Kevin Atkins Posted July 6, 2023 Author Report Share Posted July 6, 2023 2 hours ago, johny said: And of course the right type of head gasket👍 I think, hope and pray it's the right one - recessed Payen for a late car. I'm no motor engineer, but the recessed fire ring head design seems like a really nice bit of design to me the layman! Link to comment Share on other sites More sharing options...
johny Posted July 6, 2023 Report Share Posted July 6, 2023 Have a close look at the core plug in the side of the block thats covered by the exhaust manifold. These seem to go long before the others, presumably because of the heat, so worth changing now if theres any doubt... Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 6, 2023 Author Report Share Posted July 6, 2023 1 hour ago, johny said: Have a close look at the core plug in the side of the block thats covered by the exhaust manifold. These seem to go long before the others, presumably because of the heat, so worth changing now if theres any doubt... Thanks Johny, that's a really good call - just been out to have a look and said core plug does look a bit grotty, to the extent that there seems to be some pretty deep pitting, definitely not worth chancing.. I'll get the core plugs changed, thanks for the heads-up on this! Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 9, 2023 Author Report Share Posted July 9, 2023 A happy ending - touch wood! New head gasket fitted, plus four new core plugs on the block behind the exhaust manifold.. I'm so thankful for the tip on those - three were OK / passable and looked like they had been changed at some point but the fourth.. as I scraped the paint away to examine, it was very rusty and immediately started weeping. I changed all four to be safe. All back together, cooling system carefully filled according to earlier posts, new radiator cap and the flange carefully flatted, new thermostat just in case, tappet clearances set, runs great and no sign of any of the earlier problems - no excess pressure left in the cooling system after running the engine and allowing to cool, no burst hoses, all seems fine. The compression test readings are still a little lower than before though.. I'm beginning to suspect either the gauge, or I might not have got the valve clearances spot on? The car runs just fine though, so very happy. Thanks for all the support! Link to comment Share on other sites More sharing options...
johny Posted July 10, 2023 Report Share Posted July 10, 2023 Excellent now if you can just get the plastic radiator overflow pipe to stay full all the time (assuming the bottle has sufficient in it) your cooling system will be working 100% correctly.... 1 Link to comment Share on other sites More sharing options...
Peter Truman Posted July 10, 2023 Report Share Posted July 10, 2023 did that on a Morrie 1000 nearly 60 years ago, cousin towed me with rear wheels dragging before the penny dropped! Link to comment Share on other sites More sharing options...
Ian Foster Posted July 10, 2023 Report Share Posted July 10, 2023 11 hours ago, Kevin Atkins said: The car runs just fine though, so very happy. That's excellent news. Hopefully you can enjoy the rest of the season. Ian 1 Link to comment Share on other sites More sharing options...
johny Posted July 10, 2023 Report Share Posted July 10, 2023 17 hours ago, Kevin Atkins said: All back together, cooling system carefully filled according to earlier posts, new radiator cap and the flange carefully flatted, new thermostat just in case, tappet clearances set, runs great and no sign of any of the earlier problems - no excess pressure left in the cooling system after running the engine and allowing to cool, no burst hoses, all seems fine. The compression test readings are still a little lower than before though.. I'm beginning to suspect either the gauge, or I might not have got the valve clearances spot on? The car runs just fine though, so very happy. Out of interest will you be retorquing the head after a few miles? Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 10, 2023 Author Report Share Posted July 10, 2023 31 minutes ago, johny said: Out of interest will you be retorquing the head after a few miles? Yes, I've been advised to retorque after about 500 miles? 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 10, 2023 Report Share Posted July 10, 2023 gauge results can be quite varied and they are an indication not a concise test its often results are not repeatable just similar figures its the variation across the range thats the best clues. Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 10, 2023 Report Share Posted July 10, 2023 and after a retorque you need to recheck the tappets as they will close up a little Pete Link to comment Share on other sites More sharing options...
johny Posted July 10, 2023 Report Share Posted July 10, 2023 Has the rocker shaft got to come off anyway to get to the head bolts on a mk2? Link to comment Share on other sites More sharing options...
Iain T Posted July 10, 2023 Report Share Posted July 10, 2023 31 minutes ago, johny said: Has the rocker shaft got to come off anyway to get to the head bolts on a mk2? Yes it does which is a real pain! Iain Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 10, 2023 Author Report Share Posted July 10, 2023 1 hour ago, Pete Lewis said: gauge results can be quite varied and they are an indication not a concise test its often results are not repeatable just similar figures its the variation across the range thats the best clues. Pete Thanks Pete, that's reassuring to know. The cylinder-to-cylinder results were nice and close (within around 5 psi) so felt that was a good omen. I will check and adjust the valve clearances after the re-torque. I remember my parents had a Mini that needed a head gasket and they got it done at a garage, and afterwards the clatter from the top end was awful.. the garage had clearly not bothered to reset the tappets afterwards.. it was a later fuel-injected car so ran fine, guess the ECU must have compensated (it wasn't injector noise, it was definitely noisy valve gear!) Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 12, 2023 Author Report Share Posted July 12, 2023 (edited) Oh dear... today I took the car for a short spin (maybe 2 - 3 miles), and during the drive, I decided to move the interior heater control back from 'hot' to 'cold' - don't want to have to be driving with the heater on full blast, the interior is toasty enough as it is in summer. Anyway, found the car wasn't running quite right so returned home to investigate - that was just a vacuum hose on the servo had come adrift. But I then noticed the top radiator hose was blown up like a balloon, so I think I'm back at square one with the cooling system.. I'm thinking if there's trapped air in the system, it must be expanding? Or badly sealing radiator cap? Luckily the hose hasn't burst this time.. going to wait for the engine to cool completely and investigate.. Maybe the whole system needs a back flush? PS - The temperature gauge is stable at around the 'quarter' mark during driving, which it has always done. I did find if I stop the car and start again after a few minutes, heat soak sees it climb up towards 'half' before drifting back down to 'quarter' over a period of a few minutes' driving. It hasn't tended to do that before, I never saw it ever climb above the quarter mark. Edited July 12, 2023 by Kevin Atkins Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 12, 2023 Report Share Posted July 12, 2023 if a hose has ballooned due to the pressure the hose is scrap they are supposed to be kevlar lined and that stuff doesnt "give" Time for some new hoses would seem a plan silicon are double the price ( also look nice ) but have a lifetime warranty from club shop Pete Link to comment Share on other sites More sharing options...
