Moby gaskets

Taylor Trotter /

I've been planning on porting my 79 50v but haven't gotten around to it. It definitely has some air leaks around the head gasket.

I want to get it up and running by this weekend, though. I plan on replacing the gaskets. I bought a gaskets kit from treats. Do I have to remove the piston in order to swap gaskets?

Thanks,

-JTM

Re: Moby gaskets

no

Re: Moby gaskets

No. You remove the piston from the cylinder, but the piston remains attached to the wrist pin/con rod.

Re: Moby gaskets

Kiel the Canuck /

Three main gaskets on the engine:

Head (Between head and cylinder), base (between cylinder and carter), and carter gasket (between the two carter halves)

The head gasket is an easy swap. Remove nuts, pull head, clean mating surfaces and drop new gasket on, then torque to spec

Base gasket means all of that, plus pulling the cylinder off. Piston comes out, but stays attached to the connecting rod.

The carter gasket I would leave alone unless it's leaking. If you're taking it apart that far, you may as well do the bottom end bearings and seals, because it's damn near the same amount of work.

Re: Moby gaskets

Taylor Trotter /

I plan on leaving the carter gasket be for now. It doesn't seem to be the cause of my air leaks. Is there anything special I should do or take into consideration when disassembling the head and replacing the gaskets? What is the best way to clean the mating surfaces? And when I pull the cylinder off should I be extra cautious of the piston rings?

One final question- so I disassemble everything and clean the mating surfaces. When I go to put on the new gaskets and install the cylinder and head do I go in this order:

Base gasket>cylinder>headgasket>head and then torque to spec?

Thanks,

-JTM

Re: Moby gaskets

Kiel the Canuck /

Cleaning the surfaces isn't too fancy - wipe it down, then wipe with a little parts cleaner/brake cleaner, etc.

Make sure that any old gasket paper is thoroughly removed.

Mine was so baked on I made a tool to scrape it off. Most gasket scrapers are steel - didn't want to risk damaging the aluminum; so I took a small brass tube and hammered one end flat. Filed the end so it was square, and you've got a scraper that's a bit easier on the aluminum surface. Copper pipe should work as well. Touch up with a file once in a while to keep it working.

Piston rings aren't too big of a deal during removal, just take care not to catch them on anything during reassembly. It may not be a bad idea to check the ring end gap on them if you've noticed compression is a bit low. Other than that, you can usually compress the rings by hand while installing the cylinder. Be careful to keep them aligned on their posts!

>Base gasket>cylinder>headgasket>head and then torque to spec?

Yep. I (as a matter of habit) soak my paper gaskets in 2T oil before assembly. I find it helps with disassembly during future work.The head gasket is aluminum and should be installed dry.

One other thing - some aftermarket gaskets don't fit as perfectly as one would like. Be sure to check the fit before you're caught halfway through installation. I discovered my base gasket had holes too small for the studs and they were spaced a little off! Ended up making my own in photoshop, laser printing the outlines onto gasket paper, and cutting them out with an xacto knife.

Lastly, don't use any RTV or gasket goop at all ;) if the surfaces are in good condition and properly prepared, they should seal fine without any.

Re: Moby gaskets

Taylor Trotter /

I was having some trouble removing the old gasket and I ended up gently using a double edged razor blade. Most of the gasket is now removed but there are some areas where it is still slightly present. Should I remove the rest of it (it might scratch the aluminum)? If I do scratch the aluminum a bit would it be safe to use some RTV- in that scenario? just a small amount.

Re: Moby gaskets

Kiel the Canuck /

Taylor Trotter Wrote:

-------------------------------------------------------

> I was having some trouble removing the old gasket

> and I ended up gently using a double edged razor

> blade. Most of the gasket is now removed but there

> are some areas where it is still slightly present.

> Should I remove the rest of it (it might scratch

> the aluminum)? If I do scratch the aluminum a bit

> would it be safe to use some RTV- in that

> scenario? just a small amount.

Two things to try:

1) Blue Scotchbrite pads. Non-scratching but helpful for scrubbing it off.

2) Permatex gasket remover. Cover bearing surfaces/crank/painted areas, etc. Follow directions on can. Basically sprays on and eats old gasket. Scrape off softened gasket.

Re: Moby gaskets

Taylor Trotter /

Awesome! I will pick some of the Blue Scotchbrite pads up. Just out of curiosity, why is RTV so frowned upon. I would ideally only use a very small amount.

Also Kiel, would there be anyway you could send me a .jpeg of that base gasket in case I have to create one? That would be a major help. (edited)

Re: Moby gaskets

#CrazyWayne™ rocks. #CrazyWayne /

Kiel the Canuck Wrote:

-------------------------------------------------------

> Three main gaskets on the engine:

>

> Head (Between head and cylinder), base (between

> cylinder and carter), and carter gasket (between

> the two carter halves)

>

> The head gasket is an easy swap. Remove nuts, pull

> head, clean mating surfaces and drop new gasket

> on, then torque to spec

>

> Base gasket means all of that, plus pulling the

> cylinder off. Piston comes out, but stays attached

> to the connecting rod.

>

> The carter gasket I would leave alone unless it's

> leaking. If you're taking it apart that far, you

> may as well do the bottom end bearings and seals,

> because it's damn near the same amount of work.

Most intakes use gasket's to, slickems.......

Don't use scotchbright, just do it and have leaks, nubbs...........

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