347 stroker woes

[twolo4u2c2]

OK.....I had this knock check by a builder and He was sure it was piston slap. it goes away when warm but knocks when cold. Can I exchange the pistons with forged units without messing up the balance of the engine? assuming the .030 overbore wasent screwed up by the machine shop.

thanks:SNSign: :SNSign: :SNSign: :SNSign: :SNSign:

 

[Grn92LX]

No. You'd ideally need to have it balanced.

Is it a knock or a tick?

 

[CoupedUp]

No. You'd ideally need to have it balanced.

:Word:

You probably have the 5.4" rods with the intersecting pin bore = short skirt that can rock in the bore until the friction heats the piston skirt enough to expand it just a fraction. That will make up the gap on a mediocre quality piston ... Piston/valvetrain noise should always be constant (aside from lifter bleed off on initial. A lot of guys drive a slapper for a long time before being forced to delve into it. Me, it would drive me batty.

You might also have a 4:55pm Friday bore job ... or a combo of both issues ... or something entirely different

Man, the more I read these 347 posts, the more I love my 331 with the 5.3" rod and longer skirts :Word:

 

[twolo4u2c2]

No. You'd ideally need to have it balanced.

Is it a knock or a tick?

Its a knock...almost like a rod knock and changes with RPM. I goes away when Its warm.