May be good for relieving the crankcase pressure and improving horsepower but it hardly fits the intent of ADR 27 does it? The gases are going straight out the exhaust and into the atmosphere instead of being reburnt as is the case with a PCV.
How important is a PCV valve???
Started by
LXCHEV
, Mar 29 2007 03:08 PM
30 replies to this topic
#27
FastEHHolden
-
- Members
-
- 5,114 posts
Steptoe
- Location:Central Coast NSW
- Joined: 16-November 05
Posted 03 April 2007 - 12:16 PM
Unless you can argue that the emissions are being burnt in the exhaust system..but you sort of cant argue that...EPA wouldn't take kindly to it.
It would be allowable on a pre PCV engine with a "hockey stick" breather.
It would be allowable on a pre PCV engine with a "hockey stick" breather.
#28
_jklumpp_
_jklumpp_
-
- Guests
Posted 03 April 2007 - 01:35 PM
I've rigged up a system like this on my new 6, after a recomendation by my Mechanic, due to the fact i'm running triple webers (vaccum line obstructs the air flow to only 1 carb, causing balancing problems).lxchev in the passed few days i have done some resurch with this i ran the filter type on top of the rocker cover and they started to leak so i got some pcv vales what a joke slowed the engine right up so today i went to vpw and brought a crankcase ventlation system for $60 it is the breather you put on top of the cover and then a hose to a valae to the end of the extrotors and my mech said i should pick up 5+hp and that was over the filter system and this mech knows his stuff too
cheers caine
Picked up a reed valve at the wreckers that was off the anti-pollution system of a Jap car, and welded the screw fitting into the exhaust (18inches from the last collector is apparently where the exhaust pulse creates the most vaccum) On the LJ this ended up being just near the gearbox X-member.
The reed valve opens when there is vaccum in the exaust, and in turn opens the PCV. Seems to work quite well, although I think I need to baffle my rocker cover, as there is some oil in the catch can, and on the rocker cover from the breather (I think the Hi-Vol oil pump may be the culprit here!)
#29
Dr Terry
-
- Moderators
-
- 3,325 posts
Technical + Numbers Guru + Moderator
- Location:Eastwood (Sydney) NSW
- Joined: 13-November 05
Posted 03 April 2007 - 02:25 PM
Hi Guys.
2X044 said :- "Does anyone know of an ADR that specifies the use of a PCV to avoid "evaporative emmissions"? I believe it may be ADR 27 or ADR 27A...
Which torries came from the factory with a PCV system? "
PCV systems pre-dated ADRs. The first PCVs on Holdens were fitted to the HR 186 S (May 1967). Soon after, all the normal engines (161/186 etc) were fitted with a PCV valve. All Toranas have PCV systems.
Also, there are 2 types of PCV system, open and closed. Put simply, the open ones have a oil filler cap open to the atmosphere, where the closed type have a sealed filler cap and the system is vented to the air cleaner. When ADR27 came in (Sept '73) closed systems became compulsory. Prior to that the Chev V8s (307,327,350) that were fitted to Holden all had PCV, because it had been compulsory in the US since the early 60s.
In my experience, when tuned properly, a car with a PCV is more economical at traffic speeds than the same car without one. In the late 60s and early 70s they used to sell a PCV 'kit' to fit to older cars and one of the advertised benefits was improved economy. I'm only talking about stock engines here, a PCV is useless on a race car, because most of the time this is no manifold vacuum and race motors usually have more blow-by than a PCV valve could handle anyway. I used twin 'vacu-pans' on my drag car for years, they work well.
Dr Terry.
2X044 said :- "Does anyone know of an ADR that specifies the use of a PCV to avoid "evaporative emmissions"? I believe it may be ADR 27 or ADR 27A...
Which torries came from the factory with a PCV system? "
PCV systems pre-dated ADRs. The first PCVs on Holdens were fitted to the HR 186 S (May 1967). Soon after, all the normal engines (161/186 etc) were fitted with a PCV valve. All Toranas have PCV systems.
Also, there are 2 types of PCV system, open and closed. Put simply, the open ones have a oil filler cap open to the atmosphere, where the closed type have a sealed filler cap and the system is vented to the air cleaner. When ADR27 came in (Sept '73) closed systems became compulsory. Prior to that the Chev V8s (307,327,350) that were fitted to Holden all had PCV, because it had been compulsory in the US since the early 60s.
In my experience, when tuned properly, a car with a PCV is more economical at traffic speeds than the same car without one. In the late 60s and early 70s they used to sell a PCV 'kit' to fit to older cars and one of the advertised benefits was improved economy. I'm only talking about stock engines here, a PCV is useless on a race car, because most of the time this is no manifold vacuum and race motors usually have more blow-by than a PCV valve could handle anyway. I used twin 'vacu-pans' on my drag car for years, they work well.
Dr Terry.
#30
orangeLJ
-
- Members
-
- 10,261 posts
Yes, yes I do post alot!
- Joined: 02-May 06
Posted 03 April 2007 - 03:28 PM
Jklumpps system is quite tidy actually, as i welded the valve into the exhaust, would beinteresting to see if it actually makes a difference in HP....
#31
_lurkin308_
_lurkin308_
-
- Guests
Posted 03 April 2007 - 06:58 PM
the vac pans are greatand there is hp increse for shore took about 2hrs to fit but yes you have to weld them in too
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users
