Topic: Better way to stop oil leak: HD studs or MLS gasket?

[Juan1]

I will be working on the top end of my engine in the near future, and was wondering whether I should splurge on HD studs or MLS gaskets.  The engine is stock and I am just concerned with preventing oil leaks (and fixing the present one).

[tool14]

replace the studs

[Bailgang]

I'm currently using a MLS head gasket from cycle-x on my 550 with old studs. So far no leaks. I chose the .030 thick gasket which bumped my compression just a bit and the bike runs great.

[Jerry Rxman Griffin aka MuthaF'er]

If you want to be serious about this use both.

[Juan1]

I know both would be ideal, but I don't have the budget for both.  The question is which one of these two would be more helpful.

Heavy Duty Engine Studs - I assume the argument here is that most non-leaking engines have stronger studs with minimal flex and don't use high-tech gaskets.  Oh, and stronger studs allow one to tighten the nuts a bit more, putting more pressure on all mating surfaces.

MLS Gasket Set - I assume the argument here is that other engines that leak oil can be fixed with high-tech gaskets.  These gaskets are very effective on bikes with mating surfaces that either aren't compressed enough, or are imperfect.  Because of this, they work well on the CB750 engine with its weak and flexible engine studs.

[PeWe]

I think that HD studs are better due to less flex. Do not over tighten.
I snapped one APE HD stud at just before 22 ftlbs on my CB750 despite careful torquing in steps with a good tool (5,10,15, then by +1). New gasket and torqued all again, 18 ftlbs.  Maybe a quality issue?
Lets see if it will leak or not. I think not when I sealed the pucks and headgasket around cam chain tunnel and oil holes extra.

[Bailgang]

I agree that getting both is the best option but I also understand that budget restrictions don't allow that convenience. When I put my son's 750 together during the winter his budget was real tight so neither an MLS gasket or HD studs were an option so I was stuck using the original studs with a run of the mill composite head gasket that came with his Vesrah gasket set so what I did to help ensure the head gasket would seal properly the first time was re torque all the studs, the problem there was pulling the engine out again just to re torque all the studs wasn't appealing. There was no hurry to get the engine back in the frame so I had all kinds of time so what I did was after I initially torqued all the studs I simply walked away from it, let it set for a day and come back and re torque again, walk away from it and come back the next day and re torque again and each time I could feel the nuts move just a fraction till my torque wrench clicked. It wasn't till maybe the 4th try that the nuts didn't turn at all as the torque wrench clicked and at that point I knew that was as good as it was going to get. It did take nearly a week because I would let it set for a day before re toque but being there was no pressure to get the engine back in the frame asap it wasn't an issue. I did the same on my 550 even though the MLS claimed that it didn't require to be re toqued it's just that by the 3rd time it was good to go. It's still kind of early to say if it will remain sealed for the long term but so far no leaks on either engine.

[Bootlegger56]

I am not so sure that after a point its the gasket compressing as much as it is the studs stretching or the lubricant factor associated with the assembly.  Bolt stretch is discussed more often in high performance automotive applications.  Unfortunately we cant measure stretch on studs.  Repeatability and Reproducibility of the torque wrench is also a factor.  For a cheepee like me I am sure my Harbor Freight wrench's are poor in both categories but the probably beat my torque by feel guesswork on critical applications.  ARP has an interesting site with some good reading for all of us.  I hope the link works.

http://arp-bolts.com/pages/technical_installation.shtml

[bjbuchanan]

Car craft magazine ran a comparison of the harbor freight and better tools and found that the Harbor freight isn't as bad as thought. Long term repeated use obviously wasn't reported but out of the box performance really wasn't pathetic.

[Bootlegger56]

I will sleep better tonight!  LOL  Some people think us Americans are torque crazy any way!!!

[nokrome]

heavy duty studs with permatex copper gasket spray on a standard gasket, no leaks with 4 or five different heads.
  I understand what Bailgang is saying about torquing them and letting them sit and torquing them again etc.etc. and I agree but I think the real point is to let the engine go through a few heat cycles and let everything settle and then re-torque. (MHO) Total PITA

[Bailgang]

heavy duty studs with permatex copper gasket spray on a standard gasket, no leaks with 4 or five different heads.
  I understand what Bailgang is saying about torquing them and letting them sit and torquing them again etc.etc. and I agree but I think the real point is to let the engine go through a few heat cycles and let everything settle and then re-torque. (MHO) Total PITA

I agree that letting the engine go through a few heat cycles is at least in my opinion the preferred re torque method but the idea of pulling the engine to do it just didn't fly. With my method I was basically being lazy. 

[jamesbekman]

You just have to see if the threads have stretched on the studs, if not your good to go. 

[lucky]

Make sure that if ANY material was removed from the cylinder head to measure you locating pins (little cylindrical sleeves to see what their height is.

IF you had any material removed from the cylinder head then that same amount must be removed from the locating sleeves. Otherwise the head will not crush down the gasket and you could have an oil leak.

On a stock cylinder head...
How many people know how much space is left over if you measure the depth of the locating sleeve pocket in the head and the height of the locating sleeve. Almost no one.

Or another way, How tall are the locating sleeves above the height of the cylinders?
Now subtract that from the depth of the pocket in the cylinder head.
How much will the gasket be able to crush?