Head gasket progress
Discussion
adam quantrill said:
Nice one Rev - the beast breathes again...
While people are revealing technical data, do Elring also specify the roughness of the head/block surfaces? (I have heard it doesn't do to have them too smooth...)
These later composites also seem to have little prickles all over them in the dark grey areas, which come out and bite into the head side. I guess that helps to stop things moving about.
Composites are designed to work well with an uneven head/deck finish. If you had an mls gasket it would probably leak coolant. For an mls gasket to work there needs to be a very smooth finish on the head/deck. The metal sheet withinn a composite has the pin prick effect to allow it to grip the head and deck once it's clamped down. Just like you said :-)While people are revealing technical data, do Elring also specify the roughness of the head/block surfaces? (I have heard it doesn't do to have them too smooth...)
These later composites also seem to have little prickles all over them in the dark grey areas, which come out and bite into the head side. I guess that helps to stop things moving about.
Yeah Rev is revving!
Mine is coming along just replacing ancillaries tonight and found my micrometer which unfortunately is a 25mm-50mm one so I had to make a 25mm "shim". Couldn't find my 0-1" one... ;^(
Anyhow it seems that the gasket I took off measures 1.3mm in the compressed area and 1.5mm in the uncompressed area. The one I am putting on measures 1.35mm before fitting. The feeler gauges show 1.2mm where I can stick them in between the newly fitted head and the block.
So I think we're looking at the difference between 1.2mm and 1.3mm.
Plugging that into the "CR calculator" gives: 9.82 (1.2mm) to 9.72 (1.3mm) which is only about a 1% difference. I don't think it will make all that much difference. Also, as the very slightly lower CR will be on the old side, it's less likely to experience further detonation and "go bad" like the one I've just replaced. Time will tell and I'll do the other side as and when, I've got enough spare gaskets now.
Just gotta finish off the exhaust manifold and get that back on and finish torquing the head. I want to check my wrench calibration before the final torquing (and build up a bit of arm strength!)
Mine is coming along just replacing ancillaries tonight and found my micrometer which unfortunately is a 25mm-50mm one so I had to make a 25mm "shim". Couldn't find my 0-1" one... ;^(
Anyhow it seems that the gasket I took off measures 1.3mm in the compressed area and 1.5mm in the uncompressed area. The one I am putting on measures 1.35mm before fitting. The feeler gauges show 1.2mm where I can stick them in between the newly fitted head and the block.
So I think we're looking at the difference between 1.2mm and 1.3mm.
Plugging that into the "CR calculator" gives: 9.82 (1.2mm) to 9.72 (1.3mm) which is only about a 1% difference. I don't think it will make all that much difference. Also, as the very slightly lower CR will be on the old side, it's less likely to experience further detonation and "go bad" like the one I've just replaced. Time will tell and I'll do the other side as and when, I've got enough spare gaskets now.
Just gotta finish off the exhaust manifold and get that back on and finish torquing the head. I want to check my wrench calibration before the final torquing (and build up a bit of arm strength!)
Edited by adam quantrill on Monday 12th January 22:48
Got a few more bits done today - got the boss welded into the manifold and also tidied up some of the pipe bashing it suffered when the stainless end went on which should flow gas a bit better.
I have realised that the manifold won't go on from above now I have the head on so I have to jack up the whole car - I think I have done this with the car up 18 inches in the air and the engine jacked up too. Another pain in the arris...
I have realised that the manifold won't go on from above now I have the head on so I have to jack up the whole car - I think I have done this with the car up 18 inches in the air and the engine jacked up too. Another pain in the arris...
I'm in the Jeep, although I only use the M11 for a junction then it's offski west.
Got the manifold back in place today, it went in with the starter off, engine jacked up and car about 18" off the ground, and it was pretty tight getting it back in. Not sure if I needed the starter off but at least I now know I can undo the bolts (they can be a pig sometimes!)
Just cut up 3 more copper manifold gaskets to I now have a full set for the offside.
Most of the remaining jobs are topside just putting bits back on.
