Joined: Aug 2017 Posts: 1,715 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
Hi Sam, I may be misinterpreting your pictures but I am still not convinced that you have good even water flow though the block then back into and out of the head. You may be cooling part of the engine but getting stagnant water flow and steam pockets in main water jacket around the front cylinders, this will boil forcing steam up throughout the rest of the system. I am even more convinced of this when you say you could not get it properly warm on test runs but it then boiled after 5 laps. I may be completely barking up the wrong tree and as other have suggested you may have too much water flow but all my instinct's and A7 experience suggest otherwise. As Steve suggested it a simple scenario to check simply ad a restrictor in the top hose. But also have a good look at where water enters and exits the block itself, if as I suspect you are using the valve chest water gallery I believe therein lies your problem. I will be extremely interested to learn what is the root cause when you eventually find it.
Black Art Enthusiast
Joined: Aug 2017 Posts: 313 Threads: 9
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Location: TINOPAI NZ
HI SAM
The Dia of the outlet from the pump which i suspect is 20mm id should be 20mm going into front of block and from the block to head, if you need to you can always restrict the outlet from the head to radiator.
reason for suggesting no reduction in hose id until the outlet from head is to reduce the likely of Cavitation in the pump as the revs increase.
Also your Idea of fitting a Rad with built in header tank is sound just make sure that the inlet to the pump is allways flooded even if it means lowering the pump
Cheers
colin
NZ
Joined: Jan 2019 Posts: 48 Threads: 9
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22-09-2022, 08:27 PM
(This post was last modified: 22-09-2022, 08:38 PM by Dirk73.)
Thanks Steve, Cliff, & others
I've made up 2 different sized restrictors (12 & 16mm) and will test them over the weekend. Cheers
Thanks Ian for the input,
I forgot to say, on the Saturday before the race I changed the layout going into the block. I refitted the conventional side water branch on the block and connected the pump outlet to it directly, then took the flow out of the block via both the front and rear valvechest core plug fittings. I tested it with those pipes open running into the water butt, and the flow was even amounts from both. I then connected those to the rear and side fittings on the head.
I understand what you are saying about air-pockets, especially in the block where the original coolant passages have been blocked off.
The only way I can think of to eliminate that would be to fill the coolant with the car/engine on a 45 degree slope to give any air bockets more chance of escaping.
Thanks again for all the comments,
Sam
Joined: Sep 2017 Posts: 10 Threads: 1
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Hi Sam
Have you blocked all the water holes in the block and head joint faces, or just fitted the solid gasket?
Joined: Jan 2019 Posts: 48 Threads: 9
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Hi Alex, yes all blocked off, brass plugs in the block and ally plugs in the head
Joined: Aug 2017 Posts: 1,463 Threads: 26
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Location: North Yorkshire
Feel free to delete this as it's not relevant but many of us can't read posts nor generate posts as all we get are error messages. I've found I can read and post on this thread but nowhere else. I'm imagine our managers are aware of the problems but, in case not, maybe this will alert them.
Steve
Joined: Aug 2018 Posts: 281 Threads: 38
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same here, getting fatal error message !!!!!!, this is the only way in ??????
Joined: Jan 2019 Posts: 48 Threads: 9
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I hope management can get that link breakage on the back end side of domain control sorted (what does that mean?!)
If only websites were mechanically operated, the membership could have had it up and running on all cylinders in time for tea...
