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Why buy a cracked block?
Posted: Sat Mar 10, 2012 9:21 pm
by livewire
Saw this on ebay and i can't understand why people buy a cracked block?
http://www.ebay.co.uk/itm/251009691937? ... 1436.l2649
Any ideas?
Re: Why buy a cracked block?
Posted: Sat Mar 17, 2012 5:17 pm
by electrosys
I saw that earlier on and thought that it couldn't possibly get a single bid - but I see somebody's paid £16 for a badly cracked block ! It beggars belief.
He's a decent seller though - bought a few bits from him - always ok.
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 12:22 am
by Niander101
IT can probably weld up
so if so he got a cheap block
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 1:16 am
by us_patent_4163437
IT can probably weld up
The plain, inescapable, fact is that cylinders that have splits in the outer layer of the casting have fatal internal corrosion which has caused extreme pressure sufficient to cause rupture of the outer wall. (just in case you missed the "**ffing" key word please let me repeat it, " FATAL"). End of story; the capitalisation shouting was for effect to get your attention.
Yes, you (Niander are personally proficient and) can weld up the outer layer of the water jacket or fill it with silicone but that doesn't do anything to address the water jacket blockage. It will most likely overheat and *will* split again as the internal corrosion continues to get worse. Bit like cancer. If you don't cure it at source it will come back to bite. Not pleasant but fact. No long term remission here.
It wasn't clever; and no,the buyer didn't get a cheapo block. They bought into aggro. Bollock the seller for tarting up a block using emery cloth cloth to clean up the gasket face. That's the last thing to do! As soon as you see a picture and auction like that run a mile!
Hmm ......................... "it has a split, I don't know if it is a problem....."
Pah!
Flash,fact, or what ......................................?
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 2:00 am
by electrosys
Repair it ? Welding cast iron is far from straightforward, although it might be feasible if it were just the jacket - but it's not.
I've also got a block which has cracked right across the exhaust stub like that - and believe me, it's irrepairable - even if you are proficient with nickel rods - 'cause you can't get full access to the cracks in order to weld 'em.
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 3:35 am
by us_patent_4163437
electrosys wrote:Repair it ? .................
I've also got a block which has cracked right across the exhaust stub like that - and believe me, it's irrepairable - even if you are proficient with nickel rods - 'cause you can't get full access to the cracks in order to weld 'em.
What we are not addressing is the fact that all current Seagull blocks are corroding internally, and fast. And that is irrespective of whether they are run in salt water or freshwater. They are all failing from internal corrosion. The oft seen eBay claim " pumps water like it should/like a fire engine" is a total load of cods wallop if it is meant to reassure a buyer that the motor is free of water jacket corrosion. It means nothing. It simply means that there is at a minimum a pencil diameter hole from inlet to outlet through the cylinder block with everything else possibly blocked solid! Are you really sure your "freshwater" only Seagull has never run in salt-water?
Running in salt-water is far more detrimental that running in freshwater. They will last longer if they have only *ever* had freshwater user. Once used in salt water they will corrode faster than those that only ran on Dutch canals or Lake Windermere......... This is simple fact; cast iron is very very porous and loves to store salt. Salt kills blocks very quickly.
Blocks split from a build up of corrosion in the water jacket. The most troublesome area is behind the exhaust port which is why we see frequent eBay auctions with blocks with splits in this area .
Now that is not a welcome fact. It means that many motors are fast becoming "display only models". Many owners already realise that Marston models really are "display only " but it is fast catching up 102 owners with much later models. Motors from the 40s and 50s kept on display stands are starting to fracture blocks even though they haven't been near water in seasons. The internal corrosion doesn't stop once the motor is taken out of service The same is true of the Century and Silver Century models of the sixties and seventies. This is evident now; and will only get worse.
These outboards may well have been over engineered in terms of the crankshafts and bronze main bearings and be able to last well into the 21st century but all have an Achilles heal in the life of their cylinder blocks.
The surge in auction prices on all Seagulls over the last couple of years may not take this reality into account............Those buying up motors to break and sell at a premium may thankfully get a hosing as their stock splits open in the garage ..........
Flush your motors well...it won't guarantee immortality but may get you a few more seasons .......
Flash, crap or what................
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 9:05 am
by Niander101
O0ps i see i stirred it up again!

Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 9:21 am
by NeilF
I haven't removed the heads from my WSPCL and CPL on the basis that they had good flow through the head. Should I have removed them as a matter of course?
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 9:42 am
by Horsley-Anarak
I think it an essential part of any seagull restoration/maintenance, I always remove the head.
H-A
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 10:40 am
by Charles uk
It's not a "must do" but more of "if your going to do the job right it would be better", I always do them, just for peace of mind.
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 10:47 am
by NeilF
More to the point, if the buyer is going to fit his old parts, including a nicely cleaned exhaust tube to hid the crack, and sell a 'fully rebuilt motor', somebody will end up buying a pig in a poke.......
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 11:55 am
by Niander101
To be honest i would not have time to remove all the heads on my seagulls
if it works and doesn't overheat then i leave well alone
sometime you can create problems by taking off the heads
lets face it these things haven't been disturbed in countless years and rust up etc etc
you can find the bolts may shear off just trying to undo them!
obviously if there is a problem then i will have to investigate..
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 1:14 pm
by Taspiper
It's a wonder the Chinese aren't selling us repro blocks by now......
Someone may have to start casting......
Or maybe air cooled blocks cnc machined, similar external shape but with fins......
Re: Why buy a cracked block?
Posted: Sun Mar 18, 2012 2:32 pm
by Niander101
This tiny market would not interest the Chinese
The amount British seagull made will keep us going that and fleebay

Re: Why buy a cracked block?
Posted: Mon Mar 19, 2012 9:47 am
by The Tinker
I have had some great results using this stuff. When de-rusting completed you can solder up the cracks in the outside walls of a barrel, if you can get surfaces clean enough.
http://www.evaporust.com/