Boydie Posted April 8, 2013 Share Posted April 8, 2013 Question without notice. (copied from my engine rebuild & Blueprint thread) Which clown in the LR design school came up with the idea of having the three triangular cut-outs in the cylinder head gasket to match the water-ways in the cylinder block between 1-2; 2-3 and 3-4 when there is no corrosponding water-ways in the cylinder head all this seems to produce is corosion on the head as there is no easy way for any air trapped in the top of the water-way to easily escape. Also why are there restrictors in the head gasket corresponding to half the engine block to cylinder head water-ways? I'm seriously considering removing them to see how it affects (if at all) the water flow and engine cooling -- can anyone in the forum assist with some logical answers. Quote Link to comment Share on other sites More sharing options...
Boydie Posted July 27, 2013 Author Share Posted July 27, 2013 ????? Anyone with any ideas ???? I get the impression that the restrictors are to ensure corrrect water circulation due to the poor pump location & design, I can live with that (no options!!) but why the cut-outs in the head gasket ? Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 28, 2013 Share Posted July 28, 2013 I'd hazard a guess, but it's only that: the original development engines may have had the coolant holes in the head aswell, but with relatively unrestricted flow through the front of the block into the front of the head and back to the rad, the flow through the back of the engine may have been poor, so the head apertures were closed up but there was no need to do so on the block or gasket. Just a hunch... Quote Link to comment Share on other sites More sharing options...
cackshifter Posted July 30, 2013 Share Posted July 30, 2013 Hi, might be unrelated but there are later heads with 'improved' cooling - whatever that is. Motor and Diesel in East Anglia also offer a head mod to 'improve' cooling. Maybe these passages get used? Quote Link to comment Share on other sites More sharing options...
Tanuki Posted July 30, 2013 Share Posted July 30, 2013 Yes, the coolant-flow should be: In-at-the-bottom-of-the-forward-end-of the block Along past the cylinders to the rear of the block. Up in to the cylinder-head. Forward through the head to the thermostat and then - only if you've got a hot engine - onwards to the radiator. This circulation gives the most-uniform heating of the engine (and equally as important the most effective shedding of heat into the oil so it runs good and hot to prevent contamination by unburned fuel or condensed combustion-acids). Some misguided people bore out the small air-bleed holes in the head gasket in the misguided belief that this gives better cooling: all that then happens is that the coolant circulation takes the path-of-least-resistance and the cylinders at the back of the block then get inadequate cooling. Remember: a hot-running engine is an efficient engine, which will live long and prosper. I have no issues at all with a turbodiesel engine whose coolant typically runs at 98-100 Centigrade and which typically runs with the oil at 100-120 Centigrade and hits 140 Centigrade then holds that after a few minutes of 100% load. Some current-generation engines (BMW, Mercedes) don't open the coolant thermostat until the head temperature is 105 Centigrade! Quote Link to comment Share on other sites More sharing options...
Boydie Posted August 25, 2013 Author Share Posted August 25, 2013 Okay Tanuki and I agreed completely with what you said after looking at the block - the circulation is noe fully explained, (incidentally mine runs at 115 degrees C) and the air blood holes in the gasket are apparent --- but that doesnt answer my main question -- why the openings in the block between the bores, and if they were due to a previous design cylinder head why are they in the head gasket ?? Surely it would be easier to make the latest multi-plate head gasket without them. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted August 26, 2013 Share Posted August 26, 2013 Perhaps the block openings are more to do with getting sand out when casting rather than water flow? Quote Link to comment Share on other sites More sharing options...
Boydie Posted August 27, 2013 Author Share Posted August 27, 2013 No, I dont think so, thats what the welsh plug openings are for. In all other engines I've ever seen these openings would normally connect/join up to corresponding openings in the cylinder head. Quote Link to comment Share on other sites More sharing options...
Snagger Posted August 30, 2013 Share Posted August 30, 2013 As I said, the design was probably altered after testing, with all production heads "sealed up" to ensure more even cooling. It's easy to alter the machining process in the head, but expensive to change the casting tooling of the block or punch tools for the gaskets, so those were left as per the original design, the head alteration being sufficient by itself. It's a guess, but seem logical. Quote Link to comment Share on other sites More sharing options...
Boydie Posted September 4, 2013 Author Share Posted September 4, 2013 Snagger, to a certain extent you are right, removal of punches in the gasket press would cost zero, but then a rings of sealant, or in the multi-plate version a sealing "ridge" would need to be pressed in to replace the holes and seal the openings in the block. To alter the casting of the block would however be minimal as well, seeing as how the cores are removed through the welsh plug openings. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted September 5, 2013 Share Posted September 5, 2013 Boydie, I notice no-one involved in the original design has posted here or attempted to shed any light on it. I hoped that they would, to give an enlightening answer, but no. I admire you for attempting to get a rational answer to this. You'd reasonably think this kind of decision would be based on engineering issues, what would be most durable etc, and a decision made after careful consideration. I fear the major factors here would have been either the accountants or time pressures, both of which trump issues like sensible design, so I tend to think you are attempting to rationalise that which cannot be rationalised. Quote Link to comment Share on other sites More sharing options...
Boydie Posted September 6, 2013 Author Share Posted September 6, 2013 As the yanks would say the basic engine water jacket design seems to be a total SNAFU -- Situation Normal, All F***ed Up. But youre quire right, it would have been interesting to have heard from one or more of the original design engineers to explain the whys and wherefores. The spare block gets welded up next week under the expectation of while more is better, less is desirable !!!! Quote Link to comment Share on other sites More sharing options...
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