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I haven't posted for a while but I recently got into a descussion at work about v6 vs inline 6 pros and cons and my co worker come out with the statement that v6's throw rods and rod bearings more. I asked him to give a technical explanation for this and his statement was "v configurations throw out rods and bearings. Go outside take a look at your front shock. Straight vertical froce idea there is basically the same idea used in inline engines"

To me this is nothing other than verbal Diarrea what do you guys think?
 

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... & Insanity Ensues .....
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verbal Diarrea

according to his argument, anytime you go up and down an incline, your struts / shocks arent properly aligned with the universe

ask him wich of the following 2/4's would fail first

answer: no way to tell, because both are egauly loaded in the same direction, it will come down to which one is inherintly weaker

just like with rod bearings, its in the design of the bearing & rod, angle is meaningless
 

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Hates: Liver. Loves: Diesel
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Agreed. Verbal poop.

Its possible to argue that I6s tend to be a bit more bulletproof than a similarly designed V6 due to the fact that most I6s have 7 mains and individual throws for each cylinder. Most V6s have 4 mains and pairs of cylinders share 3 rod throws.

But that would have nothing to do with spinning bearings. He's full of ****e
 

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"Throwing" bearings, an odd term, is not a design flaw. It is a flaw in maintenance, assembly, rebuilding, or the result of abuse of the engine (over-revving, low oil, incorrect weight oil, etc.), or just plain wearing out due to high mileage.
 

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Alright well this was his arguement today:


Its proven inlines last longer, physics behind this changes as you change the person you are talking to. You hear widely the direction of torque applied to the crank being square on for all cyclinders. Where as the direction of the vectors in a v configuration are on different axis's
 

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I can give a technical reason why, by design, a V-6 would experience rod bearing failure at a higher rate than an I-6.

Buick produced the first widely used American V-6. The 3.8, or 3800 is still in service in hundreds of thousands of cars today. When it was first produced, it was an "Odd fire" engine. It basically used a V-8 crank with one throw cut off. It used the same diameter, and width bearing as a typical V-8 would use. Bearing failures where a non-issue.

In the late 70's, the motor was changed to an "Even Fire" configuration. To do this, the crank pin was split. This required the rod bearings to become narrower to clear the web of metal connecting the, now separated crank throws. The area of the bearing was reduced to the point that it would prematurely fail......A design flaw.....


The 2.8 Chevy is another prime example of the "Thrown rod bearing" perception with V-6 engines.

I still hear jokes about Chevy shipping some of the 2.8 V-6's with a rod already hanging out of them. In reality, the problem was fixed mid year 85' with a larger diameter bearing.

20 years later, and they still have a bad rap.
 

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that's the dumbest thign I've ever heard. The rod bolts around the journal with a bearing inbetween. Its a circle. All points on a circle are the same. He's saying that the force coming down on an angle of a circle will cause more damage to the bearing than if it was coming down at the "top" of the circle. Cirlces dont have tops or sides... in fact, that's the whole point of the shape.

In the 40's airplanes had piston driven engines with a cylinder at every point around an axis (sometimes as many as 12 or 16). Which means some were upside down, some were strait out, some were horizontal, and the others were inbetween. By your friends logic, the engines would always have broken down sooner because of the angled pistons, which was clearly never the case.

K
 

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You know, also you could probably make the case that inlines may have historically been a little more bearing prone because some of them (I think maybe the old stove bolts? Help me out here guys) had only 3 main caps over a huge crank length which is clearly harder on the bearings than a short, compact crank that flexes less and has more main caps like a chevy V8.

K
 

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killerformula said:
You know, also you could probably make the case that inlines may have historically been a little more bearing prone because some of them (I think maybe the old stove bolts? Help me out here guys) had only 3 main caps over a huge crank length which is clearly harder on the bearings than a short, compact crank that flexes less and has more main caps like a chevy V8.

K
when your talking 3 main caps, your talking babbit bearings also, which are in a leauge of there own when it comes to throwing rods. most I6's made in the last 40 years have 4 or more main caps. a 216-261 has 4 main caps I think, but babbit bearings, and the '37-'52 engines are noted for throwing rods and spinning out bearings.
 
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