15 replies to this topic

[uksnowman]

Hi everyone,

I need your expert eyes and knowledge. My engine is leaking like a sieve. When cool on tick over the engine is as dry as a bone. After a trip out there is oil all under the car and on the under side of the bonnet.  This along with a few other little jobs has become my winter project. Drive shaft seals, rocker cover and timing cover seals are new. The oil on the underside of the bonnet seems to be coming out of the small hole in the cap. Oil pressure seems ok as does the engine temperature. 

I have seen some people with a small catch tank attached to the inner wing. Would this help? 

Thanks 

Peter 

[fwdracer]

What effect is it having on the sump oil level, are you losing very much? Can you ascertain where it is pissing out from or is there too much spread around?

 

It sounds like crankcase pressurisation due to blow-by. On an NA unit it can cause seals to let go and the engine will find every possible leak path, as you've replaced all these the oil will find the path of least resistance - I'd think on an S/C engine unit it would be like adding an air compressor, hence it pissing all over the engine bay.

 

The catch tank you mention is to catch oil when engines 'breathe" very heavily - via large bore open circuit breathers. I have one on my race A-series (Normally aspirated) and empty it a couple of times a season.

 

Is your engine on closed circuit breathing (tubes from engine breathers-transfer case/timing cover) piped back to inlet manifold) - Or open circuit (vent to atmosphere)? Have you got enough breathers?

[maccers]

I use a small ally catch tank for crank case venting. I fitted a vent where the fuel pump would normally go on the back of the engine, got rid of the standard canister type on the transfer case side, and fitted another vent there, and also into the rocker cover. All 3 are piped into a catch tank that's vented and connected to throttle body vac. Works perfectly, no fumes in the car and no leaks anywhere.

[uksnowman]

Ok so i only have a breather on the clutch side and a hole in the rocker cover cap. All are vented to the open air. Oil Seems to be mostly coming from the rocker cover cap and then following the fins on the rocker cover, which distribute oil nicely all over the engine.  Researching this on various sites seems to suggest i need more breathers.  I am therefore planning to modify my rocker cover to take pressure away from that area. I will also try and find a way to install a breather to the right hand side of the engine, however this may be tricky with the supercharger in the way. 

I will probably pipe all of the breathers into a catch tank rather than to the carb. I will try and take some pictures when i have modified things so you can all cast your eye over it.  

What are people using for catch tanks? home made or sourced ? 

[maccers]

The timing chain cover breather on mine was removed, since like you say it would foul the belt. Instead I got a little attachment for the fuel pump hole that allows a pipe to be connected for venting.

 

Catch tank I use is a 1 litre alloy thats been modified to take extra pipes. Cant recall where I got it from now but internet search or ebay it.

[uksnowman]

Maccers, For the fuel pump breather you mention, was that a bolt on piece available from a shop or was it something you had to make up ? Looks like i may make up a custom catch tank out of aluminium. 

[maccers]

I got it from DSN classics, and also the transfer case adapter too, ie to remove the big canister type as it got in the way.

 

Link for fuel pump hole breather : http://www.dsnclassi...t-billet-alloy/

 

Link for transfer case hole breather:  http://www.dsnclassi...t-billet-alloy/

 

They come in various bore sizes, I went for 5/8" for both, in black

 

Cheers,

Richard.

[maccers]

Just looking again at their site, they have more alloy bits than when I bought the above, wish I'd not looked now, kid in a toy shop I am!! I already got the interior handle set, very nice it is too!

[OfMini&Men]

have you had a leak down test done?

 

My mates mini use to breath oil everywhere on a run, turned out the piston 2 was a goner, rings then followed by piston complete melt down

 

Edited by OfMini&Men, 12 December 2013 - 10:10 PM.

[uksnowman]

Maccers you are teasing me.  Luckily for me my birthday is in a couple of weeks. Think i should get round to assembling everything towards February ready for testing.

[maccers]

DSN do some good bits eh!!

[uksnowman]

So the new breathers are on, i went for one on the fuel pump blank and the other above the clutch. Piped them both into a 1 litre catch tank, Now when the engine is running there is fine smoke coming out of the filter fitted to the catch tank. should i fit a larger filter to the catch tank or pipe the filter out under the wing? 

[MIGLIACARS]

if there is fine smoke coming from the breather is means the engine is on its last legs.

 

there should be no smoke on a fit engine.

 

does it smell oily

[uksnowman]

Yes it smells oily. This has only happened since i fitted the supercharger which led me to believe it was a result of the modifications. Do you have any suggestions on what may be on the way out ? piston rings? 

[MIGLIACARS]

worn bores.

rings worn.

 

is there a white/oily sludge congregating to