Atomic Motors (Merged Topic).

[Quasi XR6T]

Yeah, Seres seem to be doing some good stuff down there, but Mornington is just a bit out of my way.

[spinr33]

Its only $150-$250 freight to pallet an engine mate not that expensive

[Adamfiza80]

Hey guys.

Just got brad at Atomic to rebuild my fg f6 engine. I would like to report that my engine, although runs fine, is just noisey. Pretty quiet when cold but noisey when warm. Which goes against what we normally hear about forged internals. Im running recommended weight oil of 15w 50 and have had the timing chain etc upgraded, also head ported n serviced, heavy duty valve springs but oem lifters etc.

Motor has been balanced and blueprinted as per his specs sheet.

Just want to know if this id acceptable? Spent alot of $ on this.

Thanks

[turbotrana]

It may not be piston slap if only on warm. Ask him what piston to bore clearance he runs. Nowadays they are pretty tight with forgees depending on brand. The only other thing is valvetrain noise. When you start doing head work you gotta be careful with lifter clearances.

[Adamfiza80]

Yeah not much was mention on the spec sheet regarding head work except that it had 2 valves replaced that may have been damaged. Since it was all part brad reseated valves, cnc ported and serviced head. Do heavier valve springs relate to more valve train noise. If so, it could b that. Once revs go past approx 1600rpm the noise disappears. The noise is always the same and moves with revs till that 1600 point. Its also not intermittent. Any ideas are welcome. Im going to take the car to brad next week for him to see.

[jimmixr]

could it be timing chain noise ??

[welshy_89]

Or possibly cam phaser

[Adamfiza80]

Spoke to Brad and we sort of agree that it could be timing chain noise. Find out more next week guys. Will keep you posted.

[Ninka]

I think your oil is too heavy, and though this may not be the cause of your noise, I have found that you want to stay below 40 viscosity (I run a mix of 30 and 40 weight oil to achieve something around 35)

I have found that 50 or 60 viscosity oil makes engine more noisy, as I think not enough oil escapes from bearing journals to adequately lubricate bottom of bores, thus causing pistons to 'slap' from side to side.

My 2c worth - Good luck with getting this fixed.

[Wenier]

The weight of the oil is to do with temp. If you are racing you want to run a higher viscousity as a 60 will be the same as a 40 at the higher temps you will see when giving the engine that much stick for a long period.

If however you are generally driving about normally with the occasional bit of spirited driving then you should stick with the manufacturers recommendation.