Jammin'Trey

Ok guys I replaced the lower rod bearings in my 355, All i replaced is the lower rodbearings, now the motor is very hard to turn over and you have to use a big prybar. This is not normal I am told by many people. Is this normal or what? the motor hasnt been run with the new bearings so I am wondering if its just because they are not on right or what. All main caps were stamped and put back EXACTlLY as they came off.

So is this normal or what>>>

OldCelica

Did you platigauge the clearances? Maybe the bearings that you got are for a turned crank, but yours hasn't been turned? Usually they mark the bearings with a number indicating if they are oversized. Did you torque them down to spec? Maybe you overtightened them. Proper torque on bearings is very important.

jv9999

iTrader: (1)

What do you mean by "lower rod bearings"? Just one of the shells per bearing? That's not going to work. At this point you should get the crank turned or buy a "crank kit".

OldCelica

I missed the working on that. Rods only have one set of bearings each. You replaced all of the rod bearings right? Also, while you were in there how were the main bearings? You should check the clearance on these as well anytime you remove them.

Also, did you use assembly lube on all the surfaces before putting it all back together? You don't want to install dry bearings. They'll get tore up pretty bad the first time you start it up. Can cause damage to your crank as well.

Jammin'Trey

I lubed them liberally when I installed them, and yes I installe all 16 new ones. Not just the cap half. all of them. Is this normal for a nonbroken in motor?? The crank was turned to 1.0870 on all journels. I bought -.010 sized bearings, sealed pro 2555cp .010 bearings. (federal mogul). I am unsure by what everyone tells me...

jv9999

iTrader: (1)

Sounds like you did it right. You need to buy some plastigauge (green). It's a thin wax that you use to measure the clearances. Did you do rings too? That could make it tight. Just bearings shouldn't though.

Jammin'Trey

The motor is bored .030 over but was broken in since rebuild, I bought the motor rebuilt and broken in. It turned over by hand before, but since the bearings were put in its relativly hard to turn over. I tourque dht erod caps to 45ft pounds in 3 increments.

intex1982

iTrader: (2)

something aint right if u could turn it over by hand. hards that what u want that why they have to broke in.. i wouldnt worry about it. maybe do what they said above. to be safe.

Jammin'Trey

ok, so i dont need to be concerned? I am sure they will be better when they are broken in ......

jv9999

iTrader: (1)

You should measure all the bearing clearances with plastigage before you button it up.

vette9190

iTrader: (2)

Can't count the number of times I've seen bearings fail on breakin bc they didn't check the clearences on the bearings. Plasticgage its you rbest friend

Jammin'Trey

aah, ok Ill pull motor and plastiguage them.....

Jammin'Trey

well, me and my dad are going to pull motor and plastiguage it, and inspect all caps to ensure they went back where they came from...

jv9999

iTrader: (1)

That's the smart move. Let us know what you find.

Jammin'Trey

worse comes to worse my dad has a freind that runs a 7sec 8th mile car, and he has built a million 350 sbcs'. He will take a look at it if we cant figire uot whats wrong...

Daves03

plastigauge is cheap and very cost effective when doing an engine build, we gave a demonstration in class there is 2 to 3 thousandths bearing clearance on the crankshaft, we plastigauged it and that is what we came up with by the book 2 to 3 is good, we removed one rod bearing and installed a piece of notebook paper on a display engine, we also measured this with a dial caliper to 4 thousandths, the engine would spin by hand when the cap was torqued the engine was locked down. so 1 thousandth of an inch will bite you every time.

Jammin'Trey

Ok, I was measuring the bearings thickness that came out of the motor and the new ones I bought yesterday. There were a few old ones that were 2-3 thousandths smaller, This concernes me. I think I am going to buy a new crank, this one is out of wack. I can buy a new Eagle crank for 190$, how much would it cost to turn my stock crank...?

jv9999

iTrader: (1)

Around here (MA) it costs about $160 to have one turned.

Jammin'Trey

ok, hopefully its cheaper here. I will have to call a local engine building shop and have them look at it... Now I am guessing i will need .020 undersized bearings....