Well I installed all my pistons and my #5 piston is slightly cocked in the bore. I can turn it by hand, but it doesn’t change (it’s not any harder to turn than it should be). Does this mean I am going to have to pull it out? Could a ring be out of place? I’ve just installed the heads and oil pan yesterday. Will it mess up the gasket if I uncompress it and reuse it? Should I get a new one (it’s the expensive one though)?

 

Why would you install the heads and oil pan if the pistons were not in right??

 

well it didn't really seem that far off when I first installed it and I was starting to rush myself because I wanted to do this in 2 weeks time (on my days off that is which totals about 4-5 days and that's with the install). The next mourning that's all I could think about and I figured it would be easier to just remove the head and oil pan and figure out what was wrong with the setup than take a risk and have to completly pull my engine apart after being installed and ran. Good thing I have ARP bolts for the heads and rods so I can reuse them. At least I took note of the cylinder before mounting the heads so I didn't have to pull both sides. Next week, on one of my days off I am going to try swapping pistons in the bores to make sure it's piston related and I've already removed the rings so I can try it installed to see if it's a ring issue because the ring groves were never cleaned. The guy at the machine shop said not to because the combustion in the chamber should turn all that crud into ash and I wouldn't have to worry about it. Before I removed the rings, I did check too see if maybe some crud could've been holding out the ring, giving it an offset, and one part stuck out alittle bit, but I can't tell if it was enough to case that to happen. I will know tuesday at the soonest.

 

The rings shouldn't have much if anything to do with how the piston looks in the bore.
What exactly do you mean by "cocked in the bore?" How slightly?

 

Did you measure the piston to bore clearance? That is a basic engine building step. If the piston rocks in the bore, it's too loose.

Rich

 

...And do you have the piston installed the right way around? Many pistons have a notch in the piston face that must point forward regardless of which cylinder bank it's installed in (many stock and some aftermarket pistons are like this). Some pistons are specific to the valve orientation above the cylinder where they are installed, i.e. which side the intake valve is on (many Keith Black hypereutectics are like this and come in 2 sets of 4, although they are not side-specific). Some pistons it doesn't matter and you can install them either direction on either bank.

 

yes, I am 100% sure I installed tehm in the right direction. Not only did I stamp the rods when I took them out, but the machine shop put the pistons on to match the rods. I also made sure the arroe on the piston was pointing the right way as well when I installed it.

The LT1 pistons have those notches on both sides, but I still made sure the arrows were pointing to the front of the block.

I can't measure the bore size because I don't have a bore gauge and noone around here sells one (I checked with ever shop I could around here). The machine shop said they checked all of it for clearances and it should've been good.

It's enough to be quite noticable. It was roughly half as far away as it should be.

I checked just alittle bit ago (before I read this) and the piston has some play in the bore, but not much at all. That was also with out rings and I put it on the crank and it looks center enough without rings. I also cleaned the rings groves and there was some grit in there so I'm guessing that could've been the problem. This comming tuesday I will install the rings again and try it out. If it doesn't look right I will pull out the #3 piston and compare it in the 2 bores against each other to hopefully find out if it's something with the piston/rings/rod. I dont think it's the rod because when I turned it in the bore before I took it out, it stayed in the same offset position and I'm thinking it's not hte piston because it seems pretty straight in the bore without rings, but I'm still new to all this.

 

Easy way to figure this out for sure rather than "eyeballing it" would be to measure the bore and measure the piston. I once had a set that had two pistons .015 under what they were supposed to be. So needless to say everything needs to be checked.

 

did the machine shop mark which piston is for which cylinder?

When they honed your block it should have been done for each pistons size to have the perfect fit.

You can by a dial bore gauge off ebay or out of Summit. Machine shops always say is should be good. In my engine class we found a bad hone job.
It doesn't take much

 

I'll call them later today. Yes because I marked both sets of rods with number stamps. I didn't try and reuse the LT1 rods because they are pink rods and the ones from the crate engine were powdered metal. The pistons from the crate engine were chamfered and probably would've dropped the compression a good 0.5 .

Should they be wider on the sides than left to right? Where the skirts are it had alittle more play then 90 degrees from it.

 

no I haven't called just yet, but I cleaned the groves and it seems to be sitting much better. There still is alittle play (this was before I torqued it and it wasn't even engaged on the crank yet), but I think it's acceptable. Well my friend sold me a set of comp cams roller tip rocker arms (non-self aligning), but I know I read somewhere that you had to either have self aligning rocker arms or guide plates and seeing how I've got the regular pressed in studs, I can't get the plates so I'm forced to use the latter until I tear it down and start over again later on (one day later on I want to finish the porting job I started on the heads because the stock flow was pretty high and get screw in studs along with a better cam and maybe even turbo charge it. Forged pistons .04-.06 over on 6" rods and a nice cast crank all balanced and blueprinted). I will hopefully be starting to install it tomorrow and finish it up the day after so long as everything goes to plan.

 

Make sure ya "PIN" those stud's if ya are running more than stock spring's.

 

PIN those studs in? I am staying with stock springs right now for money reasons and I am going to get screw in studs and the machine work that goes with it when I upgrade later on.