What is this noise? Carton on offer

[Tawfxr6t]

Any updates on this? Got a similar noise coming from my built motor however it's quiet on cold start and develops the same noise after a minute or two of running.

[3Katz]

No updates other than I haven't been able to find anything definitive. One bloke I was talking to that had the same thing happening on his built engine removed his pistons and had them coated to take up a bit of clearance and that seems to have fixed his noise issue. Mine goes in for a tune on the 12th noise and all so we'll see what happens...

[cat007]

Hey mate.
Just wondering how you got on?
I've got a similar noise and also running CP pistons. I've tried a few different oil thicknesses to try and eliminate the lifters being the issue. Although if yours is anything like mine, it's more of a rattle than a lifter tick?
I've got Empire Elite timing chain/guides and sprocket though - not Atomic like you. Mine also appears to be towards the rear of the engine - possibly between 5 and 6 like yours.
I was thinking of taking the cam cover off and running the engine to see if I can hear/see where the noise is actually coming from as when the engine is sealed up, it's almost impossible to actually pin point the location.

 

What oil are you using?

Cheers

Hunt

[3Katz]

Hi mate,

Nope I never got to the bottom  of it, we ended up putting it down to noisy pistons for lack of any other possible issues as everything has been checked. I've run Castrol Edge 10/60 and Edge 5/40 no noticeable difference between the 2. Yeah it's super hard to pin point let me know how you go with the cover removed... For what it's worth we built another one on the side as we were sure the issue would come to light on the dyno or track but it has never given any grief aside from the noise. And we're at 500kw with more to come next tuning session with some more gate spring. I'm just living with the noise, I've found once it's proper warmed up with some decent pulls the noise goes away - gotta be pistons right? Who fkn knows lol

[cat007]

Hmmm dam it's so weird aye. I haven't got any videos of mine but will try and get one this next week or so.
I've not had my tune done yet but would like to get it sorted, or at least figure out what it is and if it's bad, before the tune.

I'll try and get a video with it running without the cam cover on too.

I have tried 20W-50 and now running 10W-60 Penrite. No change in noise. Mine will appear shortly after start up from stone cold. Isn't so bad at idle but you can just hear it, then it is very noticeable at about 1000-1800rpm, goes away at from 1800-2000rpm and above. When the engine is really hot, it's less noticeable/not at all.

I've got crow cams lifters in - and stock cams.

Yeah my engine builder and a few others have said it could just be those CP pistons. It sounds awful though - almost like an old diesel VW Tourag lol

[3Katz]

Yeah mate for sure, sounds like it could be the same issue as mine. My engine builder sized the bore as per CP instructions but I've heard quite a few stories now of the CPs being particularly noisy. We've measured the pistons and bore again to be sure and they're as per spec. Meh it's a sh*tty noise and sounds like a bucket of bolts but is certainly hanging together lol be interested to hear what you find 👍

[cat007]

I had some comms with crown cams, where my lifters (and springs) are from. They said that they haven't had issues like this before and the oil I'm using now and have been using during initial start up and break in, shouldn't be an issue. So might not be lifters.

Once I get my cam cover back from the painter shop I'll move the car inside and take a look at the top end while it's running.

[Manu]

Did you guys find out what was it?  Mines making same rattle on idle. It goes away under revs in gear. 
I am guessing it could be cat, cams, flywheel or bottom end. 

[Tom Tucker]

Sounds like timing chain tensioner