Head removal

Technical questions and answers about the Mazda Bongo

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Spenner
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Location: Derbyshire

Head removal

Post by Spenner » Thu Jun 23, 2011 3:49 pm

Got the head off and have a few queries if people can help?

1) Head Gasket - Is it supposed to be made up of 5 thin layers? see Image

2) Should the gasket block off some of the holes between the head and the block? Does anyone have a picture (good quality) of a new one so we can compare mine with it?

3) After inspection of the head there is no evidence of cracking. Is it likely to be damaged internally?
Is my next step pressure testing and potentially skim?

Any useful information gratefully received
Thanks
321Away
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Re: Head removal

Post by 321Away » Thu Jun 23, 2011 4:30 pm

1. Yes its a multilayer gasket

2. Yes it does cover some of the holes on the block

3. Cracking sometimes is up in the ports, cracks arent always visible and open up under pressure.

Julian
Spenner
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Re: Head removal

Post by Spenner » Thu Jun 23, 2011 6:12 pm

Thanks Julian
Much appreciated. Going to get it pressure tested locally and will keep the thread updated.
Regards
Jeff
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timmyt
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Location: saundersfoot, pembrokeshire, west wales

Re: Head removal

Post by timmyt » Thu Jun 23, 2011 6:33 pm

Hi,i am currently in middle of replacing head with new unit,inc radiator and all pipes.So im feeling your pain!

From my personal experience and with lots and lots of advice i wouldnt even bother getting it pressure tested....its likely to be cracked inside chamber as already said,normally no2 cylinder for some reason.and there is no point in skimming these heads either as if they are warped at all then you can guarantee that the head is toasted :(

I know its not what you want to hear,i certainly wasnt what i wanted to hear either.

Better do i properly now rather than have to take it all back off again!

If you need any info regarding torque settings/sequence then let me know.after lots of searching i now have them!

If it helps im buying all parts for around the £600 mark
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Doone
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Re: Head removal

Post by Doone » Thu Jun 23, 2011 7:06 pm

Bear in mind that if the head passes a cold pressure test, it may still fail when hot (under pressure), as some cracks are not apparent when cold. But I hope yours is OK.
Allans Garage retired. Try PGS (Plymouth Garage Services) or Mayflower Auto Services Plymouth
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widdowson2008
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Re: Head removal

Post by widdowson2008 » Thu Jun 23, 2011 7:52 pm

Doone wrote:Bear in mind that if the head passes a cold pressure test, it may still fail when hot (under pressure), as some cracks are not apparent when cold. But I hope yours is OK.
TBH Lorna, I hope it fails (for Jeffs sake). Not being a prophet of doom, but at least if it failed the test, he could bite the bitter pill and move on. If it passed, then he's back to square one, which is finding out what is causing the overheating problem.
Steve
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Northern Bongolow
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Re: Head removal

Post by Northern Bongolow » Thu Jun 23, 2011 7:58 pm

if you contact a member bikerider on here.he's just done a head job.his head was bent like a naaaaaana. and snapped the cam.
he may post some pics.
the point im making is that it may appear ok, but if you measure things, the top may be as warped as the face. skim the face and you still have a prob.

good luck with the build.
Spenner
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Re: Head removal

Post by Spenner » Fri Jun 24, 2011 1:05 pm

Ok - here is an update....
it is a good, bad, good(ish) sandwich.
The pressure test was a reasonable £30 (good) :D (Foxwood Diesel Chesterfield) it failed (bad) :( we now know what we are dealing with and can move on with a fix (good)ish. :) Please could someone get Ian at the bongo bash deleriously drunk and get him to offer me a good price on a new head?! :lol:
Have a good time and hopefully see you next year...
ta
Jeff
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timmyt
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Location: saundersfoot, pembrokeshire, west wales

Re: Head removal

Post by timmyt » Fri Jun 24, 2011 8:10 pm

Spenner wrote:Ok - here is an update....
it is a good, bad, good(ish) sandwich.
The pressure test was a reasonable £30 (good) :D (Foxwood Diesel Chesterfield) it failed (bad) :( we now know what we are dealing with and can move on with a fix (good)ish. :) Please could someone get Ian at the bongo bash deleriously drunk and get him to offer me a good price on a new head?! :lol:
Have a good time and hopefully see you next year...
ta
Jeff

count me in on one of them too! :D
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lazyb5
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Re: Head removal

