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Are regular valve seals and umbrella seals interchangeable?
The 350 in my truck is leaking oil into the cylinders through the valve seals I'm assuming (rather hoping it's not the rings!). I hear that umbrella seals are better than the original valve seals but to be honest I'm really inexperienced when it comes to cylinder heads. I'd like to know what would be the best option to seal the valves from the top. I read about the compressed air to keep the valves up during the seal change, so I think that would be a fairly easy thing to do. Also, If i have to take it to a mechanic to have it done, would it be cheaper to have him replace the seals, or rather, purchase some new heads? Any info would be greatly appreciated, thanks!
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Re: Are regular valve seals and umbrella seals interchangeable?
I installed a set on a small block that was leaky (valve seals). I just slid them on the valve stems. They don't replace the seals you have they just help keep oil from leaking down the stem into the cylinder. They worked well.
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Re: Are regular valve seals and umbrella seals interchangeable?
So, if i understand you correctly, i would need valve seals, in conjunction with umbrella seals? I'm assuming an umbrella seal would then, act just as an umbrella and have the oil roll off of it, away from the seals?
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Re: Are regular valve seals and umbrella seals interchangeable?
I am a machinist and am very familiar with this. Being the '67-'72 section ... the stock seals on your 350 are O rings which fit inside the spring retainer. That in conjunction with the sheet metal oil shredder on top of the spring act as an umbrella. You can take the retainers off as you suggested and install rubber umbrellas inside the springs. Now that is IF your valve guides have been machined to accept them. Otherwise you will have to remove the heads & pay a machinist to cut the outside diameter down. Cost and your budget depending of course. Then there are positive locking seals which fit tightly on the valve guide and do not ride up & down with the valve like the umbrella does.
Here is a pic. A= Positive locking, B and C = umbrella (soft & hard), and then an O ring which fit into a groove on the valve stem and inside the retainer cap. http://image.carcraft.com/f/28275298...alve_seals.jpg |
Re: Are regular valve seals and umbrella seals interchangeable?
I'm new to this issue and you helped me.
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Found out my head are off a '78. Junk smog heads to be replaced with aftermarket on the spring Anyway. The previous only only put the o ring seals on which basically did nothing Did mine with heads on the truck with compressed air in cylinder and spring compressor. 12 pack and a buddy and they were done in an evening I'm certainly no engine builder by any means and found it an pretty easy project. Set valve lash and zero oil burn since I used gel pro seals Posted via Mobile Device |
Re: Are regular valve seals and umbrella seals interchangeable?
Which style did you install? Did you have to modify head to get them to fit?
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Re: Are regular valve seals and umbrella seals interchangeable?
Back in the early 70s, ( when I was young,) I used Ford 260 c.i. valve seals on my sbc which were umbrella style, worked well since they were cheap and I couldn't afford to have valve guide work...
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Re: Are regular valve seals and umbrella seals interchangeable?
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FYI The intake and exhaust umbrella seals are different It's a pretty easy job and heads don't need to be pulled. |
Re: Are regular valve seals and umbrella seals interchangeable?
I did one umbrella seal on 1 valve only....lol and no I'm not kidding.
A couple of years ago you might recall I lost compression in my No. 7 cylinder (the one at the back nearest the driver). I thought I had burnt and exhaust valve but in actual fact the spring had broken and slightly set the valve open...so no compression. I used the 'soft cord' approach where you slowly fill/thread the cylinder up with some soft cord then move the piston upwards...thus forcing the fill of cord up against the bottom of the valves...keeping it/them up. Oh, don't forget to keep some of the cord outside the cylinder so you pull it out afterwards, lol:lol: Then I used an overhead spring compressor to clamp/set the new spring and voila'...the new spring was on as well as a single new umbrella seal. It all did the trick...at least on that cylinder. Trouble is, some of the other valves suffer from oil leak down so I burn some oil on start up....so maybe I would be well suited to add the umbrella seals to all the remaining valves. To my understanding it only really works on the exhaust valves....correct me if I'm wrong. All good Coley |
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