Re: [Amc-list] noisy after rebuild

[Frank Swygert <farna@xxxxxxx>]

You should be fine with overall oil pressure. Cam bearings (or any bearings)aren't the issue with that kind of pressure. You probably aren't getting enough oil to the rocker shaft though. That's a common problem with the early 232. AMC issued two fixes. One was an external oil line, the other was a modified head bolt. The bolt is the best way to go -- see this site for instructions: http://www.mattsoldcars.com/techinfo/boltmod.shtml. That will fix the oil delivery problem.

You stated running the engine for 15 minutes after installing the lifters. Did you run it for that long at a fast idle? I'd run it the same as breaking in a cam -- 15-20 minutes at 1500-2000 rpm. The whole reason is to break the lifters in with the cam. That might fix the pushrod rotation problems. If not you may have to replace the non-rotating pushrods. They likely have some uneven ear on the ends or are very slightly bent. Either situation will cause them to have a "favorite" spot. 

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Date: Thu, 30 Aug 2007 12:49:47 +0000
From: "Andrew Blomer" <lotharamc@xxxxxxxxxxx>

This relates to some discussions recently. This is on a 66 232 in a Classic

I just did a rering job along with a newly ground crank. I didn't change the 
cam bearings, or cam. I did replace the lifters because I forgot about them 
the first time I turned the engine over (physically) without the head on. 
About half of them fell out and landed in the grimmy pan I had under the 
engine stand.

It is all together and running now, but noisy. I have 60 psi oil pressure at 
startup, and 45-50 when its warm. When I start it after letting it sit 
overnight, I get very loud lifter/valvetrain type noises for about 3 
seconds, and then it quiets down. It is almost as loud as a bearing type 
knock, but sounds like a valvetrain type sound. After that, it sounds like a 
small Kabota deisel tractor. Kinda groully ticking. Oh yeah, I did run the 
engine for 15 minutes to try to match the lifters to the cam.

Thats what I have....so far what I have done...
I removed the valve cover to listen and see if anything was wrong. The 
rockers seemed a little dry so I removed the bolt where the oil comes in, 
and found I had a partial clog. I cleaned that location out, along with all 
the other bolt locations, in order, down the shaft to make sure there wasn't 
another clog down the line. I did this while it was running so the oil would 
push out whatever I got loose. When I was done, there was plenty of oil up 
top, and the consistent noise had reduced some, but not even close to what 
it should be.

Now I notice that the marks I put on the pushrods for reassembly are 
spinning. All except for 3 of them at various unrelated locations. 2 are 
spinning like tops (1 rev per second), and the rest are turning about 1 rev 
per 4-5 seconds. Concerning the 3 that arn't turning. If I turn one (any) by 
hand about 90 degrees, it will rotate around at the 4-5 second pace until it 
gets to its favorite spot and stop again.

My deduction.... I think the loud startup noise is from the old worn cam 
bearings allowing the oil to drain down overnight. The lifters drain and 
take a few seconds to pump up again. The quiter constant clacking/ticking is 
from the new lifters not conforming to the old cam, not rotating, and 
probably wearing down the cam lobe the more I run it.

The recent discussion content?... I broke it in with 15W40 rotela, and had 
assembly lube on the cam. (new lifters, old cam)

Does anyone have any thoughts or suggestions? I just put this thing back 
together and am not looking forward to taking it apart again.

I know this is long, but I wanted to get all the information I could out 
there.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)

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