Jump to content


Photo
- - - - -

Time For A Catch-Can Breather Setup?


  • Please log in to reply
17 replies to this topic

#1 Midas Mk1

Midas Mk1

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 4,941 posts
  • Location: Manchester
  • Local Club: S.U.N.M.C

Posted 14 June 2018 - 11:27 AM

Hi All,

 

I've been looking at the MED catch can  & rocker box kit, for potentially one or both of my Minis.

 

I'm currently running CCV on both, using timing cover, transfer cover fed into the inlet (using SC injection kit)

 

Now the engine is fairly high spec, 1312, forged omega pistons etc, and i've read up that these forged pistons use abit of oil. 

I've been dailying her for the past few months, and noticed im going from max to min on the dipstick in about 250 miles.

 

 Now I think i've got a slight leak from the timing cover, and temp sensor on the oil fitter is misting, but im just a little concerned its alot? I've noticed the oil cap has a slight bead of oil on it when checking, through the breather hole. 

 

It is a road car, but both get driven hard. I do lots of high revs aswell, usually sitting  above 4k for a good few miles each day, aswell as regular blasts to 6k+

 

Im under the impression ccv works best at low revs / idle? and maybe im not getting enough breathing when im on the move, so was considering a catchcan setup? Im conscious of the fumes from this though, which is a concern.

 

 

I've checked the breathers, their clear and not gummed up, compression is good across all 4, and done both that and a leakdown test before and recently, both being fine.

 

Am I just worrying about nothing with the 250 ish miles max to min?

 

My other engine is pretty similar, but then is driven hard too. It's not smoking, on wide open throttle, or on overun. 

 

Any advice ccv or catchcan welcome, just wanting to see how others have found both setups on hot spec engines?

 

Cheers!



#2 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 14 June 2018 - 11:44 AM

so why would you want to change? it aint a race car.

 

you have not said anything that suggests that you need to change.

 

change if you want but expect smells. and more oil leaks. it is amazing what a slight vacuum can do for an engine.



#3 Midas Mk1

Midas Mk1

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 4,941 posts
  • Location: Manchester
  • Local Club: S.U.N.M.C

Posted 14 June 2018 - 11:49 AM

Thought that maybe at sustained higher revs it's not breathing aswell, therefore using the oil quicker? , is 250 miles is not too bad then max to min for a hot spec engine?

I've been doing 130ish miles a day the past week so been topping it up nearly every other day, and just thought better breathing might have helped. 



#4 Allrounder

Allrounder

    Mini Mad

  • Members
  • PipPipPipPip
  • 177 posts
  • Local Club: Hereford Motor Club

Posted 14 June 2018 - 12:46 PM

Think min to max on the dipstick is nearly a litre so I’d say yes that’s alot of oil for the mileage. What do the plugs look like, I’d expect to see deposits on them if it burning the oil.

#5 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 14 June 2018 - 12:53 PM

Think min to max on the dipstick is nearly a litre so I’d say yes that’s alot of oil for the mileage. What do the plugs look like, I’d expect to see deposits on them if it burning the oil.

more like 1/2 a liter, actually a Pint.



#6 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 14 June 2018 - 01:01 PM

Thought that maybe at sustained higher revs it's not breathing aswell, therefore using the oil quicker? , is 250 miles is not too bad then max to min for a hot spec engine?

I've been doing 130ish miles a day the past week so been topping it up nearly every other day, and just thought better breathing might have helped. 

you say it is a hot engine but you only gave a size and that you are using an injection set up.

 

a vacuum set is better than any other set up. as it gets the water vapor and combustion by products out of the engine and out.

 

an open system does nothing other than let air move in and out, and if you have a mechanical there is somewhere to catch the oil.



#7 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 14 June 2018 - 01:02 PM

 

 

Am I just worrying about nothing with the 250 ish miles max to min?

 

 

that would be high for a standard engine but not quite rebuild time.



#8 Midas Mk1

Midas Mk1

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 4,941 posts
  • Location: Manchester
  • Local Club: S.U.N.M.C

Posted 14 June 2018 - 01:51 PM

Thanks for the quick replies guys', i'll get some pics of the plugs lat er after a 30 mile drive. 

Chilli Wise it's got a tame sw5, but fully lightened, balanced bottom end, 1.5 rockers, 37/31 race head etc.
Head was checked 4k ago, new mpi type seals, guides were bang on.
Spends hours sitting at 4-4.5k on  the motorway occasionally hitting 6.5k on blasts, which got me onto thinking is this where the oils going. Oil doenst get past 90 degs either. 

It does have a slight leak, which I put down to the rocker box, changed and still there, its a little leak, not dropping half a pint on the floor sort of leak. 

 

Running Millers CTV, 



#9 Midas Mk1

Midas Mk1

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 4,941 posts
  • Location: Manchester
  • Local Club: S.U.N.M.C

Posted 14 June 2018 - 05:10 PM

Right then, got home to find oil over the rocker cap, and having ran down directly in front and behind of the cap onto the rocker box. Undone the breather pipes and all clear, so wondering why I'm getting oil out of the cap? :/ 

 

 

Whipped plugs out, look fine, not oily. Gave it some stick, goes good and no smoke, just a few drips of oil when parked up. 