Got the manifold back in place today, it went in with the starter off, engine jacked up and car about 18" off the ground, and it was pretty tight getting it back in. Not sure if I needed the starter off but at least I now know I can undo the bolts (they can be a pig sometimes!)
Just cut up 3 more copper manifold gaskets to I now have a full set for the offside.
Most of the remaining jobs are topside just putting bits back on.
I'm using some 1mm (ish) scrap copper sheet (if you can call copper sheet "scrap"!)
I don't think the thickness is particularly important anything between 0.8mm and 1.5mm will probably do. Even aly sheet is probably worth a try - I might try making an aly one too.
In terms of accuracy you don't have to bee too accurate, tinsnips are easily good enough, as long as you drill the holes in the right place. I scribed around the perimeter and middle of Rev's big-bore gaskets and then scribed crosshairs for each round hole.
The hard bit is cutting out the middle....
I don't think the thickness is particularly important anything between 0.8mm and 1.5mm will probably do. Even aly sheet is probably worth a try - I might try making an aly one too.
In terms of accuracy you don't have to bee too accurate, tinsnips are easily good enough, as long as you drill the holes in the right place. I scribed around the perimeter and middle of Rev's big-bore gaskets and then scribed crosshairs for each round hole.
The hard bit is cutting out the middle....
I drilled out the corners (drill just inside to give the radius) and then drilled a couple more holes in from one corner.
Then you can get the tinsnips across the diagonal.
Cut away the rest inside the scribed line.
When it's mostly out then hammer it flat against a flat bit on your vice. Because it will bend a bit with the snips.
Then file back to the scribed line - copper is soft and this doesn't take long.
Then you can get the tinsnips across the diagonal.
Cut away the rest inside the scribed line.
When it's mostly out then hammer it flat against a flat bit on your vice. Because it will bend a bit with the snips.
Then file back to the scribed line - copper is soft and this doesn't take long.
Got the head torqued to final 80lbf and most of it connected back up tonight and water back in. Tried firing it up but the exhaust manifold isn't on properly and it was f*** loud and spitting flame, so I'll finish that off first.
Next to run it up to temperature, let it cool and redo the torqueing just to make sure.
I recalibrated my big torque wrench last night and it's well off, about 30lbf too low (according to the graduations) I knew it was low but not that much. Might explain why the last one failed - not quite tight enough.
Next to run it up to temperature, let it cool and redo the torqueing just to make sure.
I recalibrated my big torque wrench last night and it's well off, about 30lbf too low (according to the graduations) I knew it was low but not that much. Might explain why the last one failed - not quite tight enough.
Electronic fishing scales and a ruler. Stick square drive in a vice and apply force measured with fishing scales. When it clicks....
The scales are pretty accurate - we also use them on holiday to get our suitcases to within a nad's of the weight limit for the return trip... ;^)
My hands are now hurting where I've been pushing on the wrench to get 80lbf!
The scales are pretty accurate - we also use them on holiday to get our suitcases to within a nad's of the weight limit for the return trip... ;^)
My hands are now hurting where I've been pushing on the wrench to get 80lbf!
Edited by adam quantrill on Wednesday 21st January 22:06
A few days' running now, Monday was a bit worrying as the heater didn't work and it burped out about half an overflow bottle of fluid despite keeping the revs down (well mostly).
Today a lot better I removed the excess from the overflow and no more has come out (so it must have been overfilled) and I gave it some beans too - it seems quite happy to accept a bit of a caning.
There is still a little outgassing but it's not burping fluid so I am not worrying myself.
And the heater? I had a bit of a "Carob" moment and the heater levers were in the wrong direction! Durr - in the weeks not driving I had forgotten which way is "hot". Really must put some stickers on the dash veneer.....
Today a lot better I removed the excess from the overflow and no more has come out (so it must have been overfilled) and I gave it some beans too - it seems quite happy to accept a bit of a caning.
There is still a little outgassing but it's not burping fluid so I am not worrying myself.
And the heater? I had a bit of a "Carob" moment and the heater levers were in the wrong direction! Durr - in the weeks not driving I had forgotten which way is "hot". Really must put some stickers on the dash veneer.....
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