Cracked Cylinder Head

[greenbean]

Hello Everyone.

My Cylinder Head has cracked on my 1996 Bongo 2.5 Diesel (minty green in colour)

Does anybody know where I can get another one without breaking the bank?

Cheers

[mister munkey]

Ouch!!

Make 1st port of call Wheelquick in Wigan. They'll certainly point you in the right direction.

Good luck.

[mister munkey]

Saying that though, this has just been listed on ebay, if you can get to Cumbria . . . .

http://cgi.ebay.co.uk/Mazda-Bongo-Engin ... 240%3A1318

[maxheadroom]

Why not give this stuff ago, it does say permanent??

http://www.amazon.co.uk/Insta-Seal-Perm ... 745&sr=1-1

or this

http://www.steelseal.co.uk/index.asp?fu ... roductid=1

[helen&tony]

Hi
Just a thought....has anyone had a head crack re-welded and skimmed? I've had such work done on a cast-iron head, but an alloy head i'm not certain on. It may have to have the whole casting heated in the same way as iron....Just curious.
Cheers
Helen

[francophile1947]

Hi
Just a thought....has anyone had a head crack re-welded and skimmed? I've had such work done on a cast-iron head, but an alloy head i'm not certain on. It may have to have the whole casting heated in the same way as iron....Just curious.
Cheers
Helen

I've heard of them being "stitched", but I've no idea what's involved and if it can be done in all cases.

[francophile1947]

Why not give this stuff ago, it does say permanent??

http://www.amazon.co.uk/Insta-Seal-Perm ... 745&sr=1-1

or this

http://www.steelseal.co.uk/index.asp?fu ... roductid=1

Could just be snake oil but, for less than a tenner, it may well be worth a try

[helen&tony]

Hi John
From what I was told at the time, in relation to cast iron, they put them in an oven, get them to red heat, and then weld, as weld won't work on cast iron....however, more recently someone I met said they could weld cast metal without that....so....hence my thought/ enquiry. To be honest, I'd try the snake oil....it worked for me on a really bad core plug once!!!
Cheers
Helen

[bongolow]

I'm no expert but I think the problem with welding cast iron is that unless you heat the whole lot up you get localised heat expansion which causes internal stresses in the metal which then causes it to crack. I know someone who said he repaired an old cast iron cement mixer by continually hitting it while welding - I'm not sure how that works!

However, an old cement mixer is one thing - a Bongo cylinder head is another thing entirely!

[maxheadroom]

If you are talking about the head it is cast aluminum and can be welded and re-machined quite easily by using AC Tig with an ali filler wire.
I did weld a VW Golf head years ago with this method.
As for the Block which is cast Iron this is possible but much more difficult. It will need pre-heat of around 450ºC to 650ºC but no higher. You can use MMA or Tig.
I have used DC Tig on SAAB exhaust manifolds many years ago. The trick is to use a very high Nickel filler wire (99%) and wrap the item after with a lagging blanket and let it cool very slowly to minimize cracking.
So yes both can be done but the head is easier.

[maxheadroom]

by continually hitting it while welding - I'm not sure how that works!

This is called peening, I have again used this method when hard facing a large roller used to crush lime stone. It helped stop the weld from cracking.

http://en.wikipedia.org/wiki/Peening

[helen&tony]

Hi Max
So the question is....would it be cheaper and better to get the head welded, or buy a new one?
Cheers
Helen

[maxheadroom]

Hi Max
So the question is....would it be cheaper and better to get the head welded, or buy a new one?
Cheers
Helen

Sorry don't know but I'm sure somebody does helen&tony

[greenbean]

Thanks for all your help guys......even tho I'm still a little confused!
I'm a welder by trade and to be honest I wouldn't risk welding it so I'm going to buy a new head. My cousin (the mechanic) has recommended I use "Bridge Cylinder Heads" over Manchester way, as they guarantee them for twelve months.

I'll let you know how I get on.

Thanks again

[The Great Pretender]

Why not have a word on TEOC, Toyota Estima Owners Club greenbean they have similar head problems to us and many have had them welded.