Engine Guru's What's this sound?

Hey all, finally got things put together. I swapped in the 4bbl intake/500cfm edelbrock, hei distributor and fuel pump. After a few adj. on timing and the dist. it fired, but with a loud knock(sounds like a clicking on the video). You can hear it after I close the choke and it fires. I don't know enough about the noises, but it can't be good. SO, just an adj needed, rod knock or did a loose bolt fall into the intake I pulled off the rocker covers and everything seems in it's place and tight. Thanks for the help.

P.S. think I'll invest in a tripod for the camera


http://www.youtube.com/watch?v=n7lAtJtZoLc

 

Its not a rod, and being very intermittant like that I dont think it's a valve adjustment issue. The only thing I've experienced that sounded like that was a bent couple of valves on a car. They were sticking open and the piston would hit them and close them. Sounds crazy but thats what mine was. Hope this helps.

 

thunder rattle, bumber babble boom boom boom better call your CAR-X MAN

 

sounds like something is intermittently hitting maybe flywheel clearance? can you hear the sound when your turning the engine over? <meta name="ProgId" content="Word.Do***ent"><meta name="Generator" content="Microsoft Word 10"><meta name="Originator" content="Microsoft Word 10"><link rel="File-List" href="file:///C:&#37;5CDO***E%7E1%5CMatt%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"><!--[if gte mso 9]><xml> <w:WordDo***ent> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDo***ent> </xml><![endif]--><style> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]-->

 

Sure sounds like something rattling around on top of one of the pistons. PS-it sounds like your starting problems are a combo of not enough fuel (pump the ****ing thing a few times), and too far retarded on timing

 

I agree. It sounds like you've maybe got a weak valve spring some place, coupled with a lifter that doesn't like its bore very much. Whatever the cause, it sounds like an exhaust valve hitting a piston. I say this because it seems to do it for several revolutions as the RPM increases, and then stops again as the RPM comes down.

Whatever the cause or the actual source of the noise, I'd not start an engine making that sound again until I was 100&#37; sure I'd found and remedied its source.

The only way to be sure is to start pulling things down until you find it. Pull the plugs and look for crud or missing electrodes (I've had that happen once, lost a whole center ceramic electrode that ended up leaving a dandy footprint in the piston before finding it's way out the exhaust, in many little pieces I'd imagine). If you can sneak a bore-o-scope, have a look at the piston tops, the valve mark should be easy enough to see.

If you don't find anything when you pull the plugs, and you can't borrow a bore-o-scope, you might as well resign yourself to pulling the heads and checking for bent valves. While it's apart, check all the lifters and check/change the valve springs. When we build motors, we never reuse valve springs. When you turn 'em tight like we do (talking ~8,300 rpm here), they get a pretty heavy workout. They're too cheap and easy to replace to risk a high dollar engine over. Same thing with valve locks. High stress item, cheap and easy to replace, so we don't use them over.

It might be nothing, but it might also be the harbinger of a blown motor. Better to pull it down for nothing than ignore the noise and break it.

 

I don't know but since you had the manifold off, I would take it off again and see if anything in the lifter valley looks wrong. Left over wrench, parts, bent anything.

 

It sounds like you might have dropped something that got down an intake port and on top of a piston while you had the intake off. You might pull the plugs and look at them. If something is in a cylinder, the plug in that cylinder usually looks like someone took a hammer to it. Don't ask me how I know.
Larry T

 

I would pull the valve covers off and crak it over and watch the valve train movement carefully.

 

alot of guys gave you the right info--watching video it seems to start too hard--something is off--timing? aslo kinda sounds like something flexplate related--maybe loose bolt or starter a little close or something laying in the valley??? they are all right--pull the intake and vavle covers--turn it over slowly with plugs out and see if all valves are operating correctly and if any lifters have slack when on bottom-lots of possiblities-stuck valve, broken spring stud coming out of head-did the motor run fine before you did this swap or is this the 1st fireup

 

Man, AWSOME info guys! The engine ran with the TBI system before I took it out of a silverado, it just would have looked HORRIBLE on an open roadster with the hundreds of wires! I just bolted the parts on and did my best to install/adj. the timing and distributor. I didn't want to keep running it with the noise and without a cooling system. I'll pull the plugs and rocker covers tuesday and take a look. Thanks, Paul

 

If you have a mechanical pump that noise could be the fuel pump rod. You may have broke the fuel pump spring if everything wasn't lined up right. They can be a *******. Check that before you tear anything else apart.

 

Well I can rule that out. That whine that sounds like a buzz saw in the background is my electric pump. My block doesn't have a provision for a mechanical one. THANK YOU for your input.

 

Well, if it ran fine recently w/TBI, it prolly is NOT flex plate related, valve adjust, lifters unhappy in their bores, etc. I still think it sounds like something dancing on top of one of your pistons. As suggested, pull the plugs. If something's in one of the cylinders, it's spark plug should be pretty beat up looking

 

Could also be something simple as a piece of carbon sitting on top of the piston. Not uncommon when you have changed an intake. Why not take out all the plugs and crank it over and see what happens. Hard to tell from the video but it doesn't sound that serious. However, I'm no guru......

 

I agree with olscrounger, I'd look into the possibilty that the starter drive just might be ticking against the flexplate ring gear. Sounds real tinny like that. I'd check that before removing any real big parts.