Post by lazyb5 » Fri Jun 24, 2011 8:50 pm

Well at least you found the problem before you put it back on. as you say fix it and move on.
Image
Spenner
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Re: Head removal

Post by Spenner » Fri Jun 24, 2011 11:27 pm

Ian - I can only draw a comparison to U2's headline set - women falling at your feet, asking for a cheap price on a new head. I will call you on tuesday to discuss....
timmyt join me in a chorus - and you give yourself away - i can't live, with or without you....
whooo ooooo repeat until the deal is done......
cheers
Jeff

it will all work out well in the end
peace
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timmyt
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Re: Head removal

Post by timmyt » Sat Jun 25, 2011 9:42 am

Spenner wrote:Ian - I can only draw a comparison to U2's headline set - women falling at your feet, asking for a cheap price on a new head. I will call you on tuesday to discuss....
timmyt join me in a chorus - and you give yourself away - i can't live, with or without you....
whooo ooooo repeat until the deal is done......
cheers
Jeff

it will all work out well in the end
peace

:lol: :lol: :lol: :lol

Thats the story of my life with my Bongo at moment!!... :roll: :roll:

Good luck and keep us posted on your progress
progroup

Re: Head removal

Post by progroup » Tue Jun 28, 2011 3:12 pm

Hey guys; missed this thread entirely!
Check out my threads regarding the whole head renewal process. Peer Parts have new built head packages for 420GBP. That includes new bolts, belt, and gasket set.

For visual; check out my YouTube videos on the subject. Search for BongoBonnie, 1995Bongo, where I have no less than 15 vinettes on cylinder head issues. Because I am in BC, Canada, it has taken more than a month to sort out. I installed one head that was defective; but the 2nd is working out just fine.

I focused on more specific Bongo related refitting issues and left the general mechanics to the viewer.

cheers,
Dave
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timmyt
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Re: Head removal

Post by timmyt » Wed Jun 29, 2011 1:19 pm

progroup wrote:Hey guys; missed this thread entirely!
Check out my threads regarding the whole head renewal process. Peer Parts have new built head packages for 420GBP. That includes new bolts, belt, and gasket set.

For visual; check out my YouTube videos on the subject. Search for BongoBonnie, 1995Bongo, where I have no less than 15 vinettes on cylinder head issues. Because I am in BC, Canada, it has taken more than a month to sort out. I installed one head that was defective; but the 2nd is working out just fine.

I focused on more specific Bongo related refitting issues and left the general mechanics to the viewer.

cheers,
Dave

Hi Progroup,just had a converstaion with a certain head supplier about you!looks like we have purchased from the same place!
Ill be sure to check the clearances on mine!

Thanks for your effort in uploading videos...very handy as a guide when mind goes blank on re-assembly! #-o
progroup

Re: Head removal

Post by progroup » Wed Jun 29, 2011 5:53 pm

timmyt wrote:
progroup wrote:Hey guys; missed this thread entirely!
Check out my threads regarding the whole head renewal process. Peer Parts have new built head packages for 420GBP. That includes new bolts, belt, and gasket set.

For visual; check out my YouTube videos on the subject. Search for BongoBonnie, 1995Bongo, where I have no less than 15 vinettes on cylinder head issues. Because I am in BC, Canada, it has taken more than a month to sort out. I installed one head that was defective; but the 2nd is working out just fine.

I focused on more specific Bongo related refitting issues and left the general mechanics to the viewer.

cheers,
Dave

Hi Progroup,just had a converstaion with a certain head supplier about you!looks like we have purchased from the same place!
Ill be sure to check the clearances on mine!

Thanks for your effort in uploading videos...very handy as a guide when mind goes blank on re-assembly! #-o
Hey no worries on the videos; glad to help back on techie issues. I can't escape this segment of the forum because actually haven't driven my Bongo more than week since I bought it. I did sit in it for many hours dreaming about what it would be like to drive w/trailer attached into the beautiful BC backyard... Then reality set in as my wife calls me in for dinner... oh well, another day I say! :cry:

The supplier specializes in 'heads' for many JAP imports, etc. Overall, they have treated me well considering I am afar off!
I would recommend them to anybody in the UK that is facing a head job. :wink:

Dr. Dave
Physician In Charge for the infamous 'BongoBonnie'
suffering from all sorts of weird ailments including, but not limited to, a complete blood transfusion a.k.a. cooling system and 'pacemaker' a.k.a. coolant alarm. :lol:
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