Gush.

Post by **Peetee** » Fri May 19, 2006 8:00 am

OK, so I filled him with the wrong grade of engine oil

but it only emphasises the fact that there is a leak that needs tackling. I believe it may be from the rear crank seal (converted Ital 1275) as the scroll thing can be unreliable, but it also weeps from the rear of the rocker cover. it's definitely predominantly when the engine is running which makes me think it's the scroll but anyone got any other ideas?

Post by **Cam** » Fri May 19, 2006 9:40 am

What grade did you use?

If it's the rear crank seal then usually (if it's bad) it gets onto the clutch and causes slip.

The rocker cover problem should be solved easily enough with a new gasket.

How much oil is it getting through?

Post by **bmcecosse** » Fri May 19, 2006 6:32 pm

Leaks are sometimes exacerbated by high pressure in the crankcase. (Note - NOT high oil pressure!). So - make sure the breathers are clear - and it's best if one of them is connected to the inlet somehow - some SUs have a little pipe on the side for this - i have used a connection on the manifold with a small hole to limit the suck !

Post by **rayofleamington** » Fri May 19, 2006 6:59 pm

yes - breathers need to be open otherwise the crank case pressure will cause a leak!
Relfy's car had a blocked breather from the tappet chest cover - this caused the engine to blow out of the filler cap - this let oil an oil mist out which was dripping off the inside of the bonnet and everywhere else too!

Trace the leak back as much as possible. If the cylinder head is covered in oil - then the leak is from above.

If something is leaking onto the fan belt it's going to get sprayed around, but at least you will know where to start looking.

A leak at the rear crank seal will cause oil to get into the bell housing. They all do this to some extent so all high mileage Mionrs will have a slimy bellhousing.
You should be able to see a lot of oil coming out the bottom of the bellhousing if it is bad leak.

Post by **Peetee** » Fri May 19, 2006 8:27 pm

There is no evidence of clutch slip. The oil is dripping off /near the plate that is welded to the sump and overlaps the bellhousing. I guess it could be the sump gasket, the rocker cover gasket or both.

Post by **rayofleamington** » Fri May 19, 2006 8:33 pm

The oil is dripping off /near the plate that is welded to the sump and overlaps the bellhousing. I

Are you sure it's a Minor? ;)

my best guess is that you mean the engine back plate, bolted to the rear of the engine just behind the sump. If this is covered in oil on the sump side it won't be the rear crank seal (wrong side of the plate), but could be sump leak or anywhere higher right up to the rocker cover.

Post by **plastic_orange** » Fri May 19, 2006 9:16 pm

Would agree with bmcecosse. My mate built a quick midget motor (1430 I think) and he was plagued with this fault until he connected the crankcase breather to the inlet.

Pete

Post by SR » Fri May 19, 2006 9:22 pm

on a similar note ,is mine set up right? breather from rocker cover connected to air filter housing, tappet cover pipe just points down to ground?

Post by **Willie** » Fri May 19, 2006 9:32 pm

Steve ,yes, yours is correct for that engine provided that the oil filler cap is
solid i.e. not the type with a wire filter in it.

Post by SR » Fri May 19, 2006 9:38 pm

cheers willie

Post by **Cam** » Sat May 20, 2006 1:56 am

rayofleamington wrote:Are you sure it's a Minor? ;)

That sounds very much like a Marina/Ital sump. The plate (with two holes in the end) is conected to the sump and then trails under where Pete explains.

Unfortunately it will catch oil from the sump gasket AND/OR the rear crank seal (well the bell-housing/backplate joint). Bit difficult to locate with this sump, but the best thing would be to steam clean the area and dry it then go for a drive and observe where the leak seems to come from (with a torch looking above the plate).

Post by **WPR678B** » Sat May 20, 2006 8:24 pm

I have a similar problem! I discovered today that the engine is pressuirizing the rocker cover and causing smoke/oil mist to force its way out through the filler cap! The only breather there appears to be on the engine is from the timing chain cover and that is linked to the backplate of the airfilter and causes the airfilter housing to build up with oil and drip down onto the engine bay floor! I took the pipe off and blew through it and it was clear, and when it is connected to the timing cover and you blow through it there is no resistance and the air comes straight back out of the rocker cover (this is with the filler cap off!). I have noticed that it has been leaving quite a puddle when its parked after a run and i wondered if anyone had any idea's on what else to check / what is wrong? It has only just gone back on the road after being layed up for 6+ years if that may have some bearing on it?

