Head tech question

[viperdoctor]

How hard is it to check/replace the valve stem seals/guides?

Can they be checked and, if necessary, replaced without removing the head itself, just the valve covers?

Thanks!

 

[Greg Good Cylinder Heads]

The seals can be changed without removing the heads. You have to air up the cylinder, pull the spring, and change the seal. But I'm curious why you want to know. I have yet to see a set of Viper valve stem seals fail.

To replace the valve guides the heads must come off and go to a machine shop to get this done. A valve job must also be performed on the heads after guide replacement.

And this is totally optional, but you'd be crazy not to port the heads while they're off.

 

[viperdoctor]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by GregGood/TNT:
The seals can be changed without removing the heads. You have to air up the cylinder, pull the spring, and change the seal. But I'm curious why you want to know. I have yet to see a set of Viper valve stem seals fail.

To replace the valve guides the heads must come off and go to a machine shop to get this done. A valve job must also be performed on the heads after guide replacement.

And this is totally optional, but you'd be crazy not to port the heads while they're off.

<HR></BLOCKQUOTE>
http://vca1.viperclub.org/ubb/Forum14/HTML/006500.html

That's why. It's still a problem and I need to have it fixed. But I don't want my engine pulled. That could stir up all sorts of problems like electrical, a/c, etc... As a result, I would even consider replace/installing the seals myself if Dodge insists that engine be pulled and the work is not too hard.

Can you just put the cylinder at top dead center to keep the valves from falling in while you replace the seals?

Do you need a special tool to remove/replace the seals?

I am pretty sure it's not a guide problem, and I wouldn't go down that route on my own...

Thanks!

 

[1TONY1]

I have seen some engines with compression pistons that the valve would kiss soon enough to break down the valve spring. Not sure about the v10.....Greg???

 

[Greg Good Cylinder Heads]

Wow, those plugs were gnarly! Definitely looks like deposits from an oiling valve guide.

I have to agree with some of the guys on your other thread that you may not have valve seals on that one head. Like you, I doubt the guides are bad.


The seals simply snap onto the valve guide by hand. No special tools needed. The old ones come off using a pair of pliers. You might be able to get by without airing up the cylinder but think it would be better to.

In my opinion the first thing to do once the covers and rockers are off is to(with the piston down in the bore)take a small hammer and give the retainer a light rap on the edge of it to break it loose from the locks. Viper retainers are usually very hard to break loose (caused by valve float). If you try to compress the spring with the piston at TDC and the valve follows the retainer down it could hit the piston and bend a valve. Break the retainer/lock fit loose, then bring the piston to TDC and finish removing the spring with the tool. After that it's a cinch.

 

[Greg Good Cylinder Heads]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 1TONY1:
I have seen some engines with compression pistons that the valve would kiss soon enough to break down the valve spring. Not sure about the v10.....Greg???

<HR></BLOCKQUOTE>

Tony, you never want to force the valve into the piston as when breaking the retainer loose while changing valve springs. This is especially true for an engine with 5/16" valve stems like a Viper that are easy to bend.

 

[HP]

Even though most of the concerns have been mentioned, I see
a few things that can be added. First, compressing the cylinder, can be easily accomplished with a cheap screw in
compression tester and a portable air tank - just follow the
instructions in the Viper manual. It can be accomplished without compressing the cylinders bearing in mind - the cautions posted. Points to remember - the pistons just have to be up far enough to not let the valves fall into the cylinders- best if the valve groove stays above the valve guide(but if the top of the valve stem falls below that point, it can be pulled up with a magnet. As you begin spring compression, watch the keepers, and pop the top valve spring collar with a rubber mallet as the tension is relieved(wear protective glasses for obvious reasons). Unless the valve assembly is in a bind, there should not be enough pressure to damage the valve- in the case it touches the piston, but if you're concerned, feed
a foot of rope into the spark plug opening. Anyone who's tackled this job, has their own angle on how this should be done; this is just an insight into some of my experiences. Use Loctite-Green (or recommended sealer) on the valve seals, to prevent oil from being sucked under the seals, and keep the parts organized, so they can be put back in the same order.
If it was my car(and under warrenty), I would insist the head
be removed, so the chamber, and valves, could be cleaned - The crude inside the chamber must be awful. ------------
Hugh Perkins
96 RT Black/Blue Stripes

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by HP on 10-28-2002 at 10:33 PM</font>

 

[viperdoctor]

Many thanks for the replies! Lots of good information to digest.