forged internals/pison slap?
 

ok, me and my boy replaced his stock (slightly toasted) b16 bottom end this weekend, in it's place, a jdm b16a with forged rods and pistons (already assembled when purchased). we got it in and running last night, but there was a little knocking/tapping sound when we first started it, it was about 10°F outside and the block sat outside over night, etc., basically, the block was freezing cold. i told him forged internals make noise when they're cold, he doesn't want to believe that and thinks it's something serious. we never let the car fully warm up, but the slapping was getting noticeably more faint the longer the car ran. can you guys please post in here some reassurance for this ass hat that fogred internals make noise :P

Re:forged internals/pison slap?
 

most cars make slap noises when cold, forged or not.
up here when its -30c out the pistons slap, until the car warms up , the pistons expand and fill out the cyl better.

does it have a block heater?

Re:forged internals/pison slap?
 

wtf is a block heater :-[ :-X

Re:forged internals/pison slap?
 

it plugs into a wall outlet and heats the block (hense, block heater) so it's easier to start int he morning.

Re:forged internals/pison slap?
 

lol, i thought that's what you were talking about, na, we don't have/use those silly things, it's usually not that cold here, sometimes i just bring my engine in and let it sleep on the couch if it's real cold

Re:forged internals/pison slap?
 

My d16a6 with forged internals was definitely noisy compared to a stock motor, especially when cold.

Re:forged internals/pison slap?
 

what kind of pistons did you use (brand name)


and yes forged pistons will sometimes make a bit of noise when cold. I've yet to build one, but I've heard other peoples engines.

Re:forged internals/pison slap?
 

i believe they're je pistons, he bought the block already assembled from a very trust worthy guy that we know and he personally put the block together, you may know who he is jeff (import jedi, larry). what do you mean you've never built an engine with forged internals????

Re:forged internals/pison slap?
 

I've never built a engine that made any noise w/ forged internals ;)

I've heard alot of people complain about arais pistons making noise when cold, something about the alloy they use in their pistons are a bit differnt.

Re:forged internals/pison slap?
 

My stock internals sound like this when the engine is started cold. In the mornings, its been anywhere from 5 to about 15 degrees F out so I just let the engine warm up for 10-15 minutes before heading out.

Re:forged internals/pison slap?
 

every forged piston motor i have built sounded like that... it normally goes away after the first 1000~2000 ish miles

Re:forged internals/pison slap?
 

piston manufacturers usually recomend a specific bore diameter to account for the expansion of forged pistons once they heat up. This can create piston slap when cold. Although not all forged internal engines have piston slap. ;)

Re:forged internals/pison slap?
 

my dads old 1968 mercedes had one of those. I didnt know they still make them. His was on a diesel engine.

Re:forged internals/pison slap?
 

cars come stock with them up here, and if they don't, people pay up to 200 bucks to have one installed, infact there is many different kinds.

Re:forged internals/pison slap?
 

u dont really need a block heater if ur running 5w30

Re:forged internals/pison slap?
 

try starting your car in timmins when it's -50c out.