Oops a cracked block - what next?

Fenlander · Post by **Fenlander** » Tue Sep 18, 2007 9:29 pm

Shame I was getting really keen on the possibilities of my bargain Silver Century. Fresh fuel and it started after the second pull... and it's not been run in years.

However after a couple of minutes I noticed a wet stain right next to a hairline crack on the carb side of the block.

I've been unable to get any idea of a used block price from the net... I'll have to ring John and ask tomorrow. Is it going to make this an uneconomic prospect. I wonder?

Be a shame to break/scrap it as it runs very smoothly with great gusto!

David

Post by **charlesp** » Wed Sep 19, 2007 8:49 am

Oh dear - a cracked block is not good news.

Mind you, there are lots of people out there who would simply shrug and run it as it is...

Fenlander · Post by **Fenlander** » Wed Sep 19, 2007 11:22 am

Thanks Charles... I only paid spares money so no problem. Just spoken to John who confirms he hasn't a shelf full of used blocks for the price of a pint! Hen's teeth come to mind apparently.

I'll keep it in the shed until I can make use of the bits on another project. I've got that kind of mind where I can't bear to use something with a major fault.

David

Post by **charlesp** » Wed Sep 19, 2007 1:15 pm

until I can make use of the bits on another project

... do I detect the beginnings of another large collection of Seagulls here?

CatiGull · Post by **CatiGull** » Wed Sep 19, 2007 1:36 pm

I confess I dropped one of my Gulls and cracked the lower crankcase at the tiller handle attachment and....

(close your eyes David)

Applied 3M 5200 Marine sealant and ran it for a season...it ran very well

I have tried welding it with the Al rods and got a fairly good looking repair but it cracked when I retightened. I will give it another go and get it a little hotter next time.

Its a workbench Gull so it doesnt interfere with my boating pleasure

Charles UK · Post by **Charles UK** » Wed Sep 19, 2007 5:59 pm

Your cracked block was probably caused by a build up of rust & salt water crud in the water jacket.

My suggestion would be remove the cylinder completely & clean out the water jacket if this is the problem, clean out the crack as best you can & fill with one of the epoxy glues like araldite.

If it's only the outer layer of the water jacket this should hold it for the next 10 years.

Read all the other posts on how to clean the water jacket & remember no one will be eating their dinner off the inside all it has to do is cool the outer sides of the cylinder.

Anneal the head gasket if it is in reasonable condition & stick the head back on with some RTV silicon, & if it looks real good on the cylinder front treat it to a coat of black paint.

Good luck

Fenlander · Post by **Fenlander** » Wed Sep 19, 2007 8:08 pm

Stephen I'm fine with the sealant on the crankcase... in some ways a little easier on the sealant than trying to do teh same with the cast block.

However I appreciate the input Charles UK... I have no problem doing the work so to experiment would be no hardship for one that would just stay in my ownership... never never for one to sell on though!

And CharlesP you are right... my interest has been very quickly taken by these old motors. I've just finished a 13yr plus association with old and classic tractors so these are a nice easy to store/work on interest.

David

mrdraddy · Post by **mrdraddy** » Wed Sep 19, 2007 9:30 pm

Can i sugest the following method to effect a repair,first off drill 2 small holes either end of the crack( not right through to the water gallery !!)this will stop the crack spreading( remember the b.o.a.c comet and the square windows)Next cut yourself a square of metal to cover the crack and either glue it over the area using epoxy or drill/tap the block and screw it on.
this method has been used for years to repair cracks in castings.
professionals use a method called stiching were the crack is drilled and tapped along its lengh and small screws are wound in and ground flush stiching the crack together.I really wouldnt condem the engine to spares department just for that!Follow Charles advice and clean the crud out fisrt though,if worst comes to worst you will have gained a little experiance.
Hope this helps

Fenlander · Post by **Fenlander** » Wed Sep 19, 2007 10:15 pm

Thanks for thr further thoughts. I will use this motor as a fact finding experiment... first for getting the head bolts out!

David

Fenlander · Post by **Fenlander** » Fri Sep 21, 2007 3:01 pm

Well hopefully a resolution has come to light. Managed to pick up a complete "for spares" Silver Century today for little money as it had seized from standing. This has a block free from cracks and a couple of other bits I need so hopefully the two will make one good one and leave enough parts for a long term re-build.

Interestingly I mentioned the first Silver Century with the cracked block was a longshaft but just marked S and we concluded it had been swapped at some time.

In all honesty it was sold to me as a shortshaft and stupidly I collected in the dark without noticing it was longshaft. I was a bit miffed when I got home as I'd wanted a shortshaft.

Well this seized one has the code WSL but is actually a shortshaft so I guess that has been converted the other way!

In any case it gives me all the bits to end up with what I need.

Would it be out of order to fit the later Wipac ign to the earlier Villiers ign model... would it give more reliability or a better spark?

David

Post by **charlesp** » Fri Sep 21, 2007 5:29 pm

People say the Wipac was the better unit, and yes it'll fit as a direct swap (complete with baseplate of course.

But I like the Villiers ones, myself. Sort of more British, if you know aht I mean. Reassuringly old fashioned.