clean pistons or just install new hg?

[e30Rooster]

My roommate's a mechanic by trade and he says there is no need to clean the pistons before I install the head, what's the real answer?

[WatchMyDrift]

Honestly they are just going to get all dirty the first time you run your car. unless there is a large build up of carbon i wouldnt worry about it.

[jlevie]

There is no point in cleaning the pistons unless they are very heavily carboned. But it is important to have the head checked by a shop for warp & cracks. My experience is that a used head always has some warp, so I always have it surfaced. And while at the shop I'll have the valves ground and I'll install new seals.

[Bearmw]

And if you do decide to clean them for inspection purposes or to improve combustion be careful to avoid scratching or marking them up. I think there are some posts about that.

[e30Rooster]

There is no point in cleaning the pistons unless they are very heavily carboned. But it is important to have the head checked by a shop for warp & cracks. My experience is that a used head always has some warp, so I always have it surfaced. And while at the shop I'll have the valves ground and I'll install new seals.

I have a myster-e head :up:
thanks

[reelizmpro]

There is no point in cleaning the pistons unless they are very heavily carboned. But it is important to have the head checked by a shop for warp & cracks. My experience is that a used head always has some warp, so I always have it surfaced. And while at the shop I'll have the valves ground and I'll install new seals.

I concur.

[digger]

the carbon buildup is essentially a free coated piston as it is a good insulator. I know of pro highly respected builders who bead blast pistons to encourage a thin uniform build of carbon on the crown