340 valve train noise clacking loudly

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seahawk said:
We appreciate all your input..your not going to believe this.. back in "02" I walked into the SpeedMerchant in San Jose and ordered Edelbrock Performance RPM package, heads, intake, carb, I told them I have a small block 340, the heads I recieved were small block heads #60779 63cc combustion chamber but not the heads for the 340 #60179 65cc combustion chamber. When we pulled the motor this time, we did it to pull the heads as we have checked everyyyyything else. We noticed the pistons coming out of their sleeves just a wee bit,(18 thousands) the pistons were slapping the deck of the heads and that's what was causing all that racket. The heads are going to the machine shop to have a recess cut into them to accomadate the pistons. You can see where the heads and the tops of the pistons were actually slapping.. shiny little spots about the size of a June bug. Their does not appear to be any damage beyond that. I will look into degreeing the cam, now that the motor is out of the car. Thanks you guys for all your help.

http://www.edelbrock.com/automotive_new/mc/cylheads/chrysler/sb_perf_rpm1.shtml
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I don't see a picture of it, just a link to Eddelbrock heads, but it's amazing it never hurt anything. You were lucky.
 
If it's only a small spot the pistons were almost touching without the rock at TDC. When things got warmer I'd expect they got louder... This would be why sometimes simple assmbly isnt the best thing to have done or do. Blueprinting or even more attention to detail during the assembly process would have found that. The harmonics that creates is a mess. If the bearings measure fine (not plastigaged, and not visually inspected) you should probably check all the rods and for straightness and the pistons and pins for deformation too. Pull a couple pin retaining clips and if the piston pins dont slide out with a finger's pressure or gravity alone, you have damage there too.
 
moper said:
If it's only a small spot the pistons were almost touching without the rock at TDC. When things got warmer I'd expect they got louder... This would be why sometimes simple assmbly isnt the best thing to have done or do. Blueprinting or even more attention to detail during the assembly process would have found that. The harmonics that creates is a mess. If the bearings measure fine (not plastigaged, and not visually inspected) you should probably check all the rods and for straightness and the pistons and pins for deformation too. Pull a couple pin retaining clips and if the piston pins dont slide out with a finger's pressure or gravity alone, you have damage there too.
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X2 do like moper says you will be glad you did we had the same trouble with a 15to1 alky motor for dirt raceing about 30 laps in to a 50 lap race things got real ugly we brout the motor home in buckets....Artie
 
340sFastback said:
You running 3/8" or 5/16" push rods? Either way make sure the push rods are not rubbing on the push rod holes going through the heads. Should not be a problem with a flat tappet cam but it is something that needs to be checked.

How does your push rod geometry look? You need to verify that the roller tip contacts the valve tip correctly through the full valve open and close cycle. You may need to run the oil pump as you turn the engine to pump the lifter up. A check spring is a good idea too.

Degreesing the cam refers to the process of getting the cam in perfect sync with the crank shaft. You use a degree wheel, TDC pistons stop, and dial indicator to measure it. You would then use offset cam keys to adjust as needed. Some cam and crank sprockets have different slots and will change the timing based on how they were installed. Check the documentaiton that came with the timing chain set. Definately something that needs to be checked.

Like said above remove the torque converter cover and check if its been hitting the converter bolts.

I would not run it until you check the entire engine over. If it were mine I'd be pulling that thing out and getting it on a stand ASAP.
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Same problem on my old 408 with a flat tappet cam only 540 lift. All the pushrods were hitting the head. Its at such an angle they will wedge in than come loose making the lifter chatter.
 
I have run into the same problem with a set edel brock heads. I have a 408 stroker and decided to install a set of 60779 heads for a 360 and while i was installing them I noticed how flat they are compared to the stock heads. When I went to fire the motor up I had the same noise. The engine builder is going to show up tonight to hear it and I suspect that I will be tearing it appart again. His suggestion was to pull the motor and bring to his shop for him to inspect it and than put it on a dino before I re-install it back in the car. Like others have said to check all these clearances before you assemble, nothing is a direct bolt on in most cases.

Pat Faley
67 NB S Clone
408 stroker 4 speed
Peoria IL
 
Well, it's all coming apart and I'm goint to put together a 408. This time paying much closer attention to detail.
 
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