Then you need hardened pushrods and guideplates. This is why I haven't changed my valve seals yet.
Oh yea, and since I have the old cast iron heads, it probably isn't even worth doing all that when you can just go buy some preassembled afr heads.
In other words, it doesn't seem like big job to do the seals if that is all you want to do. I would refer to the factory service manual for exact steps and torques for removing and reassembling the valvetrain. Good luck.
Dave
I have to do this too. I don't think it is that bad of a job. I don't have a step by step write up, but here are the basics. You just need the hose from a compression check guage that hooks to your air compressor. Some gauges have the same fitting as air tools. This will hold your valves up while you work on them. You also need a spring compressor that screws onto the heads to remove springs w/o pushing valves into the head. From there it should be cake, but I don't know yet b/c I have not done it. My car smokes on startup for a sec though, so I know I am due.
I just want to buy some roller rockers and springs before I go in there, but then I should upgrade the 3/8 studs to 7/16. Seems like everyone says the old 3/8 studs are just pressed in and pull out when you use good springs. Then you need hardened pushrods and guideplates. This is why I haven't changed my valve seals yet.
Oh yea, and since I have the old cast iron heads, it probably isn't even worth doing all that when you can just go buy some preassembled afr heads. In other words, it doesn't seem like big job to do the seals if that is all you want to do. I would refer to the factory service manual for exact steps and torques for removing and reassembling the valvetrain. Good luck.
Dave
Team Owner
Joined: Jan 2003
Posts: 20,320
Likes: 248
From: Summerland B.C. Canada
Pro
Joined: Jun 2001
Posts: 520
Likes: 6
From: Elverson PA
There we go. That is a nice writeup. One thing I read here on the forum is to use all intake seals instead of 8 intake and 8 exhaust. The intake ones are supposed to hold up fine and be way better.
Dave
Dave
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Your Al heads will have the same valve seals for int & exh; I got a full set from my local Chevy dealer to avoid any fitment issues. Also buy a set of new machined keepers.
Add to that tool list a tele magnet for removing the keepers; it will be handy on future jobs for retrieving "lost" metal parts from their hiding places.
If you don't have compressed air you can use the "rope trick" to hold up the valves as you do each cylinder. In any case it's a good idea to turn each piston to TDC on the compresson stroke to prevent dropping a valve, even with compressed air in case of a leak. This will also make setting valve lash easier as both lifters will then be on the base circle of the cam.
Add to that tool list a tele magnet for removing the keepers; it will be handy on future jobs for retrieving "lost" metal parts from their hiding places.
If you don't have compressed air you can use the "rope trick" to hold up the valves as you do each cylinder. In any case it's a good idea to turn each piston to TDC on the compresson stroke to prevent dropping a valve, even with compressed air in case of a leak. This will also make setting valve lash easier as both lifters will then be on the base circle of the cam.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
Originally Posted by black85
I have to do this too.
if your car ''puffs'' a little blue fart on start-up, and trails a blue haze when going down long hills with your foot off the pedal, new seals may help some but more likely your ''guides'' are worn in the heads....yank the heads , have em freshened (new bronze guides, three angle valve seats, back-cut the valves, resurfaced with malice) and you will be amazed at how much stronger your car runs and even starts better...and your present heads have been ''stabilized'' by numerous heat cycles, will out-last the aftermarket ones.
Pro
Joined: Jun 2001
Posts: 520
Likes: 6
From: Elverson PA
redrose-
Thanks I like the way you think! I probably will just pull the heads off. I don't mind spending a few nights with a die grinder and beer porting them out some either. My car doesn't smoke when driving that I know of. It did a little bit on my first pass at the drag strip a couple weeks ago, but it was a really cool night and a cold car. No smoke on second pass. In any case, I'm sure the guides could stand replacement.
Another realistic option for me is a set of 113 AL stock castings. I know where some are for $400. Of course they need everything my heads would need, because they are from a Corvette salvage yard. Losing 50 lbs on the front end is attractive. And they would be easier for me to port!
Dave
Thanks I like the way you think! I probably will just pull the heads off. I don't mind spending a few nights with a die grinder and beer porting them out some either. My car doesn't smoke when driving that I know of. It did a little bit on my first pass at the drag strip a couple weeks ago, but it was a really cool night and a cold car. No smoke on second pass. In any case, I'm sure the guides could stand replacement.
Another realistic option for me is a set of 113 AL stock castings. I know where some are for $400. Of course they need everything my heads would need, because they are from a Corvette salvage yard. Losing 50 lbs on the front end is attractive. And they would be easier for me to port!
Dave
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
$400 should get a good used set that won't need another $400 in rework, but don't just grab em cause you can carry one in each hand...buying a set of run-out heads and fixing those may get so close to new ones that its not a bargain.
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