Suggestions for engine rebuild

Hey everyone, I'll try not to make this too long but provide as much details as possible. Been wanting to do a rebuild on a 2007 Accord EX sedan (K24A8 engine), has over 189k miles but still is in great condition. My dilemma's with pricing (rebuild), considered buying instead a lower mileage (76K) engine but running numbers saw that would be better to add aftermarket parts instead to my current engine. Any suggestions on what steps to take in bringing the engine back to top notch condition without needing a complete rebuild?

Or if just machining the deck to replace the gaskets is enough? Thought on replacing the transmission too since engine's going out and given the symptoms it looks like it'll be necessary. Still looking at pros/cons between replacing vs rebuilding current one. Not taking this car to the track, only wanting to bring out the K24's potential while doing it myself/ learning 🤔 and having a ride that'll last.

I know that replacing pistons is out of the question since that requires boring/ honing. What parts from the block/head can be replaced without it affecting engine performance negatively? Could I just take it to the shop for cleaning instead? Not expecting a perfect engine, this is my first project so I'm gonna be re assembling it back again and want to learn while doing it right. Also with the engine out the chassis, it'll be easier to spot bad sensors/ connectors and replace then as well and clean the bay too. Some mods come to mind: new cams, sprockets, VTC, engine mounts, timing chain kit, tensioner, intake manifold, throttle body, cold air intake, etc. Would appreciate some feedback before making a decision I might regret 😕. Thanks!

First thing is why are you wanting to 'rebuild' the engine? Is there a known problem, such as burning oil, 'strange' noises, or whatever? Even is it seems to be running well, upon stripping you may find there are unexpected issues that NEED to be addressed.

If it's running fine and you're looking at a precautionary look at the engine, the old adage "don't fix it if it isn't broken" may need to be considered, in which case it may be worth looking for a core engine to build to drop in later - this is especially true if you think you will be 'leaning on it' later, with other modifications. This option may be a little more expensive, but it allows you to take your time on the build, as parts and budget allow, while still having it to run around in. Plus, you have the further option of selling the current engine as a known runner - especially if it's still in the car as you can demonstrate this for a price premium. This is what I'd normally recommend doing.

If you don't need the vehicle, and can park it up for a while, by all means rebuild the engine in it, but think on why you're doing it, and DON'T assume anything, because there will always be unexpected work, or parts, needed and sometimes there can be supply delays.

Re: the transmission - if manual, replacing the clutch and skimming the flywheel is worth doing while it's out, with the fluid being changed. If an auto', I would expect a basic filter and fluid change would be a good idea. In eaither case, axle and input shaft seal renewal would be a good idea.

Great questions Jetro.

If you want to rebuild the engine for the experience and learning, I say go for it whenever it's convenient, or when it eventually needs it.

If you are building to enhance the engine, perhaps higher compression pistons to run E85, stronger rods for a turbo setup, or otherwise, then building makes sense.

Otherwise I'd run the engine you've got until it actually has an issue, then swap another used one in. Getting a whole engine is cheaper than the rebuilt parts cost adds up to by the time you add up bearings, VTC parts, timing components, gaskets and seals, etc.

I guess it's a perfection syndrome) Knowing to have engine with big milage on it and automatically assume it's not in perfect condition therefore it's not providing best performance.

I would start with diagnostic first. Measurement of compression, making leak test to find out what condition the piston rings are in. Based on that information you can make a decision if your engine needs refreshing indeed.

If rings need to be replaced I would rehone the engine cylinders and install new piston rings. Maybe do pocket porting if you have budget (or you can even do it yourself). That will be enough to enjoy fresh built.