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Discussion Starter · #1 ·
Hey guys, I have another question for all of ya concerning my new 383 sbc build. I Have broke in the cam (comp XE 274) I have since heat cycled the motor a couple times, and have some valve train noise that seems odd. I took all the roller rockers off, and went back through the adjustment sequence looking for the problem. Now, it seems to be coming from one spot on the left bank, and it sounds like a hollow "tock" "tock" "tock" sound....its not like a lifter tick as I have heard them before. And...it sometimes goes away at idle once the motor is up to temp. Should I be worried? Thanks for any help.
 

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Discussion Starter · #5 ·
Yup, checked that....I have a standard pan, but I did have to slighlty dimple it in one spot. The noise is definately on the top side of the motor, and it has come and gone once or twice during break in. When I readjusted the rockers, I did notice on a couple of them, that after aquiring zero lash vertically on the pushrod, there was little to no resistence turning the polylock the half extra turn. All of the others, I could tell I was squeezing against oil in the lifter body when I turned the nut. If a lifter bleeds down that easy compared to others in the bunch...could it be defective? When they were new in the box, I did notice that some of them were VERY resisitant to me pushing down the plunger. Hope this info may help? Thanks again.
 

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It is quite possible a lifter or 2 could be bad. What brand of lifters, and rockers do you have?

I have found some roller rockers, that needed to be 'relieved' a little, to clear the valve spring retainer. Not every rocker in the set though.

I would do a engine running valve adjustment on that side, while keeping a close eye on the valve train. Also inspect the baffle, and the inside of the valve cover for rubbing.
 

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Discussion Starter · #7 ·
The lifters and cam are comp XE 274 kit. The roller rockers are crane energizer. Good idea to check the valve covers. I have a couple rockers that even after loosening the plates and sliding it over as far as I could to one side, still are not straight up and down. I did check the patterns/side to side location of the rollers, and none of them are in danger of coming anywhere near falling off the valve tip, but is it possible to bind up the pushrods even if they are roller and not self aligning? Also, is there any way I can check for a dead lifter without removing the intake? Thanks for your help.
 

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lngliv3 said:
The lifters and cam are comp XE 274 kit. The roller rockers are crane energizer. Good idea to check the valve covers. I have a couple rockers that even after loosening the plates and sliding it over as far as I could to one side, still are not straight up and down. I did check the patterns/side to side location of the rollers, and none of them are in danger of coming anywhere near falling off the valve tip, but is it possible to bind up the pushrods even if they are roller and not self aligning? Also, is there any way I can check for a dead lifter without removing the intake? Thanks for your help.
Yes, tighten them another quarter turn. If the noise does not go away, or it is easy to collapse the lifter, then it is bad.

Proper Push Rod alignment is critical. It can cause valve guide wear, and broken rocker studs.

They do make adjustable push rod guide plates.

Each of these faults will cause a noise, to come and go while the valve rotates.
 

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If you locate any soft lifters, take them apart- keeping the internal parts separate from one another- and clean and reassemble them.

Pay special attention to the check ball/spring (very tiny) and the cup that retains them. If the cup is cocked or loose from the bottom of the internal plunger, or the spring or check ball is missing or bad, the lifter can be soft- but salvageable.

In the event that this doesn't cure it- like if the plunger itself or the seat's bad- if you put a new lifter on the cam, the chances are high that it will fail.

Before I would do that, I would take a new lifter and replace everything in the old lifter except the body that had worn in to the cam, w/the new lifter's guts.
 

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Discussion Starter · #10 ·
Thanks for the help carsavvy and cobalt....I will do a little investigating, and post what I find. I figured I was good to go buying comp stuff...but anything can happen I guess.
 

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FWIW, a friend of mine had a new 572 GM Crate engine develope a noise that very quickly morphed into a searious engine problem that wiped out the camshaft and destroyed the block. Here is the offending party.

It's in a 70 Chevelle and GM stood by the warranty and below is the new engine about to go into the Chevelle in the background on the lift.


Vince
 

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Discussion Starter · #12 ·
That picture really scares me.....o.k., this next week, I am going to pull the manifold and look at the lifters. I did another 1/4 turn on the lifters, and no real change. I did change the oil and filter to napa gold filter and Valvoline racing 20/50 with comp additive and the oil pressure came up to 40 psi at hot idle. Still could hear it, but less noticable. I ran it at idle with valve covers off, and all rockers are geting good oil. Is it possible that what I am hearing is just what a 435 hp 383 just sounds like? I hope? I have a small oil leak that I think is coming from the corner of the intake anyway so....off she comes! Thanks to you all.
 

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Discussion Starter · #18 ·
Ok...ok...you tipped me over the edge. I ordered some adjustable plates yesterday. Also, have two guys coming tomorrow to listen to my valve train clatter. These guys definately have some engne experience, so I will post what we find. Thanks everyone.
 

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Discussion Starter · #19 ·
Ok guys....here is the follow up. I pulled the intake and a couple of lifters, and oh crap! There is definitely a problem with the cam and lifters. The surface of three of the four I have pulled so far are "pitted" on the face of the lifter. It seems there was good rotation, but really bad surface finish. I need some good feedback from all who can give it as to what may have gone wrong. Please Help!
Here is a run down:
Comp cams XE 274 cam/lifters
Trick flow springs- 110lb seat/1.250 dia./.500" max lift ( ok'd by trick flow to use as they came with my TFS street/strip heads)
Valvoline oil with a full bottle of comp cams additive for break in. Pre lubed oil system for 2 minutes. Break in went great, with only one stop in the middle to fix the fuel pump that broke its lever arm and killed my pressure. The surface of the lobes looks scarred, but I think it was going flat especially at cyl # 7. I really would like to dump a grand on roller cam/lifters, but I simply cant afford it. I cant afford the time to rebuild this thing either, but I have to move forward and was thinking of going with a lunati cam and lifters for round 2. What do ya think.
 

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Oh Hell

Damn, I was hoping it turned out minor. Your fuel pump lobe is likely damaged as well. I really don't know what to tell you as far as a cam recommendation. With all the flat tappet failures these days. Nitrided lobes? Lifters with the surface oiling orifice? Just as soon go roller, problem over. :confused: olnolan
 
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