Author Topic: Continuing saga  (Read 2425 times)

0 Members and 1 Guest are viewing this topic.

Offline Ian

  • Master Member
  • ****
  • Join Date: Jul 2004
  • Posts: 1287
  • Location: The Oaks, NSW, Australia
Continuing saga
« on: 11 Oct 2011 at 02:33 »
I must be getting close to sorting all the issues on my E28 !! (I seem to have replaced or rebuilt almost everything on the rear cylinder). The latest issue which explains a lot is that the barrel has a crack around one of the head hold-down lugs - only noticed it when I removed the old head gasket - the whole lug is starting to break off. I do have some other barrels - but my question is can this sort of thing be repaired ? Seems a shame to throw away an otherwise perfect barrel !!

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4246
  • Location: Glen Mills, PA, USA
Re: Continuing saga
« Reply #1 on: 11 Oct 2011 at 06:34 »
Ian,

I have seen these on the 350 and 600EW brazed and welded on, more or less successfully depending on the skill of the welder. If more than two are broken, then you are better off replacing the whole top of the cylinder with a steel ring incorporating the lugs. This is usually only worth while on rare cylinders like the K/M32 series.

If welding up the lug, it is often better and usually necessary to braze/weld it up solid then re- drill and tap. Also the adjacent cylinder wall is likely to warp, almost certainly if welded, such that running a hone or a re-bore will be required.

Some pics of the K32 repair of how to go about it if feeling really energetic:


Badly repaired lugs.


Machining the new top flange/cross.


Orienting the flange for pinning, preparatory to silver-brazing.


Ready for brazing, one of the 1/8 inch blind pin holes can be seen between fins. Aslo the oppertunity was taken to fix some chipped fins around the head bolt. The K32 has bolts that go up blind into the head, whereas the 600 and later 350 EWs have the bolts through from the top.


Preheat for brazing.


Boring. This is just for show as the job was already done (there are no bolts holding the cylinder to the boring chuck!) 

-Doug

[fix typos.  -Doug 11Oct11]
[update image links to https.  -Doug 12Jan20]
« Last Edit: 12 Jan 2020 at 14:49 by Doug »

Offline Ian

  • Master Member
  • ****
  • Join Date: Jul 2004
  • Posts: 1287
  • Location: The Oaks, NSW, Australia
Re: Continuing saga
« Reply #2 on: 11 Oct 2011 at 06:43 »
Thanks Doug - you seem to have done everything  :) - I will find someone who can do this and get it repaired.

Took my other barrels to the shop - looks as though I will have to go with oversize pistons - now to find ones which will work !