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Discussion Starter #1
OK, another question!
This one is about a 402 big block. The engone was rebuilt by a high performance engine shop about 5 years ago. All was great nice lope to the idle, made decent power for the money laid down (418hp, 425+/-tq). And it was a very nice fun to drive car.
Last year for some reason I get the call....my lifters are noisy can you come check it out? (It's my uncles car this time).
So I go pick up the car, adjust the rockers (more times than I care to admit!), and I cannot make it quiet! So just for fun I check the oil. Full. So, I smell the oil. Seems fine too. I call him up and ask when the last time he changed oil was? "He says, well after we got back from the dyno.!." "Holycow!!!You mean to tell me this oil has been in here for three years" I ask. To which he answers something about it only having so few miles yadda yadda yadda!
So, I kindly bring the car back to him, clattering away, and politely tell him to change the oil and the problem will likely go away. And for awhile it did.
This year, brand new 15w40 Brad Penn oil, start the car, nice and quiet. Drive the car till warm, makes more lifter noise than my sbc with a solid cam!
The engine has a Engle 2225h hydraulic cam in it, stock heads, last week in hopes to quiet the lifter noise I installed new Harland Sharp roller rockers (we were thinking that the stock nuts may have been loosening, and he has wanted roller rockers since it was built). I have it lashed to about 5/8 of a turn after zero lash. I will be inside the motor this weekend to give 'em all another 1/4, but I am also looking for ANY suggestion you guys may have!

The post is way too long, trying to get as much info as I think you may need.
If you have any questions, let em fly!

Thanks in advance

Clint
 

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Clint,

What kind of rockers did you take off?
I have seen a situation where most aftermarket roller rockers are designed to be run with a solid lifter cam and the oil hole in the rocker lines up with the push rod in a way that is wrong for a hydraulic cam. Causes the lifters to bleed down, sounds really loud at an idle, also rattles pretty bad when you kill it hot, then crank it back up a few minutes later.
Can you run a stock type long slot rocker arm?
Hope this helps.
Jim
 

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Discussion Starter #3
Clint,

What kind of rockers did you take off?
I have seen a situation where most aftermarket roller rockers are designed to be run with a solid lifter cam and the oil hole in the rocker lines up with the push rod in a way that is wrong for a hydraulic cam. Causes the lifters to bleed down, sounds really loud at an idle, also rattles pretty bad when you kill it hot, then crank it back up a few minutes later.
Can you run a stock type long slot rocker arm?
Hope this helps.
Jim
The rockers I took of were stock, probably original to the engine. He does have 2 rockers that do not quite line up perfectly with the valve stem, but this noise is way more than two rockers. It sounds like all of them.
I have never heard of roller rockers being meant for solid cams, I will definately look into this.
A long slot, stock type rocker would work, it would just feel like going backwards, ya know?

Thanks for the quick reply

Clint
 

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Hmmm,

For whatever reason the lifters won't stay primed.
Can you tell if they pump up when you increase the rpm say to about 2000?

Jim
 

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Discussion Starter #5
Hmmm,

For whatever reason the lifters won't stay primed.
Can you tell if they pump up when you increase the rpm say to about 2000?

Jim
Actually, he just mentioned that driving down the highway is when he really notices it start. Then, once it's warm from driving, it'll make noise at any rpm.

Clint
 

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RE: BBC valvetrain noise after warmup

What do you have for oil pressure when this engine is warm? If you are down below 20psi at 3000 rpms, you certainly have a worn oil pump, loose bearings or other internal leak in the engine, although you will usually have to be lower than this to deflate lifters. The hydraulic lifter is just a little hydraulic jack, with a metering valve to keep it from pumping up too far, so it will do it's job if it gets enough oil. If it is fed too little pressure, it will sink, giving you lots of valve lash. You also need to have enough oil volume being delivered to the lifters to keep them pumped up. You should have enough oil coming out the pushrod ends of the rocker arms at idle to continuously trickle down the rocker arm, onto the valve spring. Some pushrods will typically squirt some oil beyond the inside of the head, onto the inner fender. Finally, 65 and 66 Big Blocks had a camshaft with a groove ground into it, to distribute oil to the lifter galleys. If you use a non grooved cam, the valvetrain will get little to no oil, and hydraulic lifters will not pump up reliably. I know that you said that this engine is a 402 (Late 69 and newer in stock applications) Any chance that your block is a 65 or 66?
 

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Discussion Starter #8
In reply to 57driver: I will more than likely be playing with this car over the weekend, between our local annual airport drag race weekend. I will record oil pressure and get back. In response to the idea of having an older block, this is a real, numbers matching block. Don't get me wrong, I think "numbers matching" is about the most over-used term in our hobby, but the block IS numbers matching, and original to the car.
On a side note, if you're interested in rare Chevelles I can give you something to think about on this car!

In repsonse to moses: This was a thought of mine too, until I found screw in studs. Thanks for trying though!

Keep 'em coming, and I will keep you posted as the weekemd developes.

Clint
 

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Check the oil filter to see if the cam has "relocated" some of it's lobes.....
 
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