Rod bearings? Looked @ other posts need a fresh answer

[louied]

Hello fellow K5ers, i am all set to install my new TCI Trans!!!!!!

So i am also replacing my flywheel, and thought id replace my Rear main seal ,

I dropped the pan today and was looking around, wiggled the rod caps to check for play, well it does move a tiny bit, what should i do ?

I am thinking since the heads and cam are new and trans is new and the new ring and pininon, new tires and rims, just let the motor go (2bolt main) , and replace with a new crate motor minus the heads???


Whats the correct answer?


Thanks,
Louied
87 K5 TBI
Custom love ..........

 

[PhoenixZorn]

Yes!!! replace your engine... not for any other reason than to have a new one. =)

Wait for other answers... don't take mine as law.. =)

 

[1979jimmy350]

there is going to be a little play in the rod caps when you are moving them twords and away from the front of the engine. If you have play in the other direction then you have problems

 

[louied]

thanks, the play is from front to back, just a little,

engine has about 190000 runs strong. just checking the advice of the fourms.

 

[dirtwarrior17]

188,000.... right where i lost my main bearing. Just keep driving it until it gives up, no need to waste what little life it has left... unless you want a new motor now.

Actually to be honest 200,000 isn't alot for a 350. I know a couple guys with 290,000+ on theirs... i wouldn't give up on her until she starts knocking.

 

[diesel4me]

a little play is ok...

If you can slide them side to side,thats not a big deal--in fact,they NEED clearance on the sides!(only 10-15 thousandths though,not 1/8 of an inch!)-if there is any noticeable play in the other direction(up and down in relation to the rod and piston)then the bearings are worn--of course pulling off a rod cap and visually inspecting them will usually reveal any damage or play,the copper will be showing if a lot of wear is present...you could use "Plastigauge" to measure the clearance,or a micrometer...

My experience is once a rod bearing wears,the crank is worn too,even if it appears to be perfect,smooth,etc...they often wear "tapered" at a slight angle--and putting a new rod bearing that is "square" wont ride all the way across the crank journal,puts all the load on one spot,and rapid wear occurs,and its knocking before you know it--havent seen too many motors live long that had new rod bearings thrown in without having the crank turned,or at least polished and checked for "taper"--there are a few that have lived,but I'd say 80% of them dont unless the crank gets attention too..