Valve cover replacement

[Guest ckamin]

I haven't done this in a while, so I am going to seek some Guzzi advice.....

 

When I used to have my valve covers on/off on all of my old Chevy V8's, a little silicon (Permatex) on the cork gaskets was great and they never leaked. Any advice on what to use (if anything) on my Guzzi valve covers? The gaskets look to be the paper type.

 

Thanks in advanced and happy new year!!

 

-Carl

[Guest ratchethack]

Carl, this one seems to be another one of those "religious" topics, and I've been burned at the stake a coupla times for my opinion on this one, too. *sigh* I reckon any effective, well-proven technique is just gonna take a lot of heat from those who do it another way. The one requirement that seems mandatory for some to oppose a technique that's different than their own to the last drop of their blood is that they've never tried it. Many kinds of sealants work, and even puttin' 'em on dry works, but I'm with you on silicone sealant. I've rebuilt more engines than I can remember and I've used many kinds of sealants (still do). For valve and cam covers, I've found that using a very THIN application of silicone (just enough to permeate the surface) on both sides of gaskets works the best. If you get ALL the oil and crud off the mating surfaces with a good solvent and apply silicone to the gasket between your fingertips - just enough to make the gasket shiny - no "bathtub caulk" beads!!!!! It'll give you a weep-proof, seep-proof seal. The best thing about this is that your next job is made so much easier. Silicone zips off instantly without scraping, and even paper gaskets can be easily removed without breaking, cleaned-up, and re-used many times.

[Guest ckamin]

Thanks for the reply. That was essentially the same technique I had used on all of the musclevars I had- I very thin bit of silicon on both sides prevented any weeps/leaks and made later removal easier. I have heard other arguments for other techniques but I figured "if it works for me..." Obviously, too much silicon could be a problem if some squeezed into the inners of the engine and then came loose, bu thats why ya need to be conservative with the amount applied.

 

Thanks for the affirmation of what I had kinda thought.

 

-Carl

[Guest ratchethack]

Obviously, too much silicon could be a problem if some squeezed into the inners of the engine and then came loose, bu thats why ya need to be conservative with the amount applied.

Yeah, I've heard the rumors of the dreaded "silicone sump worms", plugged oil galleries, and torched big-end and main bearings. But this must only happen in the land of The Neanderthal Bathtub Caulkers, 'cause I've never experienced anything like it. Matter of fact - I've never even heard of a single actual case - though I'm SURE they exist!!!

 

EDIT: I can remember seeing some absolutely AMAZING "bathtub caulk" jobs on the OUTSIDE of a few japper motors - .....things that make ya wanna go,

[jrt]

I've never had a leak with valve covers and I use just a bit of oil on them. Although- there are a couple of other options than silicone.

*There are some 'extra thick' valve covers that have been mentioned here. I don't remember the source off-hand (MGCycle maybe?), but I'm sure someone does.

*I'm a huge fan now of permatex hylomar. It's non-hardening and seals tighter'n a .... Seriously- it works great.

I've never had a lot of luck with silicone- I probably use too much and it's a pain to clean off the metal and I tend to break gaskets when I do use it.

But that's just me.

[jrt]

Neanderthal bathtub caulkers

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Ratchet, you seem to have ongoing issues with bathtub caulk. Does someone need a hug?

[Guest ckamin]

I think you are giving neanderthals too much credit. There are enough humans with the iq of a dead hamster that actually pose as mechanics ("I'm not a mechanic, I just play one at work") that are still out there.

 

Which reminds me about the time I took my Harley to an actual Harley dealer for it's first break-in service and they forgot to change the oil.........

 

-Carl

[Guest ratchethack]

Ratchet, you seem to have ongoing issues with bathtub caulk.  Does someone need a hug?

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Well, I'm sure there's a Neanderthal Bathtub Caulker somewhere who could use a hug, if y'er so inclined...

[Guest trispeed]

I've had good luck using Yamabond ( or other non-hardening gasket sealer) next to the cover and a small amount of grease on the head side. No worries re: the silicone syndrome and the gasket stays with the valve cover when you remove it.

[Greg Field]

On my own bikes, I grease them well with normal grease and just snug down the screws. Never had a leaker, and I can re-use the same gaskets for 10 years or so 'til they finally tear and have to be replaced.

 

On customer bikes, I use new gaskets and grease them. Never had a leaker. Why replace them everytime, then? The bastards complain if I don't! I'm not kidding, either.

[dlaing]

On my own bikes, I grease them well with normal grease and just snug down the screws. Never had a leaker, and I can re-use the same gaskets for 10 years or so 'til they finally tear and have to be replaced.

 

On customer bikes, I use new gaskets and grease them. Never had a leaker. Why replace them everytime, then? The bastards complain if I don't! I'm not kidding, either.

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I should give that a try.

I have used the engine oil method and usually only get about 3 valve adjustment, before leaking starts and then I have to torque down pretty tight till I can buy some more.

 

I also tried the silicone gaskets from RealGaskets.com, but they got crushed by apparently too much torque on the screws. If I get his silicone gaskets again, I'll use lock washers and torque it a little less.

 

I have also tried siliconing to the valve cover and oiling the side to the head.

This seems to work just a little better than the oil each side method, but I am usually too lazy to bother...

 

Maybe next time, I'll try grease one side and silicone(or yamahabond(thanks trispeed)) the other and use lockwasher so I don't over tighten the gasket.

Greg, what type of grease do you use?

Has anyone tried silicone grease on the gaskets?

[Greg Field]

I use just whatever grease is closest at the time.

 

Leaks from the access plug for the inboard cylinder studd are 100 times more common than valve-cover gasket leaks, in my experience.

[Guest ratchethack]

Leaks from the access plug for the inboard cylinder studd are 100 times more common than valve-cover gasket leaks, in my experience.

Greg, the O-ring under the access plug must be the culprit, but it's internal to the rocker box. So how can you tell when it's leaking?

[Guest trispeed]

The Yamabond ( and other similar) works great as there is no 'dry' time. Just lay a thin bead, pop the cover on and you're ready to go right away. Standard wheel bearing grease in the big plastic tub is all you need for the other side.

This is a proven method with the really cheap, really thin japanese paper gaskets ( old school 70's and 80's era) that get brittle after heating up. They are designed to be replaced everytime and you can get several uses with this technique. Some of these gaskets are $50 and up, so it's quite worthwhile. The guzzi gaskets are twice as thick, by comparison and should last a very long time this way. You don't need much torque, either.

[Greg Field]

There's a tunnel between the inboard side of the head and the plug side. If that o-ring weeps, the oil leaks down the tunnel to the plug side of th head and gets blown back and on your knees or throttle bodies. It often looks like it's coming from the rocker cover.