Official S65 Rod Bearing Condition Example Thread

[jcolley]

Originally Posted by Sneaky Pete

Was I impolite or dismissive to anyone in my earlier posts that warranted an unpleasant nature of reply?

Further, lets say for the sake of argument that with new bearings, fresh oil and normal operating temperatures, all is good with extra clearance bearings.
That in no way guarantees that once the coating wears off creating even further clearance and at elevated oil temps that this will remain the case.
Should no one care about possible unintended consequences and any suggestion of it should be firmly discouraged?

Instead of asking broad "what if" questions in a pedantic manner, why don't you present a calculation of said scenario using worst case assumptions of the variables you're questioning. Calculate the clearances of OEM, BE, and a bearing with worn coatings or whatever. Then calculate the mass flow rate of oil through those bearings in each scenario. Then calculate the percentage increase in flow as a result of each.

The reason most get frustrated with your questioning here is you present ill-constructed theories as fact or reason for fear and then when a logical, mathematically provable reason is presented, you ignore it and then move on to the next question. As it is you present yourself as someone who either craves to be spoon-fed information you're not willing to learn on your own or seeking attention in whatever means. I think most of us are inclined to believe the latter based on the replies to your posts which you choose to respond to.

[notouching]

Originally Posted by admranger

Since making the bearings isn't financially feasible (clearly), would modifying stock ones in a controlled manner be? I could see the need for jigs to hold the bearings and then the appropriate sized boring tool(s) and then possibly coating them as a path forward.

However, I recognize that this is easier typed from my recliner than actually designed and completed by skilled people such as yourself.

Regardless, I've installed 3 sets of BE bearings so that's 3 S65 owners (me being one of those) that only have to worry about their mains now.

Interested in this as well. Anyone know if this would be doable?

[Green-Eggs]

Originally Posted by jcolley

Instead of asking broad "what if" questions in a pedantic manner, why don't you present a calculation of said scenario using worst case assumptions of the variables you're questioning. Calculate the clearances of OEM, BE, and a bearing with worn coatings or whatever. Then calculate the mass flow rate of oil through those bearings in each scenario. Then calculate the percentage increase in flow as a result of each.

The reason most get frustrated with your questioning here is you present ill-constructed theories as fact or reason for fear and then when a logical, mathematically provable reason is presented, you ignore it and then move on to the next question. As it is you present yourself as someone who either craves to be spoon-fed information you're not willing to learn on your own or seeking attention in whatever means. I think most of us are inclined to believe the latter based on the replies to your posts which you choose to respond to.

Originally Posted by notouching

Interested in this as well. Anyone know if this would be doable?

A bearing isn't perfectly round inside. It's slightly oval shaped to help push the oil around it. If you stick a hone to it, you'll make it perfectly round...and you don't want that.

[Sneaky Pete]

Originally Posted by jcolley

Instead of asking broad "what if" questions in a pedantic manner, why don't you present a calculation of said scenario using worst case assumptions of the variables you're questioning.

Oh please...its self evident that you can't keep increasing bearing clearance (by design and/or wear) without risk or consequence.
Or maybe it isn't when you have a vested interest.
Anyway no need to fret...I'm sure new, previously unseen, data from BE will be along any minute to demonstrate there is nothing to worry about and everyone can sleep safely at night.

[jcolley]

Originally Posted by Sneaky Pete

Oh please...its self evident that you can't keep increasing bearing clearance (by design and/or wear) without risk or consequence.
Or maybe it isn't when you have a vested interest.
Anyway no need to fret...I'm sure new, previously unseen, data from BE will be along any minute to demonstrate there is nothing to worry about and everyone can sleep safely at night.

I'll take that as a "no, I'll keep being pedantic".

Correct. If you used a bearing with 8.75" of oil clearance, it might be problematic. That why we math.

Additionally, if you actually understand how things work and can read graphs properly, the answer to your latest question is already there as well.

If your'e pointing the "vested interest finger" at me, it actually works the opposite. I make way more money on spun bearing rebuilds than I do selling a set of bearings and/or changing them out.

[rantarM3]

After all the back and forth I am wondering two things:

1) What connecting rod and main bearing clearance specifications are being used by reputable stroker builders (e.g., RD Sport, Dinan, etc.)? If they have a larger clearance than OEM clearances and are using the stock oil pump with no ill effect (I've not heard of any such strokers suffering bearing failure), does that not contradict the argument that some additional clearance can be detrimental to the main bearings?

2) I wonder if the connecting rod wear that is being shown on bearing samples can also be a factor of piston and connecting rod mass. In other words, are the pistons and connecting rods too heavy for the relatively high RPM nature of this engine? It is my understanding that stroker builds generally use lighter weight connecting rods and pistons.

[jcolley]

Originally Posted by rantarM3

After all the back and forth I am wondering two things:

1) What connecting rod and main bearing clearance specifications are being used by reputable stroker builders (e.g., RD Sport, Dinan, etc.)? If they have a larger clearance than OEM clearances and are using the stock oil pump with no ill effect (I've not heard of any such strokers suffering bearing failure), does that not contradict the argument that some additional clearance can be detrimental to the main bearings?

