b18c pcv system on b20vtec possible?


qais_vtec

qais_vtec

Member
Joined
Jul 15, 2012
Messages
113
Hi, i am doing all the research for my forthcoming b20v build and was reading up on the breather system and its all abit confusing to me tbh. From what i understand b18c/b16a's have a pcv system that comprises a breather box at the back of the block with two fittings running from it; one going to a pcv valve leading to the intake mani and the other back into the block just before the head/block boundary. The b20b3 block i have does not have a breather box (hole plugged with a cap) or the outlet above this cap like b18/16vtecs.

Would i be able to install my b18c6 breather box where the hole is plugged and tap another fitting above this location like the original b18c6 system? In theory im thinking yes but only if the inside of the blocks are the same in terms of oil passages/routes etc.

Please include your input/knowledge.
Btw it will be running all full boltons (except intake mani), mild cams, pnp, 84.5mm rs or ycp itr pistons yeilding a CR of around 11.7:1 static...
 
Did you have any probs or issues with installing this?
Any oil leaks from anywhere?
What is your setup?
 
nope, very easy to do, and never had a problem or leak. only thing was where to mount the catch can. had to make up metal panel round the battery and bolted on to that.

B20 vtec turbo
 
iv had another look at the b20 block and i was mistaken because the actual location for the breather box insertion hole (the big one) is non existent so the answer to my own thread is that b18c/b16a pcv systems cannot readily be fitted to b20 blocks

thanks for your input sambo but can you just answer a few questions regarding b20v builds seen as you have done one:
whats is your rev limit?
CR?
sleeved, stock or blockguarded?
con rods stock or after market?
arp rod bolts?
miles since build?
forged or cast pistons?
reliability probs (not wear/tear)?

im gathering as much first hand info about this build as i can because on all forums ppl say that b20v's are unreliable due to weak sleeves, rod/stroke ratio etc.
 
i am running at 8650, stock block, stock sleeves, no guards, etc. skunk2 head components, good port job, etc. pushing out 242bhp for 2 seasons of racing. i am using just arp head bolts.
 
im am running standard B20b3 block with ARP head bolts and standard B16b head. Rev limit set to 8000rpm as peak power is about 7600rpm. 200bhp and 155lb/ft at flywheel. Engine done over 2000 miles now and never had a problem, and i drive my car hard all the time, there is never a day when i drive my car that i don't hit vtec, its an addiction lol

That was before i put turbo on it though, car not been mapped with that yet, so driving about sensible just now, which is hard. But still running standard engine and internals

As for reliability, its really down to how the engine is built and most importantly a good tuner to map it, there a member on here Harvey J who has had a built b20 turbo and done 10s of thousands of miles on it running 12psi on stock sleeves and never had a problem, if your doing a built bottom end make sure its done properly, and make sure its mapped properly. If thats all done you won't have a problem
 
Last edited:
sambo711 said:
im am running standard B20b3 block with ARP head bolts and standard B16b head. Rev limit set to 8000rpm as peak power is about 7600rpm. 200bhp and 155lb/ft at flywheel. Engine done over 2000 miles now and never had a problem, and i drive my car hard all the time, there is never a day when i drive my car that i don't hit vtec, its an addiction lol

That was before i put turbo on it though, car not been mapped with that yet, so driving about sensible just now, which is hard. But still running standard engine and internals

As for reliability, its really down to how the engine is built and most importantly a good tuner to map it, there a member on here Harvey J who has had a built b20 turbo and done 10s of thousands of miles on it running 12psi on stock sleeves and never had a problem, if your doing a built bottom end make sure its done properly, and make sure its mapped properly. If thats all done you won't have a problem
Click to expand...

its up to the cr you running!!! one of my m8 had a b20 fully built with 12.5 cr and blockguard and cracked the 2nd and 3rd cylinder only after 1000 kmh of hard running!! i had a b16b fully tuned 12.5 cr wtih blockguard also and cracked the 1st cylinder in about 5k kmh... so my conclusion is that honda sleeves cant take high comp builds
 
Hello mate you can use a pcv system on a b20. If you look at the back of your block you will see 2 block ports that have large alan type screws in the back, you can run a hose from one of these ports to a catch can then run the other hose from the can to the vacuum pipe on your intake manifold that would of plugged into you charcoal cannister, then insert the pcv valve inbetween the pipe going from your catch can to your intake manifold and you will have a fully working pcv System.

The b20 block vents its crank pressure through the non vtec head which is not possible with a vtec head on it.

Hope this makes sense and helps you out as i wrote this on my phone
 
Hello mate you can use a pcv system on a b20. If you look at the back of your block you will see 2 block ports that have large alan type screws in the back, you can run a hose from one of these ports to a catch can then run the other hose from the can to the vacuum pipe on your intake manifold that would of plugged into you charcoal cannister, then insert the pcv valve inbetween the pipe going from your catch can to your intake manifold and you will have a fully working pcv System.

The b20 block vents its crank pressure through the non vtec head which is not possible with a vtec head on it.

Hope this makes sense and helps you out as i wrote this on my phone
 
Yeah you can also do it that way as well. You could make your own or buy the kit in the link i sent u at top of page, either way they will work.
 
2 from the rocker and one from the rear left gallery (14mm hex) is what I would go for.
 
Thanks for all the info guys, i think il just go for the kit from endyn as its tried and tested.
Im worried about running 11.6:1 cr on 84.5mm blockguarded cylinders now that iv heard about hi comp reliability issues so il reduce the cr by reboring comb chamber to 84.5mm (should help quench) and blend the edges around the seats etc and limit it at 8000 even though the cams il be using (edelbrock 4730) should make power to 9k.
 
As money is tight at the moment so i will not be paying $200+shipping+customs charges+vat for the endyn kit so my question is would the b18c6 pcv system work adequetly if i rebored/tapped the b20b block exactley like the c6 to mount/fit the breather box? I love engines and the science behind them but this pcv thing is a ball ache to get my head around.
 
Why spend so much money on a breather kit? the can be had really cheap.
 
$image.jpg
 
You must log in or register to reply here.
Back
Top