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Re: Crank Bearings what to use?
[Re: POS Dakota]
#920471
02/05/11 01:52 PM
02/05/11 01:52 PM
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Joined: Oct 2003
Posts: 11,686
W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,686
W. Kentucky
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Quote:
1/2 groove king bearings here in my smallblock. 
318/340/416? When I built my 408 King didn't make a bearing for a 360 based crank. I do have Kings on the rods though, full groove Clevites on the mains. I've been using full grove for years and never had any issues  .
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Re: Crank Bearings what to use?
[Re: justinp61]
#920472
02/05/11 02:16 PM
02/05/11 02:16 PM
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Joined: Jan 2003
Posts: 10,019
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
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Posts: 10,019
Frostbitefalls MN (Rocky&Bullw...
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"It’s also interesting to note that as
groove length increases so do Horsepower Loss
and Peak Oil Film Pressure which is transmitted
directly to the bearing."
I run 3/4 grove,but this post is getting my attention.
The only way I can figure there is power loss would be windage. On feeding the rod bearings, the exit hole for the rod bearing will have a window .003 times the circumferance of the feed hole, which isn't much of an opening. I can see where it may not be important to have full time oil feed to those openings.
Last edited by gregsdart; 02/05/11 02:21 PM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Crank Bearings what to use?
[Re: b1dartsport]
#920475
02/06/11 10:40 AM
02/06/11 10:40 AM
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Joined: Dec 2006
Posts: 3,396
Pa
Hot 340
master
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master
Joined: Dec 2006
Posts: 3,396
Pa
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This stuff is fun to talk about but Id like to see proof that running a groove takes away HP. Especially when you consider the crank isnt riding on one bearing but five. I understand the thought that goes behind having more surface area. I am just skeptical that any hp is in it. As far as longevity, I believe alot of people have better or worse bearing experience based on their tune of the engine, which IMO is the biggest factor in bearing life aside from good clearances.
Last edited by HOT 340; 02/06/11 10:46 AM.
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Re: Crank Bearings what to use?
[Re: 69Cuda340S]
#920478
02/06/11 12:26 PM
02/06/11 12:26 PM
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Joined: Jan 2004
Posts: 903
Saskatchewan, Canada
cudabin
super stock
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super stock
Joined: Jan 2004
Posts: 903
Saskatchewan, Canada
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I like the 3/4 groove bearings...
King makes great bearings in their allecular series, that are softer than the tri metal clevites if you are making big power or running nitrous (= big power).
I have unfortunately failed a few rod bearings in differrent motors though the years, but never a problem on the mains, so I agree the longer time oiling the rods with 3/4 or full groove seems more relevant than the increased support to the crank from a 1/2 groove design...
Good luck!
Arnie
67 Cuda 8.48@ 158.7 mph 1.18 60' 2,600 DA(so far...)
70 Super Bee 440 Six Pack 4-speed. 13.2 @ 104 Stock exhaust/Street tires.
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Re: Crank Bearings what to use?
[Re: Quicktree]
#920479
02/06/11 01:39 PM
02/06/11 01:39 PM
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Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
Performance Only
top fuel
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top fuel
Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
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Quote:
this is one of them posts you would think with all the builders we have on here they would be telling us their experience  sponsoring this site is great and I  to those that do. but a little info every now and then wont hurt either.
FWIW, here are my thoughts on the subject.
the debate about 1/2, 3/4 or full groove bearings will probably live on forever. based on my own experience, my conclusion is this. the full groove bearings aren't necessary but they can be more forgiving for the average do-it-yourselfer home engine builder. the average home builder typically doesn't haver the tools or the experience to accurately measure the bearing oil clearance. a full groove main will flood the rod bearing with oil full time. is it neccesary to do that? IMO no, it's not, as long as both sets of bearings (main and rod) have the proper oil clearance to begin with. rod bearings that have less than adequate clearance for the application can overheat, among other things. the extra oil not only lubricates but has a cooling effect too. a bearing with proper clearances doesn't need the extra lube or cooling to do its job.
some will argue that the full groove bearing doesn't have as much surface area to support the crankshaft. well, that's true, but it obviously has enough surface area to get the intended job done, so who really cares?, not me.
