I would put an extra flat washer under the head nuts,note any improvement on not,to narrow the problem down.
skin1235,
Jan 16, 11:44pm
you're going to pull the head this weekend I suggest you mix say 300mm of water based paint, say a dark green or dark blue into the rad and run it until the issue becomes evident prior to rip down, then as part of the rip down procedure drain the rad and engine while it still has some heat in it and deliberately leave it to dry for an hour or two before taking the head off , and do that carefully you will be able to see the paint mark where it is bypassing to the studs or gasket face
my first thoughts have already been covered - remove the studs and check that the blockface has not pulled ( small ridges around the stud holes - they will absorb your torque from the nut and still leave the gasket with diddly clamp)
all it takes if someone to crank the studs in too far or too tight ( 10 yrs ago), cast ( block) has a different expansion rate than malleable(studs), if the studs had or gained moisture they will now have a rust under them, rust has another expansion rate, and be assured rust will win in the battle to push the others apart, it will push the cast block stud thread out like a rotten helicoil
skin1235,
Jan 16, 11:47pm
not an uncommon issue with bedford motors in earlier days, was well known and the fix engineered at initial build, they used 2 locator pegs between the head and the block, all the stud holes were drilled at 15mm for the 12mm studs - large clearance around the studs allowed the bulge to uneffect the head, when rebuilding them we often put an even bigger bevel on the head face stud drillings
skin1235,
Jan 16, 11:58pm
why a copper gasket, the head is not that strong, copper may be causing a lot of the issue
the bmc heads were well known for distortion under normal operations and torques - they were soft and light - composite gaskets allowed more clamp to more of the gasket due to the composites ability to crush
higher compressions on some shaved bmc engines sometimes meant you had to fit two composite gaskets
had a mk2 zed overbored and bedford 214 pistons, valiant rods, gm truck exhausts as inlets some obscure brand for the exhausts , shaved block and head combine 180 thou, comp went to over 9 approaching 10, couldn't run the standard tin plate gaskets and 2 or 3 together were too unreliable, had to get copper sheet from the plumbers and cut a gasket for it, ( had to use 24v for starting too - beast could go places in a hurry when we could keep gaskets in it
nzoomed,
Jan 17, 6:18am
Copper gaskets is all our MG supplier stocks, but we were still having trouble with the original Composite gasket we used, so i dont think its that.
zephyrheaven,
Jan 17, 6:23am
Thats odd, even my 40 year old car manuals say not to run a fresh engine with antifreeze - weirder still the 4 engine shops I use with a combined knowledge of say 1000 years between them, also say to use straight water for a bed in period of a cast/cast combo
What would they know
smac,
Jan 17, 6:43am
Ahh but do they know why!
nzoomed,
Jan 17, 6:48am
ive never ever heard of running a new engine without antifreeze, and dont know what that would achieve, unless it affects a new gasket from sealing! dont see how though.
jmma,
Jan 17, 6:49am
If it leaks internally, will stuff new bearings, so I'm told (o:
snoopy221,
Jan 17, 6:54am
-Dum DEEDoo
-Dum DEEDoo
scuba,
Jan 17, 7:49am
yes :)Heldite liquid gold forclassic cars .
interesting some of these guys don't know how aggressive anti freeze is
smac,
Jan 17, 7:58am
Still waiting on the why, before I explain why it's bollocks ;)
snoopy221,
Jan 17, 9:18am
I did the 27th head gasket on an engine once.LOL
It was a marine engine- and well- the guys that did the last **full recondition**
Had it *politely* explained to them that the !Fulla from coconut country! that rammed 2 big end bolts in to the crank could damn well polish it to MY SATISFACTION And the block that they SHOULD have decked they could damn well deck PROPERLY if they wanted any self respecting mechanic to assemble the damn engine.
Incidentally the assembled engine filled with HOT water and pressure tested on an engine stand with sump and side covers off was seen to leak down the push rod area- due to block cratering.
I made and fitted brass shims to that area even after machining and Heldited that sucker.LOL
Ten years later after about five or six engines had been put in that boat-(It was sold)- I met it again - and yip still hadn't missed a beat and had OUTLASTED all the other engines in reliability. So yip it was back in and hummin.
cowlover,
Jan 17, 9:18am
Antifreeze will find every little leak that it can.Just think how often you see green fuz around radiator hoses etc. The MGB head gasket will be a copper/asbestos/steel type (not a plain copper gasket as some were possibly thinking) with some sort of varnish on the copper.
