CrawlinTBSS

rebuilding a 04 4g63. car had crankwalk yada yada.

new block, and crank and bearings. measured the new cranks journals and got specs from AMS and they where standard spec, so i order new cranks and rod bearings online, clevite 77s.

isntalled crank. spins and is workign correctly. tolerances are within spec as well.

installed pistons and rods with NEW rings, and rod bearings. clearances for rodbolts where .038 and factory spec is .030 - .050. Torqued to 15ft/lb +90* like mitsu manual says for stock. and then we can turn over the engine. if i loosen the rod bolts/nuts then the engine is able to turn over....?

are my torque specs wrong? am i down to bearing clearances?

CurseDSM

iTrader: (3)

Hope this info helps out.

I have 15 +- 1 +90*to 94*

Connecting rod big end side clearance mm (in) 0.10 − 0.25
(0.0039 − 0.0098)
0.4 (0.016)

Piston-to-cylinder clearance mm (in) 0.02 − 0.04
(0.0008 − 0.0016)
Bearing cap bolt shank length mm (in) 71.1 (2.799)

CrawlinTBSS

yeah i have all those specs.

when we lossen the rod nuts to like handtight, engine spins freely. once applied 15ft/lbs ( not even doing 90* yet) the crank wont turn.

so im guessing i have incorrect rod bearings? crank bearings are right as the crank spins effortlessly on its own once torqued.

CrawlinTBSS

measured my crank rod journals as well and i get 1.771", which is standard OEM crank spec. i dont get this at all...? so with a standard bearing i should be good.

now we re plasti-gauged the rod caps and its showing we are too tight ( .068) . so i get thats why my motor wont spin, but the crank measures out to stock clearance and theres no such thing as smaller bearings, jsut bigger for machine-cut crank.

okevolutionVIII

iTrader: (71)

Do you have the tangs on the bearings facing the exhaust side and have you checked the rod to crank side clearance?

CrawlinTBSS

Tangs are facing intake side. Pistons have a dot on top to face front and that pputs the tangs on the intake side.

okevolutionVIII

iTrader: (71)

Everywhere I've read, the tangs are supposed to face the exhaust and that's how mine was built. My assembly wouldn't rotate at 1st and a bent crank was the problem.

The reason for the tangs facing the exhaust side is for a full bearing surface to be touching the crank during the downward stroke when the bearing is taking the most force.

blowngasket

iTrader: (4)

ive always used a plasti Gauge when in stalling new internal parts in a engine, stay within spec to keep the oil running round the bearing, if you dont do this right you will fail within 500miles of the engine,youll get a nice knock. Sometimes Even on brand new parts, brand new bearings ive had to file the ends of the bearings down to get within spec otherwise it would have been to tight and the crank would have a issue moving or bind up, this means no oil can proceed past that bearing causing Major engine failure if left untouched.
ive seen people go as far as measuring Rod Bolt Strech, it insure no engine malfuntions at the rods

CrawlinTBSS

Ok very understandable. But im confused... the dot on top of piston thats supposed to face the front(timing side) puts my tangs on intakke side....if i go other way theyd be facing the rear?


Did i install wrong? Had the crank checked yesterday for out of round and its all good and in spec. Going to pick it up now and toss back in. Maybe have a rodcap on wrong one?

sourcelx

iTrader: (6)

Every motor I built had the piston dot pointing to the front(timming side).
Is vote either bearings are oversized .00010 or.00005 oversized, rods flipped, or even caps backwards on rods.
Best of luck.

okevolutionVIII

iTrader: (71)

Are these stock pistons and rods?

GreenAWD

iTrader: (19)

Make sure you rod caps are on the correct way. If you put those on the opposite way the engine won't spin either

CrawlinTBSS

Specs: ( all parts where purchased besides rods and pistons, only parts that came from old motor)

Stock 04 Evo block 32k miles. Cylinders where honed and everything.
stock 04 Evo Crank - stock journals. Engine shop even checked it all.
stock rods and pistons - from old motor
new piston rings
Clevite77 -STANDARD size bearings

With crank and main bearings in, and torqued, crank spins freely by hand. once the rods where added and just torqued to 15ft/lb ( not even the 90* turn yet), it was unable to turnover.

engine shop checked crank journals for any out of round and came out all within spec. so now its down to the rods/bearings i guess. I guess we are down to a wrong cap, bearing or out of round.

we removed the rods caps to do some switching, and now piston #1 , the cap with fit back onto. almost like the bore of the rod has out-of-rounded itself. seems like the studs are angled out a tinnny bit. its odd.

Going to just end up taking the pistons/rods/block to the shop to have them check it all.

okevolutionVIII

iTrader: (71)

You may need a machine shop to torque the caps to the rods and have them honed. Rods and caps are made to fit each other and cannot be switched around.

CrawlinTBSS

yeah had the rods checked yesterday and ended up the caps where on wrong rods .

motors back together and timed and spinning nice and freely now. Thanks for the help yal!