I have a 65 Elky with a freshly rebuilt 350 driving a 700R4. When I start the beast up first thing in the morning, it makes a loud clicking sound for about the first 10 seconds after I gas it, and then it diminishes. The sound won't come back all day long unless it's really cold out.

I can also somewhat hear it for a little while later after I've run the engine for a few seconds, but it's very faint.

Ugh, I wish I could just get this thing dialed in! smile.gif

Do you have forged pistons? Sounds like typical piston slap when forged slugs are cold. Not to worry graemlins/thumbsup.gif

Hopefully that is it. Would anyone be able to explain why this happens so I'm not so paranoid about it?

Thanks a ton!

I think I read somewhere that pistons are not perfectly round when cold, but more eccentric. When they heat up, the expand to the proper shape. Maybe someone can tell me is this is true or if it's crap. :confused:

forged pistons are dense and expand from heat much more than cast pistons so they have to be run looser in the cylinder so they dont swell up and stick to the cylinder wall making a mess out of your engine////////////// but your noise sounds like a lifter to me check your valve adjustment and change your oil a loose one could do it :cool:

Hmmmm... I don't think it's the forged piston thing, I'm not real sure what it is. I adjusted the valves on the thing, with no change whatsoever. It's a REAL loud noise now in the morning, and it slowly goes away. I should try to tape the thing, but I don't have a recorder any more.

It's a real loud knocking noise, lasts for about 10 seconds, and then sharply dies away. I don't know if it has anything to do with heat either. After I drive it for a while, and then park it, if it cools down a bit, but not all the way, when I start it up, I can hear the noise again, just not as pronounced. I'm thinking it's a lifter or something in the valve train that's not getting enough oil, or has an oil hole slightly plugged or something.

Ugh.

sounds like you have a lifter leaking down over night, makes a tapping noise till oil pressure hits the offending lifter, the fact that it takes alittle while for it to totally go away sounds like a very dirty oiling system. if you can find a product called gumgone i've personally seen it do wonders for dirty lifters.

I was kind of hoping it was just a lifter problem. I was going to try that Lucas stuff, as I have had real good success with that in other engines. I thing that something just slipped in there from the initial break-in, it's crazy how stuff has a tendency to float around like that.

I'm driving up to Orange County today to pick up all my new suspension and steering parts, and will pick up a can of gumout on my way up there and throw it in. I'll post results within the next couple of days.

Thanks again guys - you are all great.

Okay - here's the deal, after adjusting the valves and whatnot - trying running some Lucas through it, and a couple of other 'quick fixes' - the noise still remained. I was convinced it was a lifter leaking down, as had been described earlier.

Anyhow - here's the real bugger. When I got in the car to start it up this morning, I leaned out the carb a little because I've been thinking that it's running a little rich (bogs down a little when I go WOT, constant faint gas smell in the exhaust) and not having a vacuum gauge handy, I was just doing some quick troubleshooting.

So, I get in, fire it up, it roars to life, and I head down the street with the usual tapping noise. Well, it subsides in about 1/10th the time that it normally did. Coincidence? Nope, because I just did it again. So, what in the world did I do? Am I running that rich that it could have been causing a problem like that? Should I lean it out some more? I have a Holley Street Avenger 570 CFM, so I imagine I have to set the idle mixture pretty low, but sans buying a vacuum gauge, is there a simple way to tune this?