Black & Green modding thread (1998 Civic DX Coupe base)

[California98Civic]

My biannual SMOG test is coming this summer again, and I want cleaner numbers than last time, which were the cleanest the car had seen in many years because I had acid-washed the failed original 1998 Honda catalytic converter.

Installed an oil catchcan to keep as much blowby as possible out of the intake manifold. It's just better for the engine, too. Original 1998 piston rings with 274,875 miles on them.

But I learned enough about the PCV system to know that I wanted to inspect, clean, and replace my PCV Valve while I was connecting the catchcan to it.

The PCV Valve was dirty! It had a faint slight rattle. After cleaning it inside and out, the rattle was louder and it passed the blowing test of the check valve operation. I even ordered an new valve from Honda for $34 to compare. Amazingly, the new valve was defective (failed the check valve test). So I got my money back and installed my cleaned original part.



And here is the Mishimoto clone oil catchcan (really good quality materials... it's the same can without the name brand). $20 for the can got me all the great features, like the brass screen. Another $20 got me brass fittings and a brass drain valve. Here it is in place. (Still got to add the hose clamps.)



Test driving was awesome fun. Who knows how much trouble the gummed PCV was causing: starting, stumbling and surging, oil contamination, lacquer in the oil pathways, carbon in the combustion chambers, and sludge in the intake runners. It might even have been part of the trouble with the CAT. Most important little part I had no real understanding of before this project.

[Ecky]

Got a link to that catch can?

[California98Civic]

Originally Posted by Ecky

Got a link to that catch can?

I see a $17 example on Wish.com but here is one on Amazon for $18. If you compare the exploded view and features list with the Mishimoto you see it's the same. However, what realky convinced me was a dude on YouTube who bought both the Mishimoto and one of these knock offs and did a side-by-side comparison. He said they were identical and that he suspected they came from the same factory. I would agree. Mine was not packaged well, and got scratched as a result. But the item itself is high quality design and materials.

https://www.amazon.com/PQYRACING-Com...9942269&sr=8-2

[Xist]

You feel this would benefit all cars with a gas engine, not just with direct injection?

[California98Civic]

Originally Posted by Xist

You feel this would benefit all cars with a gas engine, not just with direct injection?

Yes, because the reason the PCV exists is blowby. Even an NA fuel injected (not DI) engine will have blowby. Combustion gases, H2O, unburned fuel... all will get into the crankcase and therefore into the intake via the PCV. But my car has 275k miles, so I gotta assume more blowby than in 1998. If I catch that in the can, my intake air is cleaner. Better for the engine. Better for anything that breathes air, too. No?

[Xist]

So, you are saying "Install an oil catch can if you love your Civic!"?

Engineering Explained collaborated with The Humble Mechanic. The latter showed what drained from the catch can in his Volkswagen and it was pretty disturbing, but I feel disturbed by many aspects of VWs.

I would like to see a Civic owner drain their catch can with each oil change.

[California98Civic]

I still have the "CAD" templates for this flat spoiler that showed a benefit in coast down testing at El Mirage last July. I want to rebuild it in slightly refined form and test it again. I have two great flat stretches of freeway in the region. One at El Mirage, and a new one along the central coast beach. Hmmm ... testing in the midday July sun in the High Desert or in the sea breeze on the coast?

Below are some shots of last year's templates on the car last year. I wanna adapt, rebuild, and re-test.

I don't want to make another fiberglass prototype like I made last summer. Instead, I am thinking ABS, HDPE, or black polymetal? Greasemonkey built this excellent kamm using ABS back in 2013:


I think I can reach that build quality, maybe. I love the bends and curves he accomplished. I also want to bend the sides of the spoiler down along the tumblehome but probably not below the level of the sidemarker lights.



In redesigning, I want to take this suggestion, too:

Originally Posted by Piotrsko

Any advantage to smoothing the horizontal to vertical transition?

Which would mean rounding out that sharp corner between the side plate and the decklid spoiler.



Thoughts?

[ME_Andy]

Originally Posted by California98Civic

Better for anything that breathes air, too. No?

Thanks for that.

[freebeard]

Thoughts?

The thinking is the easy part.

• Sacrificial deck-lid you can drill and weld on?
• Turnpike-cruiser skirts that terminate in a skeg. (forms outer [diverging] fence[s] of the difusser)
• Fillet the junction of the spoiler and side plate. Cut the waste out of one or the other.
• Polymetal get's my vote, but it does leave a raw edge.

I've got a pair of Nissan NX tail lights. Free if you're in the neighborhood.

https://i.imgur.com/rdlxtuF.png
Perfect for a box cavity sidewall. Else I can always use them on a trailer

[California98Civic]

Originally Posted by ME_Andy

Thanks for that.

Sure. Doing my tiny little part for our lungs! Have any wisdom on the three materials I am considering for the next iteration of my decklid spoiler? ABS, HDPE, or black polymetal?