I'd say it would be possible for the antifreeze to seep between the head/gasket/block and perhaps the gasket has not totally sealed.Once the leak is there the antifreeze will keep leaking.It acts like a tracking dizzycap in that once its there its almost there for ever.
What gets me though is that the Op says that not only is the engine leaeking from the head joint but from the front as well.Only place that could be is from the pump joint which may also be a cast/cast joint but most B pumps nowdays would be ali.Or is te pump stuffed and thats the leak!
As far as the head joint goes I couldn't see a crack causing as much all round leakage as Op implys.The head studs IIRC are all through solid casting.Simple solution there is to seal the holes at the top under the washers with RTV or similar.That will stop leaks from top of studs. For that matter put some at the bottom as well.If it truely is leaking all around the head then the head or block must be bowed beyond belief.Another poster suggested that perhaps the gasket bore was smaller than the pistons.That may be but I'd be concerned if a MGB piston was proud of the block.Checking deck height is just part of a rebuild - is it not!Has perhaps the block and head been shaved so much that the compression is now 10 million to 0ne or the pistons are now proud of he block and trying to lift the head!
Bad crank grind and BEs off centre!
Is this motor a recond OE unit or is it a recon built up from the parts bin and somehow a wrong combination of bits has been used!
Really it could be just about anything causing the problem so IMHO its time to get out the DTI etc and do some detailed checking. If all else fails chuck anoher head at it and see what happens.Any old BMC 1800 head will do for the checking.
snoopy221,
Jan 17, 9:20am
www.acl.co.nz/ Welcome to Automotive Components New Zealand Limited. We are the New Zealand supplier of ACL engine parts
smac,
Jan 17, 9:23am
Ya ya seen it before. The important bit is here:
There's a really really good online debate about this someplace that I can not for the life of me find. The crux of it was that although what ACL (and others) say is theoretically true (or at least plausible), they (and the others) were unable to provide any actual evidence that this wicking before a hot seal had formed had ever actually made the difference between a fail and an unfail (to use snoopy speak).
So yeah maybe 'bollocks' was too strong a word. However it certainly shouldn't be more strongly stated than 'a theory'.
snoopy221,
Jan 17, 9:25am
the engine had been sitting around for 10 years after being assembled
Do we insertwords like electrolysis galvanic corrosion
Here!
or simply *cratering* causing loss of gasket retention
Or go back ten years ago to the stones used refacing heads and blocks! And what on cast iron ya wanna add Tri Ethylene Glycol and get the BIG Gawd DAMMEDWICK EFFECT!
snoopy221,
Jan 17, 9:30am
mmkay
snoopy221,
Jan 17, 9:41am
Someone thinks they are funny aye
Clearly i can't help others in here but hey at least someone else can QUOTE what some joyous happy person can have removed.
I love ya SO Much we SHOULD meet in Person.
EDIT Reality is sure ya moit tink moi and zeph know Jack.HOWEVER
Tauranga:
Paykels now BLACKWOODS PROTECTOR
Listed New Zealand suppliers of a REAL mechanic in a can that YOU will find WILL actually fix ya problem for GOOD.
Heldite.Paint it on gasket block and head fit tourqe and forget. Post results anytime up to ten years later.
scuba,
Jan 17, 9:48am
you talkin too me!
nzoomed,
Jan 17, 8:47pm
Its an ACL head gasket for your information!
scuba,
Jan 17, 11:43pm
So it's BMC not MGB.now your talking land crabs .not sportscars lol. what are your head studtorque settings!
nzoomed,
Jan 18, 12:23am
MGB 1800 engine in the landcrab is the same engine in an MGB (both made by BMC) i said MGB in the title, as most people are familiar with that.
bjmh,
Jan 18, 1:50am
i would check block and head surfaces,you can buy cheap straight edges which will give you an indication,some composition gaskets need to get real hot before they adhere.i have used VHT copper head gasket cement part #SP-22 .magic stuff,just follow instructions.
nzoomed,
Jan 18, 4:21am
ive used that, initially, we thought it worked, but after running longer, it started to show problems.
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