 

 35347204_10211480193951733_5937978048350

 

35237395_10211480194831755_237717572014635416051_10211480194791754_513870343793135239658_10211480194871756_1606091136164



#10 imack

imack

    Speeding Along Now

  • TMF+ Member
  • PipPipPipPipPip
  • 318 posts
  • Location: Orpington, Kent

Posted 14 June 2018 - 09:23 PM

Difficult to see in the photo but is the oil coming out of the hole in the top of the cap or is it, like mine, coming from the joint between the inner and outer portions of the cap? I have the same cap and I prised the top off the cap to separate it from the inner bayonet part of the cap.
I reassembled the cap with red hermetite sealant between the inner and outer parts of the cap and fitted an oil separator gauze inside the cap as well - no leaks since.

#11 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 15 June 2018 - 12:21 AM

**** cap. never liked them. caps are/were a service part. change it. how are your vents connected?



#12 timmy850

timmy850

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,659 posts
  • Location: NSW, Australia
  • Local Club: MITG

Posted 15 June 2018 - 03:09 AM

A catch can does not have to be smelly or leaky. I bought a baffled catch can from my local parts shop as I was getting a bit of oil buildup in my air filter case (and I had a Christmas voucher to use). 

 

This one fits in perfectly in the corner of the engine bay
40032197834_db2cb1de99_c.jpg
This one is completely sealed too, no extra smell. It just gets installed in the middle of the breather hose and is now connected to the carb port 
40784644221_f956f25af7_c.jpg

Possibly it's overkill or unnecessary, but I've collected a little bit of oil and moisture in there in the past 1000km and in my mind it's better getting trapped in there than going into the engine.

42088985474_f90ca164ef_b.jpg



#13 Moke Spider

Moke Spider

    Crazy About Mini's

  • TMF Team
  • PipPipPipPipPipPipPipPipPipPip
  • 7,589 posts
  • Location: NSW
  • Local Club: South Australian Moke Club

Posted 15 June 2018 - 05:03 AM

CCV works best when the engine is making highest outputs and has the highest air volume flowing through the Inlet tract, which is also when you're most likely to have some blow by.

 

Catch Cans and similar systems are used in competition as tey don't dilute the Intake Charge with Oil fumes, which reduces Octane.

 

I'm not altogether sure how street legal catch can systems are and I'd suggest you look also in to this before going down this route. You'll also need to change your Oil much more often as it wil build up Moisture and Acids much faster without a positive Crankcase Ventilation System in place.

 

I doubt your Oil Consumption has anything to do with the type and Crankcase Ventilation System you have.



#14 Midas Mk1

Midas Mk1

    Up Into Fourth

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPip
  • 4,941 posts
  • Location: Manchester
  • Local Club: S.U.N.M.C

Posted 15 June 2018 - 07:28 AM

Cheers guys! The oil cap is indeed crap, i've bought a new mg metro orange from MiniMine on ebay, so will see what things are like with that! Also noticed that my alloy dipstick is sloppy and lose compared to my other Mini, so im sure this won't be helping. Oil from the existing cap looks like its both from the hole and around the filler neck, fitted a new rocker gasket on tuesday as this was leaking.

 

I'm going to clean up the engine / block over the weekend, try the new cap, then see where if any there is oil coming from. Would adding an extra breather from the fuel pump blank be beneficial or overkill?

 

 

The sc pipework to the inlet manifold is narrow - will measure, but maybe this could be an issue, certainly looks smaller than the ccv inlet on my hif44. 

 

 

Currently the CCV is plumbed in to the inlet & air filter, using the standard MPi pipework on the block from crankcase / timing cover. (MPi setup, early a+ block)


Edited by Midas Mk1, 15 June 2018 - 07:34 AM.


#15 imack

imack

    Speeding Along Now

  • TMF+ Member
  • PipPipPipPipPip
  • 318 posts
  • Location: Orpington, Kent

Posted 15 June 2018 - 08:25 AM

Adding an additional breather to the fuel pump take off can't do any harm, seem to remember the vizard book saying you can't have too many breathers on a big bore engine.
I seem to have solved the oil leak issues from my filler cap with the above mods, but when I did the cap I also made an additional breather/oil separator cannister attached to the rocker cover.
I run 3 open breathers on my 1380, standard bmc one on the timing cover with a small k&n filter, an early 1967 austin 1300 open breather/separator (nla) on the transfer case, my home made open breather/separator on the rocker cover plus the small hole in the filler cap. I've never noticed any fume smells from the open breathers and I dontget any oil misting around the breathers from my current engine although I did get misting around the transfer case breather on my previous worn out 1380.
If you're using an A+ block I find even genuine dip sticks are a loose fit in the block. I've added a piece of heat shrink tubing to the seal area of my dipstick to make it a snug fit in the block and then added a carburettor return spring between the dipstick handle and dizzy clamp to further secure the dipstick.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

Mini Spares