Flathead noise! Need help!

Ok Fltahead guys... this isnt good! SO after fixing the sticky valve, we started the engine and it has the exact same noise with no change whatsoever! I guess I picked up some horsepower but didnt cure the problem... It is DEFINITLY coming from the #8 cylinder. Intake is coming off to check the valve clearances again. Next is head and then dropping the pan to pull out the rod and piston. Maybe the pin? Again, new motor. sat 3 or so years.... SOMETHING went wrong... I am stumped.. sick... frustrated... etc etc etc.

Anybody have any suggestions besides valves? its still at the shop so they are doing the work. The only good thing so far is after having it sit there for over 2 weeks, turning the motor and oiling the valve, he only charged me $50! There are still honest people out there!!!

Will keep everyone posted but if someone has an "ah ha" moment and comes up with a stellar idea, I would love it! $50 gift card to the HAMBer that says "check this" and it is that!!!

thanks again for the earlier comments and suggestions!

Brando

 

It certainly sounds like valve noise, not piston pin or rod. Before tearing the bottom end apart, I would pop the valve assemblies out of #8, disassemble and carefully inspect them. Check for proper stem to guide clearance, no burrs on stem or in the guide bore, etc. Also inspect the tappets and their block bores for and burrs, etc. Make sure the lifters move freely in their bores- epecially if the bores were drilled for adjusting the tappets. That process can always leave ragged edges inside the bores that will cause the lifters to hang.

 

I forgot to mention another thing I always do when running any flathead motor- add MMO (Marvel Mystery Oil) to the fuel, 4 oz to 10 gallons of fuel, as a top-end lubricant. It will help keep the valves lubed and is quite good at preventing those nasty flathead valve and combustion chamber deposits. Just some added insurance that actually works..

 

Sorry, I see I was interchanging tappet and lifter in the first message. Same, same. Wasn't trying to confuse anyone, only myself..

 

Pull the plugs and make sure they aren't too long, and getting tapped by the valves. Had that happen to me.

 

Another "oh s**t " I encountered while assembling, got the crowfoot lock in wrong, or missed it. In the case of the split guides I use, can get it in wrong & the halves are offset. Not in your case of course, and a stupid question but is the lock in place?
Also, when valve is open, is seat tight in the hole? Done that one too