Chromidium Block.

[Chris Garner]

   
For those who've never seen one. A rare item.

[Ivor Hawkins]

First I’ve ever seen Chris, but then I’ve never had a sports seven!

[Martin Baker]

I've got one of those too from my Speedy engine, only problem iis t has a crack around the back of no. 4 (unlined +.80).

Replaced with Tony Betts new block.

I keep wondering if it's worth having it laser welded. Any suggestions?

Happy Christmas all.

Martin

[Peter Butler]

I've got one of those too from my Speedy engine, only problem is it has a crack around the back of no. 4 (unlined +.80).

Happy Christmas all.

Martin

Martin -

Did you mean "(unlined + 80)" ? If so, does this explain the performance of your Speedy? To what does this increase the c.c.'s? 

Happy Christmas!

As ever,

Peter Butler

[Reckless Rat]

surely it's +0.080" and not 0.8.... ???

[Robert Leigh]

I have not bothered with the calculation, but have long understood that +.080" gives 803cc. Inevitably we confuse the units in this situation.

[Ruairidh Dunford]

The new metric slipper pistons are actually +0.004” bigger than the markings on the box.

+80 are actually +0.0084” - for each size.

This is sometimes very useful, particularly at the larger sizes…

[dickie65]

I have had all the valve seats on my 9E Chromidium block welded up as well as some of the stud holes and other damage.
The block was given to me by a fellow Seven owner as it was un usable.
I took it to EMP in Havant for them to weld up using Lazer Welding which was cheaper than a new block but only just !!
It has saved an original part from scrap or being used as a doorstop.
I also have another 9E block without the Cromidium marking which I suspect was a Factory replacement as it came with an un numbered 9E crankcase.