tight engine

[deathcharger71]

how tight should a fresh engine be? ive been building me jet boats 327 myself at the local junior college and i finished the block and damn that thing is hard to turn over. i used speed pro forged aluminum pistons which are 4.025 and call for .005-.006 clearence, which seemed like a lot but i did what the box said and built it with that clearence . plastigauged the main caps and were all .002-.003 clearence, checked clearence on all the connecting rods and its all good, had my teacher look it over too. double and tripple checked EVERY torque spec. i havnt checked the exact torque it takes to turn the engine over but im sure its a lot, im a pretty strong guy and i have to put a lot of my weight into it to turn it over.

[Chryco Psycho]

no rod or mains caps on reversed ?or overtorqued ?

[tecmopar]

Sure sounds as if something is bound up. Even with the plugs in, it should turn without much effort. Checking with plasti-gage is fine but if as Chryco said you reversed a main or rod cap, theres the rub, ( no pun intended ). Are you sure the valves aren't just touching the pistons, is it bolted up to a tranny. Seems as if you'll have to go through it again, not fun at all but I wouldn't try to fire it until your sure, good luck.

[John_Kunkel]

I'm surprised that you only notice this after the block is assembled.

You had to turn the crank to install the pistons. Before any pistons were installed did the crank turn freely?

While turning the crank to install the pistons did it become progressively harder to turn as each piston assembly was installed?

Is the camshaft installed? Did the cam turn free before installing the timing gears/chain?

What type rear main seal? Rope seals increase the turning torque.

[TylerCharger69]

Sounds like a binding to me.....

[Steve P.]

Or something is egg shaped.... Was this a machine shop job or a home hone and bearing job??

[deathcharger71]

the crank and cam turned freely, i did all the machine work myself and nothing is out of round. i stamped each connecting rod so i put each one back with the correct cylinder and facing the right direction. as i installed the pistons i noticed it getting tighter and tighter. i used a feeler gauge between each connecting rod cap and there was clearence between every one. still cant figure out why its so tight...the heads arnt even on yet, they go on this week.

[8WHEELER]

On the last engine I did, I had to file down just about every piston ring to get the correct feeler gauge
gap on the rings. I used TRW pistons with single chrome moly rings, I was supprised how much some of the rings
were off by, did you gap your rings?

Dan

[tecmopar]

Could be the ring end gap as 8 stated or the radius on the journals is to narrow for the bearings. Also, being repetative, even though you marked the rods, look again. They are stamped at the factory on the rod and the cap on the same side so make sure those stampings are lined up. If you used quality rod bolts you can try loosening them one at a time until it frees up, good luck.

[Sendero]

Check that the bolts from the flexplate to the crank are not a bit too long and thus binding on the engine webing.

[deathcharger71]

i did not check the ring end gap, but i could close the ring compressor completely tight around the piston while installing the pistons. the fly wheel isnt on yet. its clearly something tight with the pistons or connecting rods. i already have the pan on so tomorrow im gonna put the oil in and prime it just by turning the pil pump with a screw driver while the distributer is out, get the oil flowing to all the bearings then turn it over a couple times with a long wrench and see if it frees up at all. if not then i guess its time to disasemble 
my class ends this week, if i cant fix the problem then it looks like ill be bringing my work home with me over the summer lol

[deathcharger71]

took the pan off today and loosened all the connecting rod caps then spun the crank and it was MUCH easier to spin. tightened the caps up one at a time spinning the crank after tightening each cap. it spun much easier after just loosening and torqueing again, then my teacher tapped each cap with a hammer a couple times and it spun easier. either it was torqued down too much or something was binding and loosened up after i loosened then tightened again. either way im very relieved teh problems gone 

[ChargerBill]

I was going to suggest looking to see if any shop rags were missing...but I'm glad you found the problem.