oil flow in the 6A13TT

[Davezj]

does anyone kow what the actual oil flow is as i am a little confused after taking my rocker cover off.

I know it goes from the sump through the oil pump (presume mechanical) to the heads but how.

what do the 2 oil jets achieve by the oil filler cap why arn't there more along the rest of the rocker.

what are the baffle type things in the top of the rocker cover.

where does the lash adjuster oils come from, as when you push a lash adjuster back in its hole after removal oil come out of the corrisponding hole next to the spark plug hole.

i will add a picture in few minutes, just need to get it off my camera.

21081

the 2 small silver holes at the right end i between the cams are the oil squerters one of which always splatters around the filler cap.

the 4 holes round each spark plug hole are the oil ways for the lash adjusters nearest hole to corisonds to the nearest lash adjuster.

Large hole in the middle on the left hand side? but very oily.

the fifth hole in the round the middle spark plug is the rocker cover mounting hole.

Lash adjuster top second left removed for cleaning.

top left cam secure cover seems to be damaged and welded at some point. but does seem to be causing any problems.

Can't see any other drain holes or oil feeds.

Why would there be 2 oil feeds on the right hand side (silver holes) and none on the left.

does the oil that gets squerted up from these holes (silver holes) get distributed across the rest of the cam area when in operation. via the baffling in the rocker cover.

i can't see how.

[Davezj]

Bump!!

someone must have an idea on this.

[Kenneth]

Cant be 100% on this without going and taking a look at the heads I have in the garage (and I am at work now, so no chance of that)

If you look at the lines drawn in red, the oil should come up into the head at the top left and bottom left. From here it travels down the oil channels as indicated by the red lines and goes through the lash adjusters and exits the top of the lash adjuster and at the same time lubricates the rocker/lash adjuster.

It also travels up to the cam journals and through a hole in the bottom of the journal to lubricate the cams

The oil then just gravity drains back into the sump.

[Davezj]

great info there kenneth.

i didn't really have a clue what the flow was. it was all theory.

1. why do you think the oil jets out vertically from the 2 holes at the right hand end of the red lines. is it just an end of the oil way and it needs to go somewhere so it squwerts out of there and then drains back to the sump.
if the oil ways were semi blocked to the lash adjusters would the vertical jets of oil be reduced in force or would they be stronger as the pressure does not get released through the lash adjuster and has to go somewhere. i ask because when i remove the oil cap the jet of oil hits the neck of the filler cap and splashes about, some of it coming out of the filler hole. is this normal.

2. the 4 hole around the spark plug hole when the lash adjusters get pushed down into there hole a squwert of oil comes from there. These 4 holes would pressed right up against the under side of the rocker cover. i supose if the oil didn't come out of there you would get a build up of oiland back pressure and would not be able to push it in it's hole.

3. what is the big hole on the left is it a oil feed to the head or an oil drain. it looks to be a bit high of the bottom of the head floor to be a drain.


sorry to ask so many question i am just interested. as some of my lash adjuster are ticking quite loudly.

[Davezj]

any more thoughts on this kenneth

[Kenneth]

Sorry, didn't take a look at the heads I have in the garage.


great info there kenneth.

i didn't really have a clue what the flow was. it was all theory.

1. why do you think the oil jets out vertically from the 2 holes at the right hand end of the red lines. is it just an end of the oil way and it needs to go somewhere so it squwerts out of there and then drains back to the sump.
if the oil ways were semi blocked to the lash adjusters would the vertical jets of oil be reduced in force or would they be stronger as the pressure does not get released through the lash adjuster and has to go somewhere. i ask because when i remove the oil cap the jet of oil hits the neck of the filler cap and splashes about, some of it coming out of the filler hole. is this normal.

Does the oil get out from the 2 holes to the left? It looked to me like those holes were blocked up....

I believe that there is room around the outside of the lash adjusters also (they taper in the middle) which pretty much means it doesn't matter if the lash adjuster is blocked.

If you take the oil cap off with the car running, then yes oil does squirt out and make a hell of a mess.




2. the 4 hole around the spark plug hole when the lash adjusters get pushed down into there hole a squwert of oil comes from there. These 4 holes would pressed right up against the under side of the rocker cover. i supose if the oil didn't come out of there you would get a build up of oiland back pressure and would not be able to push it in it's hole.

This might be to move oil around the head and specifically get it to fall on the cam lobes? take a look at the inside of the rocker cover.
The chance of these getting blocked is very very slim. Is there a reason why you are thinking about blockages?



3. what is the big hole on the left is it a oil feed to the head or an oil drain. it looks to be a bit high of the bottom of the head floor to be a drain.

take a look at the other side of the rocker cover. oil gets up between a metal plate and the actual cover. There is a little ramp type bit at one end, I think you will find this directs the oil down this passageway.

[Eurospec]

Not 100% cause i'm sat in an airport lounge, but off the top of my head......

Oil comes up out of the sump, through the strainer and into the oil pump. Out of the pump into the oil filter housing. The pump has a pressure bypass valve which will is designed to limit maximum oil pressure. From the filter housing you have your take off into the main gallery for the mains, big ends etc and the feed up to the top end.

IIRC, the 6A13TT block also has oil squirters positioned under the bores to cool the bottom of the pistons. A good cause of low oil pressure is when these little gits stick open all the time.

The Turbos, IIRC, are fed off the main gantries as the oil comes up from block to heads, and the drains are to sump and the lower block casting for the rear. (that might be the other way round)

The galleries in the heads (1 for each cam) work as keneth has pointed out. Oil comes up out of the main galleries and is fed to each cam journal and each lifter jacket. The holes next to the lifter jackets seem to be just relief holes for when oil gets under the lifter. (it spurts out of there when you sit a new lifter down)

Your oil drains at the top end are the big round holes, specifically designed to be too small for a follower to fall down, but to be the perfect size for a lifter to fall down if you drop one and to cause you to remove the sump to get the bugger out!

The big raised hole is the crank breather- that is your atmospheric link between top end and bottome end. It will match up close to where the breather plate on the rocker cover is.

By the way, not that i see loads of people doing it on here, but, say you wanted to make your engine all pretty and powder coat everything. Behind that riveted on plate on the back of the rocker cover is a load of wire wool type stuff. When they powdercoat, they shot blast first. If you are not very careful to seal up every little hole in there, the grit will get behind the plate and no amount of puffing with the airline, or washing will get it out. Once the engine starts to run though and the oil vapour etc starts going through there, it will soon come out, bringing the grit with it, and chewing into your nice bearing journals. Off topic that bit, but hey.

Cheers,

Ben.

[Davezj]

Thanks again both of you, that has shed a load of light on the subjust and given me something to think about.