65 corvette L/79 engine noise

[harry nye]

Hello to all my fellow corvette brothers and sisters. I have a question for all that may have had or still do have the L/79 engine 327/350 HP in their corvette. I have owned over 2 dozen 69 Z28 camaros with a couple of crossrams and a few COPO and one Yenko and I'm very positive on engine sounds and noises that come from the 302 and the 427s with solid lifters and high compression. This 327 in my 65 corvette has me stumped.I'm hearing a noise that sounds like a water pump bearing noise but I just had the original pump rebuilt. The engine revs excellent with no noise at all untill the very end where the motor is getting back to idle for a split seconced you hear the noise than goes away. Sounds like a ball bearing coming from the front of the engine like the lower pully or maybe the fuel pump. Is this the way the 327 L79 high compression Hydraulic lifer engines sounds, could it be just the sound of the cylinders firing? I hate being that pickey and most people wouldnt hear it. This is the first high compression Hydraulic engine I had. Does anyone out there have this L79 and can shed some light on what this noise could be. I know its not the rockers because its not a tap. Its not a lower end noise because its not the sound of engine main bearings and it has great oil pressure. Its something stupid that I just cant figure out. I have been at this for days. Any help or suggestions or same experience would surely be appreciated. Thanks

[john daly]

Re: 65 corvette L/79 engine noise

harry,
My 67 L79 made a similar noise and what I found was a crack in the water pump pulley at the fan attachment face. A new pulley with the reinforcement plate designed to prevent the cracking solved the problem.

jd

[harry nye]

Re: 65 corvette L/79 engine noise

Thanks JD, was the crack visible? Do you think a crank pully would make the same noise?

[Mike McKown]

Take the belts off and listen. *NM*

[Mike G.]

Re: 65 corvette L/79 engine noise

does your L79 have an 365 hp idler pulley that's been added? could be a bad bearing in there...

[harry nye]

Re: 65 corvette L/79 engine noise

Well,its a real early 65, born in nov of 64 so I think the Idler pully is suppose to be there, but maybe taken the belts off, both belts may be the best thing to do to listen. Thanks for your suggestion.