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welding aluminium crank case
tompat3463 - 17/5/11 at 04:50 PM

I recently bought a spare fireblade engine from ebay..

I has on of the mounting points snapped off from the accident

Im wondering the best way to repaiar this

a friend of mine is a welder and he can weld alu coz he's done it for me before but what is the best way to do this ??

1. Build up a series of welds and then shape these to the correct size and shape then drill and tap the hole. Vwalla

or

2. Grind the damage doen to a flat and make the missing beice from a solid peice of alu then weld this on ??

Im a little belittled to which will be the strongest fix for the job ??

Help will be great

TIA Alan


mad-butcher - 17/5/11 at 05:38 PM

I would say 1, but if I could obtain the complete broken/missing piece off a set of holed cases I would say 2
(reasoning behind my way of thinking is the alloy would be like for like.)
Sorry not much help really

tony



[Edited on 17/5/11 by mad-butcher]


BATHO - 17/5/11 at 05:39 PM

Personally i think they would both be as strong as each other as long as you weld prep the aluminium block and engine case sufficiently and put down a really good penetrating route run.
Just my two pence worth


doddy - 17/5/11 at 05:52 PM

i have a set of 919 crank cases you can have for free if there any good come with pitsons fitted you can cut the bit you need out or use for rebuild let me know


britishtrident - 17/5/11 at 06:06 PM

Weld a lug on, the less heat the casting is exposed to the better. It would also be quicker.


tompat3463 - 17/5/11 at 06:31 PM

ok thanks for all your advice.. and thanmks for the generous offer for the free cases...

I was maybe thinking just welding the lug on will be the best option and I think ill go with that ??

could anyone offer advice on which grade alu to use as a good match to the blade casing ??

TIa Alan


907 - 17/5/11 at 06:53 PM

IMHO a repair on alluminium is seldom as strong as the original as the new lug (or weld metal)
will be in the annealed condition, together with the surrounding area of the casting.

Paul G


nick205 - 17/5/11 at 06:54 PM

quote:
Originally posted by britishtrident
Weld a lug on, the less heat the casting is exposed to the better. It would also be quicker.


That would be my preference too - reduce the risk of further damage due to the amount of welding heat required.


Peteff - 17/5/11 at 06:54 PM

4043 is usually used for unknown or cast aluminium welding. Ask 907 Paul what he recommends.


britishtrident - 17/5/11 at 09:33 PM

To uncommon for fengines to be cast in hyper-eutectic aluminium silicon alloys rather than more conventional casting aluminium silcon alloys such as LM3 and LM25


tompat3463 - 22/5/11 at 10:30 AM

my firend came and had a look at the job this week and now is a bit scared of welding the block because he has never welded cast alu before ( thought he had ) .

is it jusy the same as weldind ordinary alu or is there a different method involved ??

also if I.m beat is there anybody in the northumberland kinda region that could do this for me ??

Many thanks Alan T