Hi all,
sorry I missed this post, been extremely busy and feel terrible about saying “I forgot to clock in for a chat”
I just had a good chat with David on the phone last night and seem to be on track now thanks to all the good info here, of which I agree very much with.

Generally the Meadows 4.5 is a very good reliable and strong engine, however calcium, old designs, uprated engines, blocked rads and socks, corrosion in the head and block etc all reduce the capacity of the basic system to control things.
With a new block and head, engine fully rebuilt with all the right stuff and the later LG water passage addition in the back of the block/head, all fitted with a new water pump. A standard but fully re-cored and perfect M45/LG45 radiator can cope with a 200+bhp reliably and efficiently with no overheating, even in a hot climate. (obviously the full power is not used all of the time, or even part time on the road)
This does show us that we do need to keep the whole package in tip top condition, and if we do, it will look after us. We always use water with a little glycol to limit corrosion and/or freezing, depending on the month.

Blocks and pistons are and always will be a talking point and the use of liners especially.
I don’t want to preach here but we have the following rule and we stick to it extremely rigorously.
If the block needs more than one liner in any pair. ie. 1 and 2 3 and 4 5 and 6 then the block is scrapped. We will not build around it even if the customer insists. We know it will come back, usually within one year and we will have a warrantee case on our hands. (we don’t like that ;o)
The reason is two fold. a. heat dissipation is limited, even if fitted very well. b. there is not enough material left between the bores and this thin area cracks extremely quickly, especially if the liner has a good “fit” the liner then loosens, and even if it has a “top hat” section at the top to stop it from slipping down, it can still spin and then the rod hits the cut-out and Bang!! we have lots of these to rebuild so like other people who do it :o) Not really, but we do see a lot of them. My only advice if you are forced to use a fully linered block is to pin the liner in place as well as press. and use a good modern piston with a good clearance. We use 0.005″ for road and up to 0.010″ for racing. but the clearance depends on the manufacturer also. Volvo pistons need 0.008″ in my opinion and experience but we don’t use these as they tend to be noisy at this setting and tight if set smaller.

Very interesting thread this though so thanks for posting David but sorry for the reasons behind it.
Julian

Maybe we should start a page especially formulated to be a problem reference page with a quick search function etc?

Very best regards to all.
Julian

PS.
Interesting maths Alec, I like it!

Very sorry to hear of your woes but very grateful to you for sharing them and I congratulate you for keeping your car as a saloon.

About 15/20 years ago we did have problems with that bottom hose, I discovered (eventually) that it would collapse when revs were up. The collapse was not obvious at first as the hose went back to its usual shape when the revs dropped and it wasn’t easy to see through the blur of the fan ? but sudden temp changes and boiling were the result. It is just starting to show signs of collapse again above 1500rpm but not so badly as to cause any noticeable cooling problems. On our car the exit from the rad and the entry to the pump are slightly misaligned which puts an extra stress on the hose distorting it very slightly and making this problem more likely to occur. The rad was re-cored before the problem first occurred and had been run with either a sock or stocking for most of the time since so I do not think rad blockage was an issue, its just that that section of connector/hose/connector presents one of the greater restrictions in the system I suspect, and in our particular case one which can easily accommodate the pressures on it by collapsing.

Thank you both David and Alec for the links about Evans which are very helpful. In light of the above I think pressurisation is essential and consequently I would not choose to use Evans. However, I also have great doubts about replacing water with a coolant with lower specific heat capacity in a cooling system which is already compromised by a wide variation in coolant flow rates through the engine (or so it appears to me!), and crucially which lacks the ability to be as self circulating as water is when heat is applied to a motionless or very slow moving volume.

A cooling system oddity came to light in the late 80s when my father replaced the coolant manifold and discovered that the tank engine manifold was substantially obstructed between the two block connections by an irregularity in the internal diameter of the manifold. The result of this was that 4,5,6 would probably have been getting a lot less coolant than 1,2,3. The spares scheme replacement did not have any such obstruction/constriction, nor did the manifold that my father had removed from the car’s original (blown up!) engine. We dismissed it at the time as a casting failure that we had been lucky not to be affected by. More recently I have begun to wonder if it might just have been intentional – your own case adds to my suspicions. However, it is also odd that historically 5 and 6 seem to be the problem bores (my father had no5 rod through the side of the original engine when the piston seized/broke up) but our tank engine had survived this manifold obstruction for 35 years before it was removed. This could be partly due to the fact that it is (now) a well worn engine and uses a lot of oil ? so rings and pistons are kept cool by this as much as by anything else.

On the subject of a bigger waterpump: has anyone else ever had the experience of finding a central heating radiator very hot at the bottom and barely warm at the top, and not having any air to be bled? I found that normal flow through the radiator could be restored by further closing the return/exit valve (and not the flow/entry valve) until normality was restored. This happened after I turned up the pump speed during cold weather to improve flow to rads at the very end of the system. Too strong a pump and thermo circulation/turbulence in the extremities could be reduced perhaps? Its just a thought, I have no direct experience of this in a car engine!

The only time I have ever seen melted HT leads was on a modern with a head gasket leak that had been driven flat out on the motorway until all the coolant had gone and eventually it melted a hole in a piston. On our M45 the distributor side HT leads are perilously close to the exhaust downpipe but still they haven’t melted.

It would be interesting to know what clearance Adam Pointer went for on the new rings, I will need to consider new rings very soon as oil consumption is not good, that is unless a more profound and expensive remedy is required.

Apologies for being late to the party on this topic – my first post too!

James

Just in case you missed it on the VSCC Forum there was an answer about my thermo syphon system point above posted (by someone who seemed to know) as follows : –

“I suggest that the reason is because Glycol does not expand as much as water, does not absorb as much heat per pint, and is thicker (more viscous). All these factors make it less successful in a system which relies on expansion, etc to work, with no pump.”

Of course if the coolant does not absorb as much heat (as water) then maybe this is the reason why you can get localised overheating in a system which is very inefficient in design (as I think we all know).

Anyone with more technical knowledge out there care to comment please ?

Thanks for all that information Bill as it rather confirms everything that I had come to believe about waterless coolants. I do however find it rather worrying that these expensive “waterless coolants” appear to being “pushed” quite strenuously at vintage and classic car owners – as if these products are the answer to all our problems !

Hi Chaps

I have been following this discussion with interest and have two points to make.

Firstly, I am a great fan of cutting oil (suds) which I use on my lathe and milling machine. It has interesting properties. Not only does the metal cut nicely with a great finish, but when you spill some on the floor the detergent properties show up as well.

In fact the only problem with using cutting oil is that it stinks and my wife complains that I “smell of garage” which I remedy with a few drops of Jasmine aroma therapy oil which makes the workshop smell lovely….

With cars, I am also an old fan of a product called ” Bar?s Leaks Radiator Stop Leak”. When you add it to the cooling system the brown liquid goes white just like cutting oil. Has anybody any experience of using cutting oil in a car cooling system? I think it might work rather well.

Secondly, I have also been servicing my central heating system and used Fernox DS3 to de-scale the domestic hot water heat exchanger on my combi boiler. I now have lovely hot baths again. As many of you know, DS3 is our old friend for de-scaling car radiators as well. I then started thinking about central heating treatments such as Fernox DS40 system cleaner, as well as MB-1 which is an all-round protector. DS40 is very good at flushing lime-scale and black sludge etc from a heating system. Surely, isn’t this what we need for our cars? Opinions please?

If anyone thinks that I am barking up the wrong tree, please tell me.

If I meet any fellow readers in a pub and I smell of Jasmine, you will know what I have been doing…

Colin M34