Rocker Shaft & Valves

[Peter Douglas Winn]

Colin yes the one at the back end to the pedestal. I know it should be tight. Mine was!!! In spite of that it loosened and caused the damage and cost in the end a hell of a lot of money. Is there any reason not to locktight this screw? My experience with locktight was when unscrewing give it a jerk to break the seal, then the screw comes out. Locktight has a very low torsional strength

[Mike C]

" when unscrewing give it a jerk to break the seal" - that's Blue Loctite 242, the Red Loctite 271 will need an oxy or gas torch to loosen

[c.hydes]

18 minutes ago, Peter Douglas Winn said:

Colin yes the one at the back end to the pedestal. I know it should be tight. Mine was!!! In spite of that it loosened and caused the damage and cost in the end a hell of a lot of money. Is there any reason not to locktight this screw? My experience with locktight was when unscrewing give it a jerk to break the seal, then the screw comes out. Locktight has a very low torsional strength

I did think about Loctite. Think I might take of the cover and do this. I have loctite 638 and 648 which are both "high strength retainers" (green),which should do the job and would probably be removable if needs be. I dont think that the "nutlock" would be man enough. What do you think?

Colin.

[Peter Douglas Winn]

I have never used this high strength locktight so I must accept the experts comments. Has anybody else got an idea how to keep this screw in place. As it is countersunk you cannot use a spring washer.

[c.hydes]

23 hours ago, Peter Douglas Winn said:

I have never used this high strength locktight so I must accept the experts comments. Has anybody else got an idea how to keep this screw in place. As it is countersunk you cannot use a spring washer.

Peter I have tried Loctite 238 High Strength (green) on a sample bolt and is far too strong for this application, impossible to remove even with huge spanners. As Mike previously stated would need serious heat to remove.

I have found some Loctite 222 which is a "threadlocker" and is removable with hand tools, and ideal for the job and still locks the threads for retention. Also good for aluminium, oils etc.

Thanks for all the tips.

Regards, Colin.

[Waldi]

As a result of contributing and following this thread....I have put dismantling/opening/ cleaning my rocker shaft on my winter list. During the recent rebuild I found a “very good used one”, cleaned it with solvent and compressed air, but without removing the plugs. Think I can do better than that.

Cheers,
Waldi

[Peter Douglas Winn]

To be honest I did not know there were that many types Loctite. Apology for the bad spelling of Loctite.