Paul H Posted July 12, 2023 Report Share Posted July 12, 2023 When I bought mine from the Club Shop they looked the same as original ie Matt finish . Is there a way of telling they are silicone ? Purchased them at Duxford a couple of years ago Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 12, 2023 Report Share Posted July 12, 2023 (edited) shop catelogue says Matt is the std finish now and if they are nasty rubber copies they fail in a couple of years if your lucky silicone go on and on and on Pete Edited July 12, 2023 by Pete Lewis 1 Link to comment Share on other sites More sharing options...
Iain T Posted July 12, 2023 Report Share Posted July 12, 2023 (edited) 14 minutes ago, Pete Lewis said: Time for some new hoses would seem a plan Kevin said he installed new hoses but worth a try. Kevin as to heat the engine naturally gets hotter when turned of as the heat cannot be quickly dissipated by circulating water and air. Edited July 12, 2023 by Iain T 1 Link to comment Share on other sites More sharing options...
johny Posted July 12, 2023 Report Share Posted July 12, 2023 Have a look at the overflow pipe of the radiator and poke a piece of wire through to ensure its clear. This connection must be open to atmospheric pressure via the overflow bottle as if not the coolant in the system cant escape during warm up (even though the rad cap lifts) and as liquid is incompressible it will try to burst hoses or worse... Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 12, 2023 Author Report Share Posted July 12, 2023 1 hour ago, Pete Lewis said: if a hose has ballooned due to the pressure the hose is scrap they are supposed to be kevlar lined and that stuff doesnt "give" Time for some new hoses would seem a plan silicon are double the price ( also look nice ) but have a lifetime warranty from club shop Pete Hi Pete, OK I think it might be time to invest in silicone hoses. The hose itself is brand new from Paddocks, and I bought two just in case, but if silicone is the way to go I'll do that.. The item currently fitted, as well as the others that burst, does seem to be rather thin walled and there is a welded seam which is where the last one gave way.. 1 hour ago, johny said: Have a look at the overflow pipe of the radiator and poke a piece of wire through to ensure its clear. This connection must be open to atmospheric pressure via the overflow bottle as if not the coolant in the system cant escape during warm up (even though the rad cap lifts) and as liquid is incompressible it will try to burst hoses or worse... Thanks Johny, I'll check that. I've just had the car up on ramps, topped up cooling system and massaged all hoses - I was kind of thinking get the radiator orifice up high - and there was some more trapped air released from the system. Put rad cap back on with extra rubber gasket as it didn't seem like a very tight fit, brought the engine up to temperature, all seemed fine, so just been for a short run and it looks OK. This is one finicky cooling system! Link to comment Share on other sites More sharing options...
johny Posted July 12, 2023 Report Share Posted July 12, 2023 Its just really strange that you have hose inflation as they should easily withstand any pressure in the system up to the radiator cap lifting (13psi max?) without distorting. So either they are very poor or youre exceeding the radiator cap lifting pressure somehow... Link to comment Share on other sites More sharing options...
Kevin Atkins Posted July 12, 2023 Author Report Share Posted July 12, 2023 2 minutes ago, johny said: Its just really strange that you have hose inflation as they should easily withstand any pressure in the system up to the radiator cap lifting (13psi max?) without distorting. So either they are very poor or youre exceeding the radiator cap lifting pressure somehow... It is, really strange - like you say, max pressure should be around 13 psi, unless that expansion hose is at fault like you suggest - that scenario makes sense, so definitely going to check that when the car has cooled down.. Link to comment Share on other sites More sharing options...
johny Posted July 12, 2023 Report Share Posted July 12, 2023 Yes mine has blocked on more than one occasion but I have an after market aluminium radiator which has a tiny overflow pipe. Cant say Ive ever had infated hoses though😮 Link to comment Share on other sites More sharing options...
Gully Posted July 12, 2023 Report Share Posted July 12, 2023 57 minutes ago, Kevin Atkins said: It is, really strange - like you say, max pressure should be around 13 psi, unless that expansion hose is at fault like you suggest - that scenario makes sense, so definitely going to check that when the car has cooled down.. Worth checking that your rad cap isn't too deep for the neck of the radiator. If the sprung seal is completely compressed, it can't lift to release the pressure. Mind you, it's unlikely - main issue I had was finding a cap deep enough! Gully Link to comment Share on other sites More sharing options...
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