35 replies to this topic

[MFM]

Please advise what you believe should/would happen if the PCV valve was to be blocked off in a 202 XU1? 

[claysummers]

Crankcase fumes will find a less tidy exit, either via filler cap, breather pipe in to air filter, seals, gaskets.


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[MFM]

I guess I'm trying to work out at what it actually does considering the XU1 motors already have a breather on the filler cap? Wouldn't the valve distrupt the air/fuel mixture of the carbies?

[claysummers]

Not really unless you have a high overlap cam in which case they don’t work very well and then fitting the road draught tube is the way to go. Manifold can be tapped and PCV from another car fitted. On a mildly cammed engine blocking or fitting PCV won’t make any significant difference to how it runs though.


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[N/A-PWR]

Good read >>> http://www.bur.st/~o...nno/page37.html

 

 something to do with gumming up the motor with deposits, if not fumigated. 

Edited by N/A-PWR, 01 June 2020 - 07:49 PM.

[rexy]

Just run it. It’s a lot cleverer than you think. It doesn’t cost any power and helps with oil leaks to a degree - lord knows holden sixes love to leak!

[Dr Terry]

I guess I'm trying to work out at what it actually does considering the XU1 motors already have a breather on the filler cap? Wouldn't the valve distrupt the air/fuel mixture of the carbies?

All Holden 6-cyls from mid-1967 to late 1973 have the same set-up. (Also 253/308 V8 from 69 to 73). At idle the PCV sucks fumes from the crankcase while fresh air enters via the breather cap. 

 

At low vacuum (acceleration) any excess fumes that the PCV can't handle exit via the breather cap. It's a 2-way system.

 

Keep the PCV it will keep the engine less messy from oil leaks.

 

Dr Terry

[MFM]

Thanks Dr Terry. The car has the Bathurst grind cam so its pretty lumpy. I blocked it off temporarily to see what would happen and it wouldn't idle and when it did it ran like a pig. Driving was like I'd put a bigger cam in the engine? lots of fuel fumes. I can't remove my PCV valve to check its function as its stuck hard in the original rubber mount and hose, so I wound the mixtures half a turn in on the 'jet adjuster' (was adjusted to factory) and the whole thing sweetened up. I'm just playing around as there seems to be two schools of thought on these PCV valves. Some say by-pass it and use a catch can which I won't use as not original (rivet counter  ) others say leave it?

[crabba67]

Mark you have the wrong PCV valve for a 72 and the hoses have been replaced.Not sure what you mean by Bathurst cam?

 

Cheers

[MFM]

Anthony you got me on that one. Its not a HX or XH profile I know that much as had a GTR with that profile and it was timid compared to this one in the car. So to be honest I have no idea. As for the hoses on the PCV you will have to elaborate on what you mean as mine are very old and hard and should be replaced so figuring they are original. 

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[crabba67]

Mark The hoses you have is MacKay hose the grain looks a little different....maybe me or later hose

 

Cheers

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[claysummers]

Just give it a tug mark. It should pull out of the tappet cover. Been a long time but your PCV and main hose looks like HK 186 etc to me.


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Edited by claysummers, 02 June 2020 - 06:06 PM.

[Liz Clare]

Anthony you got me on that one. Its not a HX or XH profile I know that much as had a GTR with that profile and it was timid compared to this one in the car. So to be honest I have no idea. As for the hoses on the PCV you will have to elaborate on what you mean as mine are very old and hard and should be replaced so figuring they are original.

Don’t throw them out until you find replacement hoses. I’ve been told that the bent hose for the PCV is not available anywhere. I need one...

Cheers,

Liz


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[MFM]

Not sure about the hose heritage. Anthony you say my PCV valve is wrong for 72. Now that you have a photo, is it correct for May 72? If not what is it meant to look like?

[MFM]

No I won't be throwing hoses away. The brake booster hose is of a different texture and looks unusual. Can anyone tell me if this is original? Doesn't look like it would be.

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[S pack]

Brake booster vacuum hose 100% not original.

[S pack]

Not sure about the hose heritage. Anthony you say my PCV valve is wrong for 72. Now that you have a photo, is it correct for May 72? If not what is it meant to look like?

PCV is supposed to look like the one in Anthony's pic.

[MFM]

Thanks Dave, thought as much. Weird looking texture which I can't say I've ever seen before. Am pleased because its also perished and hard a rock so will be a pleasure to replace it. What type of hose do you suggest as a close resemblance to the original?

[MFM]

What is my PCV valve off? just curious. Is it off LC 186?

[crabba67]

The one on the left is 72 the one on the right is 73 just talking LJ XU1's.The Changeover from 72 to 73 is slightly different at Adelaide to Brisbane but both in Dec72.

 

Cheers

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[Bazza]

What is my PCV valve off? just curious. Is it off LC 186?

Mark, the PVC is the same part number (1533669) from at least the HK series right through to at least the LX series for the 6 cylinders - so don't worry about it.

 

Bazza

[MFM]

Thanks Bazza.I was worried and was crazily looking up XU1 engine bays on the internet looking at their PCV valves  and weirdly enough there was an  assortment of both types from the LC to late LJ (the common being the left version in the photo) so I'm back to your sound suggestion on just leaving it. Now just going to try and find a booster hose which looks close to factory texture as is not a show car.

[Zook]

I'd go with Crabba on this one. You want to get it right. Manufacturers change parts all the time yet retain the same part number because the replacement is a 'form, fit and function' replacement. The replacement parts do the same job but are not the same.

[crabba67]

The one on his car is not even a GMH one. The p/n number for a HK PCV valve 6 cyl is 6484309.

 

Be Happy

[MFM]

Shite now I'm back to confused again mines not even a Holden PCV WTF?