welding an aluminium head

[pmorris]

I've just took the head off a mini petter single, in the first process of a rebuild as there was not enough compression to get it to start easily. (When it was running it sounded quite smooth.) One of the water ports has corroded nearly to the edge of the cylinder, but apart from that evervything else seems as new. There is no other corrosion, no movement in piston and the bore looks fine.
Is it possible to have the head welded and reground, and if so, are there any drawbacks with this.

The boat has been standing for over a year, but previous to this I think was a good starter.
Could this be the cause of the bad starting.

Would it be feasible to just have the head done and refit it, as to overhaul the whole engine I'm told will cost between £300 and £500.
I didn,t want to spend this kind of money when in probably a couple of years time I might change it for a larger engine, as it is supposed to under powered for the boat a Seal 26

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[Nat]

Hi Paul
If your head is just corroded on the exhaust port & not to far gone then its possible to get it filled and skimmed. just make sure you get it done by a company experienced in cylinderhead reconditioning & not someone round the corner with
a mig welder otherwise you will finish up with loads of hairline cracks & a stuffed head. However If your head is cracked between valves or round the injector hole
throw it away & buy a new or good secondhand one as these type of repairs seldom last very long. I have been in the motor trade fo 30 years & speak from experience, not what i've heard or read. I have firm in London that I use all the time for this type of work. but its a bit far for you to come.
Good luck.........Nat

<hr width=100% size=1>2655

 

[supermalc]

http://www.boatsandoutboards.co.uk/view/F28187

If you have room, there is a cheap Yanmar YSB in good condition just come up for sale. Spoke to the owner out of interest last night. I have just got a recon YSM so finding out all I can about them. (see my website) http://geocities.com/malcsworld/
Recon worth about £1200.

You may be able to get your head welded. Ally heads used to be thrown. See a Hillman Imp society. They may repair them now, and modern welders may eliminate some of the problems with warping.

<hr width=100% size=1>Malcolm.
<A target="_blank" HREF=http://www.angelfire.com/malcsworld/>http://www.angelfire.com/malcsworld/</A>
Take a look at my boating pages.

 

[steve_cronin]

Yes...

.. when we ran a motor repair shop we used to use a local company who specialised in this type of work. That was a good few years ago though. I have tried to remember their name and find it in yellow pages but these firms often go out of business when the owner retires. I'm sure that there must be someone in the west mids who does it. Look under "Engine Reconditioning" in Yellow Pages.

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[AndrewB]

Yes, but ...

I had a welding repair on my engine's ali heat exchanger about a year ago, after it was dropped during maintainance and an elbow cracked off.

But there don't seem to be many specialists around for this sort of repair, so it took a while, and the cost was £120, 3 times the cost of a cost of a comparable steel weld. It looks pretty agricultural too, but has worked fine this last year.

 

[steve_cronin]

Re: Yes, but ...

There was a "metal spraying" technique that deposited new aluminium onto erroded castings around in the 70s. I once saw an aluminium head repaired by this method. My first view of it was that surely the fresh build up would be porous bit evidently it wasn't.

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[DMGibson]

It's quite possible that the gap between water port and cylinder is now so small that the gasket was leaking compression between the two. I suppose it is too late to check the gasket for signs of leaking?

The problem with trying to re-build the port is that the corrosion of the aluminium makes it porus, and thw wels will have to go back a long way into the casting to find solid metal, so it may burn out quite a bit of the head, which would have to be machined back as the combustion space is quite critical. Also, what is it like inside the casting? If it has corroded away at the face, has it also gone inside the casting- is there another hole?

What's the cost of a recon head for one of these?

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[ipw]

as a engine recondioner i could possibly tig and machine the head pm me if you want this done. it is a problem in many car engines

<hr width=100% size=1>don't eat yellow snow

 

[steve_cronin]

That's it really isn't it?

Cost /effectiveness or just the acceptance of reality.

Unless it's a rare old engine, often it's better to replace than attempt a repair. Then you're sure and maybe you might just get a guarantee, not tpo mention the "Sales of Goods and Services Act 1979" and the "Supply of Goods and Services Act 1982" and the "Sale and Supply of Goods Act 1994"

When will legislators get their "act (s)" together?

Steve Cronin



<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[richardandtracy]

..When will legislators get their "act (s)" together? ..

Never. It's not in their interest to. If they come up with an effective and concise law, that'll set an unwelcome precedent. In 20 years time, having worked through all the old stuff and come up with good laws, no new laws would be needed. So no legislators would be needed. This is an obviously intolerable situation for those dreaming up new laws.

Sorry. Do I seem slightly jaundiced about those in charge? If not, I will try harder next time.

Regards

Richard.


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[dwarwick]

sent two pms (19/2/04) re apparent low compression and welding prob
regards

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