Rocker Plate and Pin Assembly and oil modification

[Jolls]

Hi Team,

Just about to put the head back on the motor and cleaned up the rocker gear yesterday. I noted that there was only one of these instead of two:




Parts Group: 0.366 PLATE AND PIN ASSEMBLYâ€"Valve rocker shaft locating PLATE AND PIN ASSEMBLY FE from Engine No. L426904 FC, FB, EK, EJ
Part Number 7412821
Qty 2

I went and checked my other head and it also only has one of these instead of two. Both sets of rockers have had the oil distribution gallery in the connector blocked, one fully blocked using a screw and the other partially by having a split pin inserted. Was there a reason, back in the day, to only use one locating plate and pin or do I just happen to have two reconditioned heads that are both missing one of them?

My gut feel is that I have two rocker sets that are both missing the locting plate. If I require two I can easily scavenge one the head I am not using to make a a complete rocker set so no problems there. Then the hunt starts for a pait of a stuffed set to make the spare complete.

I have read up about the benefits of the blocking the oil gallery in the connector nut, and follow the logic; however, of the two solutions I have (fully or partially blocked) and the thrid option of removing the split pin which one would be a better solutiuon in a warm grey and why.

Thanks in advance for your advice.

Cheers n Beers

[Sheriff]

Gday Jolls,  A couple of years ago I replaced my L series motor with a rebuilt J block one.   The L series one had the self-tapper screw in the connecting nut, so I put it in the J block after I had done a few K with it in the car. .   Car started to smoke profusely from the exhaust when accelerating after going down hill, or even slowing down for an intersection, and then accelerating again.    Went through a process of elimination, then tried removing the self tapper.  Car immediately stopped smoking.   Apparently too much oil was being delivered to the rocker gear and getting down onto the valves through the stem seals somehow.  Apparently the screw works well with worn engines, not rebuilt ones.?  Wiser people than me might be able to confirm or deny this.   cheers, Mike.

[ardiesse]

Yep.

The rocker oiling system was designed to supply just enough oil to the top end *with all new components*.  As the rocker bushes and shafts wear, oil leaks out past the bush instead of through the oiler hole at the top of the rockers.  The rocker adjusting ball and the rocker tip wear out rapidly.  The "coal-mine canary" is the no. 1 exhaust valve rocker, as always.

The common remedy is the self-tapper or split pin in the oil fitting's relief hole.  But if your inlet valve guides are worn, then oil gets drawn down the inlet valve stems and the car blows smoke.  And maybe even if the valve guides are not worn.

Craig A on FB/EK has a work-around for this problem: chamfering the top of the valve guide to minimise the possibility of oil pooling up around the valve stem.

Plate and Pin Assembly:  Yes.  In the "Qty" column in the masterpartscattledog you'll see "2".  You need both.  If the pin's not there, oil will leak out the open hole and starve the rocker gear of oil.

Hint for Assembly of Rocker Gear:  Heat the pedestals.  They're a much easier fit over the shafts when hot.

Rob

[Jolls]

Gday Jolls,  A couple of years ago I replaced my L series motor with a rebuilt J block one.   The L series one had the self-tapper screw in the connecting nut, so I put it in the J block after I had done a few K with it in the car. .   Car started to smoke profusely from the exhaust when accelerating after going down hill, or even slowing down for an intersection, and then accelerating again.    Went through a process of elimination, then tried removing the self tapper.  Car immediately stopped smoking.   Apparently too much oil was being delivered to the rocker gear and getting down onto the valves through the stem seals somehow.  Apparently the screw works well with worn engines, not rebuilt ones.?  Wiser people than me might be able to confirm or deny this.   cheers, Mike.

Thanks for the advice. I found plenty of threads on blocking the connecting nut but this is the first I have read that recommends not doing it. Of course the search function only finds what you are looking for. The head I am using has just come back from the reconditioners where it was ported for 202 valves and fitted with all new components. the other head was reconditioned to standard and never used by a restorer who passed away. I was originally going to use it to freshen up the L series donk that appears to be original but opted to warm up a B series initially and get to the L when time (and more $). The rocker gear (on both heads) seem to be in good condition. I think I will spin up the oil pump once I have the head on and see how the oil pressure is at the top end. I have reconditioned the oil pump as well so I suspect that I can get away with removing the modifications; but we will see what the oil pump test shows before jumping to conclusions. Cheers

[Jolls]

Yep.

The rocker oiling system was designed to supply just enough oil to the top end *with all new components*.  As the rocker bushes and shafts wear, oil leaks out past the bush instead of through the oiler hole at the top of the rockers.  The rocker adjusting ball and the rocker tip wear out rapidly.  The "coal-mine canary" is the no. 1 exhaust valve rocker, as always.

The common remedy is the self-tapper or split pin in the oil fitting's relief hole.  But if your inlet valve guides are worn, then oil gets drawn down the inlet valve stems and the car blows smoke.  And maybe even if the valve guides are not worn.

Craig A on FB/EK has a work-around for this problem: chamfering the top of the valve guide to minimise the possibility of oil pooling up around the valve stem.

Plate and Pin Assembly:  Yes.  In the "Qty" column in the masterpartscattledog you'll see "2".  You need both.  If the pin's not there, oil will leak out the open hole and starve the rocker gear of oil.

Hint for Assembly of Rocker Gear:  Heat the pedestals.  They're a much easier fit over the shafts when hot.

Rob

Thanks Rob, appeciate the advice and feedback. I suspected that both of the plate and pin assemblies were required; I just found it odd that both rocker sets are missing the same plate so I was wondering if it was a result of a grey motor to end oiling mod or simply coincidence. I will start looking for plate and pin assemblies on damaged or partially complete parts to replace the missing ones.  I am a big fan of the over/freezer method of putting gear together, Mrs J would have af it if she knew some of the things that go into the oven and freezer. 

Apart from the missing plate and pin assembly and the modified connecting nut the rocker gear appears in good nick. I will do a manual check of oil flow etc before I close up the top end as I have restored the oil pump as well.

[ardiesse]

Craig,

To pass oil from the gallery to the top-end there's a groove in the second-from-rear camshaft journal, but it doesn't go all the way around the journal.  From memory, you need to set the engine at TDC on compression stroke for number 5 cylinder.  Or thereabouts.  Then when you drive the oil pump with a drill, you should see the oil come up to the rocker gear in only a few seconds.

Rob

[Jolls]

Craig,

To pass oil from the gallery to the top-end there's a groove in the second-from-rear camshaft journal, but it doesn't go all the way around the journal.  From memory, you need to set the engine at TDC on compression stroke for number 5 cylinder.  Or thereabouts.  Then when you drive the oil pump with a drill, you should see the oil come up to the rocker gear in only a few seconds.

Rob

Got away early so got the head on and hooked up (yet to do the valves) but was able to get oil flow using a drill. Definitely TDC compression for No 5 to get flow to the rockers.

So tick - oil pump work - lubrication system appears OK.

[Errol62]

Kicking goals boys 👍👍


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[fcute]

Not sure if this is of any help to anyone, but I soldered the hole in on the connecting nut and then drilled it smaller than original, never had a problem again, motor was in the car for at least another 24yrs.

Cheers Dave

[Jolls]

I think that is a similar approach to the split pin system I have on the other rocker set. It will be interesting to see what I find when I behead the original motor to freshen it up.

Once I get this one runing with the cutaway rocker cover I will get a feel for the need to reduce the gallery in the nut.

Thanks for the heads up.