2) I wonder if the connecting rod wear that is being shown on bearing samples can also be a factor of piston and connecting rod mass. In other words, are the pistons and connecting rods too heavy for the relatively high RPM nature of this engine? It is my understanding that stroker builds generally use lighter weight connecting rods and pistons.

I can answer the first one directly. I have had a couple of billet cranks made and waiting on an another now from the same crank shop that Dinan uses. In fact, one of the ones that I purchased from them initially was excess inventory from a Dinan production batch. Yes, those crank main journals are the same size as OEM and yes the rod journals are about .0005" smaller in diameter than OEM.

[Richbot]

Originally Posted by Scharbag

That is so wrong.

I wish there was a way to filter posts from people who choose to argue just for the sake of arguing. You never back up anything you say with fact AND you spout nonsense such as the above. It truly does detract from what could be a great discussion.

Welcome to Monday I guess.

User CP - edit ignore list

[rantarM3]

Originally Posted by jcolley

I can answer the first one directly. I have had a couple of billet cranks made and waiting on an another now from the same crank shop that Dinan uses. In fact, one of the ones that I purchased from them initially was excess inventory from a Dinan production batch. Yes, those crank main journals are the same size as OEM and yes the rod journals are about .0005" smaller in diameter than OEM.

So it would seem that while the discussion about the oil pump's capacity and increased flow through the rod bearings is fascinating, it is primarily academic.

Do they use OEM rod bearings or something else?

And I'm still wondering about the piston/conn rod mass. Hopefully someone can chime in on that.

[kawasaki00]

Originally Posted by admranger

Since making the bearings isn't financially feasible (clearly), would modifying stock ones in a controlled manner be? I could see the need for jigs to hold the bearings and then the appropriate sized boring tool(s) and then possibly coating them as a path forward.

However, I recognize that this is easier typed from my recliner than actually designed and completed by skilled people such as yourself.

Regardless, I've installed 3 sets of BE bearings so that's 3 S65 owners (me being one of those) that only have to worry about their mains now.

Just not feasible, that would change the eccentricity of the shells.

[admranger]

Originally Posted by kawasaki00

Just not feasible, that would change the eccentricity of the shells.

Understood. Forgot about that little tidbit.

[McSwine]

These bearing threads make my head hurt.

[admranger]

Originally Posted by McSwine

These bearing threads make my head hurt.

As long as they leave your wallet alone, you're good.

[McSwine]

Originally Posted by admranger

As long as they leave your wallet alone, you're good.

My wallet's good...I ain't skeered. Odds are most of our cars are fine and I'm not going to worry about it.

[dmk08]

Guys spend 2k to clear bra their cars these days. Whats $2500 for peace of mind with your engine.

[serranot]

For the technical experts here, does the substantial increase in flow bear any fruit for the main bearings? Said another way, if there is less restriction and increased flow downstream of the mains, does that mean that the mains also get increased flow?

If my questions is nonsensical, feel free to correct my (mis) understanding of the oil flow (flow, pressure, or direction).

[deansbimmer]

Since the oil feeding the rods goes through the mains first, yes the mains see the increased flow.

[serranot]

Originally Posted by deansbimmer

Since the oil feeding the rods goes through the mains first, yes the mains see the increased flow.

That's what I thought. Can that be of benefit given the comments regarding the mains? Or does the increased flow have to be engineered in a certain way?

[deansbimmer]

Originally Posted by serranot

That's what I thought. Can that be of benefit given the comments regarding the mains? Or does the increased flow have to be engineered in a certain way?

Most mains suffer from the same underlying issue of low clearances that the rods do. Increased flow won't do much to help that.

[Sneaky Pete]

Originally Posted by deansbimmer

Since the oil feeding the rods goes through the mains first, yes the mains see the increased flow.

That's an interesting concept...you'd not rather go with the idea that to increase oil flow through the main bearings you would require more oil pressure, all else remaining equal?

[deansbimmer]

Originally Posted by Sneaky Pete

That's an interesting concept...you'd not rather go with the idea that to increase oil flow through the main bearings you would require more oil pressure, all else remaining equal?

It's not an idea. Refer to the extensive test data shown in this thread. The data are from BE bearings (increased clearance) being installed on an otherwise stock bottom end and shows almost double the oil flow with that combination.

[Sneaky Pete]

Originally Posted by deansbimmer

It's not an idea. Refer to the extensive test data shown in this thread. The data are from BE bearings (increased clearance) being installed on an otherwise stock bottom end and shows almost double the oil flow with that combination.

AIUI
The ~doubling of oil flow measured, is essentially all flowing through the extra clearance rod bearings....as the oil will always take the path of least resistance.
As long as the oil pump remains capable of presenting oil to the main bearings at the same oil pressure (before and after the RB change) then the flow through them should remain unchanged.