I would suggest that you also consider running a glaze breaker thru the piston bores as I can just about gaurantee they were fuel washed and polished nice and smooth now and the rings cant seal the bores.

I agree, the cylinders where you fouled the plugs are gauranteed glazed. Those bores will need to be honed again! You said the ring gap is 1"?? So you took  the rings off and slid them down the cylinder with the piston? Then measured the gap? 9 x out of ten an overheated engine will need bored for best ring seal. I would do a light hone and measure your ring end gap for each cylinder and the reassemble. The one cylinder looked to have a lot of oil in it! Good luck, I hope it runs good for you! Which megasquirt is it? I'm looking at the pnp.

I agree, the cylinders where you fouled the plugs are gauranteed glazed. Those bores will need to be honed again! You said the ring gap is 1"?? So you took  the rings off and slid them down the cylinder with the piston? Then measured the gap? 9 x out of ten an overheated engine will need bored for best ring seal. I would do a light hone and measure your ring end gap for each cylinder and the reassemble. The one cylinder looked to have a lot of oil in it! Good luck, I hope it runs good for you! Which megasquirt is it? I'm looking at the pnp.

The rings were already installed on the new std bore pistons. Only oversize anything was the crank bearings.  I went one size over stock and gave them all the parts to match up.  I think they took .015 off the head to true it up.  Its been a while now so its tough to remember all the details.  This "overheat" was pre- rebuild.  Everything has been cleaned up or replaced since I pulled the long block from the scrapper.  Thx.

You can not take rings and simply run them, they need to be matched to each specific bore and could care less which piston they are matched with. You remove the rings from the piston and insert them one at a time down in the bore squarely(use the piston to square it up) and then measure the end gap and file the ends to obtain the proper clearance, rings come oversized for this reason, they are not plug and play. best to spend the coin on a small rotary ring gap file/grinder, they are not that expennsive. Follow the FSM specs for the clearances.

please tell me your not going to tell him about the tty head bolts too, I think bad news on the bottom end is enough! I hope this is not his first rebuild job.

please tell me your not going to tell him about the tty head bolts too, I think bad news on the bottom end is enough! I hope this is not his first rebuild job.

eh.... live and learn as they say right? Its good to have people around to ask questions... even if you dont know every right question to ask!

I have a few tools to add to my arsenal. Thanks for the heads up. I hope "3rd times the charm" is not the case this go around heh!

Okay so my memory just did not serve me very well.

I ordered .020 pistons OE-spec replacement (DNJ) and appropriate ring set (DNJ).

Dropped those off with the bottom end.

Machine shop did the clean-up and put everything back together minus installing the crank and pistons.  They are the ones that fitted the rings for me.  On the above posts.. I just remembered the rings were installed when I received them... forgot it was from the machine shop though.

If I double check the gaps at this point, do I still follow the FSM listing for std. pistons or from DNJ/Rock?

Edit: Gaps are stamped on the rings from Manuf. Also machine shop set the gaps appropriately. Thx again.

I think he meant the ring clocking of the gaps was 1" apart. An end gap of 1" would probably not seal too well. 

About your oil pump.
I tried using the metal gasket but it just leaked time after time. After trying 3 different types of silicon many times I now only use "Ultra Grey" and have only found it at O'rileys. You want a silicon designed for aluminum to aluminum, high torque, and high heat. Basically a transmission silicon. Its been the only way I've been able to seal my oil pump and transmission for that matter.
The oil pan had also been a bit of a problem for me. The bolts kept getting loose and oil kept seeping from the silicon. I've found that after the first 2 or 3 miles the bolts need more attention, but only tightening to roughly 12lbs. I used "Form a gasket 2" the tacky version, for the oil pan. It took a good 5 days of 30-40 degree temperatures to cure, compared to to Ultra Grey which takes 24-28 hours. I haven't had a leak or seep of oil on my garage floor, FINALLY!
If I were in your shoes I would Ultra Grey the rear seal housing, even if its not seeping or leaking. I have found nirvana with this stuff on these aluminum motors. Even works with coolant.
Hope this helps, good luck with the build, and enjoy the time your getting to spend with your motor. Put good in, get good out.

Also, simply wiping a surface does not remove all the oil, a solvent and mechanical manipulation of the sealing surfaces is the only way to guarantee that the sealant adheres to all surfaces. Any residual oil in the pores of the metal will expand more than the sealant and the aluminum, forcing it's way between the metal and sealant and eventually creating leaks.