ALFAGTV6.COM

[Barry]

Sooo,F calls me a while back saying there's a noise from the car.Now they had just destroyed a front coupling and I thought it may have been related to that.
8 minutes into the phone conversation and we diagnose the problem,

BUMMER !

No one is to blame here as Ive seen many broken cranks over the years..Remember these cranks are almost 30 years old already..

Busy sorting it out ..

As luck would have it there is no other damage to any other components.
Sorry F,unfortunately we cannot just take the broken part out and put another in..Its engine strip and doing everything properly.

[Mats]

Did the rear main actually make it? Not bent/destroyed by the piece of crank that broke off I mean.

[Barry]

Unbelievably yes ! Bearings took the pain but the block is fine..Fernandos a pain when it comes to out of the ordinary sounds and his Bella...He stops right there and there to ascertain what is up..This saved this engine..

Hey Mats..

[Zamani]

Baz,

Those rods looks stock. I'm surprised that a 3.6L + 7.2K rpm are ok for stock rods. Was any prep done to them? Haven't seen too many broken cranks, usually rods through the block.

[rz]

wow,i am sorry to hear this F.
don't you have a NEW gta crank?as you have 3,6???

[mjr]

Ouch!! hmmmm.Doesnt look like it had been shotpeened..

[MD]

Doesnt look like it had been shotpeened..

..don't know about that. I think it's been well and truely CANNON peened..in fact it looks like its had the entire firing squad off load a round or two..

[Fernando]

Sorry for the late response guys.

Yes this happened on my way home one Tuesday afternoon.At first there was only a slightly strange sound from the motor but nothing you would get into a panic about.No vibration through the drivetrain or clutch pedal at all which does sound weird when you look at the pictures I know.

Anyway this sound just got worse and worse,but this is SA,and stopping on the side of the road with nightime approaching and your girlfriend in the car is not to be done.

I made it home with very carefull driving.

A week or so before this I had my front prop rubber explode and destroy part of my yolk. This happened at 6000rpms in third going up a moderate hill.It was a Saturday morning with a clear road so I was enjoying my car. Anyway I nearly needed new underwear after that.

Fitted a new yolk,prop rubber and one of Kevins cages, then the crank went a week later .I suspect the initial course to disaster was set with the prop rubber going.My free advice to anyone running a turbo or big bore motor,fit the prop rubber cage to save yourself heartache.

[MD]

Ah Fernando. I know all about "knock on" effects on the Brick. Broken flywheel bolts, cracked clutch housing, bent clutch input shaft, broken CV coupling. It's all just so much fun isn't. Real pants wetting stuff-especially when you get the bank statement back !!

Mate, get ready for some "knock on" effects yourself-especially with the engine. I think Bazza has already signalled this for ya.

[Greg Gordon]

Wow, I don't know what else to say. I hope it all goes back together OK. It's good there was minimal damage beyond the crankshaft itself.

Greg

[ALFA GTV6 GP]

Fernando bit of bad luck there mate

I have not heard of a Crank going this knock on effect sheds a bit more light on things.

Barry didn't explain the prep work he put into your first crank are you prepping the crank different this time maybe magnetic particle inspection,micro polishing,shot peening,Cryo????

I have two engines putting out similar power and you now have me thinking

Thanks
John

[Barry]

Oh boy...........

[kevin]

Some of you guys might remember pics of mine and my dads twin turbo 3.0 on old forum. Anyway my dad took the car on holiday to the coast which is 600km from here. On his way back he picked up a knock in the engine 400km from home. As fernando said you dont hang around on the road side to check whats happening so he continued to drive. The knock did not get louder. When he got home we took the sump off as we thought we would check journals. Thats when we discovered that crank had broken right through in same place as Fernando's. Seems totally impossible that you can drive 400km on a snapped crank. We checked the block resized rods, new bearings and put it back. This motor continued to be very strong and ended up been sold to Domingoes for drag racing at high bost.After two years of drag racing it finally came apart. My point been it had no special rods or rod bolts , a block that once had a snapped crank and it took two years of hard drag racing to finally kill it.(low 12sec 1/4 mile) Dont underestimate how strong these motors are.
Baz, i have two other cranks broken in same place. Why here ?

[kevin]

Correct last line. i have SEEN two other cranks broken in same place.

[MD]

I once broke number 2 connecting rod in three parts but didn't know it. Drove another 200 km to get home on an underpowered and rough running 105/ 4 cylinder donk (engine).

When I stripped it down the next day, I discovered the big end was still wrapped around the journal causing an out of balance for the crankchaft- hence the huge vibrations and the small end was still attached to the piston stuck at the top of the cylinder. Meanwhile the rod centre section was floating around in the sump. It ran on three cylinders home over the highest mountain range in the area.

This engine was rebuilt and was raced for years in 105 historics !!

Dont tel me Alfa engines aren't tough !!