Strange noise from engine, need help with identifying it please.

[Coronet1965SWE]

Hello, i have this strange noise in my 512 cui. stroker. It has a 440source strokerkit but due to a limited budget the heads and valvetrain is original for now, the cam and lifters are new comp cams and also the valvesprings are new.

So, the problem is i hear a kinda "dieseling" sound from the engine. I cant really locate where it comes from, i have listened with a stethoscope but it doesnt sound any louder with that (not like a worn bearing, that made a high sound through the stethoscope). (The light ticking sound is the injectors)

I made a little film and put up on youtube and was hoping any of you experienced engineguys could have a listen and perhaps hear whats wrong.
Thanks in advance.

http://youtu.be/BHCrKu4CGiE

 

[66Satellite_in_NC]

How does the motor react when driving? Did this occur after the motor was put together or start sometime later?

 

[Coronet1965SWE]

It runs great, the noise has (as far as i can tell) been there since this spring when i had to pull it apart and rotate the pistons due to a sub-par enginebuilder (i made a thread about that).

 

[snakeoil24]

Sounds Like Diesel! Did you check clearance between heads and valves and Piston tops. Something is hitting!

 

[CoronetSCO]

I spoke to a guy last year with a recent 440 source stroker build and he ran into issues with a bit of piston slap/play. Obviously a build/bore problem and not necessarily 440 sources's fault but his noise was unique as well.......:icon_confused:

 

[Hemi Rebel]

It does sound like a diesel. Do you know why diesels sound like they do? Injection timing. What is controlling your fuel injection?

 

[Texpar]

sounds top end. what cam and springs are you running? maybe pushrod length is off or a bunch of bent ones

 

[Coronet1965SWE]

snakeoil24:
The clearance between valves and pistons is ok, considering they didnt crash with the pistons mounted 180 degrees wrong they should have lots of space now.
Piston to cylinder head might be the culprit, when i was mounting the cylinder heads i tried without the gasket and then the pistons lifted the heads a tiny bit
but with gasket it was ok. It was also ok after tightening the headbolts but maybe when the engine is running the pistons go a little farther.

Hemi rebel:
Im running Meqasquirt V1 wich runs bank injection, 4 injectors at the time. Although i had the exact same fuelsystem before rotating the pistons and then it was ok.

Texpar:
I run a Comp cam extreme energy .488/491" with matching Comp cams springs. The pushrods are stock as is the rockers. I did not measure the pushrod length sadly, and the block has been decked, heads milled and valves done so they might be off.

Thanks so far.

 

[68GTX440]

I would definitely pull the heads and check!! Hopefully not to much damage.

 

[Hemi Rebel]

Wait a minute. It was running before. Then you had to pull it apart? What was wrong? If it was running what led to the conclusion a piston was in backwards? And depending on the piston, you cant just turn them around.

 

[Coronet1965SWE]

Have a look here Hemi rebel: http://www.forbbodiesonly.com/mopar...Help-please-are-these-pistons-mounted-correct
Sad story hehe.

 

[Hemi Rebel]

Have a look here Hemi rebel: http://www.forbbodiesonly.com/mopar...Help-please-are-these-pistons-mounted-correct
Sad story hehe.

The very first post of the thread you sent link to shows the engines right bank. Cylinders 2 4 6 8.
The valve arrangement is wrong in that picture. It should go E I I E E I I E. you had E I E I I E I E. #4 and #6 pistons needed to swap. What did you do? You didn't turn the piston so the raised part was closest to the lifter valley did you?

 

[Garys1969RR]

The flat part of the piston appears to come up almost even with the deck surface, or slightly below. And this side of the piston comes close to the flat part of the cyl head. Even if the pistons had a quench dome, it would still be on the valley side (or top) of the block. The only head that wouldn,t fit would be a closed chamber head which he does NOT have. I don't see a quench dome on those pistons.

- - - Updated - - -

And the flat side of the piston needs to be at the top, or valley side, of the block. The piston dish goes towards the spark plug side of the combustion chamber.

- - - Updated - - -

Ok Coronet 1965, how thick is your head gasket? if you had the pistons lifting the heads slightly without a head gasket in place, and the heads laying on the block, then you may have TOO LITTLE piston to head clearance. You should have a minimum of .035". So if you are using a steel shim head gasket at .020" thickness, then you are at around .010 to .015 clearance which is not enough. Even with a .040" thick head gasket you may be too close. So what head gasket did you use on re assembly?

 

[1962polara]

^ x2

 

[Coronet1965SWE]

I used the Fel-Pro Head 8519PT1 wich should be .040" compressed thickness. Guess i need to have a look with the boroscope tomorrow and see if i see any hitmarks.

 

[Hemi Rebel]

Good God. I see. Pictures in post 7 show close up. I swore that was a raised piston in th first post. I need to get my eyes checked. It doesn't help I'm looking at it on my phone too. Anyway, yes. I see where I was wrong.

 

[Coronet1965SWE]

I had a look with the boroscope but couldnt see anything in the 3 cylinders i checked, not easy to see with a cheap boroscope and im guessing it only hits very little so i vill pull the heads off and have a look.

At the same time i will check the pushrod length, can i buy just one mechanical tappet for checking length of the pushrods or can i weld an old hydraulic tappet and use for checking?

 

[Garys1969RR]

One way to check piston to head clearance is with modeling clay. Put the head and a used gasket in place with a piece of clay on the flat part of the piston top. Put a thin coat of oil on the head to keep the clay from sticking to it. Put in a few head bolts around the cyl you are checking. Snug them down good, and rotate the engine 1 full revolution. When you pull the head the clay will be the same thickness as your clearance. Lay a feeler gauge next to the clay and you can get a fairly close idea of your clearance. One question, Coronet, does any part of the piston extend above the block deck surface? If not, how far below the deck is it? A dial indicator works well to check this. Or you can try various thickness of feeler gauge to get an approximate clearance. Let us know your check results. Good luck.

 

[Kern Dog]

With my eyes closed, that absolutely sounds like a diesel engine.
How is the oil pressure? Have you drained any oil to look for shiny particles floating in there?

 

[Coronet1965SWE]

Garys1969RR: I tried with the modeling clay but since the hole in the headgasket is bigger than the cylinder it was hard to see properly.
The pistons do extend above the block about 0,5mm or 0,02" and the gasket is 1mm/0.04" compressed thickness so that leaves 0,5mm/0,02" clearence at best with a cold engine, not good..

Gregory C: Oilpressure is good and oil looks fine.

With the heads off i can see where the pistons have touched the heads (see pics), luckily nothing seems damaged.

So to reach a safe distance between pistons and heads i should use something like this: http://www.summitracing.com/int/parts/cgt-c5464-075/overview/make/dodge
Cometic gasket with 0,075 compressed thickness, maybe a bit thick but i dont want to risk it.

I would be grateful for some feedback