ET: Engine (Twin) Latest formula sealant for main case twin.

[craig]

What is the most successful sealant for engine cases. I have a few to choose from, but would try something new.



It is probably me, but I have not had total success with any sealant.
Simply live with the small leak.

 

[greg brillus]

As long as all the mating faces are flat and clean, just about any modern sealant will work. I have only used threebond sealants for years now with no problems, just a fine bead of it over one surface is plenty........all the scare tactics you read from owners who are petrified that a piece will break off and block the oil ways.......probably the same folk who use half a tube of the stuff........I've never had an issue, I use 1215 grey on alloy cases and 1207B on black painted cases.......Its all about careful preparation, as tempting as it is to rush and get a result quickly, that is not how to do it.......You should carefully check the crank/rods are central to each bore as best you can, and make sure the front prop stand assembly is all ready to go on with the assembly as well........go through all the case studs and work out their lengths in relation to each case hole, so on assembly you can get the studs/nuts done up nicely without wasting time.......you dont want the sealant going off, whilst you are sorting out which stud goes in which hole. It is also worth checking on the crank, especialliy if thre shafts and bearings are all new, that these parts go on without using too much force........It is not uncommon for a bearing to be too tight a fit on the shaft, this can cause big problems when you are assembling it all.......Often you need to carefully linish the shaft a little so the bearing will slide on without using a big hammer.......Dont forget the bevel gear in the roof of the gearbox.......a little grease will hold it in place.........all good fun.

 

[Robert Watson]

Loctite 515, for 30 years