It is currently Sun Oct 22, 2017 3:38 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 17 posts ] 
Author Message
 Post subject: Adding an extra breather hose to reduce crankcase pressure
PostPosted: Mon Apr 30, 2007 4:00 pm 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
I am wondering if anyone has installed an extra breather hose and or 2nd PCV valve or even a bigger PCV valve to their turboed Swift to reduce positive crankcase pressure?

My car has had an issue with occassional oil smoking from the exhaust (sometimes quite bad) ever since the turbo was installed... please bear in mind the car only has 61700kms on it and the motor has no compression issues or oil leaks... It has 170psi on all cylinders... In my opinion whatever blow by it has causing the positive crankcase pressure was there before the turbo install. So I am not in any way blaming the installer for the problem... I would just like a solution to the problem. :)
The PCV valve is in perfect order with no blockages and there are no blockages in the breather hoses or any sign of oil in the breather hoses.
The turbo oil return has no blockages in it and is more than large enough.
The hot air felt out of the breather in the rocker cover at idle is well??? who knows??? no idea what is normal with no figures on it anywhere that I can find. But as it is not oiling up the lines or blocking the PCV valve I again assume it is as the factory inteded it for the stock NA engine.

It appears to me that the blow by the engine is producing is normal but is only a problem in it's turbo form and that the positive crankcase pressure is preventing (even if only some of the time) effective drainage of the oil from the turbo to the sump thus the oil leaks through the turbo seal and out the exhaust..

I am assured that the turbo was brand new when it was fitted and I have no reason to doubt that. It certainly looked brand new at the time.

In addition to the above I have done the following:
1. Confirmed that the turbo is a sleeve beasring type (T25) with no inlet oil restrictor. (no restrictor is needed for this type of turbo)
2. Confirmed with Garrett as to what is the maximum allowable oil pressure on a sleeve type bearing turbo... that is not possibly a problem.
3. Done a compression test on the motor to ensure it is within factory specs.

It could possibly be coked / carbon build up on the rings preventing proper sealing of the compression rings and thus the blow by is happening but with no figure as to what is an acceptable amount of crankcase pressure at idle for a standard engine I am not sure.

Options?
I can install a catch can of some description.

Is it just as effective or more so to install a 2nd breather at the other end of the cam cover that returns to the inlet? I would obviously have to ensure it was baffled suitably inside cam cover.
Same scenario with a 2nd and or larger PCV valve going to the plenum.

Assuming the problem described is my actual problem would fitting extra breathers... be enough to elleviate my issues? or do I really need to fit a catch can?

Any other suggestions or advice?

Oh yes, I am intending to visit the installer as they want to look at it to check the crankcase pressure (a long standing invitation) but I just haven't had the time and have been working most Saturdays as well. So again I am in no way intending for this to reflect negatively on them.

Just after ideas... I will eventually get around to going and seeing them.

Cheers,
Damian


Top
 Profile  
 
 Post subject:
PostPosted: Mon Apr 30, 2007 4:27 pm 
Offline
Moderator
User avatar

Joined: Mon Aug 25, 2003 12:00 am
Posts: 17513
Location: ACT
Firstly (and this may seem silly), have you ensured that you have no connections between the inlet and rocker cover beside the single PCV you mentioned. Secondly, does that PCV have an appropriately strong one-way valve installed?

These might seem like basic things, but I've seen a few N/A motors converted to turbo where they were overlooked, and the PCV just doesn't work if any positive manifold pressure leaks into the system.

Another question is when do you get oil smoke from the exhaust?
Only at idle from a cold start? Only at high RPM? Off boost cruising? All of the above?

One solution I have seen for bad blow-by is a pipe connected directly to the very top of the back of the sump that runs up to the top of the engine bay and into a catch can. This gets rid of any blow-by directly from the sump, bypassing the oil galleries and PCV system entirely. You just need to ensure that the pipe is sufficiently long and positioned so that oil can't be forced up it.
I'm sure there's probably a safer, more high-tech solution, but hey, it works! :lol:

Oh, and having blow-by at idle is normal. Just as long as it isn't spitting oil or blowing out like a hair dryer. ;)

_________________
Suzuki MightyBoy - Three pots and a snail.


Top
 Profile  
 
 Post subject:
PostPosted: Mon Apr 30, 2007 5:12 pm 
Offline
User avatar

Joined: Sun Oct 03, 2004 4:04 pm
Posts: 2909
Location: Brisbane
just run both ports in the cam cover to a catch can and run the catch can back to the air cleaner on the turbo (if you want to be legal)

_________________
Education is important, but race cars are importanter


Top
 Profile  
 
 Post subject:
PostPosted: Mon Apr 30, 2007 7:08 pm 
Offline
Moderator
User avatar

Joined: Mon Aug 25, 2003 12:00 am
Posts: 17513
Location: ACT
Puss-on-Boost wrote:
just run both ports in the cam cover to a catch can and run the catch can back to the air cleaner on the turbo (if you want to be legal)


I don't think a Baleno has twin breather ports mate.

