Help!! I think i've cooked the cylinder head.

Technical questions and answers about the Mazda Bongo

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g8dhe
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Re: Help!! I think i've cooked the cylinder head.

Post by g8dhe » Wed Apr 27, 2011 8:12 pm

Geoff
2001 Aero V6, AFT, full side conversion.
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bikerider
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Re: Help!! I think i've cooked the cylinder head.

Post by bikerider » Wed May 18, 2011 12:10 am

Have finally got round to taking the head. Cleaned it up & visually it looked ok no cracks etc but decided to have it checked out by having it inspected by a local engineering firm that specializes in engine rebuilds. They armed with a straight edge took one look at it and said it had been badly warped then skimmed up in a previous head failure and should never had been used because it was putting the camshaft under stress untill it gave way. their advice was to scrap it & buy a fully built up cylinder head unit. so that where i am at present.
Thinkin of buying the club shop cylinder head complete with gaskets etc( can any one recommend these ones as good quality) & a thermostat as well.
Piston look in good order.

how do post pictures up on here? would like to share the photos of what i've found with everyone
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mister munkey
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Re: Help!! I think i've cooked the cylinder head.

Post by mister munkey » Wed May 18, 2011 12:43 am

bikerider wrote:how do post pictures up on here? would like to share the photos of what i've found with everyone


Here you go.


http://www.igmaynard.co.uk/bongo/forum/ ... =42&t=9285
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maxheadroom
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Re: Help!! I think i've cooked the cylinder head.

Post by maxheadroom » Wed May 18, 2011 4:49 am

bikerider wrote:Thinkin of buying the club shop cylinder head complete with gaskets etc( can any one recommend these ones as good quality) & a thermostat as well.
I would it comes with all the bits you need, well apart from the elbow grease :D

http://www.igmaynard.co.uk/bongo/forum/ ... a+new+head
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bikerider
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Re: Help!! I think i've cooked the cylinder head.

Post by bikerider » Thu May 19, 2011 12:39 am

The middle of cylinder head has been pushed up out of shape.

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bikerider
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Re: Help!! I think i've cooked the cylinder head.

Post by bikerider » Thu May 19, 2011 12:40 am

Its a clean break!

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bikerider
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Re: Help!! I think i've cooked the cylinder head.

Post by bikerider » Thu May 19, 2011 12:42 am

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Re: Help!! I think i've cooked the cylinder head.

Post by bikerider » Thu May 19, 2011 12:53 am

I checked the pistons 3 + 4 where of the same depths as 1 + 2 as the latter was not affected by the camshaft breakage.

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The Great Pretender
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Re: Help!! I think i've cooked the cylinder head.

Post by The Great Pretender » Thu May 19, 2011 1:07 am

bikerider wrote:I checked the pistons 3 + 4 where of the same depths as 1 + 2 as the latter was not affected by the camshaft breakage.
If there was a problem with the valves bending things down there you would see damage on the piston crowns. :wink:
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Northern Bongolow
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Re: Help!! I think i've cooked the cylinder head.

Post by Northern Bongolow » Thu May 19, 2011 3:23 am

post went up 3 times.
Last edited by Northern Bongolow on Thu May 19, 2011 3:42 am, edited 1 time in total.
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Northern Bongolow
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Re: Help!! I think i've cooked the cylinder head.

Post by Northern Bongolow » Thu May 19, 2011 3:26 am

make sure the engine block is also flat, there is reason to believe this can also lift, dont want to do the job twice.
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widdowson2008
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Re: Help!! I think i've cooked the cylinder head.

Post by widdowson2008 » Thu May 19, 2011 8:05 am

bikerider wrote:The middle of cylinder head has been pushed up out of shape.

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Isn't this exactly the same place as Mattylad? or are bikerider and mattylad one and the same person?????????? :shock:
http://www.igmaynard.co.uk/bongo/forum/ ... 6&start=15
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widdowson2008
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Re: Help!! I think i've cooked the cylinder head.

Post by widdowson2008 » Thu May 19, 2011 10:50 am

bikerider wrote:The middle of cylinder head has been pushed up out of shape.

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Just a thought. If the head has bent in the middle, does this suggest that the bolts holding the head down may have either come slightly loose or even stretched allowing the centre to bend upwards?
Could be worth checking the torque settings of all the head bolts to see if there is a difference.
I'm sure I heard in the dim and distant past that the head bolts need to be checked from time to time as things expand/contract.
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Re: Help!! I think i've cooked the cylinder head.

Post by Northern Bongolow » Thu May 19, 2011 12:18 pm

thats really what im digging for steve,the 2 cams you mention have snapped in different places . i think the result is the same or similar,but the cause is different.
but the spanner in the works is the info from lorna,as no overheat issues were noted at these failures #-o .
as for the stretch head bolts being loose etc,i think that will be a result rather than a cause also.
Mattylad

Re: Help!! I think i've cooked the cylinder head.

Post by Mattylad » Thu May 19, 2011 4:00 pm

Isn't this exactly the same place as Mattylad? or are bikerider and mattylad one and the same person??????????
All be it spooky widdowson we indeed are not the same person. Yes It appears our cams snapped in the same place. Mine was apparently due to the bolts in the bearing pedestal being overtightened. I have no reason to not believe the guy as he is recommended on here but I am travelling to Brighton in her next week to a festival and am seriously paranoid that there may be other issues.
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