Pontiac GTO Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
Hi Guys,

After 500 miles on my ramAir III fresh rebuilt engine I accelerate it on the highway till i reach 110mph for 5 second. The rpm was almost 5000. I heard noise in the engine and i thought that this is the manifold leaking. I stopped after 10 minutes and was driving 70mph and opened the valve covers. I noticed that the oil does not come up to the passenger side rockers. It is brand new oil pump and i do not know what is going on???


Thoughts
 

·
Registered
Joined
·
3,759 Posts
Hi Guys,

After 500 miles on my ramAir III fresh rebuilt engine I accelerate it on the highway till i reach 110mph for 5 second. The rpm was almost 5000. I heard noise in the engine and i thought that this is the manifold leaking. I stopped after 10 minutes and was driving 70mph and opened the valve covers. I noticed that the oil does not come up to the passenger side rockers. It is brand new oil pump and i do not know what is going on???


Thoughts

Hard to say what the problem is as it could be a number of things. Something you did? Does not sound like it. Remember race cars only break in their engines and then run flat out from that point on.

You did not mention your oil pressure reading, so I assume you have no gauge in the car, so you don't even know what your oil pressure was from the beginning when you first fired the engine. You could have had a problem at "get-go."

There is a hidden oil galley plug in the back of the block that sometimes gets left out. It has a freeze/welch plug that hides it. If left out, it will do as you observed, no oil to one side of the block.

The front of the block also has 2 oil galley plugs. Often they are replaced with a pipe plug once the block has been tapped, but the factory is again a freeze/welch plug. It has to be properly sealed and staked so that it does not work free and back out. If it does, same thing can happen, you lose oil pressure on the side it drops out. Also, knocking the plug too deep can shut off the oil supply.

I would not think oil pump or wrong Chevy lifters seeing you have oil on the other side.

Seeing it is a fresh rebuild, I would drop this problem off on the machine shop that assembled the engine - unless you did the assembly.

In any case, the engine should come out if you cannot find something in-your-face obvious. This will need to be done IF it is believed one of the oil galley plugs is the problem. I would also be concerned about the bearings if the oil supply was compromised at high speed. Easy now to insert new bearings IF needed rather than find out later that some bearing damage took place and you lose the engine somewhere down the line.

Again, if you had a machinist assemble it, they should be the ones to contact and let them figure out the oil problem. They should be able to give you a few things to check as well before having to pull the engine if it comes to it.

Here is an oil system diagram where you can see where the oil galley plugs will be located at the front/rear of the oil galley that feeds the lifters. https://butlerperformance.com/files/images/techdoc/oiling.jpg :thumbsup:
 

·
Registered
Joined
·
28 Posts
Discussion Starter #3
Thank you PontiacJim, I will let them check the oil galley.

I have in dash oem gauge and the oil pressure when accelerate go all the way to the 80.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #4
Also if the oil galley plugs were the problem, should i machine the crankshaft and change the main bearings or that's doe not matter??
 

·
Registered
Joined
·
3,759 Posts
Also if the oil galley plugs were the problem, should i machine the crankshaft and change the main bearings or that's doe not matter??
You did not say if you lost oil pressure or just noticed no oil on one side of the engine.?

80 PSI of oil pressure, if correct, may have been enough pressure to pop out a factory type oil galley plug in the front if it was not secured correctly. One of the reasons to tap the hole and insert a pipe plug. But, it may not be a plug if you still had good oil pressure?

You could first try to see what you have for oil pressure. Get a mechanical oil pressure gauge and hook it up to the engine. Pull the distributor and use a drill/priming tool and watch your gauge. If the plug popped out, you probably won't see much for oil pressure. If you have good oil pressure, then it may be something else to be tracked down.

You could also revisit the rockers/pushrods and remove the valve covers to see if any oil flows while using the drill/priming tool. I have had a rocker arm or two not push oil because the rocker arm was too tight. You might try to back off on the rocker arm nuts to give you a little wiggle in the rocker arm and then use the drill/priming tool to see if oil flows.

Have also had a rocker arm loosen up and bend a pushrod, but when I looked at it, with engine not running, it looked OK. So you might want to turn over the engine by hand and grab all rocker arms and check the pushrods to make sure none are noticeably loose.

Hopefully it is something simple, so do not think the worst just yet. Find out what it is and then go from there as to what is needed to fix it. :thumbsup:
 
1 - 5 of 5 Posts
Top