Has anybody broken an S6 crank?

[PipeNslippers]

I am considering a bottom end upgrade..steel crank and con rods.

I understand the GT spec (steel) bottom end is much stronger, but I have never heard of a crank breaking in an S6?

I am aware that the early S6 'Indian sourced conrods' had a tendency to 'stretch' but these were replaced with stronger 'Linton I beam forged conrods' when Smolensky took over TVR

[tail slide]

Hi, not heard of breakage from years of dealing with the S6 engine specialists, but have learned that by it's nature like all Straight Six engines the crank has a tendency to 'whip' a very small amount at very high rpm, this flex is not an issue in standard factory S6's but can exacerbate any other problems that can occur; eg, if an engine has had low oil supply to main bearings, bearings not perfectly matched to crank causing hotspots, etc.

So only likely to become an issue if there are other problems, or it's kept for extended periods at highest rpms eg 6-7,500 which could only happen on track.

As always, perfectly matched components of highest material spec and meticulously assembled are going to significantly extend life and power of any engine, so down to your priorities and depth of pockets!

[cramorra]

Mods
if you change this to the S6 Forum more people could get involved- especially some of the engine builders/refurbishers post regularely there

[PipeNslippers]

cramorra said:

Mods
if you change this to the S6 Forum more people could get involved- especially some of the engine builders/refurbishers post regularely there

Good point, well made...I have started a new thread in the S6 Forum

[cramorra]

Nice fleet and past garage by the way (especially the T 350, but I'm biased)- are the Austins on the road?

[PipeNslippers]

cramorra said:

Nice fleet and past garage by the way (especially the T 350, but I'm biased)- are the Austins on the road?

Nothing like a bit of contrast in life.
I bought the T350 after selling the Aston DB4 ..the engines sound almost identical upto around 4,000 (s6 3.7 vs. s6 4.0) and they are both hand built, British and back to basics drivers cars, plus the TVR is much cheaper to fix!

The A40 is my daily driver to the station..it's got lots of nice A-Series mods.
The A90 is SORN'd but runs fine..the engine hasn't been touched in over 60 years..doing better than the Tiv..and counting

[cramorra]

PipeNslippers said:

Nothing like a bit of contrast in life.
I bought the T350 after selling the Aston DB4 ..the engines sound almost identical upto around 4,000 (s6 3.7 vs. s6 4.0

... and surely you wouldn't want to redline a 50 yo Aston , is suppose the change left you with enough for a proper rebuild - I think that TVRs much more represent today what Aston was back then as the modern Astons (despite they look and sound glorious)

and they are both hand built, British and back to basics drivers cars, plus the TVR is much cheaper to fix!

agree fully, but probaly breaks down more often....

The A40 is my daily driver to the station..it's got lots of nice A-Series mods.
The A90 is SORN'd but runs fine..the engine hasn't been touched in over 60 years..doing better than the Tiv..and counting

- great car and unique design

[PipeNslippers]

cramorra said:

great car and unique design

I see you were a Lancia man as well....The Integrale's were great...

My dad used to have an original Stratos, which I had the opportunity to drive..on circuits as well..what a car...the engine was silky swooth and howled when you got it near the red line (7,000 rpm)...but you had to be completely committed..foot down through the apex..if you came in too fast and let off..it got very squirmy..great memories..