_________________
Suzuki MightyBoy - Three pots and a snail.


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 7:55 am 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
thanks guys.
The Baleno has two breathers in the rocker cover... one is via a pcv valve to the plenum and the other is back to the intake just after the air filter.

There is a T piece in the one that returns to the air filter for the purposes of the venting of the 3 port boost control valve which is under the battery tray..

I haven't checked to ensure the PCV valve isn't leaking given boost... I can take it out and bring it to work and check it with compressed air.

The car smokes at idle when warm but not always... it comes and goes.
It sometimes smokes when you take off from a stop.
It may smoke at other times when being driven but I haven't really noticed.

Look at picture of engine bay..
Image


Top
 Profile  
 
 Post subject: breathers
PostPosted: Tue May 01, 2007 8:06 am 
Offline

Joined: Mon Aug 25, 2003 12:00 am
Posts: 3493
Location: Brisbane
Hi,

"There is a T piece in the one that returns to the air filter for the purposes of the venting of the 3 port boost control valve which is under the battery tray.."

1,To determine your problem I would start by putting both breathers from the cam cover into a breather bottle,blank off the pcv pipe to the inlet manifold.
2, Above you state that the T peice goes to a boost control valve ,are you talking about a blow off valve here,maybe some pics of the item would clear it up.If its a BOV then the actuation pipe should come from the plenum chamber and for diagnosis of your problem ,dump the BOV air to atmosphere, not back to the air filter.

_________________
Image


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 9:56 am 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
Thanks,

The boost control valve is a 3 port MAC valve which is a PWM valve controlled directly by the Wolf V500. (Red silicone hoses in picture)

Port 1 goes to air filter so it is not venting to atmosphere (for legalities)
Port 2 goes to wastegate actuator
Port 3 goes to pressurised intake pipe directly after the turbo as it did prior to the boost control valve being fitted.

The valve regulates the amount of air going from port 3 to port 2 with vented air going out of port 1.

The BOV is a Mitsubishi OEM style recirculating unit that plumbs back to the intake just after the air filter. Yes the activation for the BOV comes from the plenum chamber.

I will do as you suggest with blanking off the plenum and removing the PCV valve etc.... I was concerned about diong this as I was told there are heavy fines for removing the PCV valve.

Do factory turbo engines run the same sort of PCV system? ie pcv valve from rocker to plenum? if so do they have a higher rating or different style of PCV valve to an atmo engine as per yldboys suggestion that the PCV valve could possibly leak given boost.

Also I thought the vacuum effect on the PCV valve at idle was supposed to help the situation by extracting the crankcase gases and reducing the pressure... something that won't happen if you do away with it and rely solely on a bottle. am I not understanding? :?


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 11:25 am 
Offline
Moderator
User avatar

Joined: Mon Aug 25, 2003 12:00 am
Posts: 17513
Location: ACT
The way your PCV system is currently set up, the link between the rocker cover and plenum will only operate in vacuum (off boost) because of the one-way valve. When the motor comes on boost, all the pressurised air in the crank case is forced out the other vent and back through the air filter, because the air pressure in the plenum keeps the one-way valve closed.

So at idle (where you are experiencing the smoke), both of your vents from the rocker cover should be working just fine. By my thinking this would mean you have an oil leak elsewhere in the motor/turbo to cause the smoke.

To be sure though, as Ben/Dave suggested run pipes from both rocker cover vents to a vented catch can that isn't plumbed back to the intake, and plug the PCV inlet on the intake plenum. If the smoke stops after a good run with this setup, then your problem must have been caused by a dodgy PCV system.
The solution to this would be to fit a recirculating catch can, where both hoses run from the rocker cover to the can, then a hose from the can back to the air filter/intake. Completely legal and should solve any oily blow-by problems. 8)

_________________
Suzuki MightyBoy - Three pots and a snail.


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 12:17 pm 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
Thanks,
one other thing it may be which I have been in some form of denial about is valve stem seals and or valve guides.

I had a chat to my workmate who has been helping me tune it and he said he believes that to be the problem regardless of the relatively low kms on the car.
The fact is it is now 7 years old and the rubbers in the seals may have gone hard.
He rang his engine builder friend who also concurred when given all the facts and also added that the valve guides can be a bit of a problem in these engines even early on.

My Father in law suggested that valve stem seals were the problem to me some time ago but I dismissed it based off the kms on the car... (denial again) but I guess that is very possible. :cry:

Sadly prior to the turbo install I recall having to top up the oil between services so this scenario is becoming more feasible.

I might throw a set of valve stem seals in it initially before trying anything else.... use the old compressed air in the spark plug trick to hold the valves in place....

Failing that I can get the motor rebuilt at my father in laws work for cost of parts only just getting it in and out is the painstaking bit.


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 12:32 pm 
Offline
Moderator
User avatar

Joined: Mon Aug 25, 2003 12:00 am
Posts: 17513
Location: ACT
In any motor I have seen with dodgy valve stem seals they only leaked at high-rpm or during gear shifts. Smoking at idle would make me lean more towards a turbo oil seal.

