Oil leaks versus oil pressure ??

[ozziedog]

Hey guys, have this bus for a couple of years now and never opened up the motion department. Been fannying about with a lot of the other issues. I`ve done a few miles in it but usually no more than 5 ish miles when I`m trying something out. The bus has been leaking oil at a fairly steady rate since I got it and it drip nicely onto the heat exchangers etc etc. If we been out for a spin and then we park up back at the ranch within an hour the drip has subsided and it`s about the size of a *** packet in 2D not 3D. Got those really sexy cool chrome rocker covers and clips on and it looks phenomenal if you happen to get run over by my bus I bet you`d say " Wow what a cool bus " as it was going over you. So I ripped them off and the clips and put some original types on with nice new (GSF) cork gaskets with a hint of assembly paste on each side (copper). Fantastic, no more oil leaks for about three weeks, until we were coming back from W.S.Mare last Sunday and three of us responding to an international rescue effort,, :shock: It was Thunderbirds Are Go as three bays went hurtling up the motorway to the rescue of a dodgy old split, ,,, that was fixed by the time we got there. So I actually reached the giddy speed of 62 mph at one point over an 8 ish mile stretch. But when we looked back at the assembled Thunderbirds one of them was sending smoke signals out of his vents, looked like he was having a *** after the little sprint. Topped up the oil and proceeded at a more stately pace back to Bristle. Now am I right in thinking this little sprint has blown my gasket again and if I replace it with a new gasket or bolt on covers, the same will happen again on hitting breakneck speed but okay for tootling about the place. If so,, there must be a slightly more sinister issue :shock: Crankcase pressure ??? Caused by Rings ???? or Scabby breathers ??? Your thoughts please gang and recomended procedures, and a logical way of diagnosing :? Not too much then :lol:

Ozziedog,,,,,,,,, Getting my breath back :lol:

 

[ozziedog]

Just did a little search on oil leaks,, never done a search and had so many matches before :lol: I think I got about ten pages. Makes good reading. The concensus of opinion is aftermarket fillers etc are part of the issue, blocked or smaller breathers, and twin carbs slightly over taxing an aged system. Quite a mixed reaction to breather boxes ?? :? So let`s go and have a little look at what I got :shock:

Ozziedog,,,,,,,,, :mrgreen:

 

[dubdubz]

talking to yourself again ? :lol:

thought that was only me.....

it depends - getting back to your questions - what engine config you have, ie what heads, what CR, what carbs, the mileage it has potentially covered.

I have a fairly high CR for a bus in my ministroker, a 1745 [so that's a 76counter weighted crank and stock 1600 top end...well if you count big valve heads stock :lol: ], anyway I get crankcase pressure as the pistons are moving more air - longer stroke ....so I get weeps from the usual places, the consensus for me is to install rocker cover breathers.

Now if you've got a tired or mildly worn you'll get possible blowby and pressure issues, the snag is a extra breathing will help reduce or even stop it, BUT the root cause may well still exist.

So my garbled reply is possibly summarised by extra breathing will more than likely keep the oil where you want it, but at some point it'll need fixing assuming its a stock engine and the reason for additional pressure is something isn't quite right ie rings

The thing I'm not sure about is the route the pipework should take to get from the hot side rocker covers up to a n other breather in the cool top section...cool as in colder not 8)

:lol:

 

[ozziedog]

Yeah,,,,, I thought I was the only one on there today ! So I thought I`d pose the question and do the answers :lol:
I`m guessing it`s a stock 1600 twinport with crappy air filters, and I`m also guessing it`s a little tired as you suggested so a little extra breathing may keep it on the road for this summer and maybe a little more. I want to keep it as a rolling resto if I can, and do bigger issues through the winter. The oil filler pedastal thingy has a small filter attatched to it so I`ll make some coffee and go and whiz that off for a sec and see what`s happening in there, might just need a bit of a spring clean. Don`t want to open up too much realy as I just know I`m gonna find something I don`t realy want to see :shock:

Ozziedog,,,,,,,,, Just want a quick fix :lol: 8) :lol:

 

[dubdubz]

I always lurk I'm on here nearly 24/7 perhaps I should be a mod?

yes I'd make sure the gasket at the bottom of the pedastal is free of gunk as that's the way it will naturally breathe up and out into the airfilter [on a stock system ]

what carb do you have ?

