Pat-Man

iTrader: (3)

Kind of a newbish question here. This is my first FI engine as well as Iron/Forged block. Do Iron/Forged blocks tend to make a lot of noise when cold? When I first turn on my car it sounds like a diesel engine (kind of a harmonic clacking/rattling noise). It gets much quieter as it warms up.

Thanks...just looking for some answers to ease my mind since I heard that the noise was normal.

- Patrick

camarols1

iTrader: (17)

If the noise goes away after a short warm up, then it is likely just piston noise.
Try to determine which pistons your builder used.
If he used "race" pistons made of the 2618 alloy, then the piston to bore clearance will be much higher than stock and a rattle type noise when cold would be normal.
Many kits will be made up of pistons with the high silicon 4032 alloy, which does not require as much clearance as 2618 alloy, but it will still be louder than stock.

Good luck

Pat-Man

iTrader: (3)

I wish I could contact the builder. The motor was built years ago, and the shop has been out of business for awhile.

extremetoy

iTrader: (17)

i just finished building my first motor with forged pistons and had the same experence. it didnt sound like it was in the valvetrain but didn't sound as bad as a rod knock... mine would go away completely after warm. i heard lots of other people saying that forged pistons will make a little more noise... i talked with my machinist and he said it shouldn't be making any noise.. maybe a TINY bit more... im using mahle forged pistons btw, he said maybe the reluctor was slightly contacting the block and needs to be slightly tapped away... well i tore the whole motor apart again checking all clearances and couldn't find anything... while i was in i put in a cam and now i barely notice it.

OUTLAWZ RACING

iTrader: (9)

Mines makes noise on a cold start up but goes away after running for a min.

2 SSlow

iTrader: (26)

MY stock motor made ALL kinds of noise...piston slap and valvetrain noise. With the forged motor, I have no bottom end noise at all hot or cold. I do have a small amount of valvetrain noise stil though. Not overwhelming though.