But of course this is just based on my experience. I'm sure others will have contrary information to offer. ;)

_________________
Suzuki MightyBoy - Three pots and a snail.


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 2:24 pm 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
Hmmm... :shock:

anyway... I will flush the engine oil out of it and run a totally mineral oil in it for now.
To furthur add to the confusion / debate there is a vague possibility that the bores could have a glaze on them due to original owner using synthetic oil from new... and a synthetic oil will find any way out it can generally.

A mineral oil may help the situation / help in deglazing the bore (miracles can happen) :roll: in the short term.

I might bite the bullet and pull the whole thing out in coming months for a freshen up at the Father in laws work so I know where I stand with it for sure... along with a new DMW Dave clutch.

ACL can do a custom composite head gasket or copper head gasket for slightly more than a standard.


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 4:47 pm 
Offline
User avatar

Joined: Sun Oct 03, 2004 4:04 pm
Posts: 2909
Location: Brisbane
From what your describing I had the same problems in the MK1 in the early days...how did I solve it?

Both ports in the cam cover into a catch can (yes both ports Brayden :P )

Breather and PCV port

_________________
Education is important, but race cars are importanter


Top
 Profile  
 
 Post subject:
PostPosted: Tue May 01, 2007 5:56 pm 
Offline
Moderator
User avatar

Joined: Mon Aug 25, 2003 12:00 am
Posts: 17513
Location: ACT
Yeah you got me on the ports. I never noticed the second one on either of the Baleno's here! :oops:

_________________
Suzuki MightyBoy - Three pots and a snail.


Top
 Profile  
 
 Post subject:
PostPosted: Thu May 03, 2007 9:40 am 
Offline

Joined: Wed Nov 19, 2003 3:48 am
Posts: 157
Location: Calgary... Canada
Yes - factory boosted engines have will usually have a much better PVC system. You'll notice 6 (if I recall correctly) ports going through the block up to the head for breather on an engine like the TT Supras 2JZ-GTE. The Swift has two, but the factory head gasket blocks one port off. You can see pics on Page 2 of my cardomain page. I only alluded to this on my cardomain page, however no one has ever mentioned the difference there.

Something to try -

Step 1- drill out the insides of the PVC valve you have and reconnect the hose (buy another $3 for afterwards). Unless you can just connect the hose from the valve cover to the manifold without the valve in place... then do that.

Step 2 - Check for smoke at idle.

_________________
I've conformed... my CarDomain site
How-To, Dynos, and more
1992 Swift GT - Turbo


Top
 Profile  
 
 Post subject:
PostPosted: Mon May 07, 2007 8:19 am 
Offline
User avatar

Joined: Fri May 28, 2004 12:18 pm
Posts: 1403
Location: NSW
Well it is a little embarassing.
I replaced the PCV valve on the weekend.
A metal PCV valve (Fuel Miser branded item from local Auto 1) with the same inlet / outlets as the stock plastic Suzi item for $13.00 when Suzuki wanted $28 for the OEM plastic one.

Despite the fact the stock one appeared to be ok and was cleaned out with isopropyl alcohol and compressed air etc. the new one had noticeably less restriction and flowed more air with the old mouth blow test.

I only played with the car for a few hours and this included a 40 minute drive but it would appear at least initially to have fixed the issue.

Rego expires in a few days and a general lack of funds and other priorities means it wont get rego and obviously a road trip / road tuning etc.. again for a month at least probably two unfortunately. Such is life. :cry:


Top
 Profile  
 
 Post subject:
PostPosted: Mon May 07, 2007 10:20 pm 
Offline

Joined: Wed Nov 19, 2003 3:48 am
Posts: 157
Location: Calgary... Canada
$28 for the PCV, ow. Our Partsource sells them for $4 and you can browse their shelves for other pcvs. I'm glad that you tried something with less restriction. I don't recommend the stock PCV valve for boosted Swifts or Swiftalikes.

_________________
I've conformed... my CarDomain site
How-To, Dynos, and more
1992 Swift GT - Turbo


Top
 Profile  
 
 Post subject: Re:
PostPosted: Sat Oct 07, 2017 3:15 am 
Offline

Joined: Fri Feb 28, 2014 12:11 am
Posts: 65
Location: Aruba
WhatThe wrote:
The Swift has two, but the factory head gasket blocks one port off. You can see pics on Page 2 of my cardomain page. I only alluded to this on my cardomain page, however no one has ever mentioned the difference there.


Sorry to bring up an old thread but does anyone else unblocks this part in the gasket when going turbo?

_________________
1991-GTi: JE 75mm 11:1 pistons,Ported head, Single UD pulley,Sandros chip,Aluminium flywheel,3tech 222/365 cams, Cultus headers,Cultus IM,50mm tb,Crane cams adjustable cam gears,Apex suspension, 4.39fd GB.
1989-GTi.
2001-Altezza AS200.-sold
2003-EVO7 GT-A


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 17 posts ] 

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © phpBB Group