 

[ozziedog]

I hadn`t actually looked, so I just went down, 34 ict weber s. You may have sussed I know nowt about carbs so I had to get a mirror in there and a torch :lol: Not keen on the QD filters though. (touch em and they fall off) :shock: But that`s another game for another day, I hope. 8)

Ozziedog,,,,,, Now make that coffee and go and do something !!!!! :lol: :lol:

 

[dubdubz]

if you have no breather connection to your carb filters - doing so will help quite a bit as you create a bit of negative crankcase pressure by 'sucking' via carbs...

this is also something I need to do - you may find that's enough and you won't have to tap the rockers for vents too.....

QD filters??

 

[ozziedog]

QD Quickly detatchable, old motorbikin terminology, QD wheels etc, taken for granted nowadays. Also refers to something that will maybe just fall off if you stare at it too hard, :lol: As in the case of my flimsio type air filters, and they are absolutely QD :shock:
But that`s another project for another day. Today I have a piece of old water pipe, heater rad I think, hooked up to the breather assy on the pedestal, and dangled down by the engine hanger 50mm in front of zorst <--- see that was me doin metric. We is just about to test drive and see what happens. Also fitted some rather groovy mirrors, I`ll get some photos while I`m out and about terrorising the local motorists (holding them up).

Ozziedog,,,,,,,,,, Language,, all his own, 8) :roll: 8)

 

[Slammed]

Ozzie, the ONLY thing to use on rockers is genuine rocker covers and clips, cork gaskets and NO sealant - put them on dry and as long as the gasket is sitting properly they shouldn't leak. If they do you can bend the clips a bit to get more squeeze. They should be a bitch to get on, lever them with a screwdriver. If you can do it by hand they won't seal.
Plus chrome clips and covers tend to expand with heat and then leak again, and bolt up rockers are totally uneccesary too.

In my experience a breathing problem in the engine is more likely to leak out from behind the bottom pulley, possibly a blocked breather, but shagged piston rings can also cause blowby and hence oil leaks.

 

[Trikky2]

Stock breather linked to the/a carb air filter will happily cope with even 2.2 engines let alone stock ones. Extra breathing, like on rocker covers, will only be needed for race engines and turbo screamers and wont cure leaking rocker cover gaskets.

 

[dubdubz]

Trikky - that's great news as I reckon I won't need to vent the rockers then

For twin carbs is it best to goto both and do you need to go via something that will drain back?? or a simple wide Y with the middle acting as the 'natural drain' ?

I don't leak from the rockers but was recommended to vent there to help reduce 'mini stroker' additional pressures, I wasn't convinced fully, so I'll try top venting 1st me thinks.....

made my day!

 

[Trikky2]

Venting into the top of one filter (on the right) will give you adequate suction and keep the pipe run simple and almost straight. On a T1 with twin carbs the height will mean that any liquid will run back of its own accord.

A simple right angled connector into the top of the air filter (same diameter as the outlet on the stock breather) will work fine.

 

[ozziedog]

Hey gang,,, thanks for the replies.. I wasn`t suggesting or trying to suggest that venting would cure my leaks on the rocker covers, which I have replaced with regular items with regular clips and new gaskets. It was oil tight for a while when I did that. What I was hopeing was by getting a bit of a clear breather and / or hooking into the filter (air) that I could run the rest of the summer without dripping everywhere as well as popping another set of gaskets on to seal him up at the same time (again) :? That didn`t come across as simply as I thought it, :lol:

Ozziedog,,,,,,,, Makes hard work of anything simple,, :shock: :lol: :shock:

 

[67westy]

Hooking up my breather correctly improved my oil leaks. It still pissed out, just at a slower rate :lol:

Hoping I've cured most/all of my leaks this week, fingers crossed!

 

[ozziedog]

So you can almost afford to rub it now :lol: :lol: :lol:

Ozziedeog,,,,,,,,, Petrol or oil, all costs a bomb !! :shock: :shock: