when are 3/4 grooved main bearings needed for bbc ?

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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Warp Speed »

ClassAct wrote: Thu Dec 05, 2019 6:22 pm
tenxal wrote: Thu Dec 05, 2019 7:40 am
BobbyB wrote: Wed Dec 04, 2019 6:28 amIsn’t all this stuff just branch circuits in a simple hydraulic system...just one pump...right?
No. Even the simplest hydraulic system is a 'closed' system. An engine oil system is one big leak. Oil leakage around the lifters has a much bigger impact than most realize.

Right. And the leaks around the lifters is a relatively simple fix.

It's a simple hydraulic system. Not uncontrolled leaks. That's crazy to claim that.

I had a joker call me today and claim you can fix this junk with a dry sump. I said how so? And this dude (a self proclaimed expert) says you're sucking the pan dry. I say...ok thanks...goodbye.


I have a minimum of 10 quarts in the system on the dyno. And this guy thinks the pan is empty on a dyno pull. Rediculous.


Call around. Find someone who knows this stuff...like someone who does a lot of viper stuff and call and ask them about oil timing. They sure as shit know what it is. And have ways to get around it. Until you need to correct it.
Still waiting for you to answer my questions.................?
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Kevin Johnson »

tenxal wrote: Thu Dec 05, 2019 7:40 am
BobbyB wrote: Wed Dec 04, 2019 6:28 amIsn’t all this stuff just branch circuits in a simple hydraulic system...just one pump...right?
No. Even the simplest hydraulic system is a 'closed' system. An engine oil system is one big leak. Oil leakage around the lifters has a much bigger impact than most realize.
You can download this CRC Handbook at no charge: https://www.academia.edu/36099713/HANDB ... TECHNOLOGY

Thank you, academia.edu.

Chapter 1 discusses hydraulic systems as meeting defined general criteria: this is the superset. Some hydraulic systems are closed and are a subset of the superset. Some hydraulic systems are open and are also a subset of the superset. Some internal automotive engine hydraulic systems are both closed and open and the elements are members of both subsets. The latter presented the greatest impetus to control aeration outside the demands of the racing community. Violations of Pascal's Principle via the introduction of a compressible phase breaks things. It is the task of the Engineer to stop that from happening.

Set Theory
https://en.wikipedia.org/wiki/Subset
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by ClassAct »

Warp Speed wrote: Thu Dec 05, 2019 6:44 pm
ClassAct wrote: Thu Dec 05, 2019 6:22 pm
tenxal wrote: Thu Dec 05, 2019 7:40 am

No. Even the simplest hydraulic system is a 'closed' system. An engine oil system is one big leak. Oil leakage around the lifters has a much bigger impact than most realize.

Right. And the leaks around the lifters is a relatively simple fix.

It's a simple hydraulic system. Not uncontrolled leaks. That's crazy to claim that.

I had a joker call me today and claim you can fix this junk with a dry sump. I said how so? And this dude (a self proclaimed expert) says you're sucking the pan dry. I say...ok thanks...goodbye.


I have a minimum of 10 quarts in the system on the dyno. And this guy thinks the pan is empty on a dyno pull. Rediculous.


Call around. Find someone who knows this stuff...like someone who does a lot of viper stuff and call and ask them about oil timing. They sure as shit know what it is. And have ways to get around it. Until you need to correct it.
Still waiting for you to answer my questions.................?

I did. They don't have the same oil timing. Figure it out.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by tenxal »

ClassAct wrote: Thu Dec 05, 2019 6:22 pmIt's a simple hydraulic system. Not uncontrolled leaks. That's crazy to claim that.
Uhhh.....the word "uncontrolled" was not in anything I wrote.
tenxal wrote: Thu Dec 05, 2019 7:40 am An engine oil system is one big leak.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Warp Speed »

ClassAct wrote: Thu Dec 05, 2019 7:39 pm
Warp Speed wrote: Thu Dec 05, 2019 6:44 pm
ClassAct wrote: Thu Dec 05, 2019 6:22 pm


Right. And the leaks around the lifters is a relatively simple fix.

It's a simple hydraulic system. Not uncontrolled leaks. That's crazy to claim that.

I had a joker call me today and claim you can fix this junk with a dry sump. I said how so? And this dude (a self proclaimed expert) says you're sucking the pan dry. I say...ok thanks...goodbye.


I have a minimum of 10 quarts in the system on the dyno. And this guy thinks the pan is empty on a dyno pull. Rediculous.


Call around. Find someone who knows this stuff...like someone who does a lot of viper stuff and call and ask them about oil timing. They sure as shit know what it is. And have ways to get around it. Until you need to correct it.
Still waiting for you to answer my questions.................?

I did. They don't have the same oil timing. Figure it out.
Dude, your lost! #-o
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by ClassAct »

Warp Speed wrote: Thu Dec 05, 2019 9:08 pm
ClassAct wrote: Thu Dec 05, 2019 7:39 pm
Warp Speed wrote: Thu Dec 05, 2019 6:44 pm

Still waiting for you to answer my questions.................?

I did. They don't have the same oil timing. Figure it out.
Dude, your lost! #-o


Dude that's your opinion, which means jack shit to me. If don't know what oil timing is that's on you. You can't put the oil to the crank any place you want. The Chrysler engineers were smart enough to admit that. Why can't you? Too stubborn? Too arrogant?

The ONLY reason to use a full groove main is TO CORRECT AN OIL TIMING ISSUE. That's it. No other reason.

So go build a Chrysler with half groove mains and see how many dyno pulls you'll get out of it. 4 if you are lucky.

Oil timing. Learn it. The Viper has oil timing get issues. They don't use those in NASCAR so you won't know it.

Again, it's on YOU.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Warp Speed »

Well, did a 340 sbm with a buddy in 98. Makes about 600hp, and still turns 8k+ everytime he drives it (70 Dart Swinger street car).
Just did a a pretty good twin turbo viper build for the texas mile. Again, no "oil timing issues"?!? \:D/
I'm just gonna stop there, but I will say it's quite evident, that your deal could be easily improved!
But hey, isn't that why we get up in the AM?!?
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by ClassAct »

Warp Speed wrote: Thu Dec 05, 2019 10:47 pm Well, did a 340 sbm with a buddy in 98. Makes about 600hp, and still turns 8k+ everytime he drives it (70 Dart Swinger street car).
Just did a a pretty good twin turbo viper build for the texas mile. Again, no "oil timing issues"?!? \:D/
I'm just gonna stop there, but I will say it's quite evident, that your deal could be easily improved!
But hey, isn't that why we get up in the AM?!?



Let me guess...half groove mains, center sump pan with a 1/2 inch pick up...the useless crossover tube and it turns 8000 in every gear all day long.

Yep.

Then you should write a book.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Warp Speed »

ClassAct wrote: Thu Dec 05, 2019 11:13 pm
Warp Speed wrote: Thu Dec 05, 2019 10:47 pm Well, did a 340 sbm with a buddy in 98. Makes about 600hp, and still turns 8k+ everytime he drives it (70 Dart Swinger street car).
Just did a a pretty good twin turbo viper build for the texas mile. Again, no "oil timing issues"?!? \:D/
I'm just gonna stop there, but I will say it's quite evident, that your deal could be easily improved!
But hey, isn't that why we get up in the AM?!?



Let me guess...half groove mains, center sump pan with a 1/2 inch pick up...the useless crossover tube and it turns 8000 in every gear all day long.

Yep.

Then you should write a book.
You've given me enough material to write a comedy thats for sure! :lol:
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by BobbyB »

Kevin Johnson wrote: Thu Dec 05, 2019 7:28 pm
tenxal wrote: Thu Dec 05, 2019 7:40 am
BobbyB wrote: Wed Dec 04, 2019 6:28 amIsn’t all this stuff just branch circuits in a simple hydraulic system...just one pump...right?
No. Even the simplest hydraulic system is a 'closed' system. An engine oil system is one big leak. Oil leakage around the lifters has a much bigger impact than most realize.
You can download this CRC Handbook at no charge: https://www.academia.edu/36099713/HANDB ... TECHNOLOGY

Thank you, academia.edu.

Chapter 1 discusses hydraulic systems as meeting defined general criteria: this is the superset. Some hydraulic systems are closed and are a subset of the superset. Some hydraulic systems are open and are also a subset of the superset. Some internal automotive engine hydraulic systems are both closed and open and the elements are members of both subsets. The latter presented the greatest impetus to control aeration outside the demands of the racing community. Violations of Pascal's Principle via the introduction of a compressible phase breaks things. It is the task of the Engineer to stop that from happening.

Set Theory
https://en.wikipedia.org/wiki/Subset
Thank you Kevin. That is an excellent book. It is hard to believe it is available for free with the touch of a button.

Will you please answer the questions I asked in my post on Dec 4 at 7:37?
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by swampbuggy »

With all due respect to you Classact, i will ask you this question. You have been stating (expressing) the extreme importance of the hole in the crankshaft main journal lining up with the hole in the main bearing/engine block. The question is------------WHY is this so important, what does this allow to happen that didn't happen 45 degrees prior to the holes lining up ? Please give detailed/complete answer. Mark H. :?:
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by swampbuggy »

EDIT: to the above-----holes lining up at real close to 70 degrees ATDC.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by Kevin Johnson »

BobbyB wrote: Wed Dec 04, 2019 7:37 pm
Kevin Johnson wrote: Wed Dec 04, 2019 7:21 pm
BobbyB wrote: Wed Dec 04, 2019 6:58 pm

Thanks Kevin. There is deep stuff in that paper.
My understanding is that very much air in the oil will destroy the bearings if the bearing loads are very high. Is that correct?

However, very little or nothing can be done to the bearings or crankshaft to make them live with much air trapped in the oil. Is that correct?

So, we must take measures to stop air from getting trapped in the oil before it goes to the crankshaft. Correct?
I believe damage occurs in rod bearings at 30% (might be lower) and mains at 50%.

The big issue is free air -- dissolved air levels can be quite high (about 9% by volume per bar). However, for an oil pump to accomplish this the oil bubbles need to be small. https://www.sae.org/publications/techni ... 4-01-2915/

Once dissolved air goes through a pressure drop in or external to a circuit, any supersaturation will resolve by the prompt formation of copious amounts of foam. This can quite a problem as well.

Yes, the key idea is to hinder the air getting into the oil in the first place.
Thanks very much Kevin.

So, what are the main reasons that air gets in the oil on:

A 5000 rpm factory v8 from the 1970s?

The same v8 hot rodded to turn 6500 rpm on the street?

The same v8 modded to turn 7500 rpm on the drag strip?

The same v8 modded for 7500 on a road course?
There is at least a dissertation worth of discussion here. Multiple SAE papers discuss aspects of this set of problems. There are many theses written on aspects of these problems. That's quite a core dump.

Start with SAE 750051: Mercedes discusses a V8 series from the 1960s further developed in the 1970s with various displacements and rpm levels that address many of your criteria. They even developed a dry sump system for the street when their test parameters were exceeded.

Note carefully the concurrent development of suspension, braking and tire technology which can add/subtract apparent G forces to true longitudinal and lateral accelerations.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by mt-engines »

Wow.. Just wow.. Must be an oil timing problem. Lets just agree #-o

The only time i had an oil timing g problem, was about 6 maybe 7 years ago. I built a 4.6 MOD, and engine spun the rod bearings at 8800, sent the crank to Crankshaft Supply. They called me back and said the feed holes were drilled in the wrong spot. The manufacturer sent me a new crankshaft and no problem since.

Most oiling problems i see are from bad pan design, excessive clearance, poor machine work. Air will kill a bearing fast. Especially if the tuneup is crap.
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Re: when are 3/4 grooved main bearings needed for bbc ?

Post by BobbyB »

Kevin Johnson wrote: Fri Dec 06, 2019 9:23 am
BobbyB wrote: Wed Dec 04, 2019 7:37 pm
Kevin Johnson wrote: Wed Dec 04, 2019 7:21 pm

I believe damage occurs in rod bearings at 30% (might be lower) and mains at 50%.

The big issue is free air -- dissolved air levels can be quite high (about 9% by volume per bar). However, for an oil pump to accomplish this the oil bubbles need to be small. https://www.sae.org/publications/techni ... 4-01-2915/

Once dissolved air goes through a pressure drop in or external to a circuit, any supersaturation will resolve by the prompt formation of copious amounts of foam. This can quite a problem as well.

Yes, the key idea is to hinder the air getting into the oil in the first place.
Thanks very much Kevin.

So, what are the main reasons that air gets in the oil on:

A 5000 rpm factory v8 from the 1970s?

The same v8 hot rodded to turn 6500 rpm on the street?

The same v8 modded to turn 7500 rpm on the drag strip?

The same v8 modded for 7500 on a road course?
There is at least a dissertation worth of discussion here. Multiple SAE papers discuss aspects of this set of problems. There are many theses written on aspects of these problems. That's quite a core dump.

Start with SAE 750051: Mercedes discusses a V8 series from the 1960s further developed in the 1970s with various displacements and rpm levels that address many of your criteria. They even developed a dry sump system for the street when their test parameters were exceeded.

Note carefully the concurrent development of suspension, braking and tire technology which can add/subtract apparent G forces to true longitudinal and lateral accelerations.
Thanks again Kevin,
Would you expect any significant amounts of air to enter the oil, in any of the 4 engine above, OTHER THAN THE PICK UP at the bottom of the pan? Not considering dry sump systems.
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