motor ?

[79D50]

Funny topic that takes me down memory lane. This is how I started on my 2.6 build journey. I had a rod knock. I went and bought all new lower end bearing (rod and main). I plastiguaged all of them and found that that I was out of tolerance. The knock was worse. I then tore everything down and then the bug bit me.

On these motors there is no such thing as replacing the bearings and driving away..unless you have a fresh build and something just went wrong. Always balance your rotating assembly after bottom end work...

[raidinator]

I would recommend taking the attention to detail thing a bit further, i built a fresh engine new parts, no worries. On a hunch i pulled the end caps on the connecting rods and 2 out of 4 were scratched enough to spin the bearings down the road. my point is that you just have to be really careful and really pick everything apart. bearings don't just fall out there is a small tab near the corner of each that holds them in. If you lost one that means there was too much pressure on them in the first place. Also do you know if the engine was rebuilt? if it was and the rods were cold pressed that could have the same effect. i lost an engine like that
i'm sure you know all that, good luck

[netstat]

Also do you know if the engine was rebuilt? if it was and the rods were cold pressed that could have the same effect.

explain this part further please. this sounds like info i need

[MightyMax]

Also do you know if the engine was rebuilt? if it was and the rods were cold pressed that could have the same effect.

explain this part further please. this sounds like info i need

me too..

[77amc]

Manual or auto?
Does the 'new' starter make any noise?
Does it turn so far then just stop?
Are you sure that they sold you the right starter?
Could be jammed or bendix is bound.
Loose?

Did you check your grounds? OR both cables for that matter.. Sometimes corrosion seeps down into the braid where you can't see under the plastic and ruins the connection. And they tend to heat up quicker under load.

How long has it run with the 'new' bearings in?

Just a few thoughts.. Maybe get a known good and hot battery

E

[raidinator]

When the piston his attached to the connecting rod a wrist pin must be pressed through the one side of the piston through the end of the connecting rod and through the other side of the piston. I being new to cars at the time, bought a cheap press and a 15mm socket and had a buddy get a custom piece made and pressed the pin through the rod and piston. they were a bit stiff at first but the became more movable as i worked them and ultimately installed them, a few thousand miles later there is a softball size hole in the block and my crankshaft is so trashed it caused my machinist to laugh.

so i talked to my machinist (and engine oracle) he explained that the end of the rod must be headed, once it is the pin will slide in with no resistance, however if it is heated too much it won't be strong enough. presently he directs me to a machine hooked hooked into the torch tanks, i told him what i had done the first time and he explained that as you cold press the pin through the resistance scuffs the pin, on the far side of the piston it creates resistance that will "spit out bearin's all day long". He showed me some honda pistons and showed me that it took some focus to actually make the rod stand straight up with the piston sitting on the table. he also explained that he had done the same thing to a camaro early on in his career.

Cold pressing is a mistake often made by new mechanics and a short cut taken by people who are rebuilding and engine to sell a car. If your truck had the engine rebuilt by an amateur, or by someone who thought they could cut corners the cold pressing process could be frying a bearing and creating more resistance than there should be. a test would be to drop the crank and wiggle each rod if they don't move extremely easy then something is really wrong.

also before the engine really died it wouldn't tach past 4 grand or so, if that is true of your motor it is time for a rebuild

good luck man

Greg

[MightyMax]

i think napas machine shop cold pressed my wristpins lol... after the rebuild, thing wouldnt get out of its own way.. and it wouldnt get past like 3-4k rpms. after about 3 thousand miles it finally loosened up and started behaving itself... i guess i was fortunate lol

[raidinator]

you are a lucky man