Posted By: rth
main bearings - 03/20/10 06:30 PM
installing my crank 68 440.main bearings coming up with .003,that sound right.thanks
main bearings
Posted By: MoparforLife
Re: main bearings - 03/20/10 06:35 PM
IMO it is real loose. I like .0015 and no looser than .002. Have sent shafts back that fit looser than .002 and had it reground to the next size. Street, strip, and circle. Never had a too tight failure yet. 
Posted By: RapidRobert
Re: main bearings - 03/20/10 07:01 PM
See if you can locate some .001 under bearings. These were available from mopar way back then were not available for a long time and I think now they are available again (not MP but I think someone has them now)
Posted By: MoparforLife
Re: main bearings - 03/20/10 07:25 PM
001's may or may not help. Depends on what the shaft is ground too. If you have a .010 shaft a .001 bearing won't do you a heck of a lot of good. .001 bearings are meant to be used on a loose fit standard shaft.
Posted By: rth
Re: main bearings - 03/20/10 07:52 PM
shaft was cut .010.rechecked clearances all .003.street motor i'm not happy with it being so big.machine shop already closed for weekend.
Posted By: MoparforLife
Re: main bearings - 03/20/10 07:59 PM
You could get by but it is like having a worn out engine to start out with. I would take it back and have it cut to .020 and tell them what you expect.
Posted By: Anonymous
Re: main bearings - 03/20/10 09:47 PM
Relax.....003 is just fine
Honest..I build them everyday all kinds Mostly Mopar--That will work like a dream--no problems.
Lots of folks do it on purpose!
Honest..I build them everyday all kinds Mostly Mopar--That will work like a dream--no problems.
Lots of folks do it on purpose!
Posted By: John_Kunkel
Re: main bearings - 03/20/10 10:26 PM
Oil pressure might be a little low, an HV pump will take care of that.
Posted By: MoparforLife
Re: main bearings - 03/20/10 10:47 PM
If the mains are that loose what are the rod bearings like. If they are that loose they will rattle, especially cold. Like said some would run it an like it but I wouldn't.
Posted By: RapidRobert
Re: main bearings - 03/20/10 10:55 PM
Quote:See if some .001"'s are available
If the mains are that loose
Posted By: rth
Re: main bearings - 03/20/10 11:36 PM
i didn't put pistons in yet but rod journals are within specs for a .010 cut according to my mic.
Posted By: MoparforLife
Re: main bearings - 03/20/10 11:57 PM
Quote:Like I said above .001 bearings are for a loose standard shaft - not a .010 shaft.Quote:See if some .001's are available
If the mains are that loose
Posted By: Anonymous
Re: main bearings - 03/21/10 12:20 AM
No way it will rattle though
Listen...we do really big inch mean drag stuff with 3.8 or a tad more --They twist the crud out of the crank and you need it! Again--.003 is not like worn out--
I help my Dad with old farm tractors and we pull some down with .008 under the spec that were still plowing! Yep OP may have been a little low
but .003 on a 440 crank journal is everyday good to go. Don't be scared and blow $$ for crazy hard to find bearings--OP may drop back at idle but I promise it will jump right up and honest that is the sign of a great build to me--on one you want to Haul! 
Listen...we do really big inch mean drag stuff with 3.8 or a tad more --They twist the crud out of the crank and you need it! Again--.003 is not like worn out--
I help my Dad with old farm tractors and we pull some down with .008 under the spec that were still plowing! Yep OP may have been a little low
but .003 on a 440 crank journal is everyday good to go. Don't be scared and blow $$ for crazy hard to find bearings--OP may drop back at idle but I promise it will jump right up and honest that is the sign of a great build to me--on one you want to Haul!
Posted By: RapidRobert
Re: main bearings - 03/21/10 01:03 AM
Quote:I heard you the 1st timeQuote:Like I said above .001 bearings are for a loose standard shaft - not a .010 shaft.Quote:See if some .001's are available
If the mains are that loose
Posted By: MoparforLife
Re: main bearings - 03/21/10 02:26 AM
Quote:Then why keep telling him to get a set of .001's.Quote:I heard you the 1st timeQuote:Like I said above .001 bearings are for a loose standard shaft - not a .010 shaft.Quote:See if some .001's are available
If the mains are that loose
Posted By: RapidRobert
Re: main bearings - 03/21/10 02:32 AM
I'm not telling him I am telling you. If he is 10 (or more) under then he knew from my 1st post that .001's would not be applicable
Posted By: Dcuda69
Re: main bearings - 03/21/10 02:46 AM
You did not say how you measured that but......I have .003 on my 470"..been like that 3 yrs makes 80 psi cold and 30 psi hot idle. BBM's have big journals.. .003 is not out of line!!
Posted By: rth
Re: main bearings - 03/21/10 02:53 AM
i measured the .003 with plastigauge. then removed crank and mic'ed it.
Posted By: Dcuda69
Re: main bearings - 03/21/10 02:59 AM
Quote:
i measured the .003 with plastigauge. then removed crank and mic'ed it.
Mike'd what? Measure the shaft,then measure the housing with the bearing in it..the diff is clearance. My guess is if you see a REAL clearance of .003 I'd run it!!
Posted By: Commando1
Re: main bearings - 03/21/10 01:21 PM
Every spec ever shown that I have seen says .001 - .003
Period.
If anybody has reference to other specs, other than personal preference, I'd like to see them.
Personally, I would prefer .003 over .001. I like'em loose end and don't mind the noise, if any.
Period.
If anybody has reference to other specs, other than personal preference, I'd like to see them.
Personally, I would prefer .003 over .001. I like'em loose end and don't mind the noise, if any.