I need some info please

[WP29440SE]

ive searched and searched to no avail.

can someone tell me exactly what size the main and rod journals are on a standard 440 cast crank ?

and also , is .003 - .004 too much clearance on the main journals?

thanks again guys, much appreciated

 

[theman440]

I believe the main journals are 2.75, rods 2.375 , .003-.004 is OK clearance if you're using a high volume pump.

 

[RustyRatRod]

Yup, wut he said.

 

[WP29440SE]

I believe the main journals are 2.75, rods 2.375 , .003-.004 is OK clearance if you're using a high volume pump.

what is the ideal clearances on the main and rod journals? i checked it from the bottom of the main cap and came up with the .003-.004 , but where the bearings mate together , say , 1/4 inch in from each side, it doesnt look like they are touching the crank.

 

[RustyRatRod]

They danged well better not be touchin the crank.

 

[WP29440SE]

They danged well better not be touchin the crank.

thats a good thing then , cool. whats the ideal clearances on these things

 

[WP29440SE]

this makes it 10 under correct?

 

[RustyRatRod]

Yeah.

 

[lewtot184]

a little loose for my taste. it won't break or anything like that but will effect oil pressure some. i've always been a little paranoid of anything with over .003 on the mains. i don't like leakers and i've always felt that rear main seal just won't absorb a lot of wobble, but some folks don't have problems with loose mains. try to find out some information to see if a cast vs forged crank use a little different clearance recommendations. i thought they did, but i've slept a whole bunch since then. i hope your using a dial bore gauge to measure the bearing i.d.'s.

 

[Cranky]

I hope you're good with the calipers....they are usually not as accurate as a mic is and I don't care for anything over .003

 

[WP29440SE]

yah , Cranky im good with them things. ive measured them 20 times and getting the same numbers. i just looked at my old bearing containers and it looks like i ordered the wrong sets. the rods and mains are both 10 under and i ordered standard bearings. i never thought to check them before i put them in. i can be a dumbass sometimes. back to the drawing board lol. live and learn.

 

[RustyRatRod]

I know a guy through a friend who put standard bearings on a .010 under crank. Ran it that way for like two weeks before he did anything about it. It even had good oil pressure.......most of the time. Only every now and then would it drop. He took it back apart and everything looked great. He put the right bearings in it and it was fine. I don't think you'll have a problem at .003-.004 with a high volume pump.

 

[lewtot184]

my 2 cents,calipers aren't accurate enough. dial bore gauge and outside mics. another thing, if your using arp studs they'll muddy the works up.

 

[WP29440SE]

I know a guy through a friend who put standard bearings on a .010 under crank. Ran it that way for like two weeks before he did anything about it. It even had good oil pressure.......most of the time. Only every now and then would it drop. He took it back apart and everything looked great. He put the right bearings in it and it was fine. I don't think you'll have a problem at .003-.004 with a high volume pump.

i would have never taken it back apart if the pressure hadnt been so low. it was ok (like 50) at start up when i broke it in. after about 15-20 minutes it was so low after the oil got hot that i chose to shut it down because something just wasnt right. it never made any noise and never got hot. i thought maybe the oil pump was just iffy , so i took the relief spring out and replaced it with a high pressure spring. i replaced 2 quarts of the 30 wt with 20/50, fired it up , pressure was better , about 60-65 , but then after another 15- 20 minutes it came back down again to a point i wasnt comfortable with. it was right at 10-11 lbs at about 8-900 rpm.

im sure the oversize rod bearings would make that huge of a difference in oil pressure

definitely the beauty of a run stand, i can work all the bugs out before it goes in the car

 

[RustyRatRod]

I'm lost. Are you saying you assembled it with STD bearings in a .010 under crank? In that case, yeah it would make a big difference in oil pressure like I described above. It would be more noticable with a stock pump.....

 

[WP29440SE]

I'm lost. Are you saying you assembled it with STD bearings in a .010 under crank? In that case, yeah it would make a big difference in oil pressure like I described above. It would be more noticable with a stock pump.....

yep. i didnt double check what i had ordered before i put it together. dumbass move on my part. im glad i shut it off and took it apart again to check it. its all good , i just need to order the right bearings. cost me some money , but it will never happen again lol

 

[RustyRatRod]

Ok I gotchya now. Sling the right bearings in that pup, it'll be ok.

 

[RustyRatRod]

Here's food for thought. You put STD bearings on a .010 under crank. Stock tight bearing clearance is like .0015 give or take. That's a thousandth and a half. You had bearings in it that were .010 too BIG in diameter, PLUS any "recommended" clearance. LOL

 

[WP29440SE]

Here's food for thought. You put STD bearings on a .010 under crank. Stock tight bearing clearance is like .0015 give or take. That's a thousandth and a half. You had bearings in it that were .010 too BIG in diameter, PLUS any "recommended" clearance. LOL

lmao , its a wonder there was any oil pressure at all. thats what i get taking for granted i ordered the right stuff and then not double and triple checking it . that was a first for me LOL

 

[RustyRatRod]

Everybody does it. That's how you learn.