k5383

iTrader: (10)

Ok, It's an 02 LQ9, 228R cam (112LSA), stock pushrods, as obviously seen in the photos below.. The intake valves were contacting the pistons.

I'm taking all responsibility, I shaved the heads myself ( couldn't tell you a number) I did it enough to essentially get a clean gasket surface. I couldn't tell you if the heads had been shaved prior.

As I said 228R cam, no advancement, or retard timing set via the chain. Stock length pushrods.

When i assembled the engine I spun it over several, I mean SEVERAL times on the stand. To assure everything was Kosher, never felt any resistance etc.

Doesn't matter at this point, here's the pix, at idle you could hear the valves contacting the pistons. I chocked it up to incorrect pushrod lengths, Once I realized it was essentially coming from one side not the other I shut it down, and began the teardown.

As of now, My options that I see are flycut my current pistons. (Assuming the damage isn't too bad), or buy new pistons.

Sorry for the long post..

badazz81z28

iTrader: (6)

They look like fly cut pistons. I would measure and see if you can just continue the "fly cut" process...

How are the valves? I would assume some are bent?

k5383

iTrader: (10)

I built this engine, and Can assure you.. prior to start up they were stock LQ9 pistons.. with NO valve reliefs.

At the moment, the vavles don't appear to be bent. All 16 moved freely in their guides (hillbilly hammer test) Either tomorrow or thursday I will be taking them to the machine shop tearing the heads down and checking them for real.

knuts82

I don't know why but when I read this I spit my drink all over. lol but I feel for ya..

ice95z

iTrader: (10)

I would flycut. Check to see how much clearance you need first. Dont want to take too much out of the pistons. You can always get a thicker head gasket to make up some clearance though not the ideal way to do it.

badazz81z28

iTrader: (6)

What I meant was they don't appear to be damaged to the point of being unserviceable. They look like they were fly-cut, so actually fly cutting them would hopefully clean them up.

k5383

iTrader: (10)

Don't feel too bad, I've been building this truck almost a year. Soon as I pulled the first head I hit the fridge for budlight and moonshine..

The more I look into new pistons, and the added cost of boring/new rings the more I'd like to atleast try to flycut.

I'm going to search, but anybody got any good links for a "how to while in truck" ?

k5383

iTrader: (10)

Ah, I concur, Hell that was a joke I told myself to perk up when I pulled the heads. I'll check em again in the daylight, take more and better pix and go from there.

Gunslinger09

I think there is a tool that you can get that you bolt to the top of the cylinder and it allows you to fly cut the tops of of the pistons when they are at TDC. Try a search here and on google for it.

k5383

iTrader: (10)

There is, I just read a 7 page thread on here about a really nice set "lindy tools" or something rather..

Gotta find someone who will rent it to me.

dr_whigham

iTrader: (49)

I had an hour long talk with "Mr Lindy" about a month ago. The tools are 88.50 each. They are approx .035 biiger than the valve you will be running. You can rent them, but you still pay full up front. He said he might get 10% of them back. Most people use them, and then either rent them out themselves or put them in the classifieds and pass them on.

The Lindy kit is a quality piece, and a GREAT guy to talk to.

garygnu

I say fly cut them ,then rebuild the heads with new intake valves and check the push rods for straightness.mite need new lifters also.

bww3588

iTrader: (49)

Those are lq4 pistons. I would get the actual lq9/Ls2 flat tops to bring compression up.

dr_whigham

iTrader: (49)

Good Lord; I can't believe I missed that....

PREDATOR-Z

Bingo, that is a LQ4.

Z28Drifter348

If you want a set of identical pistons and rods from
My tear down that I won't be using. I had them hot tanked with the block and crank so there clean and ready to install if your interested pm me your cell# and I'll send you some pics if you want.

k5383

iTrader: (10)

New pushrods will be happening, I'm going to pull the heads apart check out the valves and go from there.

This happened almost imediately upon startup... I now know why... I assumed (foolishly) that it was set in the lifter incorrectly or something rather.

I bought the engine under the premise it was an LQ4, I had a friend tell me it was actually an LQ9.. Couldn't find any definitive pictures to prove one way or the other. haha

Z28, my cell is in my sig.. Go ahead and send some pix and info. It's an option I'm willing to consider.

k5383

iTrader: (10)

Flycutting opinions; I'm running 317 heads with stock valves 2.00/1.55 I found a gentleman who will rent me his Lindt brand tools, however, they're 2.02/1.57 I'm not too worried about the exhaust, the intake tho I'm worried night be too large.

At the same time, the larger size could help with the cleanup of the burrs left from the valves hitting..

Thoughts?

Marc 85Z28

iTrader: (8)

Why bother flycutting? You've already clearanced the pistons! Furthermore, if you line up the timing set properly, unlike your first attempt, you shouldn't have contact.

k5383

iTrader: (10)

Not sure what you mean, I set up the engine with the timing marks dead even. (Dot to dot)