Post by **bmcecosse** » Sat May 20, 2006 8:31 pm

Well - it sounds like there is a great deal of oil fume being sucked up the breather pipe - engine on it's last legs ? With the engine hot and idling - take the filler cap off - is there a plume of oil fume ? You could fit a rocker cover with a breather connection - and use that too.

Post by **WPR678B** » Sat May 20, 2006 8:43 pm

Yes, when you remove the filler cap with the engine running it is puffing out like a steam train! It doesn't smoke from the exhaust though, but runs a bit lumpy on idle but smooth and quiet as anything when driving so would hope the engine is not on its last legs!

I have tried all sorts to get it running smoother on idle but no improvement! I tried to connect the timing chain breather to the hose tail on the side of the carb but the engine wouldn't even start then until i kinked the pipe! I will try the rocker cover with a breather and tee it into the back of the airfilter housing, but i am a bit concerned that may cause the housing to fill up quicker maybe? Well worth a go though! Thanks BMC.

Post by **Peetee** » Sun May 21, 2006 9:45 am

As mentioned in the first post the engine is a 1275 Ital. The breather appears to be working as the air filter shows signs of oil contamination.
Neverthless, is there a potion that I could pour down the breather pipe that would dislodge the oil mess - something really strong that I could just pour out of the sump when I remove this to check the gasket?

Post by **Willie** » Sun May 21, 2006 10:01 am

WPR...Re your oiled up air filter, the first thing to check is that the hole
in the tube to which the breather rubber pipe fits on the filter is only approx.
1/8th of an inch in diameter. There are some filters out there which have
much larger holes which are not suitable for 1098 engines and which will allow
excessive oil into the filter. If yours is too large then you can fit a suitable
sleeve in the pipe which will cure this problem straight away. Before you do
that I would point out that your breathing arrangements are not correct IF it
is a 1098 engine? If you have a breather on the timing cover it should go
directly to the CARB not the air filter and the fact that you have a suitable
pipe on your carb confirms this. If you do have this system then it would
require an oil filler cap which has a wire filter in it because this then becomes
the breather INLET. The wrong (solid) filler cap would cause the engine to
drink its own oil.

Post by **WPR678B** » Sun May 21, 2006 11:03 am

Willie,
I have a 1275 Marina engine fitted with the breather on the timing chain cover and no tappet chest covers. I have a Mini 1+1/2 SU carb with the hosetail on the side as the later 1098 carb had. My air filter housing is a 1098 one with a modified backplate to suit the bigger carb. The hosetail on it is 3/8 - 1/2 inch diameter bore and i fitted one with the 1/8 inch hosetail but it just made the rocker cover pressure even greater, so i have changed it back to the larger one! The filler cap was the non vented type which caused a great deal of pressure build up so yesterday i changed it to the type with the wire filter in to ease the pressure but have only done a couple of miles since so not sure if it is going to spray oil out through there or not! It is definatly not working as an inlet though, there is a real hiss of pressure coming out all the time the engine is running. I did fit the timing cover breather tube to the carb but the engine wouldn't even start until i kinked the pipe and as soon as it was un-kinked the engine died due to loss of vacuum! I'm puzzled by this one to say the least so any more suggestions gratefully received!

Post by **bigginger** » Sun May 21, 2006 12:06 pm

WILLIE - just an idle thought, but is there any chance of you writing a piece on engine breathing and putting it in 'Useful tips'? I (for one) would find it very 'useful'

Post by **Willie** » Sun May 21, 2006 3:02 pm

The breather on the timing chain cover should go to the CARB and yours has
the fitting ready to receive it. That is the OUTLET and the INLET is the oil filler
cap with the wire filter in it. The wire filter is to stop foreign bodies going in
to the engine not to stop anything from coming out! It is worth checking with
1275 runners as to what needle they are using in a successful set-up as,
obviously, with the carb sucking in the engine fumes the mixture would require a particular needle. If you have been running with a solid oil filler
cap then the engine has been sucking oil so you should notice an improvement but the breather should still be connected to the carb. It could
be as simple as readjusting the mixture when the pipe is fitted to the carb but
I am not an expert on the 1275.

Post by **Willie** » Sun May 21, 2006 3:08 pm

Big Ginge....will work on it.