As I've mentioned here and there, I've been working on a '90 13bt conversion for my car. The motor only has 30K miles on it and seems to have been kept in very good condition for being 17 years old: in the process of stripping it down to the block for a paint job, I didn't encounter a single stuck bolt, flake of rust, or stuck gasket. The exhaust manifold gasket could have been put on yesterday.

The inside of the engine looks like it could use a scrubbing though, and I have the desire to polish all the ports and runners (without any kind of actual porting). It would be a lot easier to just pull the motor apart and clean the rotors and irons directly, but I don't feel like dropping an additional $350 for a full gasket kit when I could just expend a little extra effort with a lot of SeaFoam and a very long toothbrush. My question is would the kit even be necessary? When people talk about a rebuild it's usually because a seal went bad, but when the engine was fine to begin with would the whole set need to be replaced anyway just because it was pulled apart (crushables, adherings, etc).

 

You would need:

4 inner, and 4 outer coolant seals
4 dowelpin o-rings
Rear stationary gear o-ring
Front cover oil passage o-ring
Front cover gasket
Front main seal
Rear main seal
Oil pick-up tube gasket
Thermopellet plug

The coolant seals, and front cover gasket will come apart when you tear the block apart. The rest should really be replaced when the block is torn down anyway. Do it once, do it right kind-of thing. If you're tearing it apart, you should really consider doing a full rebuild.

 

So basically it's what I thought: it doesn't matter the age, they're one-time-use seals. Not worth it then just to shine the internals. It would be like... buying new furniture just because you want to vacuum the living room. If the motor was aged and worn then it would be worth it as a precautionary measure, but as I said this thing is sitting somewhere between "excellent" and "pristine", other than a bit of carbon buildup on the concave surfaces of the rotor.

 

You can do the water injection trick (not to be confused with auxillary injection normally found on higher HP turbpo set-ups) to clean out most of the carbon.

Basically you suck up a little bit of water with a vacuum line while the engine is running. You can do a search for it for more info.

 

That's basic maintanance when running the OMP. If it was as effective in one go as I'm looking to achieve (yank off a sheet of carbon 1 mm thick or more), be concerned with jamming an apex seal.

And by "a little bit" you meant a gallon, right?

 

Use a couple bottles of seafoam if you're really that worried, otherwise running it hard, removal of the oil injectors and religious oil changes will do the trick.