Well I have had my low comp ls/vtec running NA since june, sucks cause im really ready to turbo but now its too cold outside to put the kit on, anyways, when i go outside in the mornings to warm my car up upon first start up and for about 2 minutes or so after my car is really really loud and I have no idea why. I have been told its because I have forged internals and that they cause it to be somewhat loud on first start up. I think i need a valve adjustment cause my valves are a little noisy after its warm, but could any of this be the reason its so loud on intial start up?
well, i have wiseco’s and eagle rods and i start my car in the morning at about 15-20degrees F and its not loud. well, the valves are a tiny bit noisy as well as my injectors firing, but its not very noticeable. im not getting any piston slap. it does depend on the piston to wall clearence. what pistons did u go with? did you overbore?? stuff like that
This is 100% normal. Most times when you build an engine with forged internals, you will hear noticeable rod knock/engine noise because the metal ahs not heated up yet and expanded. You have no need to worry. It will always go away once the engine warms up a bit
it can depend on the amount of silicon in them as well i think. “hypereutectic”? iirc, the more there is, the less they will expand and so you can use tighter clearances, hence less noise when cold. this makes them brittle and not as strong as forged ones, so forged ones with less silicon need more clearance to expand when hot. so you sacrifice sound for strength.
well they are je 9:1 forged pistons 81.5mm bore, it def. sounds like a diesel upon start up, but after its warm i only have some valve noise, im gonna get that taken care of next week
ya im sure you have the regular ones with less silicon than the SRP line, which are more for “street” and weaker/quieter with more silicon. so the sound on cold startup is just something you gotta live with.