Oil not coming to rockers when priming

Sergi

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Jun 12, 2012
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80
Hello!

When I rebuild an engine, I always have the habit of manually turning the pump for priming and oil covering the engine throughout.
For that, I remove the distributor and use a home made tool to a drill. I turn it until the oil reaches the rocker area.

I never rebuilt the 4.3L chevy engine, so I don't have experience with this engine. Other than euro ones, I rebuilt the big Jeep ones, the Inline sixes and the AMC 5.9L v8.

When I finished the rebuild of the boats 4.3l also tried the priming trick, but the oil didn't come to the top of the engine.
I could make flow the oil, the drill felt the drag as the pump primed, but never arrived to the valve train area.
Looking through the holes on the heads there was plenty of oil on the tappets area and on the cam.
I didn't service the pump. The engine was good enough I didn't thought that was necessary.

?That's normal?


Then I jumped the starter and made the engine turn for a minute or so (without the plugs or gas), but oil didn't came to the rockers.
?Perhaps it needs some revs the first time in order to fill the valve rods?

It would hurt having to open the engine now that it's fully assembled.
 

Bondo

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Staff member
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Apr 17, 2002
Messages
70,468
Re: Oil not coming to rockers when priming

Hello!

When I rebuild an engine, I always have the habit of manually turning the pump for priming and oil covering the engine throughout.
For that, I remove the distributor and use a home made tool to a drill. I turn it until the oil reaches the rocker area.

I never rebuilt the 4.3L chevy engine, so I don't have experience with this engine. Other than euro ones, I rebuilt the big Jeep ones, the Inline sixes and the AMC 5.9L v8.

When I finished the rebuild of the boats 4.3l also tried the priming trick, but the oil didn't come to the top of the engine.
I could make flow the oil, the drill felt the drag as the pump primed, but never arrived to the valve train area.
Looking through the holes on the heads there was plenty of oil on the tappets area and on the cam.
I didn't service the pump. The engine was good enough I didn't thought that was necessary.

?That's normal?


Then I jumped the starter and made the engine turn for a minute or so (without the plugs or gas), but oil didn't came to the rockers.
?Perhaps it needs some revs the first time in order to fill the valve rods?

It would hurt having to open the engine now that it's fully assembled.

Ayuh,.... It's the pumpin' action of the lifters that pumps oil to the rockers, not the pressure from the oil pump,...

Sounds normal to Me,...
 

Sergi

Petty Officer 3rd Class
Joined
Jun 12, 2012
Messages
80
Re: Oil not coming to rockers when priming

Ok, Thanks Bond-o. We'll see soon if we get the lube when I first start that engine. Other than that, he was blowing nice through all the plugs holes. It was rebuilt becouse a low pressure at nrs 2 and 4.
 

Bondo

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Re: Oil not coming to rockers when priming

Ok, Thanks Bond-o. We'll see soon if we get the lube when I first start that engine. Other than that, he was blowing nice through all the plugs holes. It was rebuilt becouse a low pressure at nrs 2 and 4.

Ayuh,.... Crank it over on the starter without the spark plugs in it,..... ;)
 

Sergi

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Jun 12, 2012
Messages
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Re: Oil not coming to rockers when priming

Ayuh,.... Crank it over on the starter without the spark plugs in it,..... ;)

Yes, that was what I've done when I saw the oil wasn't coming to the rockers. At least cranked for a minute or two (or more) until wires started to get hot. But no oil. The rest of the engine had plenty of it, even it came through the distro hole. Uhmm....
 

xjdriver

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Re: Oil not coming to rockers when priming

When you cranked it with the plugs out, you did have the dizzy installed right? Just making sure.
 

jackd1023

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Re: Oil not coming to rockers when priming

There are two types/styles of distrubutors, the tool does not tend to work with vortech intakes because it has to seal the valley to produce pressure. If you use an old distrubutor they tend to seal a lot better than the tool
 

Sergi

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Re: Oil not coming to rockers when priming

There are two types/styles of distrubutors, the tool does not tend to work with vortech intakes because it has to seal the valley to produce pressure. If you use an old distrubutor they tend to seal a lot better than the tool

My tool doesn't have any seal at all. It's only a rod inside a protecting tube with another tube sleeve at the end for not coming out the pump tip.

Does make sense. That's the reason the distributor gasket was so robust and the claw clamped so well. In AMC engines/Mopar that gasket seems merely presential and the clamp it's flimsy.

But, if that system requires to have pressure at the valley, means that you can't inspect without valve covers or even without the oil cap on? The valley is connected to the top of the heads through the pushrod holes. What about the PCVs?
 

xjdriver

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Re: Oil not coming to rockers when priming

Uhmmmm... Not sure. I guess not.
It must be installed to drive the oil pump from the cam, which should pump up your lifters and oil should flow thru pushrods and out the holes in rockers. You can also watch the oil pressure gauge once you see pressure, you should get oil at the rockers.
 

Sergi

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Joined
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Messages
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Re: Oil not coming to rockers when priming

It must be installed to drive the oil pump from the cam, which should pump up your lifters and oil should flow thru pushrods and out the holes in rockers. You can also watch the oil pressure gauge once you see pressure, you should get oil at the rockers.

Oh, yes I should have it replaced before the crank, excuse me.
In fact, I somewhat remember looking at the turning rotor entranced.

I must have installed the distributor by the time. I did like this for not to loose TDC and timing.

EHEHEHEH...
 

Bt Doctur

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Aug 29, 2004
Messages
19,093
Re: Oil not coming to rockers when priming

you need a full dist body with the priming rod. I had ground away the teeth from the gear for mine.
 

Sergi

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Joined
Jun 12, 2012
Messages
80
Re: Oil not coming to rockers when priming

Thanks Bt, I've got a spare dist, but at the time didn't like the idea of grounding the teeth on it. I tried to remove the pinion and flip it, with no success. It was seized. May I try harder.
 
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