Graphogen and Hylomar?

[TurboFource]

In the Wilkins Twin Cam book he references the use of Graphogen and Hylomar quite often.
They are a little pricey but I am planning to use them I think…..thoughts? Alternatives?

[BDA]

I have some experience with Hylomar but not a whole lot. I used to use it for the end cover of the transaxle of my race car. It sealed well and the parts came apart easily. More recently I used it on the joint between the cam carrier and the head (I have a different engine than you). I used it there because it is thinner than silicone and if the cam carrier sits higher on the head, it affects valve lash. This is really a way over abundance of caution. It seems to be sealing there well as well.

In spite of its stellar reputation I haven’t used it for general sealing. I suppose that’s because it’s quicker and easier to get silicone at the local parts store.

Something else to think about is that some synthetic oils are apparently difficult to seal. Red Line seems to be one of them. If you can get to this link you can read of the exploits of a guy trying to seal his twin cam. He may have very high standards for sealing oil leaks and I don’t know if his is a racing or street engine. (https://vintagetechnologygarage.groups.io/g/cars/topic/pesky_oil_leak_on_my_1966/85702351?p=,,,20,0,0,0::recentpostdate/sticky,,,20,2,0,85702351,previd%3D9223372036854775807,nextid%3D1616713550095859132&previd=9223372036854775807&nextid=1616713550095859132).

[jbcollier]

Cams and cam followers need to break in quickly and properly, especially with splash lubricated engines.  I rev the engine up to 2500 rpm and hold it there for 5 minutes.  Without proper lubrication, the cams and followers will be damaged instead of broken in.  You use a graphite/moly heavy lube to make sure.  Some people use it on EVERYTHING.  But I prefer to use it on cams and splash lubricated surfaces only and pre-pressurize the oil system before start up.

The TC engine's cam and followers are not splash lubricated, you can, and should, pour oil in their wells before fitting the valve cover.  I would still coat the valve lobes with assembly lube though.

Hylomar is an excellent, non-hardening, sealer.  Another good one is Permatex Aviation Gasket Maker #3.  I use both and am happy with both.

Silicone sealers need to be "oil-proof" and used SPARINGLY.  I have seen numerous engines where excess silicone has broken off and plugged oil passages with VERY unhappy results.

[cazman]

I have always used Hylomar whenever I think I need sealing "help" like on the the oil pan. Works great.

I also use Gasgacinch Gasket Sealer when re-building an engine, mainly to keep gaskets in place when assembling. They both stay "soft".

[Grumblebuns]

Can anyone recommend a substitute for Graphogen. I believe Graphogen is an assembly lube correct? I will be needing it shortly.

Joji Tokumoto

[BDA]

+1 on using silicone sparingly. I would not use it in fuel systems. A guy told me about how he couldn’t start his race car one time. He finally found a rope of silicone from his fuel pump to the carbs. I presume his fuel pump was irretrievably clogged up. The fuel had softened the silicone enough that the fuel pump was able to pump it.

I think his was somewhat of a special case as I think his problem was that he had used silicone to seal his fuel cell - something most of us will never have to worry about.

[BDA]

Can anyone recommend a substitute for Graphogen. I believe Graphogen is an assembly lube correct? I will be needing it shortly.

Joji Tokumoto

I use Red Line assembly lube. It seems to work well. I’ve also used moly based assembly lube (don’t remember the brand) that seemed to work well also. I seem to remember that the moly stuff was messy because the moly would settle out but at the time I was running the engine very occasionally and I was panicked about my cams and so used it more than you’re likely to.

[cazman]

This is what I use. I try to use the assembly lubes that cling to the parts, because I always do not start the engine for months after its built. The Graphogen seems to do this too, although I have never used it.

https://drivenracingoil.com/i-30497851-engine-assembly-grease-1-oz-tube.html