19 replies to this topic

[Evan]

Heya Guys.

Put a new 355 motor is the Torry and it has a bottom end noise when its running.

It is a really bad noise like the big ends are slapping. (like no oil pressure)

This motor has been herd running and had only a few 1000 km's on it. (the bores still had the hone marks on them)

My neighbor who is experienced with performance holdens came over and had a listen and seems to think that the crank is hitting on the sump or oil pickup.

The only thing is that it has been herd running sweet before with that sump and pickup.
Also there is no noise when i crank it over with the starter motor, its only when it starts.
I have packed the pump with grease and have got a Stewart Warner mechanical oil pressure gauge on it showing about around 40psi.

It is running a solid cam and the rocker clearances are good. Certainly coming from the bottom.

Just want some second opinions on what it could be before i rip the motor out and have a look.

Cheers

Evan.

[Litre8]

So it has good oil pressure? Did the noise just start or has it been getting progressively worse. Worse hot or cold?

[wot179]

This is probably optimistic,but pull out the dipstick while its running and see if the noise goes away.

[Redslur]

I had a mate who had a problem similar to yours. It was the crank hitting the sump. It was a pro-stroke 360 stroker. Very odd. A quick hit on each side of the sump with a block of wood soon fixed the problem...it was a bit backyardish but effective..

[rodomo]

Too much oil in the sump and you can hear the rods slapping the oil.
Maybe the wrong dipstick?
Drain the oil and measure in 4.5 litres and see what happens.
Cheap and easy to try first.

Loose flywheel bolts can also sound like bottom end.

[A9X]

If you can get under it when running, place your hand on the sides of the sump. You'll feel it if its slapping.

[V-SLR5000-P]

I agree with A9X, if part of the rotating assembly is hitting the sump you may be able to feel it knocking. Also try progressively disconnecting plugs with the engine running, if the sound disappears or is reduced on one cylinder then its more likely a bearing or noisy piston.

[Evan]

Thanks for the quick replies guys!

It looks like it has got good oil pressure and the noise is when its cold. I haven't had the motor warm as i tun it after about 6 - 8 seconds of running.

Ill give it another go with no dipstick

The feeling the sump idea sounds good. I will give that a go and if its hitting on the sump ill rip it out and give it a massage. But it has been running with the current pan.

I payed careful attention when i torqued up the fly wheel bolts.

Too much oil in the pan may be on the money as it has a high energy (Viper pan?) sump on it. I'm not sure how much oil they take, but i put 5lt in and it wasn't showing on the dip stick. So i put another 2lt in and it was full on the dip stick.
With high energy pans , do they have to have a custom dip stick?, as i just used my old one from my standard sump.
I have attached some photo's of the oil pickup and the pan to give you an idea of the size of it.

Ive over filled my old 253 before and didn't notice that it made any more noise than normal. It used to leak heaps and i was taking it on a 200k trip so i thort i had better put extra in. I only realized when the cops pulled me up cos it was smoking heaps. It later fouled the plugs.

Ill give the pulling the plugs a go too.
If i cant get rid of the noise i will certainly be ripping it out and will check the cam movement as NZ Toranaman suggested.

If it is big end noise they will have to be replaced anyhow so i could run it for a bit longer than i currently am.

The only thing i am worried about is that it has a new cam in it and my neighbor says if i keep starting and stopping it, i can snap a cam lobe off. I don't know how that works but that is another thread i will start as i would like to find out more about it.

Evan.

 19052009056.jpg   937.69K   33 downloads
 21052009062.jpg   713.6K   26 downloads
 21052009063.jpg   948.7K   14 downloads

[Evan]

Thanks for the idea Nathan.

Surly piston slap cant be good. Wouldnt you loose compression? , or do the rings take up the slack until things expand?


Im not sure if the motor has forged pistons.

I'm away from home atm but will bring this thread back up next week when i find out what the issue was.

Ev

Edited by Evan, 29 October 2009 - 09:50 AM.

[TerrA LX]

I can't see someone assembling a fresh motor that loose ( i have seen some shockers tho) I would tend to think it is loose flywheel too, even tho they torqued up does not guarantee they are tight or haven't come loose due to stretched bolts, damaged flywheel or crank etc.

Does it get louder or go away with revs?
Is it the whole motor or just one cylinder?
You could short the plug in one cylinder that is suspected, shorting the plug takes the pressure off that cylinder, it will usually go quiet if it is a loose big end.

[Evan]

Hey Terra

It does seem strange that a new motor would have been assembled loose, It has been herd running sweet before.
The fly wheel bolts are new ARP bolts, I didn't trust the old ones.
I haven't revved it, so ill have to get back to you on that one after i give it a few blips.
It sounds like the whole motor. like the whole thing doesn't have oil pressure

I ran the torque wrench over a few of the big ends to make sure they were ok , but not all of them. It also has 4 bolt mains.

Apparently performance mods did the machining and ive herd they are pretty good.

Ev

[Evan]

Well!!!!

I happy ending to this saga! Hand on the sump revealed that the crank was hitting the sump at the front near the harmonic balancer.

Thing was that this sump has run successfully with this bottom end. So i backed off the sump bolts a bit and starred it and no more noise.

So with it running i tightened them up and its all sweet!

The sump bolts weren't super tight originally, so all i can put it down to is that it was previously assembled with a thicker gasket.

Chers for ya help guys! The forum is always a great help.

Ev.

[Heath]

Yeah I was gonna say must be gasket thickness. Nice to hear it was no big deal!

[76lxhatch]

Maybe someone sat it on the sump while out of the car?