Do 5 litre cranks break?

[bhpjon]

Seems i'm the only one who hasn't heard that 5 litre cranks have a propensity to break regularly, is this true and if it is what can i do about it please chaps (no down sizing isn't an option!)

[900T-R]

FWIW: V8 developments specifically mentions the issue in the item description of their five litre short engine, and states 'no such problems with our much stronger crank assembly' or words to that effect...

[puffsorted2]

Its not unknown, but its very very rare.

[PhilipC]

They do? I'm clearly doing well (or regular is overstating it). >74K and my only engine problem is a new camshaft (just been done).

[900T-R]

puffsorted2 said:

Its not unknown, but its very very rare.

With only about 600 Chimaera 500s built and how many - 1,700-2,000 Griff 500s I'd say any major failure that occurs more than a couple of times is a bit significant...

[puffsorted2]

900T-R said:

puffsorted2 said:

Its not unknown, but its very very rare.

With only about 600 Chimaera 500s built and how many - 1,700-2,000 Griff 500s I'd say any major failure that occurs more than a couple of times is a bit significant...

Put it like this - its that rare (even myth maybe) no one worries about it.

[andy-w]

puffsorted2 said:

Put it like this - its that rare (even myth maybe) no one worries about it.

Hey Ray_Von,

How much did this myth set you back and how long was your car off the road....!!!

[coetzeeh]

Read in a magazine some years ago Dave Batty saying that the very early 500's were more prone to breaking cranks.

[puffsorted2]

andy-w said:

puffsorted2 said:

Put it like this - its that rare (even myth maybe) no one worries about it.

Hey Ray_Von,

How much did this myth set you back and how long was your car off the road....!!!

well thats one - not exactly a "propensity to break regularly" issue yet. Can't see the Speed 6 boys crowing about how reliable their engine is compared to the RV8 for a while yet.

[puffsorted2]

Oh hang on, his didn't break, just bend, that doesn't count

[shpub]

Compared to the number of people who have stuffed their 500s, it is very insignificant.

[cre]

Having been working on these for more years than I should of, I could probably count on 2 hands the amount of crank failures where it hasnt been due to the owner being silly and running out of oil etc.

IMHO I dont think that they are too bad, yes there are better options out there if you are looking to create some decent horsepower, but usually you dont need to worry too much.

jamie

[adrian@]

When the FIRST 5 litre cranks were made the company that was to make them was asked to quote for making the pattern, and it being not cheap, TVR in a moment of madness made the pattern in-house, puttting the 'risers' in the wrong place, this caused porosity in the crank and when the cranks were then machined, aero type holes MIGHT appear at the start of the work or 2/3rds in the work OR not. LOTS of crank got written off in this way prior to being fitted. Cars did have these OR NOT cranks installed. TVR blamed the foundry the foundry blamed the pattern. My friend was asked to prove one way or another, and X-rayed the cranks asked to write a report..... problem solved. Almost a myth.
Adrian@

Edited by adrian@ on Thursday 8th March 20:01

[victormeldrew]

From what I gathered there have been a few 500 crank breakages lately where engines had been rebuilt, with the possibility that the wrong damper had been put on the engines. The cranks are externally balanced - the crank and damper are a matched pair. Swap damper with another engine (for example in a engine shop where several engine were being built up) and you have an unbalanced crank and a breakage on its way.

Certainly not a rash of breakages that I'm aware of.

[andy-w]

puffsorted2 said:

Oh hang on, his didn't break, just bend, that doesn't count

True...i wonder when he will be along to have a go at us for taking the mick...

[ray_von]

andy-w said:

True...i wonder when he will be along to have a go at us for taking the mick...

Here I am and as the master of the quick and witty response all I can say is ..... off

[ray_von]

cre said:

I could probably count on 2 hands the amount of crank failures where it hasnt been due to the owner being silly and running out of oil

Put mine on one of your hands Jamie

[andy-w]

ray_von said:

andy-w said:

True...i wonder when he will be along to have a go at us for taking the mick...

Here I am and as the master of the quick and witty response all I can say is ..... off

Is that 'Body Off'????

[ray_von]

andy-w said:

ray_von said:

andy-w said:

True...i wonder when he will be along to have a go at us for taking the mick...

Here I am and as the master of the quick and witty response all I can say is ..... off

Is that 'Body Off'????

If mine needed what yours does it would be getting broken for spares no question. Unless you fancied doing another one

[bhpjon]

ray_von said:

andy-w said:

ray_von said:

andy-w said:

True...i wonder when he will be along to have a go at us for taking the mick...

Here I am and as the master of the quick and witty response all I can say is ..... off

Is that 'Body Off'????

If mine needed what yours does it would be getting broken for spares no question. Unless you fancied doing another one

OOOOOOOOH, don't say that ( I said something similar last saturday but i've got mechanical tourettes!!)