IMO most bearing related failures are the result of just a few simple things. improper clearance, a poor oiling system without the necessary modifications for the application, dirt and debris upon assembly, a bad tune or inadequate octane causing detonation, and possibly a few other things.
so, good machine work and attention to detail along with proper bearing clearance and a clean environment during assembly will always yield the best results, regardless of how far the groove extends around the bearing.
there are other little "tricks" that many professionals use to ensure success that i won't get into here. speaking for myself only, those are trade secrets that i just don't care to share.
now on with the debate. 
machine shop owner and engine builder
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Re: Crank Bearings what to use?
[Re: Performance Only]
#920481
02/06/11 02:02 PM
02/06/11 02:02 PM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
Quote:
this is one of them posts you would think with all the builders we have on here they would be telling us their experience sponsoring this site is great and I to those that do. but a little info every now and then wont hurt either.
FWIW, here are my thoughts on the subject.
the debate about 1/2, 3/4 or full groove bearings will probably live on forever. based on my own experience, my conclusion is this. the full groove bearings aren't necessary but they can be more forgiving for the average do-it-yourselfer home engine builder. the average home builder typically doesn't haver the tools or the experience to accurately measure the bearing oil clearance. a full groove main will flood the rod bearing with oil full time. is it neccesary to do that? IMO no, it's not, as long as both sets of bearings (main and rod) have the proper oil clearance to begin with. rod bearings that have less than adequate clearance for the application can overheat, among other things. the extra oil not only lubricates but has a cooling effect too. a bearing with proper clearances doesn't need the extra lube or cooling to do its job.
some will argue that the full groove bearing doesn't have as much surface area to support the crankshaft. well, that's true, but it obviously has enough surface area to get the intended job done, so who really cares?, not me.
IMO most bearing related failures are the result of just a few simple things. improper clearance, a poor oiling system without the necessary modifications for the application, dirt and debris upon assembly, a bad tune or inadequate octane causing detonation, and possibly a few other things.
so, good machine work and attention to detail along with proper bearing clearance and a clean environment during assembly will always yield the best results, regardless of how far the groove extends around the bearing.
there are other little "tricks" that many professionals use to ensure success that i won't get into here. speaking for myself only, those are trade secrets that i just don't care to share.
now on with the debate.
thats what I was talking about, thnaks Dan
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Re: Crank Bearings what to use?
[Re: SuperStock68Dart]
#920483
02/06/11 03:10 PM
02/06/11 03:10 PM
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Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
Leon441
master
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master
Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
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If you look at the other differences in bearings you may find the length of the groove is not as important to you. I have ran full groove P bearings, half groove V bearings, and in all my aluminum rods HD bearings. The P bearing is much more forgiving with trash because it is softer. At the same time it should mushroom out easier if you did not have enough bearing in the bottom half. Never mushroomed a main bearing without detonation being the cause. I would venture to say the bearing surface is plenty on a 340 small block bearing. A 360 takes such a load of oil I may think about doing something different if turning any RPM. Something to think about.. The same engine mushroomed a couple rod bearings from an overdose of fuel but did not hurt the P bearing on the main at all. Until building an engine with an R3 block and Program caps I never realized how tight you can run the main clearances on a good block and crank combo. Problem is with alluminum rods you have a lot less control with oil clearance at the rod bearing and the deminsions change with temperature. When running a nitrous combo I prefered the full groove tried several different bearing combos. I ran .0025 for clearance for the best results. Just figured missing tuneups and hurting pistons ands the bearings always looked great something must have been working out. My current combo uses a 3/4 groove and I have tried the less than half groove. Never saw any real difference. If I could ever get enough restriction up top I may have a change of view on this subject. Every combo has different needs. I did notice a stock 360 in a Durango RT has a half groove bearing. The old 360's had full grooves if I remember correctly. Steel rod bearing clearances stay so stable I would say a full groove is unecessary.
Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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Re: Crank Bearings what to use?
[Re: Hot 340]
#920484
02/07/11 02:59 PM
02/07/11 02:59 PM
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Joined: Jan 2003
Posts: 10,019
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,019
Frostbitefalls MN (Rocky&Bullw...
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Quote:
This stuff is fun to talk about but Id like to see proof that running a groove takes away HP. Especially when you consider the crank isnt riding on one bearing but five. I understand the thought that goes behind having more surface area. I am just skeptical that any hp is in it. As far as longevity, I believe alot of people have better or worse bearing experience based on their tune of the engine, which IMO is the biggest factor in bearing life aside from good clearances.
"On the
other hand, extending the groove into the lower
half, even as little as 20° at each parting line
(220° in total), takes away from upper bearing
performance without providing any benefit to
the lower half. It’s also interesting to note that as
groove length increases so do Horsepower Loss
and Peak Oil Film Pressure which is transmitted
directly to the bearing. "
These guys must have spent plenty of time testing to have put this out to the general public.
Also I appreciate your input Dan, great info.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Crank Bearings what to use?
[Re: Quicktree]
#920485
02/07/11 03:36 PM
02/07/11 03:36 PM
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Joined: Nov 2004
Posts: 6,890
North Alabama
Monte_Smith
master
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master
Joined: Nov 2004
Posts: 6,890
North Alabama
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Quote:
this is one of them posts you would think with all the builders we have on here they would be telling us their experience sponsoring this site is great and I to those that do. but a little info every now and then wont hurt either.
I personally, have never run a full groove main bearing in anything, unless that was all I could get, or all I had at the time. 99% of the time, rod bearing failure is more about clearance and preperation, than what kind of main bearing you run. If the oil system is right, the rods are round, the crank has no taper and the clearance is right, you will have no rod bearing issues.
Does the grooved main cost power, as Clevite says, probably, or they would not publish it. Is it enough power for the average guy to worry about, highly unlikely. But me personally, knowing that every motor is trying to push the crank out on the ground, I want all the oil film I can get on the force side, that means a half grooved bearing for me.
Monte
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Re: Crank Bearings what to use?
[Re: Monte_Smith]
#920486
02/07/11 06:14 PM
02/07/11 06:14 PM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
Quote:
this is one of them posts you would think with all the builders we have on here they would be telling us their experience sponsoring this site is great and I to those that do. but a little info every now and then wont hurt either.
I personally, have never run a full groove main bearing in anything, unless that was all I could get, or all I had at the time. 99% of the time, rod bearing failure is more about clearance and preperation, than what kind of main bearing you run. If the oil system is right, the rods are round, the crank has no taper and the clearance is right, you will have no rod bearing issues.
Does the grooved main cost power, as Clevite says, probably, or they would not publish it. Is it enough power for the average guy to worry about, highly unlikely. But me personally, knowing that every motor is trying to push the crank out on the ground, I want all the oil film I can get on the force side, that means a half grooved bearing for me.
Monte
 I have never used a grooved bearing either 
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Re: Crank Bearings what to use?
[Re: Stanton]
#920489
02/07/11 07:03 PM
02/07/11 07:03 PM
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Joined: Jan 2003
Posts: 6,591
Canton, Ohio
Sport440
master
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master
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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From that tech on the HP loss graph it shows over a 12% HP loss going from 180* to a 360* grooved bearing. It also shows a significant amount of oil film thickness loss too. Theres no doubt in my mind from Clevites Tech and testing that they are pretty much Against a full groove bearing. IMO They are pretty much stating 1/2 groove only, and thats to oil the Rod bearings. If it werent for that, they implied a Simple hole would all thats needed or desired to oil the mains. That makes me feel alot better about my 1/2 groove bearings. I was considering full grooving them myself or buying new FG,s. Not anymore 1/2 groove it is and Im keeping them. mike FWIW; That 12%HP loss for full groove does seem high IMO. That % would also be dependit upon the bearing journals diameter.
Last edited by Sport440; 02/07/11 07:53 PM.
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