Valve Guides
Thread Starter
Burning Brakes
Joined: Aug 2009
Posts: 1,037
Likes: 103
From: Brisbane Queensland
Valve Guides
G'day All,
Got a question which has me totally puzzled. I have recently pulled
the heads off my 350 l46 and discovered that one of the valve guides
had the top of the guide had been totally broken off prior to the motor
being put together. This however was not creating any known
problems. Subsequently I had the guide replaced and am now in the
process of putting the heads back together.
The problem I have is in identifying the guides that are in the heads as
they are not std and are creating some headaches trying to find the
correct stem seals to fit these odd valve guides. the OD. of the valve
guide is 0.566in as opposed to the std guide OD. 0.5in.
I have included a photo of the 2 different guides side by side. If you
can identify the non std guide can you let me know so I can source
replacement stem seals. I am wanting to use Viton cup style seals in
rather than the std o'ring style.
Thanks for any help you can provide.
Mark
<a href="http://s1185.photobucket.com/user/m_fry35/media/Valve%20Guides_zpsyik9zcfb.jpg.html" target="_blank"><img src="http://i1185.photobucket.com/albums/z355/m_fry35/Valve%20Guides_zpsyik9zcfb.jpg" border="0" alt=" photo Valve Guides_zpsyik9zcfb.jpg"/></a>
Got a question which has me totally puzzled. I have recently pulled
the heads off my 350 l46 and discovered that one of the valve guides
had the top of the guide had been totally broken off prior to the motor
being put together. This however was not creating any known
problems. Subsequently I had the guide replaced and am now in the
process of putting the heads back together.
The problem I have is in identifying the guides that are in the heads as
they are not std and are creating some headaches trying to find the
correct stem seals to fit these odd valve guides. the OD. of the valve
guide is 0.566in as opposed to the std guide OD. 0.5in.
I have included a photo of the 2 different guides side by side. If you
can identify the non std guide can you let me know so I can source
replacement stem seals. I am wanting to use Viton cup style seals in
rather than the std o'ring style.
Thanks for any help you can provide.
Mark
<a href="http://s1185.photobucket.com/user/m_fry35/media/Valve%20Guides_zpsyik9zcfb.jpg.html" target="_blank"><img src="http://i1185.photobucket.com/albums/z355/m_fry35/Valve%20Guides_zpsyik9zcfb.jpg" border="0" alt=" photo Valve Guides_zpsyik9zcfb.jpg"/></a>
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
The Viton "umbrella" style seals should work just fine because they have a very large I.D.
But quite frankly the very best seals are the snap ring style because they are a positive seal that grips the valve guide AND the valve stem. Viton seals will harden and break in as little as 25,000 miles so I quit using them many years ago. Umbrella seals are also available in nylon and they are the best of the umbrella seals but I haven't seen them for a while. Your local automotive machine shop should be able to supply any style of seal you want.
But quite frankly the very best seals are the snap ring style because they are a positive seal that grips the valve guide AND the valve stem. Viton seals will harden and break in as little as 25,000 miles so I quit using them many years ago. Umbrella seals are also available in nylon and they are the best of the umbrella seals but I haven't seen them for a while. Your local automotive machine shop should be able to supply any style of seal you want.
Thread Starter
Burning Brakes
Joined: Aug 2009
Posts: 1,037
Likes: 103
From: Brisbane Queensland
Hey guys, thanks for the reply's. Zwede that would not surprise me one little bit, however
the Viton "umbrella" type seals that we removed from the heads were placed over the
valve guides as you see them.
the Viton "umbrella" type seals that we removed from the heads were placed over the
valve guides as you see them.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
It looks like the guide casting bosses have been milled away. The casting boss is what most PC type seals are fastened to. I've never heard of using just the guide insert itself for performance vlv seals. I think umbrella seals are your only choise now as they ride on the vlv stem. Hope your running single vlv springs as the umbrella seals have been known to get cut by even the vlv spring dampners inside the spring. What I'm saying is keep an eye on your umbrella seals with regular checks.
Good luck.
Good luck.
Burning Brakes
Joined: Feb 2005
Posts: 894
Likes: 91
If you are going to use a "positive" type stem seal you will need to have the the other 15 guides machined to accept the .500" size seals.
That guide that was installed is a .502" diameter, the hole they machined was done by a .500" reamer.
Thanks, Gary in N.Y.
P.S. The "positive" seal made for the .500" guide will fit "as-is" (on that single guide) without any add'l machining, BUT we would machine all 16 to make the tops proper/even for the seals.
That guide that was installed is a .502" diameter, the hole they machined was done by a .500" reamer.
Thanks, Gary in N.Y.
P.S. The "positive" seal made for the .500" guide will fit "as-is" (on that single guide) without any add'l machining, BUT we would machine all 16 to make the tops proper/even for the seals.
