Engine GooRoos! New engine, noisy top end...opinions?

[madmike]

I bought my '68 Charger last year as a rolling shell.  It came with a supposedly new rebuilt 440, but no reciepts or paperwork (I think this car changed hands at least twice in it's disassembled state).  Anyway, the engine was basically a long block, no intake, carb, ignition, or accessories came with the car.  In fact, even the rocker arm assemblies were not on the engine.  But, from all visual clues, it did appear to be a new, fresh engine.  So, instead of disassembling it and checking it out, I decided it would be cheaper to just run it as is, and hope for the best.

Yesterday, I fired it up for the first time, and ran it for it's initial engine break-in, about 30 minutes at around 2200 rpm.  I did have some difficulty getting it started (had to play with the timing), and a few minor issues (valve cover oil leaks, gas leaks at the carb), but no show stoppers.  To try and minimize the noise, so I could hear the engine and listen for any abnormal noises, I installed a cheap pair of muflers at the ends of the headers (I have no real exhaust yet).  While it was running during break-in, it seemed 'noisy', but the water temp peaked at 210 for a few minutes, and then settled to around 200.  Oil pressure started at 80 psi, and then settled to 60 psi after it got to operating temperature.  Although there was oil burning off of the headers, I didn't see any smoke coming out of the mufflers, looked clean.  Really, even though it seemed 'noisy', it seemed like a fairly normal break-in.

After that, I shut it off, let it cool down, and figured I would address the gas leaks, valve covers, and then try to dial in the timing a little better.  I started it back up (started pretty well, so the initial timing must've been pretty good), and now I think I know what the noise was.  It seems like the entire top end of the engine was nosiy, I think there is excessive clearance between the rocker arms and valve stem tips.  That is the only thing I can think of, and that is what it sounds like.

My question is, with these being shaft mounted rocker arms, how can I adjust something to quiet this down?  I don't know who rebuilt the heads, or what they did, but is it possible that the valves are not sitting in the head at the correct depth, or they aren't 'even' with each other, causing some valves (or rocker arms) to be noisy?  I'm looking for some opinions on how to address this noise.  The engine might be decent enough to run the car and have some fun with it, while I build the engine that I really want (a Hemi) on the side.  Anybody (preferably those with actual hands-on experience) have any opinions on this?  Thanks fellers!

[elacruze]

We'll need a lot more information to help.

Roller or flat tappet cam?
Solid or hydraulic?
Lash clearance?
Rocker arm style?
Headers sealed 100%?
Clear oil, no glitter?

[madmike]

You're right Elacruze...

A mild Comp Cam (Magnum 280H - about 284 duration/484 lift), hydraulic flat tappet cam.  I have stock Chrysler stamped steel rocker arms, which did come off of a used engine, so the tips may have some wear on them.  I believe my headers are sealed against the head surface.  After I ran the engine, I checked the tightness of those bolts, and they were still tight (hadn't backed off).  I have not drained that break-in oil out of the engine yet, but the oil on the dipstick looks clear, no glitter there.

[elacruze]

Ok,

Check the valve clearances, each valve by the book-you should not have any free slack in the rockers. The lifter preload should be evident, even if the lifter is pumped down of oil. What do you have for pushrods? Stock or aftermarket? How much side clearance do the rockers have? What about valve springs? Check the valve covers for contact (unlikely) and check the spring retainers for contact with the rocker arms.

[madmike]

Elacruze:

In your first question, when you say valve clearance, you are referring to the distance between the rocker arm tip and valve stem tip, with both valves of that particular cylinder fully closed, correct?  I do have stock Chrysler push rods, not aftermarket.  I don't know how much side clearances between rockers, but I do have all of the correct factory spacers on the shafts installed correctly.  In your question about valve springs, are you referring to installed height?  I don't know, but I can check into that, I'll have to buy a tool to measure that.  I have Mopar Performance aluminum valve covers, and there are no signs of them being contacted by anything.  I will try to provide some answers to those questions tomorrow, if my back feels better tonight...

[madmike]

Thanks for all the help in diagnosing this problem...

I figured it out myself.  My problem really was worn rocker arms and shafts.  The holes in the sides of the arm were extremely egg shaped, tips worn, and shafts even worn a bit where the arm rides.  I took the intake manifold off, and I also discovered the wrong lifters were used, after talking with 440source and CompCams.

I ended up purchasing new Comp Cams lifters, a 440source adjustable roller rocker set-up and custom length pushrods.  Kind of a pricey fix...but I ran the engine for another cam break-in period (to match the new lifters to the slightly used cam), and it ran fine with no abnormal issues.

I think with some basic carb and igntion tuning, it will be fine!

[elacruze]