I am guessing you have a high lift cam that requires clearancing your case or the cam has high lift and the valves may be contacting the Pistons due to inadequate valve relief.

Anything screwy going on with the rocker arms maybe?

 

The cam is an Andrews EV27 I think and ran fine before having one cylinder replaced. I'm going to pull the heads off again and try to see where the thing is locking up. This time Omaha I haven't torqued the heads done entirely because I wanted to see where the problem is and I didn't want to ruin the new gaskets a second time. I've taken it apart once already figuring I messed something up the first time but found nothing so reassembled. While I had the jugs off the first time I made sure that the rods/wheels turned without any collision in the lower end. During assembly the first time I was just about to install the adjustable pushrods when my dumb a** decided I should probably spin the motor over a few times by hand when BAM my problem...ugh thx again for all the help.

 

If you can spin the crank with the pistons removed, that eliminates the cam, oil pump, etc. Good.

Next step is to install the cylinders and pistons, rotate the engine to TDC for each cylinder, and then measure the gap between the top of the cylinder(s) and the piston(s). What you are describing would be consistent with having a mismatch between the crank and pistons and having them extend beyond the tops of the cylinders.

 

Need more info on what Wiseco pistons you installed. Are they flat tops or 10:1 or even 10.5:1.

I ask because I believe the S&S heads do not accept domed Wiseco pistons. You need to use S&S pistons for those heads, the piston dome does not match the combustion chamber..

Take the heads off and secure the jugs with 1" lengths of 3/4" pvc pipe and snug it down good with the 2 shorter head bolts. (opposite corner placement will hold down the jugs without any issues). Then crank the motor over to see if you are getting full revolutions of the motor. If so your pistons are hitting the heads. Also not a bad time to check where the pistons are, either down in or above the whole. Good thing to know.

What cam are you running?

Also your ring ends gaps must be set to at least .016" for the top ring and .018" for the seconds ring. not doing so will end up in scored cylinders or even broken rings again. you can do this with a file and the place them back in the cylinder to measure...

 

I was thinking that a Piston may be contacting a head also.
Will it turn freely with Just Cylinders...
should be checking Deck height when ya change all those components anyway.
But, heads off and roll it over is a Quick check

 

He is gonna turn motor without heads...so the jugs will need held down...have to either put shims and the nuts, or hold em down by hand...
Now,,,If it was an earlier engine!!!

 

If using domed Wiseco's, the pistons are in the wrong hole, contacting the "D" shelf.
Scott

 

But, when I read it...it appears that only One hole was addressed...

 

I grant you it is hard to keep track when the text is one big block in stead of separated into paragraphs.

OP I suspect Scott in onto something.
Clay your heads or pistons and check for clearance.

 

Reminds me ...I had a "mechanic" friend who built his engine from a catalog.
Wouldn't turn over...he was sure it was so much compression [that's what he paid for] that his starter wouldn't turn it.
Pulled it with his pickup truck...it turned over...ruined the Jugs and cases by lifting them enough to get clearance...

This is No ****!!!
BTW He was a type that ya couldn't even ask anything ...he knew !!!

Blamed it on the Parts distributors...of course, when all he needed was his kids play-doh.