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Post by dadbif on Jul 30, 2020 11:29:06 GMT
After suffering a heavy metallic knocking around 60mph and loss of a cylinder, I feared that I had dropped a valve. Today I have checked everything over under the rocker cover, finding no fault I have removed the head, what I found was surprising, considering I fitted a new head gasket only a few months ago.
The head gasket had blown between cylinders 3 and 4. will post the pics when I work out to do it, have used the mighty fives image loader but can't transfer the files to here...
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Post by Zed. on Jul 30, 2020 12:05:24 GMT
not good, any ideas as to why or is it a mystery for forensic investigation? will post the pics when I work out to do it, have used the mighty fives image loader but can't transfer the files to here... I use imgur & paste in the insert image icon (5 left of smileys on top of reply page) or send them to me & I'll upload.... Rich.
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Post by dadbif on Jul 30, 2020 12:47:02 GMT
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Post by dickie on Jul 30, 2020 15:31:35 GMT
Next time buy a Mazda OEM or Victor Reinz head gasket. Multi Layer Steel is the way to go and keep going.
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Post by wannabe on Jul 30, 2020 16:36:14 GMT
Did you do the headbolts up properly? lol Mr Mazda HG is 30-something quid IIRC, so not too bad. I guess it's a good thing that it appears to have been blown out the exhaust valves rather than doing any damage to the bores??
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Post by dadbif on Jul 30, 2020 17:04:33 GMT
Just bought OEM, wash your mouth out wannabe 🙄🙄
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Post by Zed. on Jul 30, 2020 18:05:54 GMT
Next time buy a Mazda OEM or Victor Reinz head gasket. Multi Layer Steel is the way to go and keep going. its a 1.6, standard / oem gasket is graphite & steel fire-ring construction and mls are an expensive luxuary all 1.8s had mls iirc? standard hg can handle fi as the b6ze(rs) engine is a follow-on from the b6t (1.6 turbocharged) from a 323 gtx/gtr. excuse the terrible editing, looks to me that the fire-ring is overlapped by the chamber on number 3 cylinder? if so this could become a 'hotspot' and eventually melt with blow-through following Rich.
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Post by dickie on Jul 30, 2020 18:28:33 GMT
I sit corrected
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Post by dadbif on Jul 30, 2020 18:41:03 GMT
Good call rich, I have checked for cracks on both head and block, all are fine, the overhang could cause the problem, will check tomorrow and let you know. OEM gasket on its way.. Yet it looks as if the gasket ha s blown from NO 4 into No 3 nd distorted the gasket.. Thanks
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Post by dadbif on Jul 30, 2020 20:50:24 GMT
What puzzles me is that this is the second HG failure in 4 months, first time was oil and water leak from back of the head, no evidence of steam cleaning on NO. 4 piston, this time the piston exhibits the classic signs of water ingress, yet the main point of failure is between the two cylinders, not around the coolant galleries, I am loathe to just fit another gasket and hope for the best, I want to be sure there is not some hidden problem.
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Post by wannabe on Jul 31, 2020 1:30:21 GMT
What puzzles me is that this is the second HG failure in 4 months, first time was oil and water leak from back of the head, no evidence of steam cleaning on NO. 4 piston, this time the piston exhibits the classic signs of water ingress, yet the main point of failure is between the two cylinders, not around the coolant galleries, I am loathe to just fit another gasket and hope for the best, I want to be sure there is not some hidden problem. If No 4 runs hottest as it's at the back of the engine, might you have blockages in the cooling system? (Not sure that's anything to do with this whatsoever, but...) I guess getting the head and the block checked for flatness is the next step!
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Post by dadbif on Jul 31, 2020 7:41:04 GMT
Good thoughts. I installed a coolant bypass when I fitted the supercharger, more to give clearance for the air pipe than cooling. Checked head last time, it was within .0015, will check there isn’t a burr in the location hole on the head or nick on the location collar.
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Post by wannabe on Jul 31, 2020 8:29:51 GMT
Ooh, on that note - are the head bolt holes in the block definitely free from debris that might stop torquing down as far as it goes and both surfaces meeting properly? That man Zed makes some excellent thread/hole clearance bolts lol Or if 4 *is* running too hot, could it mean a wonky injector making it run lean? Just throwing random ideas into the ring (pun intended? haha) I think Rich might have sussed it, though - if it wasn't an OEM gasket and was overlapping slightly, it could be worth overlaying the old gasket on the new OEM gasket (while still in the plastic, to keep it clean) and playing 'spot the difference'!
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Post by wannabe on Jul 31, 2020 8:36:47 GMT
Another thought (probably nonsense) - does the coolant circulate into the inlet manifold body at all to cool the charge? I recall my head looking slightly rusty(?) around one of the holes in it on the manifold side, but I can't remember if the gasket/manifold blocked it off. If it does circulate, perhaps there's a small fracture/crack in the inlet, losing water into No4 intake. Although saying that... if coolant is 80+ degrees while running, I'm not sure how it would 'cool' the air coming in at ambient temperature... lol. Ignore this post! haha
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Post by Zed. on Jul 31, 2020 8:46:49 GMT
Another thought (probably nonsense) - does the coolant circulate into the inlet manifold body at all to cool the charge? I recall my head looking slightly rusty(?) around one of the holes in it on the manifold side, but I can't remember if the gasket/manifold blocked it off. If it does circulate, perhaps there's a small fracture/crack in the inlet, losing water into No4 intake. on 1.6 engines theres a coolant passageway in the cylinderheads manifold face, its possible for coolant to 'bleed' through the gasket / seal into a port...... (as rovers wonderfull 'K' series suffered with on the plastic inlet manifold ' 'o' ring seal by number 1 inlet port ) number 3 cylinder is universally accepted as the 'hotter' cylinder on inline 4 engines (as 1&4 have more cylinder jacket 'wrap' in the coolant flow so more exposed surface area to transfer heat ) looking around the cylinders,m seems to be visable 'witness' marking of the fire-rings around the bores, just about conventric on all but number 3 cylinder so I doubt the gasket was 'pushed' into that cylinder from number 4 also, where it looks to overlap the bore wall is a thick / strong section where theres a triangullar profile in the steel fire-ring...... DB, if you want some alignment / thread chasing headbolts pm me your address & I'll post some off to you Rich.
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