ZULater01

iTrader: (1)

I bought this car about 3k miles ago from a guy on LS1.Com, well it was missing real bad and pinging about a week after I bought it, pinging before then, but missing for a while so I checked everything plugs,wires,cats,02's, all, then pulled the valve cover and there were 4 bent pushrods and a broke one. So I decided to go ahead and due heads/cam. I pulled everything and when I was cleaning the pistons a few hours ago found this...Should I replace the pistons? They are stock 2000 pistons.

GrahamHill

iTrader: (6)

Are all those LS1 pistons flycut like that or has that motor just been overwound too many times?

Beast96Z

iTrader: (21)

Looks like someone floated the valves or broke a valve spring earlier in the cars life. As long as the bore is in good shape, the pistons should be fine. As long as you can't see any cracks or anything, I wou;dn't worry about it. Just clean them up the best you can and do a good inspection.

ZULater01

iTrader: (1)

I cleaned them up, and I only found a lite scratch in the cylinder wall. Hmmm. I am lost.

The previous owner had a pushrod replaced 10k miles ago, which he didn't tell me about ,I found out after doing a carfax...and guess what it was the #1 cylinder.

Adrenaline_Z

The pistons and chamber look like hell.

That pitting resembles detonation.

As for the scratches, how did that happen? That could cause some sealing
issues on the compression stroke.

You didn't happen to check the compression across all cylinders?

I don't believe you'll have to change the pistons, but I would consider a resurface
if the crowns are still in good shape.

VSGLS1

iTrader: (8)

I wouldn't run it like that.

ZULater01

iTrader: (1)

I didn't check the compression. Those chambers are the old heads and I got new ones, so that takes car of the heads part.

Adrenaline_Z

I would seriously consider a resurface of the piston. Show those pics to a
reputable engine shop. Get their opinion on the depth of the pits and see if
you can save the pistons.

1QuickT-A

iTrader: (12)

Why in the hell would you resurface the pistons? If you are gonna go threw that much trouble then buy some good pistons while ur at it..

Oh by the way, those pistons will probably be fine... But, if you plan to beat on it alot or spray/boost it sometime then I'd be a little leary of leanin on em too hard.

PREDATOR-Z

Just get a shortblock. Cheaper than rebuilding yourself unless you have all the tool. Block has to be balanced (internally anyways).

Talk to Bryan at LME, parts for price and quality, IMO they are the best (in my book)
Otherwise Lingenfelter has a $2095 shortblock with exchange, the are good too.

Adrenaline_Z

You don't seem too sure about the piston yourself. You're saying to leave
the piston alone, but if he's going to beat on the motor, then don't use them?

Ok..well...

When you take the piston out for resurfacing, you check the integrity to ensure
that the pitting (from what looks to be detonation) hasn't left hair line cracks
in the crown.

While they're out, you can 'deck' the piston to make it smooth again.

The cost savings are well worth it.

PREDATOR-Z

Adrenaline, How would you know?
You've never built an LS1/LS6

I wish you would refrain from giving such advice without facts. And don't tell me "I've built Alcohol funny car motors" because that doesn't apply here.

From our experience, it is more cost effective to get a reputable LS1/6 builder to do a shortblock. Also,that way, in case of any failure someone can be held accountable.

This is a sleeved motor, too big a scratch and you have to re-sleeve, better get another block.
Also if you shave the pistons more than .007/.008 you run into an in hole situation.
also those pistons are coated on side skirts and are renown for slapping the bores on LS1's so re-coating would be necessary.
So the cheaper approach is fresh pistons.

Adrenaline_Z

Here we go; you still have a grudge from the last post huh?

You're telling me that buying a new set of pistons is cost effective? Do
you know the process, or price of resurfacing?

Whether I've built alcohol motors, or not....or opened up an LSx engine,
or not, doesn't dispute the facts. I hate that rebutal. Trying to discredit
someone because they haven't worked on a certain engine is B.S.

Believe me, don't think the LS1 piston is on the same level.

FWIW: I wasn't referring to your post. I would consider your option as well.

So? What does that have to with resurfacing the piston? I'm sure the sleeve
can be honed. If not, then he needs to bore and get another piston.
Maybe at that point, it IS better to buy a short block.

Like I said earlier, my response wasn't directed toward you.
If you don't like my opinion - don't fukn take it!

I just gave the man my opinion and an alternative to save money.

GrahamHill

iTrader: (6)

Buy a shortblock?? Geeze. Why not just get a new piston, press it on the rod (Or however its done in an LS engine), then weight it against the other 7.

Those marks on the piston kinda look like something small has been in there.

FlyinLow89

Congratulations. this is perhaps the gayest/stupidest thing Ive read in a while. Sounds like a childish vendetta, has surpassed your better judgement. Basic engine guidlines can still apply to LS1's. Putting red vinyl all over your car doesnt make you an LS1 engine god.

ArcticZ28

iTrader: (14)

Those pits from detonation def don't look good, and those curved ruts are def where valves have been hitting the pistons. All of those imperfections are gonna cause hot spots. The only thing this motor is going to be OK for is daily driving. If you plan on doing any forced induction, nitrous, and or make any serious power your motor is gonna go to ****. While everything is apart I would take the time to get new pistons/resurface/whatever you want to do. It will save you a lot of trouble down the road and you will have one less worry on your mind when you're out showin off.

ZULater01

iTrader: (1)

Could I sell that motor for anything? I am looking ay 346-348 forged shortblocks...But I am borke right now but every penny would help. What sucks is this is my only car.

1QuickT-A

iTrader: (12)

Since its your only ride I would just put it back together and drive it for now.. Save up some money and buy a set of forged stock bore pistons or .005 over pistons and then tear it back down and do the piston swap. IF all the cylinders look ok then get some stock bore forged pistons and slap em in.

Or you could find a set of stock ls1 pistons and put them in.. That would be the cheapest fix in my opinion.

BBADWS6

iTrader: (8)

I would run it like that, the grooves in the pistons dont look too bad. I have seen much worse in a car that was still running nitrous with the grooves in the pistons. What is really important is the cylinder wall, if you can feel any type of roughness or see grooves or scratches you need to fix it. If not run it.

ZULater01

iTrader: (1)

Thanks for the commnets guys, even though I am still lost b/c of both different sides.

BTW The cylinder walls in #1 and #2, mainly 1 has slight scratches, nothing huge but you can feel it with your hand.