427 oil pressure
Thread Starter
Racer
Joined: Jan 2005
Posts: 477
Likes: 21
From: Knoxville TN
427 oil pressure
hello all, I am building a hydraulic flat tappet 427 for a 1969 Corvette. It has a comp cams cam, springs, lifters, push rods, and 1.7 roller rockers. The motor is all put together and in the car. The problem I am having is when I try and prime the oil pump (via flat blade screw driver and drill) the oil gauge inside the car reads 35 psi but the engine will not prime. So the questions I have are..
Shouldn't oil push up through the push rods and onto the top of the heads?
Does it matter which direction the pump is spun? If so..
Which direction to spin the oil pump (clockwise, counter clockwise)?
If it was spun in the wrong direction would it cause damage?
I used plenty of assembly lube when installing all the goodies but this is my first build so I want to make sure everything is alright before firing her up for the first time. Can't afford to eat through any parts. Thanks.
Shouldn't oil push up through the push rods and onto the top of the heads?
Does it matter which direction the pump is spun? If so..
Which direction to spin the oil pump (clockwise, counter clockwise)?
If it was spun in the wrong direction would it cause damage?
I used plenty of assembly lube when installing all the goodies but this is my first build so I want to make sure everything is alright before firing her up for the first time. Can't afford to eat through any parts. Thanks.
Drifting
Joined: Jan 2006
Posts: 1,832
Likes: 38
From: Cedar,BC
You must use either a cut off distributor or priming tool!
The base of the distributor is part of the oil system,without it you wont get oil to the top of the engine.You should also get more than 35 PSI,also give the crank a few quarter turns while priming to help get oil everywhere.
The base of the distributor is part of the oil system,without it you wont get oil to the top of the engine.You should also get more than 35 PSI,also give the crank a few quarter turns while priming to help get oil everywhere.
Thread Starter
Racer
Joined: Jan 2005
Posts: 477
Likes: 21
From: Knoxville TN
another question. what would be a good oil to use for break in and then for continous use? I have heard shell rotella because of the high amounts of zinc in it which is needed for flat tappet motors, but at the same time i have heard that shell has changed the formula and it no longer contains zinc to meet new emissions.
Is it best just to by zinc additive and use it with whichever oil? what is recommended?
Is it best just to by zinc additive and use it with whichever oil? what is recommended?
Melting Slicks
Joined: Mar 2007
Posts: 2,100
Likes: 12
From: Frederick Maryland
Go to a local GM dealership (if there's any left), and get a container of GM's EOS. It's made for engine break-in. The parts manager at a dealership close to me told me that EOS is really GM's version of STP. True or not I don't know.
I have a GM Performance crate engine and I put EOS in it...over 2000 miles on it now with absolutely no problems.
Supposedly, if you're going to have camshaft failure with a flat-tappet engine, it will usually occur almost immediately during break-in. It's also more prevalent with engines with high lifter spring pressures.
BTW - you said you had a flat tappet engine then you said you also had roller rockers. I thought they were two different animals? If you have flat tappets, you need to make sure to break in the cam properly. If you have roller rockers, it's not an issue to have the ZDDP in the oil. Can someone correct me if I'm off base?
I have a GM Performance crate engine and I put EOS in it...over 2000 miles on it now with absolutely no problems.
Supposedly, if you're going to have camshaft failure with a flat-tappet engine, it will usually occur almost immediately during break-in. It's also more prevalent with engines with high lifter spring pressures.
BTW - you said you had a flat tappet engine then you said you also had roller rockers. I thought they were two different animals? If you have flat tappets, you need to make sure to break in the cam properly. If you have roller rockers, it's not an issue to have the ZDDP in the oil. Can someone correct me if I'm off base?
Thread Starter
Racer
Joined: Jan 2005
Posts: 477
Likes: 21
From: Knoxville TN
It is funny you mentioned cam failure. The reason I am rebuilding the motor is because almost exactly 100 miles ago a new cam was installed (by another person) and then it started having lifter issues. I was asked to check and see what the problem was. When I pulled the intake off I could see the cam was almost completely ground down and the brand new lifters were dished out. I asked if break in oil had been used and was told it had not been....in addition the valves had tripple valve springs on it. The new valve springs are double sprung and was matched by comp cams for this cam. The break in instructions require that the inner spring be removed for installation and the engine run for 30 mins and then the inner springs replaced.....this makes for a lot of work but hopefully a more sound engine in the end.
Thread Starter
Racer
Joined: Jan 2005
Posts: 477
Likes: 21
From: Knoxville TN
BTW - you said you had a flat tappet engine then you said you also had roller rockers. I thought they were two different animals? If you have flat tappets, you need to make sure to break in the cam properly. If you have roller rockers, it's not an issue to have the ZDDP in the oil. Can someone correct me if I'm off base?[/QUOTE]
don't know if they are completely different animals or not but i do know it is a flat tappet with 1.7 gold roller rockers and double sprung valve springs
don't know if they are completely different animals or not but i do know it is a flat tappet with 1.7 gold roller rockers and double sprung valve springs
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
BTW - you said you had a flat tappet engine then you said you also had roller rockers. I thought they were two different animals? If you have flat tappets, you need to make sure to break in the cam properly. If you have roller rockers, it's not an issue to have the ZDDP in the oil. Can someone correct me if I'm off base?
I too have a flat tappet cam and Crane roller rockers. I add ZDDP to my motor oil in every oil change to make sure I will have no cam/lifter issues. So, not just a break in thing with flat tappets.
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