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Jun 18, 2014 8:06 am
Jun 18, 2014 8:06 am
Subject: Re: 4.5 litre engine problems and upgrades
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
) 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!
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
) 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!