Bronco Forum - Full Size Ford Bronco Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
73 Posts
Discussion Starter #1
Engine on a stand, rolled new bearings into mains and conn rods.
Real stiff to turn over now.

Is that normal?
 

·
Man of endless projects
Joined
·
9,284 Posts
whats size is the bearings for? if there oversize such as .010, you have to have the crankshaft machined for it. defiantly have to use a lot of assembly lube. use plastiguage to measure tolerances as he said. did you put the caps on correctly. the mains have the numbers and an arrow cast into them pointing to the front. the rod caps are stamped to show which rod there for and you want the numbers to be on the same sides. did you make sure the nub on the bearings is in the groove of the caps?
 

·
Eric
Joined
·
2,624 Posts
Just to add:

Wipe down the cylinder walls with a paper towel dampened with straight 30W oil prior to installing the pistons. This will help lube the rings for easier piston movement after the rotating assembly install. Also, it will help preserve the cross-hatching of the hone job so your rings seat properly upon start-up.

When you use plastigage, check the tolerances offset slightly to the side of bearing you're checking by, about, 20 degrees. Caps stretch with wear, over time, and checking the tolerance, exactly, on the bottom of the cap can provide erroneous readings.

Also, you need to pry on the #3 cap to align the thrust faces of the main bearings. This process is kinda hard to describe without pics, so, research it on google, or, try to find a video so it will make more sense.

Lastly, use anaerobic sealant on the rear main cap where the oil pan seal fits into. Permatex makes some, but, it might be a little hard to find. Here in AZ, CARQUEST has it, but, Autozone and O'reilly don't. Look up pictures of, exactly, where the sealant goes because it's kinda specific.

My $0.02,
Eric
 

·
Registered
Joined
·
73 Posts
Discussion Starter #5
Did you use assembly lube? Did you also check the tolerances using plasti gauge?
I used cc moly engine assembly lube.
This is the used crank, and regular bearings, so i have not gauged them.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #6
whats size is the bearings for? if there oversize such as .010, you have to have the crankshaft machined for it. defiantly have to use a lot of assembly lube. use plastiguage to measure tolerances as he said. did you put the caps on correctly. the mains have the numbers and an arrow cast into them pointing to the front. the rod caps are stamped to show which rod there for and you want the numbers to be on the same sides. did you make sure the nub on the bearings is in the groove of the caps?
I did one at a time, and kept the caps in their right spots.
Bearing tangs are aligned.
 

·
Registered
Joined
·
73 Posts
Discussion Starter #7
Okay, loosened up the mains, turns fine.

Read about thrust bearing. Missed that the first time. Pried on it, tightened that one, then worked my way out in three tightening steps.

Turns easier, still stiffer than the old bearings, but much easier.

Thank you for the advice!
 

·
Eric
Joined
·
2,624 Posts
Awesome. :thumbup

Also, FWIW, while the engine is on the stand, without any of the pistons or rods installed (so, just the crank) fit the damper bolt to the snout of the crank. Hang an 18" breaker bar off the bolt on a horizontal plane and let go. If the weight of the breaker bar rotates the crank so that the breaker bar ends up hanging straight down, you're okay as far as no binding. If the bar doesn't swing down under it's own weight, you've got binding/clearance issues somewhere.

This doesn't mean you're bearing clearances are within spec, though, it just means the crank rotates freely. You should, always, double-check the manufacturer. If you're not gonna mic the bearings and crank to check for clearance, then you really ought to use plastigage as a minimum. It's good engine-building practice.

Again, just my $0.02,
Eric
 
1 - 8 of 8 Posts
Top