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Discussion Starter · #1 ·
I saw my friend's older 4G63 engine (Eclipse), and he had disconnected the breather hose from the valve cover onto the intake plumbing. He installed a breather filter from the valvehead side, and covered the hole in the intake plumbing. If I do this similar modification, would there by anything amiss with the engine? Many thanks!
 
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Discussion Starter · #2 ·
This is a good mod to make , it wud be best to vent the cam cover to a breather tank.

The main reason for Mitsubishi venting the breather into the airbox is emission regulations to avoid engine oil fumes polluting the environment , however if oil vapour pollutes the combustion chamber in enuf quantity it will cause detonation.

Actually , when performance is increased it is vital to vent the breather to a catch tank, as increased boost causes more blowby which makes more oil vapour from the breather.
 
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Discussion Starter · #3 ·
The breather hose is connected back into the intake for emmissions reasons. Any oil fumes or blow-by from the engine are fed back into the intake to be burnt in the combustion chamber and exit via the exhaust. The only problem I can see by venting to atmosphere with a filter is that it will eventually get blocked by the oil laden air passing through it. This will cause excessive pressure build up in the bottom of the engine. The pressure will then blow some seals or oil will be forced by the piston rings as the pressure has no where else to escape (like your dipstick Botchi, I remember your last post http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >).
However on high power engines excessive oil fumes circulated into the intake can cause detonation and eventually engine failure.
A better solution than venting the fumes to air directly is to fit a breather kit. This consists of a purpose built oil seperator in the line between the cam cover vent and the air intake hose so only clean air is vented back into the intake.

Check out [URL]http://www.powerengineering.co.uk/mitsu/index.htm[/URL] and scroll down to see the breather kit.
 
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Discussion Starter · #5 ·
Not by much !

Still , u got to post the workshop manual illustration of the sump plug gasket
 
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Discussion Starter · #6 ·
OK one for you Evoboy.
Is it just boost increases that would need a breather system to help out, obviously increased intake pressure would create increased blow-by pressure but what about other non-boost pressure increasing mods?
 
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Discussion Starter · #7 ·
Thanks guys! I guess I'll be getting my friend's Cusco oil catch tank. He's selling it quite cheap, so this would be the way to go for me then!
 
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Discussion Starter · #8 ·
Heave,
Boost does it , higher running temps does it (this wud be noticable on say a track day where high to full throttle is used much more than on road use) , more revs does it ie: upping the redline , flowed and ported heads wud do it.

The ultimate solution for the lubrication system wud be a dry sump system , this makes stabilising oil temp and engine breathing easy.

High crankcase pressure can cause oil starvation and high oil temp , but this wud only become an issue on a highly modded motor,Like mine will be shortly
 
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Discussion Starter · #9 ·
Thanks Evoboy,
I remember the Lotus Esprit had a dry sump system but was changed back to the original system after trouble with it (I think they had trouble with the scavenger pump but I'm not sure). What are the disadvantages of a dry sump system on an everyday road car?

Just like to increase my knowledge a bit
 
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Discussion Starter · #10 ·
Primary is cost , probably around £1500 for a quality installation.
Then relative complexity , locating the oil tank and routing the various oil and breather lines.
All Porsche 911 Type cars have dry sump systems , my last Porsche , a Carrera 4 , had no hassle at all with it's system.
 
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Discussion Starter · #11 ·
Oh bugger, just when I'd said that I wasn't going to spend any more on mods!

So come on, at what level of performance does this breather kit become required? Couldn't I just run without any oil and achieve a dry sump? http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle > What does a "proper oil separator canister" comprise of coz it looks like a coke can to me [img]http://www.ltregister.f9.co.uk/graphics/wink1.gif border|EQU| 0 align|EQU| absmiddle >

Cheers

Naunt
 
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Discussion Starter · #12 ·
Naunt,
Not too far wrong with the coke can analogy. In simple terms they are cylindrical, with an input feed towards the top of the can. Opposite the input feed there is an output feed, but inside the can (between the two feeds) is a plate. The oil carrying air comes in though the input and hits the plate, which the oil then begins to run down. The plate doesnt fully block off the inside of the can so the air can make it to the output. The oil collects in the bottom of the can, and there needs to be some way of draining it away, normally back into the sump. You can take the air via a filter and pass it back into the air intake or you can just filter it and vent it to the atmosphere.
 
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Discussion Starter · #13 ·
Naunt,

A universal oil catch can made by Cusco is sold locally for about 10,000 PHP, which runs to about 145 UK Pounds, plus I guess your ghastly labor cost!

Following what Evoboy said n his previous posts, I think it's safe to assume that YOU NEED the damn thing, if not a full dry-sump conversion! http://www.ltregister.f9.co.uk/graphics/happy1.gif border|EQU| 0 align|EQU| absmiddle >

Group A Internals huh?! Wow! [img]http://www.ltregister.f9.co.uk/graphics/tongue1.gif border|EQU| 0 align|EQU| absmiddle > [img]http://www.ltregister.f9.co.uk/graphics/tongue1.gif border|EQU| 0 align|EQU| absmiddle > [img]http://www.ltregister.f9.co.uk/graphics/tongue1.gif border|EQU| 0 align|EQU| absmiddle > How much did it cost, if its OK to ask? [img]http://www.ltregister.f9.co.uk/graphics/wink1.gif border|EQU| 0 align|EQU| absmiddle >
 
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Discussion Starter · #14 ·
Botchi

I’ve not got Group A internals, I’ve just got the ARP bottom end bolt kit, Ralliart ECU, HKS air inlet, Magnex/Blitz turbo back decat exhaust and HKS BOV.

Everything was fitted during the Tuning Japanese day except the BOV so I’m not sure if I really need the oil breather kit as it only just topped 340bhp

Cheers

Naunt
 
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Discussion Starter · #15 ·
Naunt,
This might explain it better:


(Pic drawn by Greg Zajaczkowski, distributed on gsr_evo list)
 
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