Crankcase seal on rebuild process

I need some input what do you guys usually use to seal the crankcase after it being disassemble into 2?
if a loctite, which type? and on every gasket do you put any silicon on it or just gasket..

I just use a silicone sealant on the crankcase halves, but use it very thin.
No sealant on any other gaskets.

MARTIN.K said:

I need some input what do you guys usually use to seal the crankcase after it being disassemble into 2?

Click to expand...

If you get 10 replies then you are likely to get 10 different answers to your question.

My preference would be Stag Wellseal.

MARTIN.K said:

and on every gasket do you put any silicon on it or just gasket..

Click to expand...

I normally use grease on ordinary gaskets (not cylinder base gasket).

On my recent rebuild (not yet on the road) I used Loctite 518 flange sealant on the crankcases. Be especially careful around the oil scavenge port.
However, to give the sealant the best chance of sealing well, it's a good idea to make sure your crankcase breather is the best it can be.
For example, my 70 model came equipped with the timed breather at the end of the camshaft. This is generally considered to be inadequate to relieve the pressure pulses of two pistons rising and falling together. Norton made a couple of changes over the years, eventually settling on breathing through the timing case.
After considering several options I decided to modify my cases to enable timing case breathing, and I am in the process of incorporating a MikesXS reed valve into the breather line, on the strength of positive comments from others on the forum who are using one and have oil-tight engines. And just to make my job harder, I am trying to devise a postive crankcase ventilation system, rather than directing crankcase fumes straight to the oil tank. But that's another story.
Like Pommie John, I don't like using gasket sealants elsewhere, but I do smear a bit of grease on my gaskets.
Cheers
Martin

why not using loctite 510 but 518?

http://au.iloctite.com/en/loctite-574-5 ... -gasketing
510 gives more rigid and high temp option,

is Stag Wellseal have color or plain?
do i need to put some on the buttom of cylinder and between cylinder and head, or just leave it with only gasket?

There are like 3 types of goops, Wellseal tar like stuff, Wellbond clay like stuff and inbetween snouty stuff like silicon or racers Hylomar. Any work fine. Not a bad idea to use silk or cotton thread to back up the goop when engine gets into its elastic rpm range over like 4500. Yes for sure put goop under barrel if no base plate and cross your finger if just plain dry gasket down there. Synthethic thread melts and mashes down and beads up leaving voids. Dental floss is used to help seal barrel tunnels. Breather PVC's/reeds keep pressure low to not blow oil out but tend to suck back in.

MARTIN.K said:

is Stag Wellseal have color or plain?
do i need to put some on the buttom of cylinder and between cylinder and head, or just leave it with only gasket?

Click to expand...

Wellseal is brown, it has a reasonably thin consistency (when wet) so is best applied using a small brush, excess Wellseal can be wiped off with solvent.

Personally, I fit the base gasket dry (no sealant or grease) while others prefer to use sealant (such as Loctite 510? 518?) instead of a base gasket.
I would normally apply a thin smear of Wellseal around the pushrod holes of the head gasket.

A trick I learned from a BSA-owning acquaintance:

I paint both halves with Permatex Aviation Form-a-gasket, then lay dental floss in the goo on one side. Works like a champ. This Permatex is brown with a greenish tinge - I use it on everything, even paint the copper washers. cleans up with Acetone.

I put my 850 together back in 2008 before this knowledge and there was always a wet seam, though rarely a drip. Tore down the engine earlier this year in a clean up gone overboard, and re-assembled with the dental floss. This time, dry as a bone.

I know there's a joke in there somewhere, but not touching it.

I have had great success with Hylomar Blue.

I'd had both my Combats so oil dry over long enough periods to find all older just wire brushed cleaned fasteners rusted. So have taken to a spriz of wheel clear coat to stifle the patina till the oiling starts again from lack of control with a 3rd piston 2S cam hit just begging ya on once past 6500.

My vote goes to welseal, smells great.

just to throw another in the mix I settled on Threebond 1211 (a white liquid gasket) and will be using in place of a base gasket also. It is meant to be the bees knees and is of Japanese make
It seems odd not putting a base gasket back in but there wont't be any leaks just using the sealant according to local norton folk lore

It doesn't smell that great though

I used Welseal on my current project. I have used the Hylomar Blue on previous projects with good success. Then on gaskets I use Thread Eze Ultra. But then almost everything gets a smear of this stuff during assembly!

http://www.chemsearch.com/productDetail ... ltra%0D%0A

Russ

OK what are the assembly lubes Nortoneers like? Some are liquid oils so thick they won't drip off a knife tip in 24 hr but are not grease with thickening particles or fibers or wax, others have metalic based hi pressure lube.