Re: Bearing clearance- how much is too much?
[Re: '72CudaRacer]
#2919269
05/06/21 11:47 AM
05/06/21 11:47 AM
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Joined: Feb 2008
Posts: 715 Central TEXAS!!!!
sr4440
super stock
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super stock
Joined: Feb 2008
Posts: 715
Central TEXAS!!!!
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Given the choice of too tight and too loose, i will go loose every time. That being said i would stick the M119's in it and not give it a second thought. There is a old saying " if your clearances are too loose, only you will know it, if they are too tight, everybody will know it".
Joe
Without Data, you’re just another guy with an opinion.
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Re: Bearing clearance- how much is too much?
[Re: cl440]
#2919291
05/06/21 12:14 PM
05/06/21 12:14 PM
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Joined: Aug 2009
Posts: 2,054 Mooresburg, Tn
'72CudaRacer
OP
top fuel
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OP
top fuel
Joined: Aug 2009
Posts: 2,054
Mooresburg, Tn
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We mocked up our 540 using Clevite 2324P and had .0029 but wanted more so we ordered 119M and that gave us .0033 which is great for our application. Maybe the 2324P would give you the clearance you are looking for (.0004 tighter in our block) The 119M was much tighter on the thrust and we had to work on that to get thrust clearance we needed.
Is this street or strip set up for you? Drag race only, 5.80's eight mile. Brian
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Re: Bearing clearance- how much is too much?
[Re: Cab_Burge]
#2919364
05/06/21 02:06 PM
05/06/21 02:06 PM
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Joined: Mar 2003
Posts: 2,527 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,527
PA
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.004 here a couple times too. You can always run gear oil in it to get the pressure up!
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: Bearing clearance- how much is too much?
[Re: moparacer]
#2919394
05/06/21 03:55 PM
05/06/21 03:55 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Almost all the engines I have built(small and big blocks)have been between .0029 and .0036 ans one at .0022 and it cooked a bearing.. went back and opened it upon all to.0032... not much but it worked on all of my engines.. I did run a old alum rod engine at .0046
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Re: Bearing clearance- how much is too much?
[Re: '72CudaRacer]
#2919408
05/06/21 04:34 PM
05/06/21 04:34 PM
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Joined: Oct 2007
Posts: 4,213 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,213
New York
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The gauge shows what the relief valve says. It's not the local pressure at each bearing, or an average. Loose clearance insures that the pressure drop between the first and last bearings in a gallery is higher than a small clearance. My conclusion: .004" is safer than too small, but stay away from the 0W20 stuff.
BTW: .001" clearance per inch of journal diameter was industry standard 100 years ago.
Boffin Emeritus
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Re: Bearing clearance- how much is too much?
[Re: 440lebaron]
#2919451
05/06/21 06:43 PM
05/06/21 06:43 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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back in the days they put aluminum foil back side of bearing to tighten up When I was a kid I watched my dad working on a Chevy 6 cyl .. he had spun a rod bearing(pretty sure it was a rod).. he pulled the bearing and lowered the crank ... he got some emery paper at a hardware and smoothed out the crank(as good as you can by hand.. cut a chunk of his belt off.. enough for a upper and lower bearing and put it back together using the old oil.. had to add a couple of qts of oil but we made it back home .. this was on our Deer hunting trip about 140 miles from home... he got another junk yard engine when we got home.. I pretty much said I was gonna become a mech at that point
Last edited by MR_P_BODY; 05/06/21 06:45 PM.
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Re: Bearing clearance- how much is too much?
[Re: MR_P_BODY]
#2919470
05/06/21 07:37 PM
05/06/21 07:37 PM
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Joined: Oct 2007
Posts: 4,213 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,213
New York
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Soviet "repair" of needle bearings in Harley-Davidson WW2 military bikes, when no needles are available? Cut pieces of coat hangar to length, pack with heavy grease. Sell the bike.
Boffin Emeritus
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Re: Bearing clearance- how much is too much?
[Re: MR_P_BODY]
#2919478
05/06/21 08:06 PM
05/06/21 08:06 PM
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Joined: Feb 2005
Posts: 530 SW CO
HemiSportFury
mopar
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mopar
Joined: Feb 2005
Posts: 530
SW CO
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back in the days they put aluminum foil back side of bearing to tighten up When I was a kid I watched my dad working on a Chevy 6 cyl .. he had spun a rod bearing(pretty sure it was a rod).. he pulled the bearing and lowered the crank ... he got some emery paper at a hardware and smoothed out the crank(as good as you can by hand.. cut a chunk of his belt off.. enough for a upper and lower bearing and put it back together using the old oil.. had to add a couple of qts of oil but we made it back home .. this was on our Deer hunting trip about 140 miles from home... he got another junk yard engine when we got home.. I pretty much said I was gonna become a mech at that point Chevy 6's had babbit rod bearings into the early 50's. That was a very common roadside repair in the days of babbit bearings. Insert bearing made it more difficult because the insert was a lot thinner so the leather that thin wouldn't last long. But, if your choice is make the repair or walk home... Wouldn't it be nice to be able to make roadside repairs like that today? But today's car are usually much more reliable.
Last edited by HemiSportFury; 05/06/21 08:07 PM.
'64 Sport Fury, 528 Hemi, FiTech EFI, 4-speed, 4.10 Dana 60 '57 Belvedere 2dr sedan, current project in process '19 Cherokee Trail Hawk Elite '03 Ram 2500 CTD HO, 6-speed 214,000 miles and still going strong
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Re: Bearing clearance- how much is too much?
[Re: polyspheric]
#2919536
05/06/21 10:35 PM
05/06/21 10:35 PM
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Joined: Jul 2005
Posts: 712 California
BigDaddy440
super stock
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super stock
Joined: Jul 2005
Posts: 712
California
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Interesting responses. I'm absolutely not disagreeing with anyone here as everyone seems experienced and knowledgeable. In all the B and RB builds I've put together I've shot for .0025" on the mains, but would have been comfortable up to .003". Being that I've never ran an engine as loose as .004 I have no experience to say it's a bad idea, but my concern would be oil pressure.
I'm currently assembling a 289 Ford. My mains are just shy of .0015" and it feels a bit tight to me although it's within factory spec. I'd be more comfortable with .002 on the smaller 289 journal.
Point being, old factory specs are much tighter than many of us like to run, even at a time when oil technology was inferior to what we have today.
To the topic starter, I would have recommended the .0025 bearing without hesitation, but it seems like you might be okay a little looser. Happy Racing!
Last edited by BigDaddy440; 05/07/21 01:15 AM.
1969 A12 Roadrunner 1970 Plymouth Cuda 1968 Dodge Dart
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