engine knock/rattle 360

[Val360]

Hi all

I have an engine knock/rattle hard to explain in my 360 that is there when cold but seem to disappear when engine gets warm.

Engine has only about 50 miles on it, it has

-stock bottom end (new bearing, shot peened rods)
-.040" oversize piston (wasn't blueprinted but briefly remeber seeing KB 10.5-1)
-Mechanical cam
-solid lifters
-Hughs roller rockers

Have had abit of a play around once knock began...Have pulled head off left bank and all seemed fine (pistons, bore, valves, valve springs etc.) re-installed head, double checked valve clearances, no bent push rods, timing is fine. Started it up again to day and sound is still there, pulled ignition plugs one at a time and no change in noise.

Any ideas or suggestion would be great at this point??

Sorry about my dodgy typing!

 

[Val360]

Here is a video if you are able to open it

[ame="http://www.youtube.com/watch?v=AGNS5kQSovU"]mopar 360ci engine knock - YouTube[/ame]

 

[Val360]

<embed src="http://www.youtube-nocookie.com/v/AGNS5kQSovU&autoplay=1&fs=1&rel=1&hq=1" type="application/x-shockwave-flash" allowfullscreen="true" width="480" height="385" wmode="transparent"></embed>

 

[Val360]

Video will be up once approved by moderator!

 

[68gtxman]

It sounds like piston slap to me. That would happen when the machine shop returned a block with a bore that couldn't be brought back to round, but forgot to tag the block as such. Then the builder puts it back together. The sound might decrease a little after the piston warmup and expands, but the sound usually never goes completely away. I hope this is not what's going on with yours!

Other than that, it sure has a bad knocking sound. It truly is reminiscent of timing being way off from ideal. How did you ensure it was timed correctly? Did you try rotating the distributor while it was idling to see if the knocking goes away?

Good luck with this!

 

[68cuda78]

Wow that sounds bad, not but if it would be that bad but maybe bad timing and some bad fuel or low octane. Maybe retime and refuel and if that doesnt work engine is going to need to come apart.

 

[OldmanRick]

Are you sure a rocker arm isn't hitting the baffle on the underside of the valve cover?

 

[pettybludart]

Are you sure you have the firing order right?It,s definetly mis-firing by the sounds/shake of it.

Edit:After stopping the vid and looking at the top of your cap(plug wires)I,m going with wrong firing order.JMO

Also move that coil wire from touching and plug wires.

 

[MRL Performance]

Are you sure the engine is not hitting something when its got that cold shaky rough idle? Maybe the idle smooths out a little when worm and it doesnt shake as much?

If that noise is from inside the engine, it sure doesn't sound like its just one cylinder it sounds like a few. Just one cylinder would be a more steady knock knock knock. not the multiple rattling sound you have.

 

[Bulldozer]

where is the timing at? it doesn't seem to be hitting on all 8 cylinders, it sounds like the timing is retarded. I would advance the timing some and see if gets better...its hard to tell though

 

[TrailBeast]

I always thought this would help people that were new to it, so I finally did it.
Of course it's only acurate if the rotor points at this plug tower on TDC.

 

[Val360]

This is what I did to get the timing, I've installed the oil pump drive shaft so the slot in the top of it is pointing at drivers side front manifold bolt when cylinder no.1 is at tdc.

Rotated dizzy to 10 deg adv for start up and then rotated to roughy 14/15 degrees adv whilst idling. I will start it up again today and advance it some more and see if the noise goes away

 

[1wild&crazyguy]

Mucho piston rocking going on, heats up , the skirt expands...and it gos away, right?

 

[Mad Dart]

Here are my guesses ill throw 50$ wager. Who is in?

Wrong piston pin height and when the piston is at BDC it is rocking and hitting the crank counter weights?

Or....

Pick up tube hitting counter weights on crank?

Or....

Flex plate/ Torque converter bolts are loose?

 

[Val360]

Didn't have much time to play around with it today but did get the chance to start it and advance the timing a few more degrees with no change at all.

Will check flex plate to converter bolts but if fails to fix i will he pulling the engine out and tearing it down, I'm highly thinking it maybe piston slap as few have mentioned on here.


Will keep all upto date with what the go is!

 

[MRL Performance]

If they are Hyper pistons, you will have piston slap if your piston to wall clearance is more than .0035". They need them to run tight, spec is .0015". If you have a new car/truck, most of them run super tight P2W at around .0008-.001"!

 

[SGBARRACUDA]

When I heard the video, first thouight is piston slap or wrist pin knock.

 

[jimjimjimmy]

this is just a shot in the dark but does your roller rockers fit your set up properly maybe the rocker is hitting the retainer just a little.

 

[memike]

Pull the oil pan and take a good look at the rod caps and bearings maybe
Flex plate/ Torque converter bolts came loose.... It sounds like it has a vacuum
problem some where to me also, but I have to agree with all posts here.
I hope this thread ends with a good out come

 

[1wild&crazyguy]

My hypers are set for .003 , they don't make much noise and make none after warming up.

 

[mbaird]

Interesting.... My motor has started doing a similar thing !
360
KB107s
Hughes Rollers
Lunati 268 cam
Balanced crank

Ran ok after breakin.... Played with carb a bit and thought that was maybe it .
Cant find any header contact points.... Hard to tell where it is coming from !
Valvetrain sounds smoothe with stethescope....

.????

 

[mbaird]

My sound is not as consistant.... Comes and goes... Thought maybe thrust bearing wear ?

 

[Cudafever]

Your description made me say, Yup, piston slap!!!!!!

Your video.....i don't thing so, not a consistent knock.

My guess is torque converter bolts have come loose.

check them and the harmonic balancer bolt........Did you us lock tight on the Torque Converter bolts???

 

[Cudafever]

I always thought this would help people that were new to it, so I finally did it.
Of course it's only acurate if the rotor points at this plug tower on TDC.

I really like this, should help him a lot.

Its real hard to tell in the video but I'm with pettybludart. don't thing its wire right.
It looks to me that 6 and 8 are together in the fire order, and that's not right.

Trail Beast NICE JOB!!!!!

 

[Mad Dart]

Another thread back from the dead. Almost 1 year to the day.