71 replies to this topic

[sonscar]

But the motor in question is a high performance supercharged engine,Steve..Each to their own and all that,suggestions were made after advice was sought.I think all answers have their merits and I know my contribution to air quality is unlikely to save the planet but I like fresh air and try to do my small bit where I easily can.Just trying to be helpful.

Edited by sonscar, 14 August 2021 - 07:12 AM.

[Dusky]

I’m with Steve
You have a performance supercharged engine
Why would you set it up like a standard engine
On mine I have following
Clutch breather to rocker
Old fuel pump to rocker
Then rocker to vented catch can
This way allows any oil to drop out into rocker before going to catch can. When I had them routed directly to can it would fill with oil during track use

Because it's not a track only car. The only reasons racers don't run pcv is because it's 1) not allowed sometimes 2) slight oil contamination could lead to pinging.
I hope you change your oil too after every trip, being a race car car and all.

Who mentioned track only car ?
And yes I change oil quite often
I have no problems with oil leaks so why would I need
Pcv?

Because pcv does more than preventing leaks.
Well, you didn't set it up like any production supercharged engine either. So there must be something extraordinary about it.

[NZMini1275]

I’m with Steve
You have a performance supercharged engine
Why would you set it up like a standard engine
On mine I have following
Clutch breather to rocker
Old fuel pump to rocker
Then rocker to vented catch can
This way allows any oil to drop out into rocker before going to catch can. When I had them routed directly to can it would fill with oil during track use

Because it's not a track only car. The only reasons racers don't run pcv is because it's 1) not allowed sometimes 2) slight oil contamination could lead to pinging.
I hope you change your oil too after every trip, being a race car car and all.

Who mentioned track only car ?
And yes I change oil quite often
I have no problems with oil leaks so why would I need
Pcv?

Because pcv does more than preventing leaks.
Well, you didn't set it up like any production supercharged engine either. So there must be something extraordinary about it.

🤣🤣
Nope just trying to share some experience with someone that has a similar setup but it seems that this forum is only for Standard engines

[Dusky]

Don't think this forum is only for production engines. Just wondering why people add "race bits" to a street engine and expect it to be an improvement. But you do you and all that :)

[Steve220]

I bet modern blown motors which are almost race engines all use closed circuit breathing.If the blow by is enough to cause detonation you probably have greater problems.I qualify this by saying I am no race engineer.Steve..

There's a difference between doing it for EU/manufacturing regulations Vs. what is achievable with after market modification and knowledge. A PCV would only mean you take in crank case pressure on idle, which is next to useless on a high performance engine as the crank case will still pressurise (all charged engines do, some OEM engines even have a crank case vacuum pump for on boost). We're going down a rabbit hole of what in real world figures would very little on an A series - The engine is renowned to breath heavily, especially when boosted. On the extreme, in 2011 the FIA ruled out F1 engines from using crank case scavanging through the exhaust (primarily for emissions), an amazing principle for high rpm/boosted engines! But would never be seen on OEM, however i know a few boosted minis using the system now.

 

On mine, i've got a filter on the transfer case and a 1" pipe (there's also a 13mm pipe coming from the timing chain cover that T's into it) going to a vented catch tank under the wing.

 

(old pic)

 

[sonscar]

Thanks for the insight and nice install.Why dont we liner the Mini engine with better liners and use better pistons and rings to achieve modern standards of tolerances.Similarly build the head and use proper management to control it all?Might be too costly for too few customers?

In my experience of classic cars there is a large swell of "we do not do that do we?All my cars are rubbish and I have tastelessly modified them some have worked and some have not but I try to not stop learning.

 006.JPG   85.33K   2 downloads  007.JPG   83.49K   2 downloads

I did this15 years ago and embarrasingly have not touched it since as it all still works and it is my daily 1800 MGB.It runs Megasquirt1.Steve..

[Steve220]

Also, some in depth watching

https://youtu.be/TvazViNq12M

[sam138]

Thanks for all the reply’s, so after all is my set up incorrect ?

-Clutch and old fuel pump connect into a tee and go to the vented catch can.

- I have a return from oil catch can to rocker cover.

Thanks

[Steve220]

Thanks for all the reply’s, so after all is my set up incorrect ?

-Clutch and old fuel pump connect into a tee and go to the vented catch can.

- I have a return from oil catch can to rocker cover.

Thanks

That's fine.

[GraemeC]

 

Thanks for all the reply’s, so after all is my set up incorrect ?

-Clutch and old fuel pump connect into a tee and go to the vented catch can.

- I have a return from oil catch can to rocker cover.

Thanks

 

You don't really have a return to the rocker cover as that will already be at positive pressure (hence why the oil filler cap is a breather system). 

So all three will be putting air into the catch can and it is venting via the filter on top of it.

Edited by GraemeC, 15 August 2021 - 10:07 AM.

[Steve220]

 

 

Thanks for all the reply’s, so after all is my set up incorrect ?

-Clutch and old fuel pump connect into a tee and go to the vented catch can.

- I have a return from oil catch can to rocker cover.

Thanks

That's fine.

 

 

You don't really have a return to the rocker cover as that will already be at positive pressure (hence why the oil filler cap is a breather system). 

So all three will be putting air into the catch can and it is venting via the filter on top of it.

 

As long as it has somewhere to vent, it will be fine. After writing, i did think how big the vent hole is on the catch can, as that will be the governing factor.. as well as if the oil cap is breathable.

[sam138]

I’ve got a vented oil filler cap and the vent on the catch can filter has 1/2” outlet.

Thanks for all the reply’s, so after all is my set up incorrect ?

-Clutch and old fuel pump connect into a tee and go to the vented catch can.

- I have a return from oil catch can to rocker cover.

Thanks

That's fine.

You don't really have a return to the rocker cover as that will already be at positive pressure (hence why the oil filler cap is a breather system).
So all three will be putting air into the catch can and it is venting via the filter on top of it.

As long as it has somewhere to vent, it will be fine. After writing, i did think how big the vent hole is on the catch can, as that will be the governing factor.. as well as if the oil cap is breathable.