this is a hard one to know. i would bite the bullet and get the one that matches your engine. They are controlled by a simple spring, though there maybe a difference in the springs for engines that rev a little bit higher than the others (I am speculating).

 

this is a hard one to know. i would bite the bullet and get the one that matches your engine. They are controlled by a simple spring though there many be a difference in the springs for engines that rev a little bit higher than the others ( I am speculating ).

Good point, I didn't think about the difference in rev limits. Maybe the more powerful engines produce more blowby that needs to be removed also due to the higher cylinder pressures. I guess I will get the proper one then.

Do the PCV valves on these engines ever actually go bad or do they just clog? Normally I just clean them with brake cleaner and reinstall and never had a problem doing that. If I could find one at a junkyard (not likely any time soon where I live) and clean it that would save me about $40. It's crazy how expensive that little thing is!

 

i am not sure how long they last. i bought a new one....

 

Thanks for your help. I ordered the correct RBB valve from Honda, I know the parts guy so he gave me a bit of a deal. In the long run I think it will be worth it. I definitely don't want to run into issues with sludge, oil consumption, etc.

If I can find my extra K24 Accord PCV valve I will do a comparison to see if there's any visual differences or obvious differences in flow rates and report back.

 

there is no connection of a rev limit to the PCV operation. Under any circumstances, the flow rates of gases though the PCV valve into the intake manifold are rather small. It does not have to have a high flow rate. The gas passing though it are only transporting condensates out of the engine, mainly evaporating out of its oil and a little bit of blow by. Fresh air enters though the valve cover.

Only once boil of or blow-by gas flow exceeds the PCV valve flow, at WOT it stops anyhow as there is no more pressure difference between intake manifold and crank case driving the actual flow, gases vent out the valve cover vent. This is also the reason it is so big. Under extreme cases of blow by, you want all gases to able to pass the valve cover vent preventing pressurizing the crank case. This would pop out the crank seals and create a huge mess and a potential fire, loss of clutch operation etc, i.e. a hazard.

The Honda system odes not operate its crank cases under partial vacuum unlike say BMW or most HGV/truck engines.

 

there is no connection of a rev limit to the PCV operation.

I mentioned I was speculating and maybe the springs maybe different b/c of the higher operation in rpm's. Thank you for the clarification.

Something I would like to mention about blow-b; 16 years ago during the tuning process, mine PCV was capped off and the VC was open with a hose connected to the CAI intake tube. It filled up the intake tube with blow-by, not much. Just as @Lotus mentioned above :

Only once boil of or blow-by gas flow exceeds the PCV valve flow, at WOT it stops anyhow as there is no more pressure difference between intake manifold and crank case driving the actual flow, gases vent out the valve cover vent. This is also the reason it is so big. Under extreme cases of blow by, you want all gases to able to pass the valve cover vent preventing pressurizing the crank case. This would pop out the crank seals and create a huge mess and a potential fire, loss of clutch operation etc, i.e. a hazard.

 

I'd not run without the PCV system unless it is a pure race car that only sees track duty. These see rather high oil temps and commonly get oil changes after every race weekend.
For a daily driver, the oil will accumulate a lot of water and condensates degrading oil viscosity and quality.

 

I'd not run without the PCV system unless it is a pure race car that only sees track duty. These see rather high oil temps and commonly get oil changes after every race weekend.
For a daily driver, the oil will accumulate a lot of water and condensates degrading oil viscosity and quality.

Agreed. Years ago before I knew any better, I disconnected and capped off the vacuum line to the PCV valve and installed a breather filter instead thinking I was improving performance by not drawing hot blowby back into the intake. But what I actually did is create enough condensation on the oil cap and dipstick that I thought the head gasket was starting to leak. After driving for about an hour with the PCV reconnected, all the condensation was gone.

I don't see anything to be gained from disabling the PCV system. At full throttle, it basically disables itself anyways since there is not enough vacuum in the intake manifold to draw blowby through the valve.