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Noisey engine

Posted: Tue Jan 24, 2017 6:11 pm
by 66NCVW
Fresh bearings, new cam, pushrods, single hd springs. Valves at .004. Any ideas ?

https://youtu.be/kt0zqAWEAx8

Re: Noisey engine

Posted: Tue Jan 24, 2017 6:51 pm
by ps2375
Drive it and let things seat. Then recheck valves and drive some more.

Cromo or AL push rods?

Re: Noisey engine

Posted: Tue Jan 24, 2017 7:02 pm
by Marc
Sometimes small exhaust leaks can make a noise similar to mechanical ticking (at least as heard on YouTube).

On `65-up rocker assemblies the shaft supports have a slot in them. Four of the rockerarms rub against the supports as they move, wearing the side of the rockerarm away everywhere but at a narrow spot that's always "in the slot". The resultant "bump" on the side of the rockerarm can produce quite a racket as it bangs against the slot after their relationship's been changed by a higher-lift cam or even just a change in rockerarm geometry, there's a very good chance that's the source of your noise.

You can wait for things to wear in (bear in mind that to do so puts a lot of metal dust into the oil, not good if you don't have a full-flow filter) or you can dismantle the rockerarm assemblies and surface off the bumps (wet-or-dry sandpaper flooded with solvent at the edge of a sheet of glass, along with elbow grease, is how most do that).

Re: Noisey engine

Posted: Tue Jan 24, 2017 9:21 pm
by Clonebug
Check your rocker shaft clearance between rockers and mount blocks if you have solid shaft rockers.
They can cause noisy valve train. You have to get them pretty tight to get them quiet.

Re: Noisey engine

Posted: Wed Jan 25, 2017 11:35 am
by 66NCVW
Stock rockers and shafts. It's running good despite the noise so I guess I'll keep running it for a bit and see if it settles in. :shrug: Thanks ! :)

Re: Noisey engine

Posted: Wed Jan 25, 2017 3:42 pm
by Chip Birks
Mine has been knocky now for about 4 years. I've changed ever bearing, cam gears, cam, rockers, heads, at least once. Still rattly. Clearanced the heck out of the piston skirts thinking that was the problem, still makes the noise. I don't have a clue what it is, the thing has not shown any signs of wear, and will rev to 7500rpm when ever i ask it too. I probably have a dozen hard 1/4 mile passes and a few thousand miles on it. It just keeps going. I hope to shelf the motor this year, replaced by my next experiment.

Re: Noisey engine

Posted: Wed Jan 25, 2017 7:46 pm
by Piledriver
I had that issue briefly, drove me nuts...
.... until the rocker screws poked little holes in the valve covers.
(OK with "new" gasket, clearance lost as cork gasket compressed)
Toch of weld and touch of ball peein hammer all was well again.

Do consider a HD solid rocker shaft/spacer kit.

Re: Noisey engine

Posted: Thu Feb 02, 2017 4:41 am
by Tony Z
I'd put money on the fact that it is your rocker shafts.
I built a 1700 for my bus (74*85.5) and the noise drove me nuts. I swore it was the crappy EMPI exhaust. Oneday I just decided to install a solid rocker shaft kit and shimmed it properly - wow, what a difference. The engine is now as quiet as it should be.

Dont play games, take it from those of us who have learned - its its still loud when it shouldnt be, install the solid shaft kit and shim it properly.

Re: Noisey engine

Posted: Mon Jan 01, 2018 1:19 am
by sidemarkers
Had an issue with pushrods tapping the pushrod tubes. Respaced and reshimmed the rockers on side 3&4. At first I was like WTF?