that pesky oil pump

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Apr 15, 2004
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On another thread, DD recommended using "purple jelly loctite gasket eliminator " on the oil pump instead of a gasket. Guess what's not available locally? Loctite anything, that's what. We have Permatex products in this locale. There's Permatex #1, Permatex #2, and an assortment of Permatex silicone compounds. In stock in my garage I have #2, the threebond gray stuff, and some threebond white silicone stuff.

Will any of that work or should I just buy a gasket? :roll:


I have had good results using paper gaskets. You don't have to worry about any excess gasket goop getting circulated and clogging up some tiny orifice. Also, paper gaskets have a long successful track history. I'm not indicting gasket goop for this application, I'm merely saying that it's perfectly acceptable to use a paper gasket in lieu of goop.

Make sure the end covers on the pump body do not stick out beyond the gasket face. If the cover interferes with the block the pump will bind, owing to distortion when it is bolted up. And more disasterously, the pump may suck air because of an incomplete seal at the block.

What you want is classified as an anaerobic curing gasketing compound. What this means is it cures where air is eliminated. It is extremely important where you are working around the oiling system. Any excess material will not cure and will dissolve in the oil and circulate harmlessly through the engine. A normal curing material (or **shudder** RTV silicone) will squeeze out little beads of cured rubber to plug oil holes and starve the oil feed. NEVER use RTV silicone on engine cases or anywhere that the excess might be squeezed out into the oiling system. I have a couple of connecting rods hanging in the shop which are totally black at the big end and have a verticle split nearly their entire length. Both engines these came from had RTV beads hanging inside the cases and I cleaned out a half teaspoon full from the cranks sludge trap.

The Loctite product has had many names in the last 30 years. Norton sold it and recommended it as Loctite "Plastic Gasket". They first recommended it in their service bulletins as a replacement for the cylinder base gasket. It seems the paper gasket would begin to disintegrate and allow the cylinders to start to move slightly in the cases. This could work the base nuts loose and the cylinder would cock slightly and break out the cases. "Gluing" the cylinders to the cases eliminated this. (Further improved with the 850 cylinder thru bolts).

The current Loctite name is "Gasket Maker 518". Permatex markets one as anaerobic Gasket Maker P/N 51813 (50 ml) or P/N 51817 (6 ml). Valco Cincinnati sells theirs as Gasket 2000 or Gasket 4000.

For years the Porsche 911 guys have used Yama-bond to seal up their engine cases. So, I thought if it's good enough for a Porsche 911 engine then it's good enough for a Norton engine. I've used this goop, which has a stringy-gray appearance, for the engine cases on several Triumphs and Nortons and have not experienced any ill effects so far.

However, if there is something better available for this job I would like to know what it is. There are a zillion anaerobic gasket goops available, which one is best suited for engine cases?

Thanks and regards,

A lot of people swear by Threebond 1104/Yamabond for case sealant. This is a rubber based sealer which has good filling capability for imperfect surfaces. Still, if you are not VERY careful, you can squeeze out little droplets into the oil stream which will cure and stop up oil feed holes. My preference is to get the mating surfaces as flat as possible then use the Loctite 518. My crankcase joints don't leak. After seeing those split rods and ruined cranks, I'm just a little anal about it.
510 515 518

I first used 515 before 518 came out. I like the idea of a slight bit of flexability, since there is some sight expansion difference at the case to barrel joint iron/aluminum . Where al/al joints are thermally more stable, the yamabond is fine and probably just as good for the norton bottom end too, where it is also an al/al joint.
On the loctite site I was reading with interest that the 510 has better hot strength retention than 518, but initial strength is slightly lower than 518.
Interesting information category;
Long long time ago when I was at a class at Embry Riddle leaning how to rebuild aircraft engines they used a reddish brown liquid gasket product that dried semi-hard. They smeared the mating surfaces of the joint with this material and then carefully laid a strand of silk thread on the joint all the way round. I don't know if this is still common practice or not but it seemed to keep oil inside the big radial engines of the time. (Yes a long time ago the airplanes actually had air cooled internal combustion prime movers)
Has anyone else heard or seen this practice applied to motorcyles?


Yes, I have heard about the silk-thread method of sealing engine cases. In fact, I saw this method implemented on a 650 Triumph twin back in the early 70s at a motorcycle shop here in Houston, Texas. I can still remember that beautiful Triumph gas tank; it was kind of a burnt orange color with a little chorme strip running down the center of the top of the tank. Triumph gas tanks have got be one of the prettiest of them all.

However, I haven't heard much about silk-thread engine sealant in recent years. Presumably, this method has been suplanted by modern gasket goops.


Just for clarification: The silk-thread was used on the engine cases. I was simply smitten by the looks of the gas tank on that old Triumph; indelible memories work that way sometimes.

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