Con rods (1 Viewer)

[olley]

Hi guys just been around brothers and we saw a programme on making BMW engines, he then told me that their con rods along with smarts are different to normal con rods, the split on the big end is not machined but broken

He was quite adamant on this, and after 35 years in the trade I don't doubt him, the only thing I could think of was that they froze them with nitrogen before snapping them. Anybody got any info on this?

Olley

 

[ruffingitsmoothly]

I find that very hard to believe Olley especially as to how precise that break would have to be in order to get them around the crankshaft and off again a perfect diameter ?????

Not April the 1st early is it

Tell us more

Regards Pat

 

[PeteH]

Fracture Split `Rods

Hi Olley

Bro` is correct. it save time in the manufacture See:-

Link Removed.

Ford aparently use this system, again to save time/cost


Pete

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[Lindy-C]

"cracked" rods have been around for some time..........see Link Removed

 

[olley]

Hi thanks Linda and Pete, never realised I was so out of touch with modern manufacturing. :Sad:

O'well back to the Glayva.

Olley

 

[ruffingitsmoothly]

HMMMMM!!! I stand correctedoh:oh:oh:

Regards Pat

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[Andy - V8 Diesel]

Hi there i work for MAN Truck & Bus.
MAN trucks also have the break and fit type conrods.
They have been like this for a long time now.

 

[Geo]

The cheeky Bu**ers Pinched my Idea, Ive been breaking Con Rods for 30 years ,and someoh:

 

[lugnutt]

The cheeky Bu**ers Pinched my Idea, Ive been breaking Con Rods for 30 years ,and someoh:

Me to....but i take them out of the side of the block

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[American Dream]

I Thought Cracked Rods and Cracked Blocks went together.....oh:

[ame="http://uk.youtube.com/watch?v=TuKYBb9wPDs"]YouTube - How to Blow Up an Engine[/ame]

 

[PeteH]

Piston Broke

(or the story of my early life!!!)

The time to worry is when 1) the "rod" weighs in at over 1 tonne and 2) it comes out via the crankcase door!!, closely followed by the Piston and parts of the lower liner!!!. Bloody nearly killed my poor Junior Engineer!!. He wasn`t wearing Khaki when he went on watch but was when he went off!!!

We "hung" the spare piston in the remainder of the liner to blank off the exhaust and inlet ports (2 Stroke) , Lifted the Fuel pump to stop it injecting and limped into Port on 5 Cylinders!!

Took 2 days to Pull the liner and fit a new Liner, Piston and rod. The crankshaft fortunately was not damaged. we later found that the rod had had a crack defect just by the Bottom end bolt.

Pete

 

[DuxDeluxe]

At least it's repairable in a marine diesel. What engine was it? We had a B&W do the same thing (but it was in 1972.....)

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[pappajohn]

yep! been there and done that.
hillman imps rev forever.
snapped rod straight through the upper side of the block luckely and jammed solid there.
knew id never get the head off due to ally head and steel bolts so i drove the 3 miles home. not much oil left as most of it got chucked out and a few large dents in the sump off the remains of the bigend but it got me there.
engines were 10 a penny then so just transplanted it.

 

[American Dream]

Touch Wood we never blew an engine......Those Imps were fun motors.

Ran Cooper S myself.

Built some pretty high-revving 2 strokes though.

BTW What revs was that Marine running?Can't have been a lot.

 

[PeteH]

Piston Broke 2

Hi

This one was a Sulzer. Ran at 105 RPM. But mostly about 101rpm (so the Chief could save some fuel to flog to the arabs!!) on gasoil would you believe!!, when the cost was much cheaper 1965/6, later we ran these Engines on Heavy Marine fuel, which had to be preheated before it would flow, at times it was like Bitumen!!, and cleaning scavenge packs was the dirty miserable job!.

Pete

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[American Dream]

Hi

This one was a Sulzer. Ran at 105 RPM. But mostly about 101rpm (so the Chief could save some fuel to flog to the arabs!!) on gasoil would you believe!!, when the cost was much cheaper 1965/6, later we ran these Engines on Heavy Marine fuel, which had to be preheated before it would flow, at times it was like Bitumen!!, and cleaning scavenge packs was the dirty miserable job!.

Pete

105 RPM......MUST HAVE BEEN A BIGGUN.

No Chance of overevving then.The reciprocal forces must have been massive.