TR2/3/3A No oil to rockers on rebuilt TR3

[Bruce100]

I bought a TR3B rebuilt by previous owner, who quit work on it. I want to preprime it, as previous owner stated it wasn't getting oil to the rockers. I am thinking of using a dowel slotted to drive the pump with a drill motor to preprime, to verify that this is in fact the case. Anyone ever done this with a TR3B engine?

 

[Bruce100]

brucejon

 

[TR3driver]

It's the other way around, you need a shaft with a tang sticking out to engage the pump shaft. It also needs to fit the bore snugly as the shaft passes through the oil passage.

Haven't tried it myself, but I suspect that because of the way the rear cam bearing meters the oil to the rocker shaft, you might not get oil to the shaft even if there is nothing wrong. My suggestion would be to install the pump drive & distributor, then spin the engine with the starter (plugs out) long enough to build pressure on the gauge. You probably still won't see oil to the rockers at that point, but it will be safe to start the engine and let it idle for a minute or two, to see if that gets oil to the rockers. The flow to the rockers is deliberately quite slow, they basically see no pressure at all even with the engine running.

If not, unfortunately, the most common problem after a rebuild is that the rear cam bearing was installed back-to-front. The 3 holes are not evenly spaced so there is only one way it goes in, and it's easy to overlook the oil hole in the top.

BTW, Welcome to the Asylum

 

[TR4nut]

If you have a spare distributor drive, just remove the drive gear and use the shaft and slot it in the pump - and yes, you can drive that shaft with a drill and you will be able to pressure up the whole system. Just did that on my 3A and it works fine.

Also, if you are not firing it up you might consider pulling the rocker assembly and just see if you are getting oil to come up through the head - maybe thats overkill but it would provide easy verification.

I agree with Randall on that cam bearing - if its misoriented I think you are looking at a pulled engine to get at everything. Hopefully that is not the case - if you get to the point of pulling the cam you can at least check the holes with an inspection mirror. I also used a small allen wrench to see if the holes were open which is a pretty easy verification method.

 

[Bruce100]

that quote was from a hotrodders forum, not a TR forum, thus the slot...

 

[Bruce100]

Fortunately the tub is off, and I can get to the engine. I assume I don't have to pull it off the chassis frame as well.

 

[TR4nut]

No, you could leave it on the frame - but if you do find you need to pull the cam bearings you will need to pull the gearbox for sure. After the rear cam bearing there is the equivalent of a freeze plug which would need to be knocked out and that can't be accessed with the gearbox attached.

 

[TR4nut]

Here's a link to some pics I took when I installed those bearings. I'm sure there's other ways to do it, but it might give you some idea of what you'd be dealing with.

TR3/4 cam bearing install

 

[TR3driver]

AHA! So that's where my cam bearing mandrels went!



Seriously, good writeup Randy. As I recall you can also verify the hole position to some extent by holding a light in the bearing and looking down the drillings. Plus of course you have to check that the locating slot is centered in it's hole, so the locking pin doesn't catch on the bearing insert and damage it.

 

[Got_All_4]

I agree with Randy to pull the rocker shaft off. You can spin the engine and see if your getting oil from the block. If not then you know where the problem is. One cushion is the cam followers. With no presser on the followers they could stick on the way down and the cam lobe will hit them on the next pass.

Could the pedestals be in the wrong order. The one with the hole in the bottom not lining up the hole in the head? Don't know if that's possible.

 

[TR3driver]

One cushion is the cam followers. With no presser on the followers they could stick on the way down and the cam lobe will hit them on the next pass.

Which is just why I don't recommend that. There is a chance it will throw a lifter completely out of it's bore, and while it is usually possible to coax them back in without removing the head, it is certainly a PITA.

Also don't forget that it can take a long time for oil to fill the passage all the way to the top, especially at cranking speeds. I make it a point to check oil flow to the rockers after adjusting the valves, and it can take a minute or two of idling to get oil out of all the rockers.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
Could the pedestals be in the wrong order. The one with the hole in the bottom not lining up the hole in the head? Don't know if that's possible. [/QUOTE]
Possible, I guess, if someone assembled the shaft wrong. The pedestal with the oil hole is also the one with the screw that locates the shaft to the pedestal. It should be the rearmost pedestal.