Why does this break then

[kja.busa]

I run an EFE turbo, 1230cc, never had an issue like this, or seen one before tbh. The only issue I ever had was the block head joint weeping, which Rog Upperton sorted by blocking the oil way off in the top crankcase then running external oil lines, been 100% oil tight ever since.

[markfoggy]

Ok, I've been letting this run past me for a while. Get some head space, 'cause this is likely to be several contributory factors.

Thanks for the input. It Helps.

Where I'm at so far is, I'm ruling out the !/2 Kilo on the end of the covers, it might well be contributing, but the other teams that have seen similar failure have not gone there.

Ageing cases, I'm ruling out, 'cause we've had previous engines with deformation after a light crash on the ignition cover that has simply pushed the casing oval. This has stopped the engine, as fitting an ignition backplate was impossible, but no cracking. Suggests that the castings are quite malleable and and as I've pointed out, Aluminium tends to Normalise fairly quickly. It might be subject to creep in operation, but  shouldn't be subject to long term fatigue failure unless there's some bit of the cocktail that I'm seriously overlooking. 

 

[markfoggy]

As a build thread, this isn't really appropriate, but you may be able to view.

http://pbmagforum.co.uk/index.php?/topic/53878-p1-2015-wotchermean-were-not-p1/

Not realy a build thread, just a lot of my presonal witterings, building a Phase One bike is the work of Legions.

We are Spartacus.

[Captain Chaos]

Linky no worky (no permission to view it)

[markfoggy]

Ok, thought that might be the case.

If we do anything interesting in the coming year I'll post it on here.

[dupersunc]

Ok, I've been letting this run past me for a while. Get some head space, 'cause this is likely to be several contributory factors.

Thanks for the input. It Helps.

Where I'm at so far is, I'm ruling out the !/2 Kilo on the end of the covers, it might well be contributing, but the other teams that have seen similar failure have not gone there.

Ageing cases, I'm ruling out, 'cause we've had previous engines with deformation after a light crash on the ignition cover that has simply pushed the casing oval. This has stopped the engine, as fitting an ignition backplate was impossible, but no cracking. Suggests that the castings are quite malleable and and as I've pointed out, Aluminium tends to Normalise fairly quickly. It might be subject to creep in operation, but  shouldn't be subject to long term fatigue failure unless there's some bit of the cocktail that I'm seriously overlooking. 

 

Thing is Mark, Aluminium does fatigue with use, not age as such but stress cycles. The closer you put the stress to the yield point of the material, the few cycles you will get before you have a fatigue failure.  There are all sorts of cryogenic process you can use to reverse the fatigue process, but they probably aren't viable in this case. 

How thick are the casing at the base of the other head studs? It may be that there simply isn't enough material there to deal with the loads you are putting through it now., and that area needs some strengthening.

Another thought is that the later oil cooled engines had rubber front mounts. Is the fact that you have solid mounts all round putting extra stress on the casings, from chassis loadings or heat expansion.